外文文献翻译ZigBee：无线技术-低功耗传感器网络

ZigBee环境监测技术中英文资料对照外文翻译文献综述简介本文综述了有关ZigBee环境监测技术的中英文资料，并提供了对照的外文翻译文献。

ZigBee是一种低功耗的无线通信技术，特别适用于物联网应用中的环境监测。

通过对这些资料的对比和研究，可以更好地了解和应用ZigBee环境监测技术。

中文资料1. 许明宝, 胡永凡, 钟红民. 基于ZigBee的环境监测系统研究[J]. 现代检测技术, 2011, 31(1): 5-8.2. 杨洛, 李明洲. 基于ZigBee的温湿度监测系统设计[J]. 现代电子技术, 2012(9): 29-32.3. 谭勇, 王群, 李吉庆. 基于ZigBee的室内环境监测系统设计[J]. 仪器仪表学报, 2015, 36(3): 571-575.英文资料1. Wang, X., Hu, Z., & Hang, L. Wireless sensor network-based indoor temperature and humidity monitoring system using ZigBee technology[C]. 2020 6th International Conference on Control, Automation and Robotics (ICCAR), 2020: 100-105.2. Gao, J., Li, R., & Zhang, L. Study on wireless temperature and humidity monitoring system based on ZigBee[C]. 2019 4th International Conference on Green Technology and Sustainable Development (GTSD), 2019: 1-5.外文翻译文献1. 许明宝, 胡永凡, 钟红民. 基于ZigBee的环境监测系统研究（英文翻译）. 现代检测技术, 2011, 31(1): 5-8. (Translation of "Research on ZigBee-based Environmental Monitoring System" by Xu Mingbao, Hu Yongfan, and Zhong Hongmin)2. 杨洛, 李明洲. 基于ZigBee的温湿度监测系统设计（英文翻译）. 现代电子技术, 2012(9): 29-32. (Translation of "Design of ZigBee-based Temperature and Humidity Monitoring System" by Yang Luo and Li Mingzhou)3. 谭勇, 王群, 李吉庆. 基于ZigBee的室内环境监测系统设计（英文翻译）. 仪器仪表学报, 2015, 36(3): 571-575. (Translation of "Design of ZigBee-based Indoor Environment Monitoring System" by Tan Yong, Wang Qun, and Li Jiqing)以上是有关ZigBee环境监测技术的中英文资料对照外文翻译文献综述。

基于ZigBee技术农业无线温湿度传感器网络与农业生产实践相结合，提出了农业无线和湿度传感器网络设计，它基于ZigBee技术。

我们使用基于CC2530 ZigBee协议作为数据的采集，传输和显示的传感器节点和协调器节点的芯片，目的是实现农业生产自动化和精确农业。

关键词：农业，生产，温度和湿度，无线网络，传感器。

1.简介目前，生产和生活的许多方面都需要提取和加工周围环境的温度和湿度信息。

在过去的技术是收集温度和湿度传感器的温湿度信息，并通过RS-485总线或现场总线再次发送数据到监控中心，所以你需要铺设大量的电缆来收集温度和湿度信息。

传统农业主要使用孤立的机械设备，没有沟通能力，主要依靠的人来监控作物生长状况。

然而，如果使用ZigBee无线传感器网络技术，农业将逐步转变为信息和生产的为主的生产模式，使用更加自动化，网络化，智能化的耕作方式，实现远程无线控制设备。

传感器可以收集信息，如土壤水分，氮浓度，pH值，降水，温度，空气湿度，空气压力等。

采集到的上述信息和所收集信息的位置被传递到中央控制设备用于通过ZigBee网络的决策和参考，所以我们可以提前和准确地识别用于帮助维持和提高作物产量的问题。

在许多面向数据的无线网络传输，低成本和复杂性的无线网络被广泛地使用。

2. ZigBee的技术特点ZigBee技术是一种短距离，低复杂度，低功耗，低数据速率，和低成本，双向无线通信技术，主要是采用在自动控制和远程控制的领域中，可以嵌入各种设备中，以实现他们的自动化[1]。

对于现有的各种无线通信技术，ZigBee技术将是最低功耗和成本的技术。

ZigBee的数据传输速率低，在10KB/ s到250KB/ s的范围内，并主要集中在低速率传输。

在低功耗待机模式下，两个普通的5号电池可以持续6至24个月。

ZigBee的数据传输速率低，并且它的协议很简单，所以它大大降低了成本。

而它的网络容量大，可容纳65000设备。

延迟时间很短，一般在15毫秒〜30毫秒。

基于ZigBee技术的低功耗无线传感器网络研究随着物联网技术的不断发展，传感器网络作为物联网的基础技术之一，日益受到人们的关注。

而在众多的传感器网络技术中，基于ZigBee技术的低功耗无线传感器网络备受瞩目。

一、低功耗无线传感器网络的意义低功耗无线传感器网络（Low-Power Wireless Sensor Network，LPWSN）是指由一组分布在空间中，通过自组织方式协调工作，能够在自身资源限制下完成感知、处理和通信等多种任务的无线传感器节点构成的网络。

它将传感器作为节点，通过无线传输技术将数据传输到基站或信关站，实现对环境等参数的监测和感知。

低功耗无线传感器网络具有以下优点：1. 能够实现对环境等参数的精细感知。

2. 可以实现对环境进行长期监测，不需要人工干预。

3. 系统具有稳定性，能够在节点数量变化和节点失效的情况下正常运行。

4. 能够实现远距离、多节点的监控，应用范围广泛。

二、ZigBee技术ZigBee是一种低功耗、短距离的无线通信技术，它采用工业、科学、医疗电磁波频段（ISM频段）进行通信，可以用于传感器网络、智能家居、工业自动化等多种场景。

ZigBee技术主要具有以下特点：1. 低功耗。

ZigBee采用间歇性通信方式，使得节点在空闲状态下能够进入低功耗模式，从而大大延长节点的续航能力。

2. 网络形态灵活。

ZigBee可以实现星型、网状、集群等多种网络拓扑形态，适用于不同场景的需求。

3. 数据传输效率高。

ZigBee采用短数据帧进行数据传输，有效减少了传输时间和能耗。

4. 安全性高。

ZigBee使用AES-128加密算法，确保数据传输的安全性。

三、基于ZigBee技术的低功耗无线传感器网络研究目前，基于ZigBee技术的低功耗无线传感器网络已经在工业控制、室内环境监测等领域得到广泛应用。

下面详细探讨它在清洁能源和环境监测中的应用。

1. 清洁能源低功耗无线传感器网络可以实现对太阳能、风能等清洁能源的监测。

Zigbee Wireless Sensor Network in Environmental MonitoringApplicationsI. ZIGBEE TECHNOLOGYZigbee is a wireless standard based on IEEE802.15.4 that was developed to address the unique needs of most wireless sensing and control applications. Technology is low cost, low power, a low data rate, highly reliable, highly secure wireless networking protocol targeted towards automation and remote control applications. It’s depicts two key performance characteristics –wireless radio range and data transmission rate of the wireless spectrum. Comparing to other wireless networking protocols such as Bluetooth, Wi-Fi, UWB and so on, shows excellent transmission ability in lower transmission rate and highly capacity of network. A. Zigbee FrameworkFramework is made up of a set of blocks called layers.Each layer performs a specific set of services for the layer above. As shown in Fig.1. The IEEE 802.15.4 standard defines the two lower layers: the physical (PHY) layer and the medium access control (MAC) layer. The Alliance builds on this foundation by providing the network and security layer and the framework for the application layer.Fig.1 FrameworkThe IEEE 802.15.4 has two PHY layers that operate in two separate frequency ranges: 868/915 MHz and 2.4GHz. Moreover, MAC sub-layer controls access to the radio channel using a CSMA-CA mechanism. Its responsibilities may also include transmitting beacon frames, synchronization, and providing a reliable transmission mechanism.B. Zigbee’s TopologyThe network layer supports star, tree, and mesh topologies, as shown in Fig.2. In a star topology, the network is controlled by one single device called coordinator. The coordinator is responsible for initiating and maintaining the devices on the network. All other devices, knownas end devices, directly communicate with the coordinator. In mesh and tree topologies, the coordinator is responsible for starting the network and for choosing certain key network parameters, but the network may be extended through the use of routers. In tree networks, routers move data and control messages through the network using a hierarchical routing strategy. Mesh networks allow full peer-to-peer communication.Fig.2 Mesh topologiesFig.3 is a network model, it shows that supports both single-hop star topology constructed with one coordinator in the center and the end devices, and mesh topology. In the network, the intelligent nodes are composed by Full Function Device (FFD) and Reduced Function Device (RFD). Only the FFN defines the full functionality and can become a network coordinator. Coordinator manages the network, it is to say that coordinator can start a network and allow other devices to join or leave it. Moreover, it can provide binding and address-table services, and save messages until they can be delivered.Fig.3 Zigbee network modelII.THE GREENHOUSE ENVIRONMENTAL MONITORINGSYSTEM DESIGNTraditional agriculture only use machinery and equipment which isolating and no communicating ability. And farmers have to monitor crops’ growth by themselves. Even if some people use electrical devices, but most of them were restricted to simple communication between control computer and end devices like sensors instead of wire connection, which couldn’t be strictly defined as wireless sens or network. Therefore, by through using sensor networks and, agriculture could become more automation, more networking and smarter.In this project, we should deploy five kinds of sensors in the greenhouse basement. By through these deployed sensors, the parameters such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity can be detected real time. It is key to collect different parameters from all kinds of sensors. And in the greenhouse, monitoring the vegetables growing conditions is the top issue. Therefore, longer battery life and lower data rate and less complexity are very important. From the introduction about above, we know that meet the requirements for reliability, security, low costs and low power.A. System OverviewThe overview of Greenhouse environmental monitoring system, which is made up by one sink node (coordinator), many sensor nodes, workstation and database. Mote node and sensor node together composed of each collecting node. When sensors collect parameters real time, such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity, these data will be offered to A/D converter, then by through quantizing and encoding become the digital signal that is able to transmit by wireless sensor communicating node. Each wireless sensor communicating node has ability of transmitting, receiving function.In this WSN, sensor nodes deployed in the greenhouse, which can collect real time data and transmit data to sink node (Coordinator) by the way of multi-hop. Sink node complete the task of data analysis and data storage. Meanwhile, sink node is connected with GPRS/CDMA can provide remote control and data download service. In the monitoring and controlling room, by running greenhouse management software, the sink node can periodically receives the data from the wireless sensor nodes and displays them on monitors.B. Node Hardware DesignSensor nodes are the basic units of WSN. The hardware platform is made up sensor nodes closely related to the specific application requirements. Therefore, the most important work isthe nodes design which can perfect implement the function of detecting and transmission as a WSN node, and perform its technology characteristics. Fig.4 shows the universal structure of the WSN nodes. Power module provides the necessary energy for the sensor nodes. Data collection module is used to receive and convert signals of sensors. Data processing and control module’s functions are node device control, task sche duling, and energy computing and so on. Communication module is used to send data between nodes and frequency chosen and so on.Fig.4 Universal structure of the wsn nodesIn the data transfer unit, the module is embedded to match the MAC layer and the NET layer of the protocol. We choose CC2430 as the protocol chips, which integrated the CPU, RF transceiver, net protocol and the RAM together. CC2430 uses an 8 bit MCU (8051), and has 128KB programmable flash memory and 8KB RAM. It also includes A/D converter, some Timers, AES128 Coprocessor, Watchdog Timer, 32K crystal Sleep mode Timer, Power on Reset, Brown out Detection and 21 I/Os. Based on the chips, many modules for the protocol are provided. And the transfer unit could be easily designed based on the modules.As an example of a sensor end device integrated temperature, humidity and light, the design is shown in Fig. 5.Fig.5 The hardware design of a sensor nodeThe SHT11 is a single chip relative humidity and temperature multi sensor module comprising a calibrated digital output. It can test the soil temperature and humidity. The DS18B20 is a digital temperature sensor, which has 3 pins and data pin can link MSP430 directly. It can detect temperature in greenhouse. The TCS320 is a digital light sensor. SHT11, DS18B20 and TCS320 are both digital sensors with small size and low power consumption. Other sensor nodes can be obtained by changing the sensors.The sensor nodes are powered from onboard batteries and the coordinator also allows to be powered from an external power supply determined by a jumper.C. Node Software DesignThe application system consists of a coordinator and several end devices. The general structure of the code in each is the same, with an initialization followed by a main loop.The software flow of coordinator, upon the coordinator being started, the first action of the application is the initialization of the hardware, liquid crystal, stack and application variables and opening the interrupt. Then a network will be formatted. If this net has been formatted successfully, some network information, such as physical address, net ID, channel number will be shown on the LCD. Then program will step into application layer and monitor signal. If there is end device or router want to join in this net, LCD will shown this information, and show the physical address of applying node, and the coordinator will allocate a net address to this node. If the node has been joined in this network, the data transmitted by this node will be received by coordinator and shown in the LCD.The software flow of a sensor node, as each sensor node is switched on, it scans all channelsand, after seeing any beacons, checks that the coordinator is the one that it is looking for. It then performs a synchronization and association. Once association is complete, the sensor node enters a regular loop of reading its sensors and putting out a frame containing the sensor data. If sending successfully, end device will step into idle state; by contrast, it will collect data once again and send to coordinator until sending successfully.D. Greenhouse Monitoring Software DesignWe use VB language to build an interface for the test and this greenhouse sensor network software can be installed and launched on any Windows-based operating system. It has 4 dialog box selections: setting controlling conditions, setting Timer, setting relevant parameters and showing current status. By setting some parameters, it can perform the functions of communicating with port, data collection and data viewing。

Zigbee Wireless Sensor Network in Environmental MonitoringApplicationsI. ZIGBEE TECHNOLOGYZigbee is a wireless standard based on IEEE802.15.4 that was developed to address the unique needs of most wireless sensing and control applications. Technology is low cost, low power, a low data rate, highly reliable, highly secure wireless networking protocol targeted towards automation and remote control applications. It’s depicts two key performance characteristics – wireless radio range and data transmission rate of the wireless spectrum. Comparing to other wireless networking protocols such as Bluetooth, Wi-Fi, UWB and so on, shows excellent transmission ability in lower transmission rate and highly capacity of network.A. Zigbee FrameworkFramework is made up of a set of blocks called layers.Each layer performs a specific set of services for the layer above. As shown in Fig.1. The IEEE 802.15.4 standard defines the two lower layers: the physical (PHY) layer and the medium access control (MAC) layer. The Alliance builds on this foundation by providing the network and security layer and the framework for the application layer.Fig.1 FrameworkThe IEEE 802.15.4 has two PHY layers that operate in two separate frequency ranges: 868/915 MHz and 2.4GHz. Moreover, MAC sub-layer controls access to the radio channel using a CSMA-CA mechanism. Its responsibilities may also include transmitting beacon frames, synchronization, and providing a reliable transmission mechanism.B. Zigbee’s TopologyThe network layer supports star, tree, and mesh topologies, as shown in Fig.2. In a star topology, the network is controlled by one single device called coordinator. The coordinatoris responsible for initiating and maintaining the devices on the network. All other devices, known as end devices, directly communicate with the coordinator. In mesh and tree topologies, the coordinator is responsible for starting the network and for choosing certain key network parameters, but the network may be extended through the use of routers. In tree networks, routers move data and control messages through the network using a hierarchical routing strategy. Mesh networks allow full peer-to-peer communication.Fig.2 Mesh topologiesFig.3is a network model, it shows that supports both single-hop star topology constructed with one coordinator in the center and the end devices, and mesh topology. In the network, the intelligent nodes are composed by Full Function Device (FFD) and Reduced Function Device (RFD). Only the FFN defines the full functionality and can become a network coordinator. Coordinator manages the network, it is to say that coordinator can start a network and allow other devices to join or leave it. Moreover, it can provide binding and address-table services, and save messages until they can be delivered.Fig.3 Zigbee network modelII.THE GREENHOUSE ENVIRONMENTAL MONITORINGSYSTEM DESIGNTraditional agriculture only use machinery and equipment which isolating and no communicating ability. And farmers have to monitor crops’ growth by themselves. Even if some people use electrical devices, but most of them were restricted to simple communication between control computer and end devices like sensors instead of wire connection, which couldn’t be strictly defined as wireless sens or network. Therefore, by through using sensor networks and, agriculture could become more automation, more networking and smarter.In this project, we should deploy five kinds of sensors in the greenhouse basement. By through these deployed sensors, the parameters such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity can be detected real time. It is key to collect different parameters from all kinds of sensors. And in the greenhouse, monitoring the vegetables growing conditions is the top issue. Therefore, longer battery life and lower data rate and less complexity are very important. From the introduction about above, we know that meet the requirements for reliability, security, low costs and low power.A. System OverviewThe overview of Greenhouse environmental monitoring system, which is made up by one sink node (coordinator), many sensor nodes, workstation and database. Mote node and sensor node together composed of each collecting node. When sensors collect parameters real time, such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity, these data will be offered to A/D converter, then by through quantizing and encoding become the digital signal that is able to transmit by wireless sensor communicating node. Each wireless sensor communicating node has ability of transmitting, receiving function.In this WSN, sensor nodes deployed in the greenhouse, which can collect real time data and transmit data to sink node (Coordinator) by the way of multi-hop. Sink node complete the task of data analysis and data storage. Meanwhile, sink node is connected with GPRS/CDMA can provide remote control and data download service. In the monitoring and controlling room, by running greenhouse management software, the sink node can periodically receives the data from the wireless sensor nodes and displays them on monitors.B. Node Hardware DesignSensor nodes are the basic units of WSN. The hardware platform is made up sensor nodes closely related to the specific application requirements. Therefore, the most important work is the nodes design which can perfect implement the function of detecting and transmission as a WSN node, and perform its technology characteristics. Fig.4 shows the universal structure of the WSN nodes. Power module provides the necessary energy for the sensor nodes. Data collection module is used to receive and convert signals of sensors. Data processing and control module’s functions are node device control, task sche duling, and energy computing and so on. Communication module is used to send data between nodes and frequency chosen and so on.Fig.4 Universal structure of the wsn nodesIn the data transfer unit, the module is embedded to match the MAC layer and the NET layer of the protocol. We choose CC2430 as the protocol chips, which integrated the CPU, RF transceiver, net protocol and the RAM together. CC2430 uses an 8 bit MCU (8051), and has 128KB programmable flash memory and 8KB RAM. It also includes A/D converter, some Timers, AES128 Coprocessor, Watchdog Timer, 32K crystal Sleep mode Timer, Power on Reset, Brown out Detection and 21I/Os. Based on the chips, many modules for the protocol are provided. And the transfer unit could be easily designed based on the modules.As an example of a sensor end device integrated temperature, humidity and light, the design is shown in Fig. 5.Fig.5 The hardware design of a sensor nodeThe SHT11is a single chip relative humidity and temperature multi sensor module comprising a calibrated digital output. It can test the soil temperature and humidity. The DS18B20 is a digital temperature sensor, which has 3 pins and data pin can link MSP430 directly. It can detect temperature in greenhouse. The TCS320is a digital light sensor. SHT11, DS18B20and TCS320are both digital sensors with small size and low power consumption. Other sensor nodes can be obtained by changing the sensors.The sensor nodes are powered from onboard batteries and the coordinator also allows to be powered from an external power supply determined by a jumper.C. Node Software DesignThe application system consists of a coordinator and several end devices. The general structure of the code in each is the same, with an initialization followed by a main loop.The software flow of coordinator, upon the coordinator being started, the first action of the application is the initialization of the hardware, liquid crystal, stack and application variables and opening the interrupt. Then a network will be formatted. If this net has been formatted successfully, some network information, such as physical address, net ID, channel number will be shown on the LCD. Then program will step into application layer and monitor signal. If there is end device or router want to join in this net, LCD will shown this information, and show the physical address of applying node, and the coordinator will allocate a net address to this node. If the node has been joined in this network, the data transmitted by this node will be received by coordinator and shown in the LCD.The software flow of a sensor node, as each sensor node is switched on, it scans allchannels and, after seeing any beacons, checks that the coordinator is the one that it is looking for. It then performs a synchronization and association. Once association is complete, the sensor node enters a regular loop of reading its sensors and putting out a frame containing the sensor data. If sending successfully, end device will step into idle state; by contrast, it will collect data once again and send to coordinator until sending successfully.D. Greenhouse Monitoring Software DesignWe use VB language to build an interface for the test and this greenhouse sensor network software can be installed and launched on any Windows-based operating system. It has 4 dialog box selections: setting controlling conditions, setting Timer, setting relevant parameters and showing current status. By setting some parameters, it can perform the functions of communicating with port, data collection and data viewing.Zigbee无线传感器网络在环境监测中的应用I.Zigbee技术Zigbee是一种基于IEEE802.15.4的无线标准上被开发用来满足大多数无线传感和控制应用的独特需求。

Zigbee Wireless Sensor Network in Environmental MonitoringApplicationsI. ZIGBEE TECHNOLOGYZigbee is a wireless standard based on IEEE802.15.4 that was developed to address the unique needs of most wireless sensing and control applications. Technology is low cost, low power, a low data rate, highly reliable, highly secure wireless networking protocol targeted towards automation and remote control applications. It’s depicts two key performance characteristics – wireless radio range and data transmission rate of the wireless spectrum. Comparing to other wireless networking protocols such as Bluetooth, Wi-Fi, UWB and so on, shows excellent transmission ability in lower transmission rate and highly capacity of network.A. Zigbee FrameworkFramework is made up of a set of blocks called layers.Each layer performs a specific set of services for the layer above. As shown in Fig.1. The IEEE 802.15.4 standard defines the two lower layers: the physical (PHY) layer and the medium access control (MAC) layer. The Alliance builds on this foundation by providing the network and security layer and the framework for the application layer.Fig.1 FrameworkThe IEEE 802.15.4 has two PHY layers that operate in two separate frequency ranges: 868/915 MHz and 2.4GHz. Moreover, MAC sub-layer controls access to the radio channel using a CSMA-CA mechanism. Its responsibilities may also include transmitting beacon frames, synchronization, and providing a reliable transmission mechanism.B. Zigbee’s TopologyThe network layer supports star, tree, and mesh topologies, as shown in Fig.2. In a star topology, the network is controlled by one single device called coordinator. The coordinatoris responsible for initiating and maintaining the devices on the network. All other devices, known as end devices, directly communicate with the coordinator. In mesh and tree topologies, the coordinator is responsible for starting the network and for choosing certain key network parameters, but the network may be extended through the use of routers. In tree networks, routers move data and control messages through the network using a hierarchical routing strategy. Mesh networks allow full peer-to-peer communication.Fig.2 Mesh topologiesFig.3is a network model, it shows that supports both single-hop star topology constructed with one coordinator in the center and the end devices, and mesh topology. In the network, the intelligent nodes are composed by Full Function Device (FFD) and Reduced Function Device (RFD). Only the FFN defines the full functionality and can become a network coordinator. Coordinator manages the network, it is to say that coordinator can start a network and allow other devices to join or leave it. Moreover, it can provide binding and address-table services, and save messages until they can be delivered.Fig.3 Zigbee network modelII.THE GREENHOUSE ENVIRONMENTAL MONITORINGSYSTEM DESIGNTraditional agriculture only use machinery and equipment which isolating and no communicating ability. And farmers have to monitor crops’ growth by themselves. Even if some people use electrical devices, but most of them were restricted to simple communication between control computer and end devices like sensors instead of wire connection, which couldn’t be strictly defined as wireless sens or network. Therefore, by through using sensor networks and, agriculture could become more automation, more networking and smarter.In this project, we should deploy five kinds of sensors in the greenhouse basement. By through these deployed sensors, the parameters such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity can be detected real time. It is key to collect different parameters from all kinds of sensors. And in the greenhouse, monitoring the vegetables growing conditions is the top issue. Therefore, longer battery life and lower data rate and less complexity are very important. From the introduction about above, we know that meet the requirements for reliability, security, low costs and low power.A. System OverviewThe overview of Greenhouse environmental monitoring system, which is made up by one sink node (coordinator), many sensor nodes, workstation and database. Mote node and sensor node together composed of each collecting node. When sensors collect parameters real time, such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity, these data will be offered to A/D converter, then by through quantizing and encoding become the digital signal that is able to transmit by wireless sensor communicating node. Each wireless sensor communicating node has ability of transmitting, receiving function.In this WSN, sensor nodes deployed in the greenhouse, which can collect real time data and transmit data to sink node (Coordinator) by the way of multi-hop. Sink node complete the task of data analysis and data storage. Meanwhile, sink node is connected with GPRS/CDMA can provide remote control and data download service. In the monitoring and controlling room, by running greenhouse management software, the sink node can periodically receives the data from the wireless sensor nodes and displays them on monitors.B. Node Hardware DesignSensor nodes are the basic units of WSN. The hardware platform is made up sensor nodes closely related to the specific application requirements. Therefore, the most important work is the nodes design which can perfect implement the function of detecting and transmission as a WSN node, and perform its technology characteristics. Fig.4 shows the universal structure of the WSN nodes. Power module provides the necessary energy for the sensor nodes. Data collection module is used to receive and convert signals of sensors. Data processing and control module’s functions are node device control, task sche duling, and energy computing and so on. Communication module is used to send data between nodes and frequency chosen and so on.Fig.4 Universal structure of the wsn nodesIn the data transfer unit, the module is embedded to match the MAC layer and the NET layer of the protocol. We choose CC2430 as the protocol chips, which integrated the CPU, RF transceiver, net protocol and the RAM together. CC2430 uses an 8 bit MCU (8051), and has 128KB programmable flash memory and 8KB RAM. It also includes A/D converter, some Timers, AES128 Coprocessor, Watchdog Timer, 32K crystal Sleep mode Timer, Power on Reset, Brown out Detection and 21I/Os. Based on the chips, many modules for the protocol are provided. And the transfer unit could be easily designed based on the modules.As an example of a sensor end device integrated temperature, humidity and light, the design is shown in Fig. 5.Fig.5 The hardware design of a sensor nodeThe SHT11is a single chip relative humidity and temperature multi sensor module comprising a calibrated digital output. It can test the soil temperature and humidity. The DS18B20 is a digital temperature sensor, which has 3 pins and data pin can link MSP430 directly. It can detect temperature in greenhouse. The TCS320is a digital light sensor. SHT11, DS18B20and TCS320are both digital sensors with small size and low power consumption. Other sensor nodes can be obtained by changing the sensors.The sensor nodes are powered from onboard batteries and the coordinator also allows to be powered from an external power supply determined by a jumper.C. Node Software DesignThe application system consists of a coordinator and several end devices. The general structure of the code in each is the same, with an initialization followed by a main loop.The software flow of coordinator, upon the coordinator being started, the first action of the application is the initialization of the hardware, liquid crystal, stack and application variables and opening the interrupt. Then a network will be formatted. If this net has been formatted successfully, some network information, such as physical address, net ID, channel number will be shown on the LCD. Then program will step into application layer and monitor signal. If there is end device or router want to join in this net, LCD will shown this information, and show the physical address of applying node, and the coordinator will allocate a net address to this node. If the node has been joined in this network, the data transmitted by this node will be received by coordinator and shown in the LCD.The software flow of a sensor node, as each sensor node is switched on, it scans allchannels and, after seeing any beacons, checks that the coordinator is the one that it is looking for. It then performs a synchronization and association. Once association is complete, the sensor node enters a regular loop of reading its sensors and putting out a frame containing the sensor data. If sending successfully, end device will step into idle state; by contrast, it will collect data once again and send to coordinator until sending successfully.D. Greenhouse Monitoring Software DesignWe use VB language to build an interface for the test and this greenhouse sensor network software can be installed and launched on any Windows-based operating system. It has 4 dialog box selections: setting controlling conditions, setting Timer, setting relevant parameters and showing current status. By setting some parameters, it can perform the functions of communicating with port, data collection and data viewing.Zigbee无线传感器网络在环境监测中的应用I.Zigbee技术Zigbee是一种基于IEEE802.15.4的无线标准上被开发用来满足大多数无线传感和控制应用的独特需求。

A Coal Mine Environmental Monitor System with LocalizationFunction Based on ZigBee-Compliant PlatformDongxuan YangCollege of Computer and InformationEngineeringBeijing Technology and BusinessUniversityBeijing, ChinaYan ChenCollege of Computer and InformationEngineeringBeijing Technology and BusinessUniversityBeijing, China*****************Kedong WangCollege of Computer and InformationEngineeringBeijing Technology and BusinessUniversityBeijing, ChinaAbstract—This paper describes and implements a new type of coal mine safety monitoring system, it is a kind of wireless sensor network system based on ZigBee technology. The system consists of two parts underground and surface. Wireless sensor networks are constituted by fixed nodes, mobile nodes and a gateway in underground. PC monitoring software is deployed in the surface. The system can not only gather real-time environmental data for mine, but also calculate the real-time location of mobile nodes worn by miners.Keywords：ZigBee; localization; wireless sensor networks; coal MineI.RESEARCH STATUSAs an important energy, coal plays a pivotal role in the economic development. Coal mine monitoring system, is the important guarantee for coal mine safety and high efficiency production [1]. In order to ensure the safe operation, the installation of environment monitoring node in tunnels to real-time detection is very important. However, commonly used traditional monitoring node wired connection to obtain communication with the control system, this node exist wiring difficulties, expensive and other shortcomings. In contrast, wireless sensor node can be easily with current mine monitoring network connection, and good compatibility, facilitate constituted mine gas monitoring network, to suit various size of mine applications. Since wireless nodes are battery powered, so completely out of the shackles of the cable, shorten the construction period can be arranged at any time where the need to use.The ZigBee wireless communication technology is used in this coal mine environmental monitor system. This is a new short-range, low complexity, low power,low data rate, low-cost two-way wireless communication technology [2]. Now, wireless sensor network product based on ZigBee technology are quantity and variety, but the real product can be applied in underground environments of special sensor node is very few[3]. The sensor node that we designed in the system is truly able to apply to in-well environment, it through the wireless sensor node security certification. At the same time, due to the special nature of the wireless network is that it can spread the wireless signal, we can easily locate staff for coal mine safety monitoring provides more protection [4].II. SYSTEM ARCHITECTUREThis system is a comprehensive monitoring system which is combined with software and hardware. Hardware part includes wireless mobile nodes and fixed nodes which were deployed in the underground tunnel, the main function of them is to collect coal mine environment data and require person’s location. Software part refers to the PC monitoring software which is designed in VC++ is used to summarize and display the data of each node. Monitoring node is divided into mobile nodes and fixed nodes; they are using ZigBee protocol for wireless transmission of data. Because the fixed node is also using wireless data transmission method, so it's deployed in the underground roadway becomes very convenient. As the mobile node is carried by the miner, it must be using wireless transmission method. This allows the mine to form a topology of ZigBee wireless sensor network. The fixed node in wireless sensor network is router device and the mobile node carried by miner is the end device. Normally, the router of ZigBee network has no sensor equipment; it is only responsible for data forwarding. But considering the practical application, we believe that add sensor devices on the router will be better on monitoring underground coal mine environment. So in our design, the router also has an environment monitoring function which is usually designed in end device.Fixed node will sent received data from mobile node to the gateway, then the gateway transmits data to monitor computer through RS232 or optical fiber. The PC monitor software in the computer will process all data and display them in a visualization window. The PC software also calculates each mobile node’s real-time location through the specific localization algorithm, according to the received signal strength (RSSI) obtained from mobile nodes.III. NODE DESIGNSince the ZigBee wireless network platform sold on present market was designed for the general environment, for special underground so they are not suitable for the environment. Therefore, we need to customize the system for underground environment whit a special hardware circuit. Node photo are shown in Fig. 1 Then wireless microcontroller CC2530 chip is the core processor of the node device, it can constitute a ZigBee network with very few peripheral circuits. TheCC2530 is an IEEE 802.15.4 compliant true System-on-Chip, supporting theproprietary 802.15.4 market as well as the ZigBee, ZigBee PRO, and ZigBee RF4CE standards. Unlike other wireless chip, CC2530 built-in 8051 monolithic integrated circuits kernel, therefore we no longer need to use a single MCU to control the circuit, and this save us a lot of cost [5].A.Mobile NodeThe mobile node is the end device of a ZigBee network that can be carried by miner; it should be a portable and low power consumption node. So the mobile node we designed is only as small as a mobile phone, and it is by built-in lithium ion battery power supply. In power loss, the core processor CC2530 is a low power consumption chip, when it is in the sleep mode, it only need to use less then 1uA work current. In order to reduce power consumption as much as possible on the display, a 100*32 pixel matrix with no backlighting LCD screen was used. The battery’s capacity of the mobile node is 1500mAh,so it is enough to meet the miner’s long hour works in the underground. The battery charge management chip is TP4057, the maximum charge current can up to 500Ma.Figure 1. Node photo.The mobile node circuit includes the gas concentration sensor MJ4.0 and temperature sensor PT-1000. As far as we know, many wireless sensor platforms use the digital type sensor. The communication between the digital sensor and the MCU need strict timing requirements. But considering the actual application, the wireless MCU usually has a real-time operating system in general, if we use the microcomputer to simulate the strict timing, it will affect the real-time of whole operating system. These two sensors output analog signals not digital signals. Only input this signal into a differential amplifier, can we get an appropriate signal that can be converted to a digital signal by an ADC mode within the CC2530 chip. In order to facilitate the carrying, external antenna was not used in our mobile node, instead ofusing a 2.4GHz patch antenna. And we customize a shell like a cell phone size; it is enough to put all PCBs, sensors and battery in it. Taking into account the small shell of the explosive performance is not very good, the design of PCBs and the selection of component are all carried out the safety assessment.B. Fixed NodeFixed node is installed in the wall of the underground tunnel. Because it is big than the mobile node, it is not appropriate to carry around. The circuit of the fixed node is almost same with the mobile node, it also use a CC2530 chip as core processor. Because of underground tunnels generally deploy with power cable, fixed nodes can use cable power-supply modes. At the same time, because we use wireless signal transmission, the deployment of new fixed nodes become very convenient, which also resolves the problem of the signal lines deployment.As a fixed node, the minor who is doing work may far from it, in order to facilitate the miners observed environmental data around the fixed nodes, it uses LED digital display. At the same time, the large current LED lights and buzzer are designed in the circuit; it makes the fixed node with the function of sound-light alarm. Considering that it may occur the emergency of without electricity, fixed node also built-in a lithium-ion battery. Under normal conditions, lithium-ion battery is in charging status, when external cable disconnect, fixed node is automatic switched to battery power, which can ensure the mobile node can deliver the information through fixed nodes in underground.Without regarding to fixed nodes’ portability, we have a customized shell that has excellent explosion properties, and the internal space is enough to hold down the 2.4 GHz antenna. To ensure safety, all cables and the location of sensors are placed with particular glue sealed, so that it has a good seal.IV.POSITIONING FUNCTIONOne of the important functions of the wireless sensor networks is localization, especially in the underground tunnel, it relates to the safe of the miner's life. Currently most widely used orientation method is GPS satellite positioning, it is a high precision, all-weather and global multifunctional system with the function of radio navigation, positioning and timing. But the GPS positioning method is not suitable for the underground work environment of coal mine, once you enter the underground, it cannot receive satellite signal, thus unable to achieve targeting [6]. We need to consider how to use wireless network to realize positioning function, means using wireless signal between the communications of devices for positioning. The existing distance measuring technology between the wireless-devices basically is the following kinds of methods: TOA, TDOA, AOA and RSSI.About the TOA method, the distance between the two devices is determined by the product of the speed of light and transmission time [7]. Although the precision of this method is accurate, but it require a precise time synchronization, so it demand hardware is higher.TDOA technology need ultrasonic signal，which is setting on a node with receive and transmit function. When measure the distance, it can sent ultrasonic wave and wireless signals together. By measuring the difference between two signals arrival time, we can calculate the distance between two devices [8]. Using this method can also obtain accurate result, but the method need to increase ultrasonic sending and receiving device on the node circuit, it will increase cost.AOA technology needs to install multiple antennas through the nodes so it canobtain adjacent nodes’ signals on deferent directions [9]. With this it can determine the location information from number of adjacent nodes and calculate its own position. This method not only need to add additional hardware, but also it's still very vulnerable to external disturbance, therefore it's not suitable for utilize.RSSI ranging is a cheap and easy technology. By using this method, we don't need to add additional hardware design. We also do not need very precise time requirements. This technique is about with measuring the wireless signals strength in the propagation of the loss, to measure the distance between two nodes. Because of this method requires hardware equipment is less, algorithm is simple, so it has been using in many wireless communication field. Comprehensive all conditions, positioning on the use of RSSI ranging technique.A. Hardware Location EngineThe CC2431 wireless microcontroller chip produced by TI Company has a hardware location engine. From the software's point of view, CC2431’s hardware location engine has a very simple API interface, as long as writing the necessary parameters and waiting for calculation, it can read the location results [10].The hardware location engine is also based on RSSI technology. The localization system includes reference nodes and blind nodes. The reference node is a fixed node that located in a known position, the node know their place and send a packet notifyto other nodes. The blind node receives packets from reference nodes, which can obtains reference nodes’ location and the corresponding RSSI value and put them into the hardware location engine, and then the blind node’s location can be read from the engine [11].On the surface, using the CC2431 hardware location engine targeting the program as a good choice, but considering the practical application, it will encounter the following problems. First of all, we have choose the CC2530 as the main chip of fixed nodes of the system, its internal programs is running in ZigBee2007 protocol, but CC2431 as a early chip, it applies only to ZigBee2006 protocol. In the communications between CC2431 and CC2530 that will have compatibility problems. Secondly, CC2431 hardware location engine use the distributed computing, all mobile nodes’ location are calculated by themselves, and then they upload information to the gateway node, this will not only occupy the mobile node processing time, still it can take up more network resources. For this reason, we have to shelve this approach, consider how to implement location by using CC2530 chip.B. Software Location EngineIf we want to use CC2530 to implement location function, that we must write software location engine by ourselves. Because that chip do not have a hardware location engine inside of it. This software location engine is still used RSSI technology; meanwhile mobile node position is calculated by the PC software, so asto reduce the burden of mobile node computing. To calculate the mobile node location, there must be at least three reference nodes. We will regard router nodes as reference nodes in network, and record the X, Y coordinates of every reference node. Then we let the mobile node send signal to each reference node, so that each reference node can obtain a RSSI values, with these parameters, we can use trilateral measurement method to calculate the specified location of the mobile node. The simpler way give the mobile node to broadcast way to send data, then around it every router node would receive the data from the mobile node, thus obtains RSSI values. Once the mobile node number increasing network, this method will make router nodes more burden, because the every radio message that the router node receives will transmit from the low layer to the top layer. Finally the application layer will analyze data packets. Infact, the mobile node need not to broadcast transmitted data, other routing node can also receive the mobile node packets. Only child mobile nodes of the router node will continue to transmit the packet forwarding upward, the other router nodes will shield out the packet in the bottom of the protocol.In order to let all router nodes can receive the packet which sending by mobile nodes, and send its RSSI values up to the gateway node, we need to modify the relevant function in Z- Stack protocol which is provided by TI. First we find the function named afIncomingData, it deals with the received data from the bottom of protocol, in which we add some code that can obtain packet’s RSSI value. Then through the osal_set_event function to add and send an eventMY_RSSI_REPORT_EVT of RSSI value task to OSAL polling system. This event’s corresponding function will be executed in the task of OSAL interrupt-driven function, thus the mobile node corresponding RSSI values will be sent to gateway node. Through this method, the packet will only be processed by bottom function of the protocol. According to this method we can obtain corresponding RSSI value and save the computation time of mobile nodes.In fact, this software location engine is not implementing with a single mobile node, but through the operation of the whole system to achieve. By which the mobile node is only responsible for sending unicast packets. The mobile node’s parent router node is responsible to forward the packet to the gateway. Other router nodes are not responsible for forwarding this packet, just clipping the mobile node of RSSI value, then forwarded to the gateway. Finally the gateway bring all RSSI values of the mobile node to PC monitoring software, the corresponding mobile node’s location is calculated. In order to reduce the error, monitoring software will collect 10 times of the RSSI value and take average on it, and then select the nearest value of the three fixed nodes. Finally the trilateral measurement method is used to calculate the location of mobile nodes.V．SYSTEM IMPLEMENTATIONAll software systems embedded in nodes are based on Z-Stack. BecauseZ-Stack is an open-source project, it is very beneficial to the secondary development. These nodes were tested in a real coal mine locate in Shanxi Province. We deployed the fixed node every 50 meters in the tunnel, and also set a fixed node in each entrance of the work area. Because the fixed node have large size digital LED displays, so the display content of the fixed node can be seen far from away the miner. Each miner carries a mobile node, the temperature and gas concentration is displayed on the LCD screen at real-time.The gateway node is placed at the entrance of the mine, through the RS232 cable connected to the monitoring computer in the control room. In this system all packets collected by the gateway node are transmitted to PC through a serial port, and it can save historical data backup to a SQL database. The main function of monitoring software is to display and store the data of every node, and calculates related mobile nodes’ location according to RSSI values. The monitoring software has two main dialog interfaces, one is used to display a two- dimensional profile of the coal mine, and user can see all the miners' working position. Another interface is data displaying interface, and environmental data were shown here. The picture of PC monitoring software is shown in Fig. 2.Figure 2. PC monitoring software.VI．SYSTEM EV ALUATIONThrough repeated testing of the system, we made the system an objective assessment. First is the power consumption assess for node hardware, fixed node’s working voltage is in 9V ~ 24V when the power supplied by cable. The maximum operating current for fixed node is 93mA; the average operating current is 92.2mA. When the power cable was disconnected, fixed node powered by lithium-ion battery. On battery power, the fixed node’s maximum working current is 147mA; average working current is 146.3mA. Fixed nodes can work 8 hours on battery power at least.Another quite important performance is the location function of the system performance. At four different locations of tunnel and working areas, mobile nodes were placed there. Two sets of different average error data were shown in From table 1. Because this system uses RSSI technology and it relies mainly on the signal strength, the signal quality will be affected by interferences. From different locations’ errors we can see that, the error in working areas was larger than it in tunnels, because the tunnel is generally straight, but the shape of the working areas are uncertainty.We gratefully acknowledge Texas Instruments for devices provided to us free of charge. And also thank staffs of XinNuoJin Company for giving us supports onsystem testing.REFERENCES[1] Xinyue Zhong Wancheng Xie. “Wireless sensor network in the coal mineenvironment monitoring“. Coal technology, 2009, Vol. 28, No. 9,pp.102-103. [2] Shouwei Gao. “ZigBee Technology Practice Guide”. Beijing: Beijing Universityof Aeronautics and Astronautics Press , 2009, pp. 27-28.[3] Yang Wang, Liusheng Huang, Wei Yang. “A Novel Real-Time CoalMinerLocalization and Tracking System Based on Self-Organized Sensor Networks”.EURASIP Journal onWireless Communications and Networking, Volume 2010, Article ID 142092.[4] Sang-il Ko, Jong-suk Choi, Byoung-hoon Kim. “Indoor Mobile LocalizationSystem and Stabilization of Localizaion Performance using Pre-filtering”.International Journal of Control, Automation and Systems, Vol. 6, No. 2, pp.204-213, April 2008.[5] .[6] Hawkins Warren, Daku Brian L. F, Prugger Arnfinn F. “Positioning inunderg round mines”. IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006, pp. 3159-3163.[7] Zhu, Shouhong, Ding, Zhiguo, Markarian Karina. “TOA based jointsynchronization and localization”. 2010 IEEE International Conference on Communications, ICC 2010, 2010, Article ID 5502036.[8] Ni Hao, Ren Guangliang, Chang Yilin. “A TDOA location scheme in OFDMbased WMANs”. IEEE Transactions on Consumer Electronics,2008, Vol. 54, No. 3, pp. 1017-1021.[9] Dogançay Kutluyil, Hmam Hatem. “Optimal angular sensor separation for AOAlocalization”. Signal Processing, 2008, Vol. 88, No. 5, pp. 1248-1260.[10] K. Aamodt. “CC2431 Location Engine”. Texas Instruments, Application NoteAN042, SWRA095.[11] Tennina Stefano, Di Renzo Marco, Graziosi Fabio, Santucci Fortunato.“Locating zigbee nodes using the tis cc2431 location engine: A testbed platform and new solutions for positioning estimation of wsns in dynamic indoor environments”. Proc Annu Int Conf Mobile Comput Networking, 2008, pp.37-42.摘要-本文介绍并设计了一个新类型的煤矿安全监控系统，它是一种基于ZigBee 技术的无线传感器网络系统。

毕业设计(论文)译文及原稿免费下载，免费分享。

让论文写得更简单,更舒适。

更容易……译文题目ZｉｇBee：无线技术，低功耗传感器网络原稿题目ZigＢｅｅ: Wireless Technoｌｏgyｆｏｒ Low-Poｗｅr Sensor Networｋs原稿出处电子文献ZｉｇBee：无线技术，低功耗传感器网络加里莱格美国东部时间2004年5月6日上午１2:０0技师（工程师）们在发掘无线传感器的潜在应用方面从未感到任何困难。

例如，在家庭安全系统方面,无线传感器相对于有线传感器更易安装。

而在有线传感器的装置通常占无线传感器安装的费用80％的工业环境方面同样正确(适用)。

而且相比于有线传感器的不切实际甚至是不肯能而言，无线传感器更具应用性。

虽然,无线传感器需要消耗更多能量，也就是说所需电池的数量会随之增加或改变过于频繁。

再加上对无线传感器由空气传送的数据可靠性的怀疑论,所以无线传感器看起来并不是那么吸引人。

一个低功率无线技术被称为ZigBｅｅ,它是无线传感器方程重写，但是。

一个安全的网络技术，对最近通过的IEEＥ8０2.１５.4无线标准（图1)的顶部游戏机，ＺiｇBeｅ的承诺,把无线传感器的一切从工厂自动化系统到家庭安全系统,消费电子产品。

与80２．１５.4的合作下，ZｉgBeｅ提供具有电池寿命可比普通小型电池的长几年。

ＺigBee设备预计也便宜,有人估计销售价格最终不到３美元每节点，。

由于价格低，他们应该是一个自然适应于在光线如无线交换机,无线自动调温器,烟雾探测器和家用产品。

(图1）虽然还没有正式的规范的ＺiｇBｅe存在(由ＺigBee联盟是一个贸易集团,批准应该在今年年底），但ＺigBeｅ的前景似乎一片光明。

技术研究公司In －Stａt/MDR在它所谓的“谨慎进取”的预测中预测,８０２．1５.4节点和芯片销售将从今天基本上为零,增加到２010年的1６5万台。

不是所有这些单位都将与ZigBeｅ结合,但大多数可能会。

Design and Implementation of a Low-Power ZigBeeWireless Temperature Humidity Sensor NetworkShuipeng Gong1, Changli Zhang1,2, Lili Ma1, Junlong Fang1, and Shuwen Wang11 Northeast Agricultural University, Harbin, Heilongjiang Province,P.R. China, 150030,gongshuipeng@2 Northeast Agricultural University, Harbin, Heilongjiang Province, P.R. China, 150030,Tel.: +86-451-55190456,zhangcl@Abstract. The key technology of greenhouse facilities is the monitoring ofenvironmental parameters. Now, monitoring system of greenhouse is based onwire transmission. It is complicated to route wire and difficult to maintain. Alsoits reliability and anti-interference performance will degrade because of heat,light and acid. This paper leads a low-power and short range ZigBee techniqueinto greenhouse monitoring system. In order to compose intelligent networksensor system, the paper analyses the composition of network nodes powerconsumption, proposes low-power design method both in hardware andsoftware. The paper selects CC2430 module which composed of transceiver andmicroprocessor, and use SHT15 temperature humidity sensor. After hardwareand software debugging, this wireless network can acquire and transmit data ofgreenhouse temperature and humidity accurately and rapidly, and this systemresistant to stable work, tight structure, large loads and low power consumption.Keywords: Greenhouse, CC2430, ZigBee, Low-power, Temperature humiditysensor, Wireless network.1 IntroductionNow, monitoring system of greenhouse is based on wire transmission. It is complicated to route wire and difficult to maintain. Also its reliability and anti-interference performance will degrade because of heat, light and acid. As wire transmission brings many disadvantages, more and more monitoring systems use wireless sensor networks.ZigBee plays an important role in wireless sensor networks. ZigBee as a priority in wireless sensor networks because its advantages, such as low power consumption, high tolerance, Ad Hoc Networks [1].In normal ZigBee network nodes use portable power (battery). Its harsh environment and large quantities make it very difficult to replace. So reducing the power consumption and extending the reliable working hours of sensor nodes become one of the key considerations. To compose intelligent sensor network system, the paper analyzes the consumption of the network and proposed low-power consumption methods both form hardware and software.D. Li, Y. Liu, and Y. Chen (Eds.): CCTA 2010, Part IV, IFIP AICT 347, pp. 616–622, 2011.© IFIP International Federation for Information Processing 2011Low-Power ZigBee Wireless Temperature Humidity Sensor Network 617 2 System DesignThe system uses a tree topology and consists of coordinator, router and terminal node. Each router and terminal node carries temperature humidity sensor. The coordinator connects PC by RS-232 serial ports. It collects all nodes’ information and sends them to PC so that the manager can monitor and manage the information. Figure 3 shows the framework of the monitor system.Fig. 1. The system uses a tree topology. This shows the framework diagram of the monitor system.3 Low-Power Hardware DesignsThe hardware of the entire network includes coordinator and sensor nodes. Coordinator is powered by USB as coordinator connects with PC. So the low power strategy of the system mainly use in ZigBee nodes. ZigBee nodes are composed of processor module, wireless communication module, temperature humidity sensor module and power module. Figure 2 shows the structure of node.Fig. 2. The node is composed of CC2430, SHT15 and power modules618 S. Gong et al.3.1 Processor ModuleMicroprocessor is the central processing unit of the node. As the data that the microprocessor handled is large, the microprocessor is one of the most energy consuming components of the node. In the low power design, the microprocessor that the node used should be low power consumption and support sleep mode. As wireless communication account for most of the power consumption, the selection of the wireless module is very important. The following advantages of CC2430 make it become the ideal solution to solve the problem. CC2430 SoC integrates the CC2420 RF transceiver and enhanced 8051MCU. Its current consumption is 0.9uA on sleep mode and can be waked up by external interrupt or RTC wake-up system. Its current consumption is 0.6uA on dormancy mode and can be waked up by external interrupt. CCC2430 requires a large voltage supply between 2.0V and 3.6V [2].3.2 Sensor ModuleSensor module uses temperature humidity sensor module SHT15. SHT15 integrates temperature humidity sensor, the conditioning and amplifying, A/D converting and I2C bus in one chip.The serial interface of SHT15 has a definite advantage both on the reading of sensor signor and power consumption. Current consumption is 550uA in measuring, 28uA in average, 3uA during sleep.Fig. 3. This circuit diagram shows the interface of SHT15 and CC24303.3 Power ModulePower module is mainly for CC2430 and SHT15. Voltage range of CC2430 is 2.0-3.6V; the SHT15 is 2.4-5.5V.The power of the system uses 2 #5 battery (3V), we can get 3.3V for the system after using DC-DC L6920 step-up chip. The following advantages make L6920 become the best choice: output voltage is 3.3V or 5V, even when the input voltage as low as 0.7V the system still can work (This can make sure that after a period of time of battery usage and the input voltage is falling the output voltage is still 3.3V ). This can enhance the stability of the system. The power consumption of L6920 is low. The working current is 18uA and only 5uA on sleep mode. Figure 4 shows Power circuit.Low-Power ZigBee Wireless Temperature Humidity Sensor Network 619Fig. 4. Power circuit diagram shows that the 3.3V battery3.4 Processing of Spare PinsThe system uses the CMOS chips. The charges cumulated by spare pins make the potential between “0” and “1”. The current complementary consist of an enhanced NMOS and an enhanced PMOS, the jumping of the potential from “0” to “1” or “1” to “0” will make the two pins instant short [3]. The intermittent short will bring short consumption. So connecting spare pins to the ground can reduce power consumption.4 Low-Power Consumption of SoftwareWith the integrated circuit technological progress, power consumption of processor module and sensor module become very low. Figure 5 can explain the sensor node energy consumption, most of the energy consumption on wireless communication module; communication module has four states: transmitting, receiving, leisure and sleep, and energy consumption on transmitting, receiving and idle state is large, but the energy consumption on sleeping state is small [4]. So how to reduce power consumption on wireless communication has become an important problem.Fig. 5. This shows all the consumption of sensor node4.1 Working Mode of CC2430In general CC2430 has low power consumption, it offers four power modes to choose: PM0/ PM1 /PM2/ PM3.620 S. Gong et al.CC2430 works on full-function PM0 mode, the frequency is 32MHz and 32.768 kHz, and the power consumption is less than 1mW. When it works on sleep mode PM1/PM2, Only the 32.768 kHz low-speed crystal run, the power consumption is less than 0.9uA, when it works on Hibernate mode PM3, there is no crystal run, so the power consumption is less than 0.6uA.After sending information, the node will be run into PM2-sleep mode. Because in this mode, it can run into full-function mode through internal sleep clock wake-up, and it does not require manual operation to wake-up.When the system works on SET_POWER_MODE (2) mode, sleep time can be set. the frequency of PM2 mode is 32.768kHz,timer of sleep is a 24-bit counter, so the longest sleep time of system is: T=2*24/32768=512s,the shortest sleep time is: T=1/32768 and it is about 30.5us.The setting function of sleep time is Set_ST_Period (uint16 sec), where sec is set according to user needs.4.2 Low-Power Software DesignThe system wakes up nodes at regular time. Temperature and humidity is a gradual process, so it is no need to monitor it all the time. Monitoring it at regular time not only can monitor the change of temp and humidity, but also can reduce the working time of nodes. it is not necessary for the sensor nodes to communicate with coordinator all the time, this can avoid data collision and can reduce the power consumption.Fig. 6. This shows the flow chart of software design and the sleep mode of CC2430Low-Power ZigBee Wireless Temperature Humidity Sensor Network 621 After the establishment of ZigBee networks all sensor nodes send temp and humidity information to the coordinator. After receiving the confirmed information of coordinator the node gets into sleep mode. The coordinator connects to PC through RS-232 serial port. The temp and humidity information will display in upper machine. When the wake-up time arrives, the node will rouse from sleep and continue sending messages to coordinator. This method can make all nodes in sleep state in most of the time, which will significantly reduce the power consumption of the entire network. Figure 6 shows the flow chart of software design.5 Implement of ZigBee Sensor NetworkThe system uses a tree topology. The advantages of tree topology are as follows: it can extend transmission distance between coordinator and sensor nodes advance the ability to carry the load and enhance the area of the network.Fig. 7. This shows the results that the PC collects. The information is temperature and humidity of greenhouse.The connection of ZigBee coordinator and sensor nodes is bonding. Bonding is a mechanism from one application layer to another [5].2, 7, 8 are the labels of source nodes in the network, which can be determined when the program is downloaded. Each network ID is the only one in the network and each network ID correspond one sensor node [6]. We can monitor the temperature and humidity of the greenhouse through network ID. The power consumption of the nodes is 32.5mA in average.6 ConclusionZigBee wireless sensor network overcome many shortcomings that wired media bring in. This paper implements a ZigBee wireless sensor network that can transmit and622 S. Gong et al.monitor temperature and humidity of the greenhouse. This wireless sensor network resistant to stable work, tight structure, large loads and low power consumption.After low-power design, the power consumption of the network reduces, the effective working time of the sensor nodes extend and the stability of the system enhance.Each node can carry many sensors and controlled equipment, so the node can be added more sensor such as light sensor and CO2 sensor to collect more information of greenhouse.This ZigBee wireless sensor network is part of Internet of Things, and can be used in precision agriculture and industry and many other fields.Acknowledgments. Funding for this research was provided by Harbin Special Funds for Research on Technological Innovation Projects (NO.2008RFXXN003). References1.Bogena, H.R., Huisman, J.A., OberdÊrster, C., et al.: Evaluation of a low cost soil watercontent sensor for wireless network applications. Journal of Hydrology, 32–42 (2007)2.Zhang, X., Zhang, C., Fang, J.: Smart Sensor Nodes for Wireless Soil TemperatureMonitoring Systems in Precision Agriculture, pp. 237–240 (2009)3.Li, W., Duan, C.: ZigBee2007/PRO experiment and practice of stack. Press of BeihangUniversity, Beijing (2007)4.Gao, J.: Study of energy consumption of ZigBee wireless sensor network node. ElectronicTest, 1–4 (2008)5.Sun, Y., Liu, Z.C., Cai, C.: Design of Low-power wireless sensor networks nodes. ComputerApplications, 21–26 (2009)6.Li, J., Zhang, C., Fang, J.: Design On The Monitoring System Of Physical Characteristics OfDairy Cattle Based On Zigbee Technology. In: IEEE Proceedings of the 2009 International Conference on Computer and Computing Technology Applications in Agriculture (2010)。

ZigBee协议低功耗无线传感器网络的协议ZigBee是一种专为低功耗、短距离通信设计的无线传感器网络协议。

它基于IEEE 802.15.4标准，旨在提供稳定可靠的通信解决方案，适用于广泛的物联网应用。

本文将介绍ZigBee协议的特点、架构以及其在低功耗无线传感器网络中的应用。

一、ZigBee协议的特点1. 低功耗：ZigBee协议采用了低功耗设计，使得传感器节点的电池寿命得以延长。

这是通过快速进入和退出睡眠状态、低能耗的硬件设计以及优化的通信协议实现的。

2. 网络拓扑灵活：ZigBee支持多种网络拓扑结构，包括星型、网状和集群树等。

这种灵活性使得ZigBee网络能够适应不同应用场景的需求，提供多样化的通信方案。

3. 自组织组网：ZigBee节点可以通过自组织的方式建立和维护网络。

当一个节点加入网络时，它可以自动发现邻近节点并与之建立连接，从而形成一个可扩展的传感器网络。

4. 低成本：ZigBee协议所需的硬件资源相对较少，这使得ZigBee设备的制造成本低，适用于大规模部署。

二、ZigBee协议的架构ZigBee协议采用了分层的架构，包括应用层、网络层、MAC层和物理层。

1. 应用层：应用层定义了与应用程序相关的功能，如传感器数据的采集和处理、设备间的通信协议等。

它通过ZigBee集群库提供了一组标准的应用功能集，简化了应用程序的开发。

2. 网络层：网络层负责网络拓扑管理、路由选择和数据传输。

它定义了路由协议、维护网络表和路由表等功能，使得数据能够有效地在传感器节点之间传递。

3. MAC层：MAC层处理数据的传输和接收，通过帧格式的定义和超帧结构来实现。

它还负责低功耗的睡眠管理和信道访问控制，实现低功耗和高效的通信。

4. 物理层：物理层负责信号的调制、解调和发送。

ZigBee使用了2.4GHz无线频段，采用了多频道和直序扩频技术，提供了可靠的无线通信性能。

三、ZigBee在低功耗无线传感器网络中的应用ZigBee协议在低功耗无线传感器网络中有广泛的应用，包括家庭自动化、工业监测、农业环境监测等领域。

文献翻译二级学院电子信息与自动化学院班级 108070102 学生姓名学号 10807010213译文要求1、译文内容必须与课题（或专业）内容相关，并需注明详细出处。

2、外文翻译译文不少于2000字；外文参考资料阅读量至少3篇（相当于10万外文字符以上）。

3、译文原文（或复印件）应附在译文后备查。

译文评阅导师评语（应根据学校“译文要求”，对学生外文翻译的准确性、翻译数量以及译文的文字表述情况等作具体的评价）指导教师：年月日基于ZigBee无线传感器网络的矿工的位置探测研究张秀萍, 韩广杰, 朱昌平, 窦燕, 陶剑锋河海大学计算机与信息工程学院中国常州E-mail:zhangxiup@ Zhucp315@摘要：随着计算机的飞速发展，通信和网络技术，特别是无线传感器和嵌入式技术的应用，使得无线传感器网络（WSNs）技术在产业领域和我们的日常生活得到了广泛关注。

基于ARM7TDMI-S CPU和ZigBee 的WSNs在提速和优化网络移动节点的应用，丰富的信息采集中，以及在通信中实时时间的协调均有可取之处，具有低功耗连续作业特点，因此它是非常适合用于确定矿工在地下的位置。

本文提出和分划WSN的网络计划及信息处理与通信技术，重点专注于实时协作。

通过传感器准确获得矿工的移动信息。

之后的位置信息传送可靠的监控中心。

不断变化的运行测试结果表明没有信息丢失或者没有未被采集到的信息。

因此，这个计划是稳定和有效的，将在煤矿安全中发挥积极作用，在我看来这正是Zigbee无线传感器网络的正确特点。

关键词：ZigBee的ARM7TDMI-S内核;CC2420的; 无线传感器网络 ;矿工位置确定一、简介无线传感器网络（WSNs）是规模大，无线自组织网络。

它是整合计算机通信，网络技术，嵌入式MCU和无线传感器技术，具有感知和沟通能力。

【1】节点有低低成本，小尺寸特点。

其中大部分可以工作区域传播，收集数据，并进行处理数据和通信。

The APL LayerThe application (APL) layer is the highest protocol layer in a ZigBee wireless network. The ZigBee APL layer consists of three sections, shown in Figure 3.44 : the application support (APS) sublayer, ZigBee Device Objects (ZDO), and the application framework.The application support sublayer (APS) provides an interface between the network layer (NWK) and the application layer (APL). The APS sublayer, similar to all lower layers, supports two types of services: data and management. The APS data service is provided by APS Data Entity (APSDE) and is accessed through the APSDE Service Access Point (SAP). The management capabilities are offered by APS Management Entity (APSME) and are accessed through APSME-SAP.The APS sublayer constants and attributes start with apsc and aps , respectively. The APS attributes are contained in the APS Information Base (APS IB or AIB). The list of APS constants and attributes is provided in the ZigBee specification [3].Network The application framework in ZigBee is the environment in which application objects are hosted to control and manage the protocol layers in a ZigBee device. Application objects are developed by manufacturers, and that is where a device is customized for various applications. There can be up to 240 application objects in a single device.The application objects use APSDE-SAP to send and receive data between peer application objects ( Figure 3.44 ). Each application object has a unique endpoint address (endpoint 1 to endpoint 240). The endpoint address of zero is used for the ZDO. To broadcast a message to all application objects, the endpoint address is set to 255. Endpoint addressing allows multiple devices to share the same radio. In the light control example in Section 2.1.4, multiple lights were connected to a single radio. Each light has a unique endpoint address and can be turned on and off independently.The ZigBee Device Objects (ZDO) provide an interface between the APS sublayer and the application framework. The ZDO contains the functionalities that are common in all applications operating on a ZigBee protocol stack. For example, it is the responsibility of the ZDO to configure the device in one of three possible logical types of ZigBee coordinator, ZigBee router, or ZigBee end device. The ZDO uses primitives to perform its duties and accesses the APS sublayer Management Entity via APSME-SAP. The application framework interacts with the ZDO through the ZDO public interface.The details of application framework, ZDO, and APS sublayer are reviewed in the following three subsections.The Application Framework The ZigBee standard offers the option to use application profiles in developing an application. The use of an application profile allows further interoperability between the products developed by different vendors for a specific application. For instance, in a light control scenario, if two vendors use the same application profile to develop their products, the switches from one vendor will be able to turn on and turn off the lights manufactured by the other vendor. The application profiles are also referred to as ZigBee profiles.Each application profile is identified by a 16-bit value known as a profile identifier . Only the ZigBee alliance can issue profile identifiers. A vendor that has developed a profile can request a profile identifier from the ZigBee alliance. The ZigBee alliance evaluates the proposed application profile and if it meets the alliance guidelines, a profile identifier willbe issued. The application profiles are named after their corresponding application use. For example, the home automation application profile provides a common platform for vendors developing ZigBee-based products for home automation use.The general structure of an application profile is shown in Figure 3.45. The application profile consists of two main components: clusters and device descriptions.A cluster is a set of attributes grouped together. Each cluster is identified by a unique 16-bit number called a cluster identifier . Each attribute in a cluster is also identified by a unique 16bit number known as a attribute identifier . These attributes are used to store data or state values. For example, in a temperature control application, a device that acts as the temperature sensor can store the value of the current temperature in an attribute. Then another device that acts as the furnace controller can receive the value of this attribute and turn on or turn off the furnace accordingly. The application profile does not contain the cluster itself. Instead, the application profile has a list of the cluster identifiers. Each cluster identifier uniquely points to the cluster itself.The other part of an application profile is the device descriptions ( Figure 3.45 ). The descriptions provide information regarding the device itself. For example, the supported frequency bands of operation, the logical type of the device (coordinator, router, or end device), and the remaining energy of the battery are provided by the device descriptions. Each device description is identified by a 16-bit value. The ZigBee application profile uses the concept of descriptor data structure . In this method, instead of including the data in the application profile, a 16-bit value is keptand acts as a pointer to the location of the data. This pointer is referred to as the data descriptor . When a device discovers the presence of another device in the network, the device descriptions are transferred to provide the essential information regarding the new device. The device descriptions consist of five sections: node descriptor, node power descriptor, simple descriptor, complex descriptor, and user descriptor. The node descriptor provides information such as the node logical type and the manufacturer code. The node power descriptor determines whether the device is battery powered and provides the current level of the battery. The profile identifier and clusters are provided in the simple descriptor . The complex descriptor is an optional part of the device descriptions and contains information such as the serial number and the device model name. Any additional information regarding the device can be included as the user descriptor . The user descriptor can be up to 16 ASCII characters. For example, in a light control application, the user descriptor field of a wall switch installed in a hallway can read Hall switch .The node descriptor fields for ZigBee-2006 are provided in Figure 3.46 . The node descriptor is a mandatory part of the device descriptions. The logical type can be ZigBee coordinator, router, or end device. The complex descriptor and user descriptor are optional and if their corresponding fields in the node descriptor are set to zero, they are not provided as part of the device descriptions. The APS flag field determines the APS sublayer capabilities. The frequency band (868 MHz, 915MHz, or 2.4 GHz) is specified in the frequency band field. The MAC capacity flags field is the same as the MAC capacity field presented before in Figure 3.25 . A manufacturer can request and receive a manufacturer code from the ZigBee alliance. This code is included in the node descriptor. The maximum size of the APS Sublayer Data Unit (ASDU), in octets, is specified in the maximum buffer size field. The maximum size of a single message that can be transferred to or from a node is provided in the maximum transfer size field (in octets). In ZigBeePro, the maximum incoming transfer size and maximum outgoing transfer size are two separate fields (16 bits each).The server mask field provides information regarding the system server capabilities of this node. A server is a device that provides specific services to other devices in the network. If each bit is set to one, the device has the corresponding capability shown in Figure 3.46 . The trust center is the device trusted by devices within a network to distribute security keys for the purpose of network and end-to-end application configuration management. The security features are reviewed in Section 3.6. The primary binding table cache is a device that allows other devices to store their binding tables with it as long as it has storage space left. The bindingprocedure is further clarified in this subsection. The primary binding table cache can be used to back up the content of binding tables and restore them whenever necessary.A device can choose to keep its own binding table, known as a source binding table , instead of storing it with a primary binding table cache. However, any device can store a backup of the source binding table in the primary biding table cache device and recover it later if necessary.A ZigBee network may have a primary discovery cache device. This device is a ZigBee coordinator or router used to store the descriptors such as node descriptors and power descriptors of some other devices. An end device, for example, that sleeps for long durations can store its descriptors in the primary discovery cache device. If a device in the network tries to locate the information regarding this sleeping end device while the device is inactive, it can get the information from the primary discovery cache device instead. If a network contains sleeping ZigBee end devices, the network must have at least one primary discovery cache device.应用层（APL）是在ZigBee无线网络协议栈中最高的一层。

英文文献翻译1.1 StandarsWireless sensor standards have been developed with the key design requirement for low power consumption. The standard defines the functions and protocols necessary for sensor nodes to interface with a variety of networks.Someof these standardincludeIEEE802.15.4,ZigBee,WirelessHART,ISA100.11,IETF6LoW-PAN,IE EE802.15.3,Wibree.The follow-ing paragraphs describes these standards in more detail.IEEE802.15.4:IEEE802.15.4[37] is the proposed stan-dard for low rate wireless personal area networks (LR-WPAN's).IEEE802.15.4 focuses on low cost of deployment,low complexity, and low power consumption.IEEE802.15.4 is designed for wireless sensor applications that require short range communication to maximize battery life. The standard allows the formation of the star and peer-to-peer topology for communication between net-work devices.Devices in the star topology communicate with a central controller while in the peer-to-peer topol-ogy ad hoc and self-configuring networks can be formed.IEEE802.15.4devices are designed to support the physical and data-link layer protocols.The physical layer supports 868/915 MHz low bands and 2.4 GHz high bands. The MAC layer controls access to the radio channel using the CSMA-CA mechanism.The MAC layer is also responsible for validating frames, frame delivery, network interface, network synchronization, device association, and secure services.Wireless sensor applications using IEEE802.15.4 include residential, industrial, and environment monitor-ing, control and automation.ZigBee [38,39] defines the higher layer communication protocols built on the IEEE 802.15.4 standards for LR-PANs. ZigBee is a simple, low cost, and low power wireless com- munication technology used in embedded applications.ZigBee devices can form mesh networks connecting hun- dreds to thousands of devices together. ZigBee devices use very little power and can operate on a cell battery for many years. There are three types of ZigBee devices:Zig-Bee coordinator,ZigBee router, and ZigBee end device.Zig-Bee coordinator initiates network formation,stores information, and can bridge networks together. ZigBee routers link groups of devices together andprovide mul-ti-hop communication across devices. ZigBee end devic consists of the sensors, actuators, and controllers that col-lects data and communicates only with the router or the coordinator. The ZigBee standard was publicly available as of June 2005.WirelessHART:The WirelessHART[40,41] standard pro-vides a wireless network communication protocol for pro-cess measurement and control applications.The standard is based on IEEE802.15.4 for low power 2.4 GHz operation. WirelessHART is compatible with all existing devices, tools, and systems. WirelessHART is reliable, secure, and energy efficient. It supports mesh networking,channel hopping, and time-synchronized work com-munication is secure with encryption,verification,authen-tication,and key management.Power management options enable the wireless devices to be more energy effi-cient.WirelessHART is designed to support mesh, star, and combined network topologies. A WirelessHART network consists of wireless field devices,gateways, process auto- mation controller, host applications,and network man-ager.Wireless field devices are connected to process or plant equipment.Gateways enable the communication be-tween the wireless field devices and the host applications.The process automation controller serves as a single con-troller for continuous process.The network manager con-figures the network and schedule communication between devices. It also manages the routing and network traffic. The network manager can be integrated into the gateway, host application, or process automation control-ler. WirelessHART standards were released to the industry in September 2007 and will soon be available in commer- cial products.ISA100.11a: ISA100.11a [42] standard is designed for low data rate wireless monitoring and process automation applications. It defines the specifications for the OSI layer, security, and system management.The standard focuses on low energy consumption,scalability, infrastructure,robustness, and interoperability with other wireless de-vices. ISA100.11a networks use only 2.4 GHz radio and channel hopping to increase reliability and minimize inter-ference.It offers both meshing and star network topolo-gies. ISA100.11a also provides simple, flexible, and scaleable security functionality. 6LoWPAN: IPv6-based Low power Wireless Personal Area Networks [43-45] enables IPv6 packets communica-tion over an IEEE802.15.4 based network.Low power device can communicate directly with IP devices using IP-based protocols. Using 6LoWPAN,low power devices have all the benefits of IPcommunication and management.6LoWPAN standard provides an adaptation layer, new packet format, and address management. Because IPv6 packet sizes are much larger than the frame size of IEEE 802.15.4, an adaptation layer is used. The adaptation layer carries out the functionality for header compression. With header compression, smaller packets are created to fit into an IEEE 802.15.4 frame size. Address management mecha- nism handles the forming of device addresses for commu-nication. 6LoWPAN is designed for applications with low data rate devices that requires Internet communication.IEEE802.15.3:IEEE802.15.3[46] is a physical and MAC layer standard for high data rateWPAN. It is designed to support real-time multi-media streaming of video and mu-sic.IEEE802.15.3 operates on a 2.4 GHz radio and has data rates starting from 11 Mbps to 55 Mbps.The standard uses time division multiple access (TDMA) to ensure quality of service. It supports both synchronous and asynchronous data transfer and addresses power consumption, data rate scalability, and frequency performance. The standard is used in devices such as wireless speakers, portable video electronics, and wireless connectivity for gaming, cordless phones, printers, and televisions.Wibree: Wibree [47] is a wireless communication tech-nology designed for low power consumption, short-range communication, and low cost devices. Wibree allows the communication between small battery-powered devices and Bluetooth devices.Small battery powered devices in-clude watches, wireless keyboard, and sports sensors which connect to host devices such as personal computer or cellular phones. Wibree operates on 2.4 GHz and has a data rate of 1 Mbps. The linking distance between the de-vices is 5-10 m.Wibree is designed to work with Blue-tooth. Bluetooth with Wibree makes the devices smaller and more energy-efficient. Bluetooth-Wibree utilizes the existing Bluetooth RF and enables ultra-low power con-sumption. Wibree was released publicly in October 2006.1.2 IntroductionWireless sensor networks (WSNs) have gained world-wide attention in recent years,particularly with the prolif-eration in Micro-Electro-Mechanical Systems (MEMStechnology which has facilitated the development of smart sensors.These sensors are small, with limited processing and computing resources, and they areinexpensive com-pared to traditional sensors. These sensor nodes can sense, measure, and gather information from the environment and, based on some local decision process, they can trans-mit the sensed data to the user.Smart sensor nodes are low power devices equipped with one or more sensors, a processor, memory, a power supply, a radio, and an actuator. 1 A variety of mechanical, thermal, biological, chemical, optical, and magnetic sensors may be attached to the sensor node to measure properties of he environment. Since the sensor nodes have limited memory and are typically deployed in difficult-to-access locations, a radio is implemented for wireless communica- tion to transfer the data to a base station (e.g., a laptop, a personal handheld device, or an access point to a fixed infra-structure). Battery is the main power source in a sensor node. Secondary power supply that harvests power from the environment such as solar panels may be added to the node depending on the appropriateness of the environment where the sensor will be deployed. Depending on the appli- cation and the type of sensors used, actuators may be incor- porated in the sensors.A WSN typically has ittle or no infrastructure. It con-sists of a number of sensor nodes (few tens to thousands) working together to monitor a region to obtain data about the environment. There are two types of WSNs: structured and unstructured. An unstructured WSN is one that con-tains a dense collection of sensor nodes. Sensor nodes 2 may be deployed in an ad hoc manner into the field. Once 2 In ad hoc deployment, sensor nodes may be randomly placed into the deployed, the network is left unattended to perform moni-toring and reporting functions. In an unstructured WSN, net-work maintenance such as managing connectivity and detecting failures is difficult since there are so many nodes. In a structured WSN, all or some of the sensor nodes are de-ployed in a pre-planned manner.3The advantage of a struc-tured network is that fewer nodes can be deployed with lower network maintenance and management cost.Fewer nodes can be deployed now since nodes are placed at spe-cific locations to provide coverage while ad hoc deployment can have uncovered regions.WSNs have great potential for many applications in sce-narios such as military target tracking and surveillance [2,3], natural disaster relief [4], biomedical health monitor- ing [5,6], and hazardous environment exploration and seis-mic sensing [7].Inmilitary target tracking and surveillance, a WSN can assist in intrusion detection and identification. Specific examples include spatially-corre-lated and coordinated troop and tank movements. With natural disasters, sensor nodes can sense and detect the environment to forecast disasters before they occur. In bio-medical applications, surgical implants of sensors can help monitor a patient's health.For seismic sensing, ad hoc deployment of sensors along the volcanic area can detect the development of earthquakes and eruptions.Unlike traditional networks,a WSN has its own design resource constraints.Resource constraints include a limited amount of energy,short communication range, low bandwidth, and limited processing and storage in each node. Design constraints are application dependent and are based on the monitored environment. The environment plays a key role in determining the size of the network, the deployment scheme, and the network topology. The size of the network varies with the monitored environ-ment. For indoor environments, fewer nodes are required to form a network in a limited space whereas outdoor envi-ronments may require more nodes to cover a larger area. An ad hoc deployment is preferred over pre-planned deployment when the environment is inaccessible by hu-mans or when he network is composed of hundreds to thousands of nodes. Obstructions in the environment can also limit communication between nodes, which in turn af-fects the network connectivity (or topology).Research in WSNs aims to meet the above constraints by introducing new design concepts,creating or improving existing protocols, building new applications, and develop-ingnewalgorithms.Inthisstudy,wepresentatop-downap-proach to survey different protocols and algorithms proposed in recent years. Our work differs from other sur-veys as follows:•While our survey is similar to [1], our focus has been to survey the more recent literature.•We address the issues in a WSN both at the individual sensor node level as well as a group level.•We survey the current provisioning, management and control issues in WSNs.These include issues such as localization, coverage, synchronization, network secu-rity, and data aggregation and compression.•We compare and contrast the various types of wireless sensor networks.•Finally, we provide a summary of the current sensor technologies.The remainder of this paper is organized as follows: Section 2 gives an overview of the key issues in a WSN. Section 3 compares the different types of sensor networks. Section 4 discusses several applications of WSNs.Section 5 presents issues in operating system support, supporting standards, storage, and physical testbed. Section 6 summa-rizes the control and management issues. Section 7 classi-fies and compares the proposed physical layer,data-link layer, network layer, and transport layer protocols. Section 8 concludes this paper. Appendix A compares the existing types of WSNs. Appendix B summarizes the sensor tech-nologies. Appendix C compares sensor applications with the protocol stack.1.3 Overview of key issuesCurrent state-of-the-art sensor technology provides a solution to design and develop many types of wireless sen-sor applications. A summary of existing sensor technolo-gies is provided in Appendix A. Available sensors in the market include generic (multi-purpose) nodes and gate- way (bridge) nodes. A generic (multi-purpose) sensor node's task is to take measurements from the monitored environment. It may be equipped with a variety of devices which can measure various physical attributes such as light, temperature, humidity, barometric pressure, veloc-ity, acceleration, acoustics, magnetic field, etc.Gateway (bridge) nodes gather data from generic sensors and relay them to the base station. Gateway nodes have higher pro-cessing capability,battery power, and transmission (radio) range. A combination of generic and gateway nodes is typ-ically deployed to form a WSN.To enable wireless sensor applications using sensor tech-nologies, the range of tasks can be broadly classified into three groups as shown in Fig. 1. The first group is the system. Eachsensor nodeis an individual system.In order to support different application software on a sensor system, develop-ment of new platforms, operating systems, and storage schemes are needed. The second group is communication protocols, which enable communication between the appli-cation and sensors. They also enable communication be-tween the sensor nodes. The last group is services which are developed to enhance the application and to improve system performance and network efficiency.From application requirements and network manage-ment perspectives, it isimportant th asensor nodes are capable of self-organizing themselves. That is, the sensor nodes can organize themselves into a network and subse-quently are able to control and manage themselves effi-ciently. As sensor nodes are limited in power, processing capacity, and storage, new communication protocols and management requirements.The communication protocol consists of five standard protocol layers for packet switching:application layer,transport layer, network layer, data-link layer, and physical layer. In this survey, we study how protocols at different layers address network dynamics and energy efficiency.Functions such as localization, coverage, storage, synchro- nization, security, and data aggregation and compression are explored as sensor network services.Implementation of protocols at different layers in the protocol stack can significantly affect energy consumption, end-to-end delay, and system efficiency. It is important to optimize communication and minimize energy usage. Tra-ditional networking protocols do not work well in a WSN since they are not designed to meet these requirements.Hence, new energy-efficient protocols have been proposed for all layers of the protocol stack. These protocols employ cross-layer optimization by supporting interactions across the protocol layers.Specifically, protocol state information at a particular layer is shared across all the layers to meet the specific requirements of the WSN.As sensor nodes operate on limited battery power, en-ergy usage is a very important concern in a WSN; and there has been significant research focus that revolves around harvesting and minimizing energy. When a sensor node is depleted of energy, it will die and disconnect from the network which can significantly impact the performance of the application. Sensor network lifetime depends on the number of active nodes and connectivity of the net- work, so energy must be used efficiently in order to maxi- mize the network lifetime.Energy harvesting involves nodes replenishing its en-ergy from an energy source. Potential energy sources in- clude solar cells [8,9], vibration [10], fuel cells, acoustic noise, and a mobile supplier [11]. In terms of harvesting energy from the environment [12], solar cell is the current mature technique that harvest energy from light. There is also work in using a mobile energy supplier such as a robot to replenish energy. The robots would be responsible in charging themselves with energy and then deliveringen- ergy to the nodes.Energy conservation in a WSN maximizes network life-time and is addressed through efficient reliable wireless communication, intelligent sensor placement to achieve adequate coverage, security and efficient storage manage-ment, and through data aggregation and data compression. The above approaches aim to satisfy both the energy con-straint and provide quality of service (QoS) 4 for the applica- tion. For reliable communication, services such as congestion control, active buffer monitoring, acknowledge-ments, and packet-loss recovery are necessary to guarantee reliable packet delivery. Communication strength is depen-dent on the placement of sensor nodes. Sparse sensor place-ment may result in long-range transmission and higher energy usage while dense sensor placement may result in short-range transmission and less energy consumption. Cov-erage is interrelated to sensor placement. The total number of sensors in the network and their placement determine the degree of network coverage. Depending on the application, a higher degree of coverage may be required to increase the accuracy of the sensed data. In this survey, we review new protocols and algorithms developed in these areas.1.1 标准协议：无线传感器标准已经发展出关键的设计要求低功率消耗。

Zigbee Wireless Sensor Network in Environmental MonitoringApplicationsI. ZIGBEE TECHNOLOGYZigbee is a wireless standard based on IEEE802.15.4 that was developed to address the unique needs of most wireless sensing and control applications. Technology is low cost, low power, a low data rate, highly reliable, highly secure wireless networking protocol targeted towards automation and remote control applications. It’s depicts two key performance characteristics – wireless radio range and data transmission rate of the wireless spectrum. Comparing to other wireless networking protocols such as Bluetooth, Wi-Fi, UWB and so on, shows excellent transmission ability in lower transmission rate and highly capacity of network.A. Zigbee FrameworkFramework is made up of a set of blocks called layers.Each layer performs a specific set of services for the layer above. As shown in Fig.1. The IEEE 802.15.4 standard defines the two lower layers: the physical (PHY) layer and the medium access control (MAC) layer. The Alliance builds on this foundation by providing the network and security layer and the framework for the application layer.Fig.1 FrameworkThe IEEE 802.15.4 has two PHY layers that operate in two separate frequency ranges: 868/915 MHz and 2.4GHz. Moreover, MAC sub-layer controls access to the radio channel using a CSMA-CA mechanism. Its responsibilities may also include transmitting beacon frames, synchronization, and providing a reliable transmission mechanism.B. Zigbee’s TopologyThe network layer supports star, tree, and mesh topologies, as shown in Fig.2. In a star topology, the network is controlled by one single device called coordinator. The coordinatoris responsible for initiating and maintaining the devices on the network. All other devices, known as end devices, directly communicate with the coordinator. In mesh and tree topologies, the coordinator is responsible for starting the network and for choosing certain key network parameters, but the network may be extended through the use of routers. In tree networks, routers move data and control messages through the network using a hierarchical routing strategy. Mesh networks allow full peer-to-peer communication.Fig.2 Mesh topologiesFig.3is a network model, it shows that supports both single-hop star topology constructed with one coordinator in the center and the end devices, and mesh topology. In the network, the intelligent nodes are composed by Full Function Device (FFD) and Reduced Function Device (RFD). Only the FFN defines the full functionality and can become a network coordinator. Coordinator manages the network, it is to say that coordinator can start a network and allow other devices to join or leave it. Moreover, it can provide binding and address-table services, and save messages until they can be delivered.Fig.3 Zigbee network modelII.THE GREENHOUSE ENVIRONMENTAL MONITORINGSYSTEM DESIGNTraditional agriculture only use machinery and equipment which isolating and no communicating ability. And farmers have to monitor crops’ growth by themselves. Even if some people use electrical devices, but most of them were restricted to simple communication between control computer and end devices like sensors instead of wire connection, which couldn’t be strictly defined as wireless sens or network. Therefore, by through using sensor networks and, agriculture could become more automation, more networking and smarter.In this project, we should deploy five kinds of sensors in the greenhouse basement. By through these deployed sensors, the parameters such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity can be detected real time. It is key to collect different parameters from all kinds of sensors. And in the greenhouse, monitoring the vegetables growing conditions is the top issue. Therefore, longer battery life and lower data rate and less complexity are very important. From the introduction about above, we know that meet the requirements for reliability, security, low costs and low power.A. System OverviewThe overview of Greenhouse environmental monitoring system, which is made up by one sink node (coordinator), many sensor nodes, workstation and database. Mote node and sensor node together composed of each collecting node. When sensors collect parameters real time, such as temperature in the greenhouse, soil temperature, dew point, humidity and light intensity, these data will be offered to A/D converter, then by through quantizing and encoding become the digital signal that is able to transmit by wireless sensor communicating node. Each wireless sensor communicating node has ability of transmitting, receiving function.In this WSN, sensor nodes deployed in the greenhouse, which can collect real time data and transmit data to sink node (Coordinator) by the way of multi-hop. Sink node complete the task of data analysis and data storage. Meanwhile, sink node is connected with GPRS/CDMA can provide remote control and data download service. In the monitoring and controlling room, by running greenhouse management software, the sink node can periodically receives the data from the wireless sensor nodes and displays them on monitors.B. Node Hardware DesignSensor nodes are the basic units of WSN. The hardware platform is made up sensor nodes closely related to the specific application requirements. Therefore, the most important work is the nodes design which can perfect implement the function of detecting and transmission as a WSN node, and perform its technology characteristics. Fig.4 shows the universal structure of the WSN nodes. Power module provides the necessary energy for the sensor nodes. Data collection module is used to receive and convert signals of sensors. Data processing and control module’s functions are node device control, task sche duling, and energy computing and so on. Communication module is used to send data between nodes and frequency chosen and so on.Fig.4 Universal structure of the wsn nodesIn the data transfer unit, the module is embedded to match the MAC layer and the NET layer of the protocol. We choose CC2430 as the protocol chips, which integrated the CPU, RF transceiver, net protocol and the RAM together. CC2430 uses an 8 bit MCU (8051), and has 128KB programmable flash memory and 8KB RAM. It also includes A/D converter, some Timers, AES128 Coprocessor, Watchdog Timer, 32K crystal Sleep mode Timer, Power on Reset, Brown out Detection and 21I/Os. Based on the chips, many modules for the protocol are provided. And the transfer unit could be easily designed based on the modules.As an example of a sensor end device integrated temperature, humidity and light, the design is shown in Fig. 5.Fig.5 The hardware design of a sensor nodeThe SHT11is a single chip relative humidity and temperature multi sensor module comprising a calibrated digital output. It can test the soil temperature and humidity. The DS18B20 is a digital temperature sensor, which has 3 pins and data pin can link MSP430 directly. It can detect temperature in greenhouse. The TCS320is a digital light sensor. SHT11, DS18B20and TCS320are both digital sensors with small size and low power consumption. Other sensor nodes can be obtained by changing the sensors.The sensor nodes are powered from onboard batteries and the coordinator also allows to be powered from an external power supply determined by a jumper.C. Node Software DesignThe application system consists of a coordinator and several end devices. The general structure of the code in each is the same, with an initialization followed by a main loop.The software flow of coordinator, upon the coordinator being started, the first action of the application is the initialization of the hardware, liquid crystal, stack and application variables and opening the interrupt. Then a network will be formatted. If this net has been formatted successfully, some network information, such as physical address, net ID, channel number will be shown on the LCD. Then program will step into application layer and monitor signal. If there is end device or router want to join in this net, LCD will shown this information, and show the physical address of applying node, and the coordinator will allocate a net address to this node. If the node has been joined in this network, the data transmitted by this node will be received by coordinator and shown in the LCD.The software flow of a sensor node, as each sensor node is switched on, it scans allchannels and, after seeing any beacons, checks that the coordinator is the one that it is looking for. It then performs a synchronization and association. Once association is complete, the sensor node enters a regular loop of reading its sensors and putting out a frame containing the sensor data. If sending successfully, end device will step into idle state; by contrast, it will collect data once again and send to coordinator until sending successfully.D. Greenhouse Monitoring Software DesignWe use VB language to build an interface for the test and this greenhouse sensor network software can be installed and launched on any Windows-based operating system. It has 4 dialog box selections: setting controlling conditions, setting Timer, setting relevant parameters and showing current status. By setting some parameters, it can perform the functions of communicating with port, data collection and data viewing.Zigbee无线传感器网络在环境监测中的应用I.Zigbee技术Zigbee是一种基于IEEE802.15.4的无线标准上被开发用来满足大多数无线传感和控制应用的独特需求。

集成低功耗无线传感器网络通信系统的设计摘要无线传感器网络系统目前在国际社会关键应用在贸易，医疗保健和安全方面。

这些系统具有独特的特点和面临的许多实施的挑战。

在所有系统中，长寿命的要求是对无线传感器节点能源供应施加的最严重的设计约束。

这就需要创新的设计方法来解决这一严格的要求。

本文首先提供了无线传感器网络技术的概述。

然后介绍了通信系统，电路设计和系统包装的考虑。

在无线电架构和电路技术的选择是重点讨论了关于低功耗的实施和经营特色相匹配的传感器网络应用需求。

最后，设计，实施和最具挑战性的组成部分，一个完整的低功耗CMOS接收系统，提出证明这些设计原则。

简介一个无线传感器网络由自组织无线通信系统相连密集分布的节点。

传感器节点架构包括传感，信号处理，嵌入式计算和无线网络组件。

每个节点可配备多种应用程序特定的传感器和节点信号所需的物理环境信息的提取处理系统。

相邻节点之间的合作可能有助于信号处理的敏感性和特异性环境事件检测。

通过节能高效的无线通讯，局部处理的信息（需要大大减少数据未处理的传感器有效载荷的数据传输带宽）可传达给用户。

低功耗是最重要的，以便为无线传感器网络的长期工作寿命。

虽然这是促进了低工作周期操作，本地信号处理，多跳网络节点间的部分也可以引进，以减少传感器网络中的每个节点的通信链路的范围。

由于通信路径作为一个尺度范围内的损失功法（有4或更大权力的规则在许多应用中指数），这在连接范围大幅度减少导致电力需求减少。

与传统远程无线系统的特点相比，减少的范围和数据链路带宽产量为典型的无线传感器应用的一个重要的链路预算的优势。

然而，极为有限的能源为无线感应器（小型电池系统）建立更强的设计挑战。

随着低成本的要求，这些极大地激发了新的基于低功耗无线通信系统和传感器应用优化技术的有利互补金属氧化物半导体（CMOS）电路技术的发展。

在下面的章节中，我们将介绍基于无线传感器网络的无线通信系统和电路设计。

无线技术不同的电路设计要求大大不同无线通信技术。

ZigBee: Wireless Technology forLow-Power Sensor NetworksGary Legg5/6/2004 12:00 AM EDTTechnologists have never had trouble coming up with potential applications for wireless sensors. In a home security system, for example, wireless sensors would be much easier to install than sensors that need wiring. The same is true in industrial environments, where wiring typically accounts for 80% of the cost of sensor installations. And then there are applications for sensors where wiring isn't practical or even possible.The problem, though, is that most wireless sensors use too much power, which means that their batteries either have to be very large or get changed far too often. Add to that some skepticism about the reliability of sensor data that's sent through the air, and wireless sensors simply haven't looked very appealing.A low-power wireless technology called ZigBee is rewriting the wireless sensor equation, however. A secure network technology that rides on top of the recently ratified IEEE 802.15.4 radio standard (Figure 1), ZigBee promises to put wireless sensors in everything from factory automation systems to home security systems to consumer electronics. In conjunction with 802.15.4, ZigBee offers battery life of up to several years for common small batteries. ZigBee devices are also expected to be cheap, eventually selling for less than $3 per node by some estimates. With prices that low, they should be a natural fit even in household products like wireless light switches, wireless thermostats, and smoke detectors.Figure 1: ZigBee adds network, security, andapplication-services layers to the PHY and MAC layers of theIEEE 811.15.4 radioAlthough no formal specification for ZigBee yet exists (approval by the ZigBee Alliance, a trade group, should come late this year), the outlook for ZigBee appears bright. Technology research firm In-Stat/MDR, in what it calls a "cautious aggressive" forecast, predicts that sales of 802.15.4 nodes and chipsets will increase from essentially zero today to 165 million units by 2010. Not all of these units will be coupled with ZigBee, but most probably will be. Research firm ON World predicts shipments of 465 million wireless sensor RF modules by 2010, with 77% of them being ZigBee-related.In a sense, ZigBee's bright future is largely due to its low data rates—20 kbps to 250 kbps, depending on the frequency band used (Figure 2)—compared to a nominal 1 Mbps for Bluetooth and 54 Mbps for Wi-Fi's 802.11g technology. But ZigBee won't be sending email and large documents, as Wi-Fi does, or documents and audio, as Bluetooth does. For sending sensor readings, which are typically a few tens of bytes, high bandwidth isn't necessary, and ZigBee's low bandwidth helps it fulfill its goals of low power, low cost, and robustness.Figure 2: ZigBee's data rates range from 20 kbps to 250kbps, depending on the frequency usedBecause of ZigBee applications' low bandwidth requirements, a ZigBee node can sleep most of the time, thus saving battery power, and then wake up, send data quickly, and go back to sleep. And, because ZigBee can transition from sleep mode to active mode in 15 msec or less, even a sleeping node can achieve suitably low latency. Someone flipping a ZigBee-enabled wireless light switch, for example, would not be aware of a wake-up delay before the light turns on. In contrast, wake-up delays for Bluetooth are typically around three seconds.A big part of ZigBee's power savings come from the radio technology of 802.15.4, which itself was designed for low power. 802.15.4 uses DSSS (direct-sequence spread spectrum) technology, for example, because the alternative FHSS (frequency-hopping spread spectrum) would have used too much power just in keeping its frequency hops synchronized.ZigBee nodes, using 802.15.4, can communicate in any of several different ways, however, and some ways use more power than others. Consequently, ZigBee users can't necessarily implement a sensor network any way they choose and still expect the multiple-year battery life that is ZigBee's hallmark. In fact, some technologists who are planning very large networks of very small wireless sensors say that even ZigBee is too power hungry for their uses.A ZigBee network node can consume extra power, for example, if it tries to keep its transmissions from overlapping with other nodes' transmissions or with transmissions from other radio sources. The 802.15.4 radio used by ZigBee implements CSMA/CA (carrier sense multiple access collision avoidance) technology, and a ZigBee node that uses CSMA/CA is essentially taking a listen-before-talk approach to see if any radio traffic is already underway. But, as noted by Venkat Bahl, marketing vice president for sensor company Ember Corp. and vice chairman of the ZigBee Alliance, that's not a preferred approach. "Having to listen burns power," says Bahl, "and we don't like to do that."Another ZigBee and 802.15.4 communications option is the beacon mode, in which normally sleeping network slave nodes wake up periodically to receive a synchronizing "beacon" from the network's control node. But listening for a beacon wastes power, too, particularly because timing uncertainties force nodes to turn on early to avoid missing a beacon.In-Your-Face CommunicationTo save as much power as possible, ZigBee employs a talk-when-ready communication strategy, simply sending data when it has data ready to send and then waiting for an automatic acknowledgement. According to Bob Heile, who is chairman of both the ZigBee Alliance and IEEE 802.15, talk-when-ready is an "in-your-face" scheme, but one that's very power efficient. "We did an extensive analysis that led to the best power-saving strategy in various kinds of environments from quiet to noisy," Heile says. "We discovered that, hands down, we were better off just sending the packet and acknowledging it. If you don't get an ack, it just means you got clobbered, so send it again. You wind up having much better power management than if you listen and determine if it's quiet before you talk."Fortunately, this in-your-face strategy leads to very little RF interference. That's largely because ZigBee nodes have very low duty cycles, transmitting only occasionally and sending only small amounts of data. Other ZigBee nodes, as well as Wi-Fi and Bluetooth modules, can easily deal with such small, infrequent bursts.ZigBee's talk-when-ready scheme doesn't suit all purposes, however. For example, in a network of thousands of tiny sensors dropped into a war zone to monitor enemy troop movements, the power savings provided still might not be enough. With each network node sending data periodically—and with transmissions repeated numerous times through other nearby nodes of a mesh network configuration in order to reach a network controller—large numbers of packet collisions and retransmissions could waste power and significantly shorten sensor node battery life. If the sensor batteries are very small and power-limited, that's especially problematic.Although contention for airwave access isn't generally a problem for ZigBee, it can be. Sensor-network company Dust Networks, in fact, says contention issues are keeping the company from turning to ZigBee—for now, at least—even though Dust remains a member of the ZigBee Alliance. "Each ZigBee device needs to contend for airspace with its neighbors," says Dust director of product management Robert Shear, "so there's inevitably some contention and some inefficiency." To avoid ZigBee's access contention, Dust uses contention-free TDMA (time division multiple access) technology. ZigBee, through the 802.15.4 MAC layer, provides guaranteed time slots in a scheme that somewhat resembles TDMA, but only as part of an optional "superframe" that's more complex and less power-efficient than TDMA.ZigBee has still more power-saving tricks up its sleeve, however. For example, it reduces power consumption in ZigBee components by providing for power-saving reduced-function devices (RFDs) in addition to more capable full-function devices (FFDs). Each ZigBee network needs at least one FFD as a controller, but most network nodes can be RFDs (Figure 3). RFDs can talk only with FFDs, not to other RFDs, but they contain less circuitry than FFDs, and little or no power-consuming memory.Figure 3: ZigBee networks can contain as many as 65,536nodes in a variety of configurationsZigBee conserves still more power by reducing the need for associated processing. Simple 8-bit processors like an 8051 can handle ZigBee chores easily, and ZigBee protocol stacks occupy very little memory. An FFD stack, for example, needs about 32 kbytes, and an RFD stack needs only about 4 kbytes. Those numbers compare with about 250 kbytes for the far more complex Bluetooth technology.From ZigBee's relatively simple implementations, cost savings naturally accrue. RFDs, of course, reduce ZigBee component costs by omitting memory and other circuitry, and simple 8-bit processors and small protocol stacks help keep system costs down. Often, an application's main processor can easily bear the small additional load of ZigBee processing, making a separate processor for ZigBee functions unnecessary.But the main strategy for keeping ZigBee prices low is to have big markets and high volumes. The ZigBee Alliance, by making ZigBee an open standard and by vigorously promoting interoperability among ZigBee devices, expects that ZigBee will be very big in applications such as home and building automation. The alliance is currently working on interoperability procedures for those particular applications, which it expects to complete later this year along with ZigBee Specification 1.0.One reason for optimism about ZigBee adoption for home automation and security is its ease of use. ZigBee networks are self-forming, making it easy even for consumers to set them up. "In the residential space, there's no configuration involved," says the ZigBee Alliance's Heile. "You take something out of the box, put the batteries in, and maybe do something as simple as button-press security—bring two devices close together, push the buttons until the green lights come on, and you're done."ZigBee networks can also self-form in commercial and industrial settings, but professional installers will have tools that provide additional control, particularly for security. ZigBee security is flexible, says Heile, to give both consumer and professional users what they need. "You don't have to have 128-bit public-key encryption for a smoke detector," he says, "but if I'm in a high-rise office complex, that's exactly the level of security I'm going to have for my fluorescent light fixtures. If you're in a high-rise building on Fifth Avenue, you don't want someone going down the street and turning your lights off."Proprietary CompetitionCompetition for ZigBee comes almost entirely from proprietary technologies. Sensor company Dust, as noted, is sticking with its own technology, and Ember, although pushing strongly into the ZigBee arena, plans to keep offering its proprietary EmberNet as well. In addition, Zensys is providing its Z-Wave technology to customers. Sylvania, for example, is already using Z-Wave for lighting control, while ZigBee systems remain at least several months away.By offering interoperability, however, ZigBee adds capabilities that proprietary products can't. For example, says Ember's Bahl, interoperability allows the ZigBeenodes of a lighting system to work with the ZigBee network of an HVAC system, or vice versa. "Philips Lighting is really excited about this," Bahl, says, "because it turns them from a ballast manufacturer into the infrastructure backbone of abuilding-automation system."Needless to say, many of the major semiconductor companies, and especially those that are big in embedded systems, are eagerly anticipating ZigBee's entry into mass markets. Freescale Semiconductor (until recently known as Motorola's Semiconductor Products Sector) is already providing ZigBee-ready technology to select customers. Other semiconductor companies, including AMI, Atmel, Microchip, Philips, and Renesas, are members of the ZigBee Alliance.ZigBee will likely be slow to penetrate the industrial market for wireless sensors, however. According to market research firm ON World, it will take five to seven years to convince industrial customers of the reliability, robustness, and security of wireless-sensor systems. ON World does predict significant long-term growth of ZigBee in industry, though. By 2010, the company projects, RF modules used in industrial monitoring and control will reach 165 million units, up from 1.9 million in 2004. About 75% of those, ON World predicts, will be based on ZigBee and 802.15.4.Eventually, ZigBee could go into a wide variety of applications. In household appliances, it could help monitor and control energy consumption. In automotive applications, it could provide tire-pressure monitoring and remote keyless entry. ZigBee could also be used in medical devices or even in computer peripherals, such as wireless keyboards or mice.Concern is increasing, though, that ZigBee could turn into a one-size-fits-all technology that doesn't fit any application particularly well. Some skeptics, for example, worry that an attempt to make ZigBee all-encompassing could make the ZigBee protocol stack too large for ZigBee's twin goals of very low power consumption and very low cost. If that happens, then ZigBee's low-power,low-data-rate niche—narrow as it is—will have proven to be too broad. And then, perhaps, we'll need yet another wireless standard to go with the burgeoning number we already have.ZigBee：无线技术，低功耗传感器网络加里莱格美国东部时间2004年5月6日上午12:00技师（工程师）们在发掘无线传感器的潜在应用方面从未感到任何困难。

摘要-本文介绍并设计了一个新类型的煤矿安全监控系统，它是一种基于ZigBee 技术的无线传感器网络系统。

该系统包括地下和地面两部分。

地下的无线传感器网络由固定节点，移动节点和网关构成。

电脑监控软件部署在地面。

该系统不仅可以实时收集矿井环境数据，也可以通过计算矿工所穿的移动节点来实时定位。

关键词：ZigBee；定位；无线传感器网络；煤矿一、研究现状作为一种重要的能源，煤炭在经济发展中起着举足轻重的作用。

煤矿监控系统是煤矿安全和生产效率高的重要保证[1]。

为了确保安全运行，环境监测节点的安装是非常重要的。

然而，常用的传统监控节点通过有线连接获得与控制系统的通信，这个节点存在布线困难，价格昂贵等缺点。

相比之下，无线传感器网络节点可以很容易地与当前矿井监测网络连接，和良好的兼容性，方便组成煤矿瓦斯监测网络，以适应各种大小煤矿的应用。

由于无线节点是电池供电，所以完全摆脱线缆的束缚，缩短建设周期，可以随时安排使用。

这是一个新的短距离，低复杂度，低功耗，低数据速率，低成本的双向无线通信技术[2]。

现在，无线传感器ZigBee无线通信技术应用于煤矿环境监测系统。

基于ZigBee技术的网络产品的数量和种类很多，但真正的产品可以应用在地下环境中的特殊传感器节点是很少的[3]。

我们设计的系统，是真正能够适用于在井下环境，它通过无线传感器网络节点的安全认证。

同时，由于无线网络的特殊性质，它可以传播无线信号，我们可以很容易地找到工作人员以便对煤矿安全监控提供更多的保护[4]。

二、系统架构该系统是一个软件和硬件综合监控系统的融合。

硬件部分包括无线移动节点和固定节点而被地下隧道部署，它的主要功能是收集煤炭矿山环境的数据和人的位置。

电脑监控软件由VC++设计，是用于以总结和展示每个监控节点中移动节点和固定节点的数据。

他们正在使用的数据由无线传输ZigBee协议传输，由于在固定节点也使用无线数据传输的方法，所以在地下巷道部署变得非常方便。

The APL LayerThe application (APL) layer is the highest protocol layer in a ZigBee wireless network. The ZigBee APL layer consists of three sections, shown in Figure 3.44 : the application support (APS) sublayer, ZigBee Device Objects (ZDO), and the application framework.The application support sublayer (APS) provides an interface between the network layer (NWK) and the application layer (APL). The APS sublayer, similar to all lower layers, supports two types of services: data and management. The APS data service is provided by APS Data Entity (APSDE) and is accessed through the APSDE Service Access Point (SAP). The management capabilities are offered by APS Management Entity (APSME) and are accessed through APSME-SAP.The APS sublayer constants and attributes start with apsc and aps , respectively. The APS attributes are contained in the APS Information Base (APS IB or AIB). The list of APS constants and attributes is provided in the ZigBee specification [3].Network The application framework in ZigBee is the environment in which application objects are hosted to control and manage the protocol layers in a ZigBee device. Application objects are developed by manufacturers, and that is where a device is customized for various applications. There can be up to 240 application objects in a single device.The application objects use APSDE-SAP to send and receive data between peer application objects ( Figure 3.44 ). Each application object has a unique endpoint address (endpoint 1 to endpoint 240). The endpoint address of zero is used for the ZDO. To broadcast a message to all application objects, the endpoint address is set to 255. Endpoint addressing allows multiple devices to share the same radio. In the light control example in Section 2.1.4, multiple lights were connected to a single radio. Each light has a unique endpoint address and can be turned on and off independently.The ZigBee Device Objects (ZDO) provide an interface between the APS sublayer and the application framework. The ZDO contains the functionalities that are common in all applications operating on a ZigBee protocol stack. For example, it is the responsibility of the ZDO to configure the device in one of three possible logical types of ZigBee coordinator, ZigBee router, or ZigBee end device. The ZDO uses primitives to perform its duties and accesses the APS sublayer Management Entity via APSME-SAP. The application framework interacts with the ZDO through the ZDO public interface.The details of application framework, ZDO, and APS sublayer are reviewed in the following three subsections.The Application Framework The ZigBee standard offers the option to use application profiles in developing an application. The use of an application profile allows further interoperability between the productsdeveloped by different vendors for a specific application. For instance, in a light control scenario, if two vendors use the same application profile to develop their products, the switches from one vendor will be able to turn on and turn off the lights manufactured by the other vendor. The application profiles are also referred to as ZigBee profiles.Each application profile is identified by a 16-bit value known as a profile identifier . Only the ZigBee alliance can issue profile identifiers. A vendor that has developed a profile can request a profile identifier from the ZigBee alliance. The ZigBee alliance evaluates the proposed application profile and if it meets the alliance guidelines, a profile identifier willbe issued. The application profiles are named after their corresponding application use. For example, the home automation application profile provides a common platform for vendors developing ZigBee-based products for home automation use.The general structure of an application profile is shown in Figure 3.45. The application profile consists of two main components: clusters and device descriptions. A cluster is a set of attributes grouped together. Each cluster is identified by a unique 16-bit number called a cluster identifier . Each attribute in a cluster is also identified by a unique 16bit number known as a attribute identifier . These attributes are used to store data or state values. For example, in a temperature control application, a device that acts as the temperature sensor can store the value of the current temperature in an attribute. Then another device that acts as the furnace controller can receive the value of this attribute and turn on or turn off the furnace accordingly. The application profile does not contain the cluster itself. Instead, the application profile has a list of the cluster identifiers. Each cluster identifier uniquely points to the cluster itself.The other part of an application profile is the device descriptions ( Figure 3.45 ). The descriptions provide information regarding the device itself. For example, the supported frequency bands of operation, the logical type of the device (coordinator, router, or end device), and the remaining energy of the battery are provided by the device descriptions. Each device description is identified by a 16-bit value. The ZigBee application profile uses the concept of descriptor data structure . In this method, instead of including the data in the application profile, a 16-bit value is kept and acts as a pointer to the location of the data. This pointer is referred to as the data descriptor . When a device discovers the presence of another device in the network, the device descriptions are transferred to provide the essential information regarding the new device. The device descriptions consist of five sections: node descriptor, node power descriptor, simple descriptor, complex descriptor, and user descriptor. The node descriptor providesinformation such as the node logical type and the manufacturer code. The node power descriptor determines whether the device is battery powered and provides the current level of the battery. The profile identifier and clusters are provided in the simple descriptor . The complex descriptor is an optional part of the device descriptions and contains information such as the serial number and the device model name. Any additional information regarding the device can be included as the user descriptor . The user descriptor can be up to 16 ASCII characters. For example, in a light control application, the user descriptor field of a wall switch installed in a hallway can read Hall switch .The node descriptor fields for ZigBee-2006 are provided in Figure 3.46 . The node descriptor is a mandatory part of the device descriptions. The logical type can be ZigBee coordinator, router, or end device. The complex descriptor and user descriptor are optional and if their corresponding fields in the node descriptor are set to zero, they are not provided as part of the device descriptions. The APS flag field determines the APS sublayer capabilities. The frequency band (868 MHz, 915MHz, or 2.4 GHz) is specified in the frequency band field. The MAC capacity flags field is the same as the MAC capacity field presented before in Figure 3.25 .A manufacturer can request and receive a manufacturer code from the ZigBee alliance. This code is included in the node descriptor. The maximum size of the APS Sublayer Data Unit (ASDU), in octets, is specified in the maximum buffer size field. The maximum size of a single message that can be transferred to or from a node is provided in the maximum transfer size field (in octets). In ZigBeePro, the maximum incoming transfer size and maximum outgoing transfer size are two separate fields (16 bits each). The server mask field provides information regarding the system server capabilities of this node. A server is a device that provides specific services to other devices in the network. If each bit is set to one, the device has the corresponding capability shown in Figure 3.46 . The trust center is the device trusted by devices within a network to distribute security keys for the purpose of network and end-to-end application configuration management. The security features are reviewed in Section 3.6. The primary binding table cache is a device that allows other devices to store their binding tables with it as long as it has storage space left. The binding procedure is further clarified in this subsection. The primary binding table cache can be used to back up the content of binding tables and restore them whenever necessary. A device can choose to keep its own binding table, known as a source binding table , instead of storing it with a primary binding table cache. However, any device can store a backup of the source binding table in the primary biding table cache device and recover it later if necessary.A ZigBee network may have a primary discovery cache device. This device is a ZigBee coordinator or router used to store the descriptors such asnode descriptors and power descriptors of some other devices. An end device, for example, that sleeps for long durations can store its descriptors in the primary discovery cache device. If a device in the network tries to locate the information regarding this sleeping end device while the device is inactive, it can get the information from the primary discovery cache device instead. If a network contains sleeping ZigBee end devices, the network must have at least one primary discovery cache device.应用层（APL）是在ZigBee无线网络协议栈中最高的一层。

甚低功耗无线通信技术——ＺｉｇＢｅｅ摘要：ZigBee技术作为无线传感器网络的主要支撑技术获得人们广泛的关注。

完整的ZigBee协议套件由高层应用规范、应用会聚层、网络层、数据链路层和物理层组成。

网络层以上协议由ZigBee联盟制订，物理层和媒体访问控制(MAC)层采用IEEE 802.15.4标准。

IEEE802.15.4物理层简单采用比特到符号映射技术、符号到码片序列转换技术、偏移正交相移键控(OQPSK)调制技术，无须信道编码等复杂算法；MAC层采用载波监听多址-冲突避免技术，支持休眠模式。

整个协议的设计使得ZigBee技术具有数据传输速率低、功耗低、成本低等特点，更加适合于工业监控系统、传感器网络、家庭监控系统、安全系统等应用。

关键词：无线传感器网络；ZigBee技术；IEEE 802.15.4协议；物理层；多址接入控制基金项目：北京市自然科学基金项目(4062023)Abstract:ZigBee, an important technology supporting wireless sensor networks, has drawn broad attention. A complete ZigBee’s protocol suite consists of high-layer application specifications, the application convergence layer, the network layer, the data link layer, and the physical layer. ZigBee Alliance focuses on defining the protocols above the network layer. The Physical (PHY) layer and the Media Access Control (MAC) layer are defined by the IEEE 802.15.4 standard. The IEEE 802.15.4 physical layer adopts technologies of mapping from bit to symbol, conversion from symbol to chip sequence and Offset Quadrature Phase-shift Keying (OQPSK) modulation, avoiding such complex algorithms as channel coding. The IEEE 802.15.4 MAC layer adopts Carrier Sense Multiple Access with Collision Avoidance(CSMA-CA) technology and supports the sleeping mode. ZigBee enables low data rates, low power consumption and cost-effectiveness, and is more applicable to industrial monitoring system, sensor networks, home monitoring system and security system.Key words:wireless sensor network; ZigBee technology; IEEE 802.15.4; the physical layer; multiple access control近十几年来，无线与移动通信以前所未有的速度迅猛发展。