What's the difference between wireless sensor networks and mobile ad hoc networks?

Zigbee: A new wireless network data communication technology Zigbee technology is produced with the demand of industrial automation for wireless communication and data transmission. Zigbee network is energy-saving, reliable, low-cost, large-capacity and safe, and can be widely used in various automatic control fields. The origin of Zigbee: In the process of using Bluetooth technology, people find that Bluetooth technology has many advantages, but it also has many defects. Bluetooth technology is too complicated for industrial and home automation control and telemetry and remote control. ....................................................................................................................................... has the characteristics of high power consumption, short distance and small networking scale. Therefore, after people's long-term efforts, Zigbee protocol was adopted in 2003 and officially announced in 2004. What is Zigbee? Zigbee is a wireless data transmission network platform composed of as many as 65,000 wireless data transmission modules, which is very similar to the existing CDMA network or GSM network and is used for mobile communication. Each Zigbee network data transmission module is similar to a base station of a mobile network, and they can communicate with each other in the whole network. The distance between each network node can range from the standard 75 meters to the extended several hundred meters or even several kilometers. In addition, the whole Zigbee network can also be connected with other existing networks. For example, you can monitor a Zigbee control network in Yunnan through the Internet in Beijing. The difference is that Zigbee network is mainly established for automatic control data transmission, while mobile communication network is mainly established for voice communication; The value of each mobile base station is generally more than one million yuan, while each Zigbee "base station" is less than 1000 yuan; Each Zigbee network node can not only connect with sensors and other monitoring objects to directly collect and monitor data, but also automatically transmit data from other network nodes. In addition, each Zigbee network node (FFD) can also wirelessly connect a number of isolated child nodes (RFD), which do not undertake the task of network information transmission within their own signal coverage. Each Zigbee network node (FFD and RFD) can support as many as 365,438+0 sensors and controlled devices, and each sensor and controlled device can finally have 8 different interface modes. Can collect and transmit digital quantity and analog quantity. Application field of Zigbee technology: The goal of Zigbee technology is aimed at industry, home automation, telemetry and remote control, automobile automation, agricultural automation and medical care, such as automatic control of lighting, wireless data acquisition and monitoring of sensors, oil field, electric power, mining and logistics management. In addition, it can also locate moving targets in local areas, such as vehicles in cities. (Patent technology of Chengdu Xigu Shuguang Digital Technology Company). Generally, Zigbee technology can be considered for wireless transmission in applications that meet one of the following conditions: 1. There are many sites that need data collection or monitoring; 2. The amount of data transmitted is not large, but the equipment cost is low; 3. Require high data transmission feasibility and high security; 4. The size of the equipment is very small, so it is not convenient to place larger rechargeable batteries or power modules; 5. battery power supply; 6. The terrain is complex and there are many monitoring points, which requires large network coverage; 7. The coverage blind area of the existing mobile network; 8. Telemetry and remote control system using existing mobile network for low data transmission. 9. Using GPS to locate moving targets in local areas has poor effect or high cost. The characteristics of Zigbee technology are: power saving: two No.5 batteries can support reliable service time of about 6 months to 2 years; Using collision avoidance mechanism, special time slots are reserved for communication services that need fixed bandwidth to avoid competition and conflict when sending data; The node module has the function of automatic dynamic networking, and transmits information through automatic routing in the whole Zigbee network, thus ensuring the reliability of information transmission. Short delay: Optimized for delay-sensitive applications, communication delay and activation delay from sleep state are very short. Large network capacity: up to 65,000 nodes can be supported. Security: ZigBee provides data integrity check and authentication functions, and the encryption algorithm adopts general AES- 128. High confidentiality: 64-bit factory number and the development prospect of Zigbee supporting AES- 128 encryption: Zigbee technology and RFID technology were listed as the top ten latest technologies with the fastest development and the widest market prospect in the world in 2004. As for this report, you only need to enter "Zigbee" in Baidu or Google search bar, and you will see a lot of related reports. In short, the next few years will be a period of rapid development of Zigbee technology. Application of Zigbee technology in China: Although many people in China have begun to pay attention to this new technology and many units have begun to set foot in the development of Zigbee technology, because Zigbee itself is a new system integration technology, the development of application software must combine network transmission, radio frequency technology and underlying software and hardware control technology. Therefore, it is not easy to learn about this new technology from abroad and then organize a support team with rich experience in these areas. Therefore, up to now, apart from Chengdu Xigu Shuguang Digital Technology Co., Ltd., there is no report that other Zigbee technologies are really developed into products and successfully used to solve practical production problems in many fields in China. Comparison between Zigbee and existing mobile networks (GPRS, CDMA- 1X): 1. No network usage fee: using mobile network requires long-term payment of network usage fee, which is calculated according to the number of node terminals, but Zigbee does not have this fee; 2. Less equipment investment: You need to buy mobile terminal equipment to use the mobile network, and the price of each terminal is about 65,438 yuan+0,000 yuan. Using Zigbee network, not only the Zigbee network node module (equivalent to the base station) is less than 1 000 yuan each, but also the price of the main network sub-node (equivalent to the mobile phone) is much lower; 3. More reliable communication: Because the existing mobile network is mainly designed for mobile phone communication, although CDMA- 1X and GPRS can communicate data, it is found in practice that not only the communication rate is much lower than the design rate, but also there are some problems in the reliability of data communication. Zigbee network is specially designed for the transmission of control data, so the transmission of control data is quite guaranteed. 4. High flexibility and low cost: firstly, Zigbee network nodes with different coverage distances and different functions and low-cost wireless transceiver modules of other non-Zigbee systems are used to establish a Zigbee local automation control network (this network can be star-shaped, tree-shaped, meshed and its * * * composite network structure), and then it is connected with a remote computer through the Internet or mobile network to realize low-cost and high-efficiency industrial automation telemetry and remote control; 5. Compared with the existing mobile network, although Zigbee is only a local area network with limited coverage, it can be connected with the existing mobile network, Internet and other communication networks to connect multiple Zigbee local area networks into a whole. Effectively solve the problem of blind area coverage of mobile networks: We know that the existing mobile networks have blind areas in many places, especially in railways, highways, oil fields, mines and other fields. Increasing the cost of a mobile base station or repeater is considerable. At this time, using Zigbee network to cover blind areas is not only economical and effective, but also often the only feasible means. Compared with existing digital radio stations, Zigbee is 1. High reliability: Because the integration of Zigbee module is much higher than that of ordinary digital radio stations, there are fewer separated components, so the reliability is higher; 2. Convenient and safe to use: Due to high integration, compared with the general digital radio station, the Zigbee receiving module can be made small in size and low in power consumption. For example, Chengdu Xigu Company's long-distance transmission module (2-5km) has a much smaller maximum transmission current than CDMA mobile phone, so it is easy to be integrated or directly put into equipment, which is not only convenient to use, but also not easy to be damaged when used outdoors. 3. Strong anti-interference, good confidentiality and low bit error rate: Zigbee transceiver module adopts 2.4G direct sequence spread spectrum technology, which has stronger anti-interference ability and longer transmission distance than ordinary FSK, ASK and frequency hopping digital transmission stations; 4. Free frequency band: Zigbee uses free frequency band. Many digital radio stations not only need to apply for frequency band, but also need to pay a considerable frequency usage fee to the State Committee every year. 5. Low price: the price of Zigbee data transmission module is only a fraction of that of similar function data transmission stations; (2.4G, 250kps, 3-5km away from the data transmission module of DSSS, each block is less than 1 1,000 yuan) How to make use of Zigbee to generate benefits as soon as possible: In order to enable people to use Zigbee technology to solve practical problems in different application fields faster and better, it is not necessary to deeply understand how the Zigbee network itself works, thus greatly shortening the time of system integration and bringing you practical economic benefits quickly. Chengdu Xigu Shuguang Digital Technology Co., Ltd. specializes in providing users with Zigbee wireless network platform demonstration/application suite and specific application development training. This suite includes: 1). 5 standard demonstration/application modules (one of which is used as a gateway node connected to the computer); 2). Accessories such as batteries and antennas; 3).Zigbee network function demonstration software; 4). Each module provides two USART interfaces; 5) Connect the application module with your computer and sensor using standard serial communication protocol. If our standard serial protocol can't meet the needs of your specific application, in principle, we can modify it according to your specific requirements. With this suite, you can write your application completely according to the wired network connection; The actual wireless network is used as a general wired network. This suite has the following demonstration functions: 1. Demonstrate the automatic and dynamic networking function of Zigbee network itself; 2. Demonstrate the automatic routing function of data transmission in the network and how data is transmitted in the network; 3. The function of displaying the network wireless link connection status and the actual data transmission statistics of each network node; 4. Demonstrate various data acquisition functions of the whole network; 5. Demonstrate the control function of the control center to remote network nodes; 6. More importantly, in addition to the above demonstration function, it can also be used to check the wireless link connection in the actual network layout and evaluate and adjust the specific layout effect of the field network nodes. Each module in the suite provides two USART interfaces for users to directly write their own applications and use them. In this way, users can determine the number of network nodes and the specific settings of the remote end according to their actual application requirements, and then they can write specific application software. When your software development work is completed, you can directly use the standard modules provided by us for on-site installation and setting, and then you can work.