Video Transmission System Based On Zigbee Technology Research

With the rapid development of computer technology and increasing awareness of the people's security, to safeguard the social stability and the masses of personal and property security, video monitoring technology is particularly important, and is widely applied in the field of city traffic management, urban power maintenance and residential security and other areas. Video monitoring system will send image information collected in a camera to the monitoring center timely in order to respond to emergencies. However,existing video monitoring system is used mostly cable network technology, and this kind of system is mostly limited by various factors, such as long construction cycle, large projects, lack of flexibility, etc. In order to solve these problems,the article presents a wireless video image transmission system based on wireless communication technology.Compared with Bluetooth, WiFi and RFID technology, ZigBee technology as a new low-rate, low-cost, low-power short-range wireless communications technology, cannot be replaced, especially the ZigBee technology is more suitable for building a wireless sensor network because of the self-building networking features.To build the wireless video transmission system, this paper is divided into four parts:basic knowledge, NS2simulation, system implementation and the system analysis deficiency. First, this paper introduces the development, application and technical characteristics of ZigBee wireless communication technology based on IEEE802.15.4protocol, and make a analysis and research on ZigBee protocol stack architecture. These knowledges that the physical layer, the MAC layer, network layer, the application layer and security with layers of specifications and function are expounded in detail,thus providing theoretical basis for the follow-up work. Second, the paper uses the simulation software NS2to build ZigBee video transmission network model and makes an analysis and discussion for image transmission packet loss and transmission model, and gives simulation result of network average throughput and average delay. Third, the wireless video transmission system is builded which is divided into data acquisition, data transmission and data reduction of three parts. The image data in system captured by CMOS serial camera is sent and received through ZigBee wireless network. ZigBee wireless network, using star topology of the main slave nodes and connecting coordinator FFD and the user terminal RFD by ZigBee wireless sensor network, will send image information. And the user terminal RFD will transmit the received data to the host computer through the serial port, thus wireless video transmission system is completed. In order to verify the data received from the host computer whether meeting the experiment requirements, the system use the software serial debugging aides to record and analyze the data. Fourth, ZigBee network self low-rate characteristics results in low network throughput, high packet loss rate, and poor generating picture quality when transmitting of multimedia information.Therefore, this paper introduces the multi-radio multi-channel technology and multiple description coding techniques to improve the ZigBee network and improve the quality of video transmission.This paper introduces wireless visible entrance guard system as an example, through the wireless video image transmission system transmission of information collected pictures. For simplified development processes, the experiment integrate the Lord equipment, client and wireless equipment on the ZigBee module, and establish a star network based on IEEE802.15.4protocol to transmit the image information.