Research On QoS MAC Protocol Based On Differentiate Services With Low-latency For Medium And High Rate Wireless Sensor Networks

MHR-WSN (Medium and High Rate Wireless Sensor Networks) compared with traditional wireless sensor network, have the character of increasing some sensor module, such as microphones, cameras.MHR-WSN focused on audio, images, video and other media, large amount of information acquisition and processing, to achieve fine-grained, high-precision monitoring of information, which can break through the traditional bottlenecks in the development of sensor networks for fast-moving applications. Solved the problem of traditional wireless sensor network can not be moved, the energy consumption of fast, slow data transfer and many other issues.In essence,it is a optimization traditional wireless sensor network.MAC (Medium Access Control) protocol, determined the used radio channel, the sensor nodes in wireless communication between the allocations of limited resources, sensor devices used to build the underlying network infrastructure. MAC in sensor network protocols underlying data link layer part of the sensor networks, which have a very big impact, is to ensure efficient communication in wireless sensor networks, also is one of the key protocols. It is the project we researched in this emerging MHR-WSN, the MAC protocol wireless network QoS problems. MAC protocol data packets to send real-time service differentiation and QoS guarante is the main characteristics of the MHR-WSN wireless sensor networks different from the traditional sensor networks.In this thesis, we researched sensor network applications of the QoS guaranted MAC protocol in MHR-WSN, the main work as follows:(1) From the existing route Quality of service perspective, proposed a QoS-based routing protocol awareness, to provide reliable data packet delivery. To ensure reliability, the protocol uses two mechanisms; at the same time multi-source node sends data packets to the base station, to reduce the collision. The first is to choose entirely different source node disjoint multipath. But if there is no available disjoint multipath, the QoSDM planning different transmission source node, to avoid sharing the node node from multiple sources instantly receive large data packets. Designed cross-layer protocol model and hybrid programs for high speed application-specific. Improved 802.11e of EDCA mechanism, to support multi-path multi-channel access, maintaining QoS characteristics for differentiated services, while reducing overall network loss rate of packets. Recognized multi-channel approach using a common control channel, an increase in its frame format in the quality of multi-path routing information available to the channel access, according to changes in network load flow for maximum number of retransmission of the adaptive adjustment. Simulation results show that the algorithm in the MHR-WSN networks while maintaining QoS differentiated services, to ensure that different services of different latency, and reduces the network traffic load the impact of changes to improve the network throughput, high-load conditions to ensure that the network delay performance.(2) Proposed a MAC algorithm node-based Task Activity Awareness, through the collection of the node itself and the adjacent nodes of different active priority task for wireless sensor networks to estimate the network load, network load according to channel access node to determine the probability, in order to reduce network latency and improve energy efficiency and throughput. To avoid the impact of Hidden terminal, we introduced anti-interference method of MR, using implicit recognition mechanism, an effective solution to the interference between nodes. Simulation results show that the improved method can greatly reduce the network delay, and by eliminating unnecessary collisions to increase network throughput.(3) Because of concern of above protocol improve the process is how to determine the nodes on the channel access probability, so it can effectively and distinguish the services of other MAC protocols based on integration. Improved algorithm based on the previous chapter is presented based on data priority DiffServ MES-MAC method. To provide end to end delay of QoS support to ensure MHR-WSN in several important parameters. S-MAC protocol improve the mechanism of listening time, the use of channel reservation and channel access priority to a combination of techniques to distinguish between different priority for packet data service, the delay requirements for different data services to provide a different delay. Adjust the priority queue, lowed the average network access delay.This protocol is designed in detail and describes the operating mechanism of some protocol, the final simulation of the protocol by the various performance indicators. Research results obtained in the MHR-WSN provided a reference, has certain value engineering.