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Research On Cross Layer Design For QoS Guarantee In Ad Hoc Networks

Posted on:2011-09-11Degree:MasterType:Thesis
Country:ChinaCandidate:H YuanFull Text:PDF
GTID:2248330338996128Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
In the rapid development of wireless network technology today, the ubiquitous characteristics of wireless mobile multi-hop Ad Hoc network makes it a wide application prospects. However, Ad Hoc network is still facing some problems, such as dynamic topology changes caused by node mobility, variable quality of wireless link, the instability of wireless channel and the sudden burst of traffic, which makes QoS provision difficult in the network. The tradition protocol stack in the Ad Hoc network indeed solve some functional problems, but there are still some problems in practical application because of the shackles of the traditional protocol stack. Cross-layer design breaks the shackles of tradition protocol stack, it achieves an overall optimization by information sharing and interaction between the network layers.This paper first introduced the development and characteristics of Ad Hoc network, the basic model and method of cross-layer design, and analysed the factors which effect end-to-end delay. Then seized the main factor, and proposed the urgent based method and congestion control protocol. The main contributions of the paper are as follows:Proposed a urgent-based queue management algorithm instead of the traditional“First come First Serve”method. The sender computes the urgent factor based on the packets’delay requirement and their remaining hops to the destination, then the packet’s urgent factor is stored in its IP header. When the node seized the channel, it would choose the proper packets to transmit according to each packet’s urgent factor. Simulation results show that the proposed algorithm can control the average end-to-end delay and jitter, which can make the average delay fall in an acceptable range, decrease the delay jitter and improve the network performance.Traditional DSR routing protocol in Ad Hoc networks are mainly based on“the Shortest Paths”, the on using path should be discarded only when it is detected broken. So the protocol can not fully support the change of traffic load and which may lead to local congestion. This paper proposed a Route Reverse based on DSR (RRDSR)routing protocol with cross-layer design. It takes delay requirement and the time the packet has already consumed into account, and will choose another path when the former one faces congestion. This method can utilize the newest channel condition to avoid local congestion. Simulation results show that the RRDSR performs better in end-to-end throughputs and average delay.
Keywords/Search Tags:Ad Hoc network, urgent factor, routing protocol, congestion, cross-layer, QoS guarantee, route reverse
PDF Full Text Request
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