Design And Implementation Of Multiple-access-protocol-supported MAC Layer Architecture Of Ad Hoc Network

With the characteristics of self-organization,multi hop and and dynamic network topology,Ad Hoc network can be set up quickly and flexibly without any fixed infrastructure support,so that it plays a very important role in military missions,emergency relief and so on.Media Access Control(MAC)layer,which can achieve data transmission,wireless channel access,reliable transmission,relay forwarding and other functions,is an important part of Ad Hoc network protocol stack system.A channel sharing scheduling mechanism can be provided by multiple access protocol to ensure that plurality of communication nodes will share the same radio channel resources fairly and efficiently,and what's more,the multiple access protocol determines the node traffic and the network throughput.In Support of combination of two or more than two kinds of multiple access protocols,together with elements of competition protocol and distribution protocol,nodes are able to avoid the defects of a single access protocol,make good use of the advantages of two protocols.To design such software architecture for MAC layer which is able to support both multiple access protocols is an important part of setting up Ad Hoc network system.This paper mainly discusses design,research and implementation of software architecture for MAC layer which can support two kinds of multiple access protocol at the same time in Ad Hoc network system.This paper firstly introduces characteristics and stack of Ad Hoc network system,as well as the research of multiple access protocol.Then,according to the requirements of Ad Hoc broadband network system with multi protocols,the paper designs overall architecture for MAC layer in the broadband network system.The architecture is divided into two modules: data transmission module and channel access module.The data transmission module,which is not affected by which kind of multi access protocol we chose,is designed to be shared for both kinds of protocol,and channel access module needs special design for each kind of protocol.The paper has described key issues in the process of realization about the two modules,including data transceiver,message relay,retransmission mechanism,GPS extraction,etc.In this paper,the design scheme of the two modules,the realization method and process are also presented.Finally,the paper has finished tests about function and service application of the broadband network system,and the test results show that the system design meets user's requirements.