Research On Service Quality Of M2M Communication Service

Along with the development of wireless communication in recent years, there is anew way of communication called Machine to Machine(M2M). M2M refers to theinterconnection between machines without human intervention, It guarantees theinformation exchange among machines through wireless communication network andhackend server. Previous communication network is mainly used to carry to II2Hcommunication services, now3GPLTE and LTE-A take into account supporting M2Mcommunication services at the same time. It has large number of terminals, smallaccount of communication dala and high bursting features, there are many keytechnologies needed to be studied in M2M, M2M communication scrvice is differentfrom11211communication bccausc the feature of huge number of devices result in acompetition-base random access mechanism to access the wireless network. Thispaper main research are how to control wireless access network load，which is causcdby the large number of M2M terminal asking for access request simultaneously,reduce the collision probability of machine terminal and improve the systemthroughput.This paper has two parts of work: how to choose the backoff time about theExtended Access Barring mechanism and how to improve existing random accessalgorithms system throughput.In the ifrst part we evaluate the success acccss probability，the probability ofcollision and the number of preamble transmission about Acccss Class Barringmcchanism and Extended Access Barring mechanism are studied under the conditionof the uniform and beta traffic distribution model. The simulation shows that thetraditional Access Class Barring mechanism is probability-based lo control thenumber of the access devices, and cannot serve the bursting trafifc well enough.Besides, the Extended Access Barring mechanism lack of dispersion mechanism, thesimulation result the probability of collision very high, in this paper Choose uniformdistribution replaces the backoff time, which is effectively reduced the probability of collision.In the second part, we analyzed the existing random access algorithms systemperformance which include ALOHA and CSMA. They have a common drawback，which is, they work well when under certain load, But, as the traffic load increase, thethroughput decrease to zero. By introducing the threshold of load control, the BaseStation according the current load to adjust the threshold to maintain the systemstability，and the simulation shows the new algorithms improved system throughput.