Research On Access Congestion Control And Resource Allocation Of M2M In LTE-Advanced

As one of the key part of the Internet of Things,M2M(Machine-to-Machine) communication could perform a variety of data measurement and acquisition and accomplish the inter-communication with others without human intervention by the use of the ubiquitous Wireless Mobile Communication networks.With the rapid development of the 5G technology,M2M communication technology has also explore enormous market potential.Due to the advantages of low cost,high speed,low delay,backward expansibility,and wide cover scope,the LTE-Advanced cellular network would be one of the most important bearer networks for M2M communication services.But the LTE-A is designed and optimized for H2H(Human-to-Human) communication service,and the sudden arrival of M2M devices and huge amounts of random access requests may result in the signaling congestion of the Access Network in LTE-A and impact the normal access of H2H services.Therefore,it is of great practical significance that an effective random access control mechanism is proposed to alleviate the access congestion,reduce the adverse impact on the H2H service and improve the access in the throughput in the LTE-A.Aiming at the access congestion problem,this thesis firstly analyzed the random access process in LTE-A,and then proposed an access control optimization scheme based on the time slot access scheme.By estimating the slot access load based on the statistics of the state of the slot preamble set,this access control scheme could select the appropriate slot access period to properly control the access load and then to alleviate the access network congestion.Simulation results demonstrate that this access control scheme has good performance,which can not only improve the access success rate of M2M equipment,but also reduce the preamble retransmission to reduce the access delay.Then,by means of analyzing existing preamble resource allocation schemes,a dynamic preamble resource allocation algorithm based on access fairness was proposed to tackle the problem that plenty of random access requests of M2M devices negatively impact the H2H devices' access.The base station could adaptively select the preamble resource allocation method according to the access load status of the current network.While guaranteeing the optimal access performance of the H2H devices,the scheme could save the signaling resources of the system and improve the access performance of the access network in LTE-A.Finally,considering the access control of M2M equipment and the preamble resource allocation in the hybrid network,a complete optimization scheme of the random access process was proposed and verified by simulation.