Research On Access Strategy For Uplink Access

With the increase of the number of devices requesting to access the network,how to ensure the service quality of wireless cellular networks and provide a good service experience for communication terminals has become a common concern in the industry.However,due to the huge number of machine type terminals,when a large number of terminals access the network,it is bound to cause serious random access channel congestion,which will greatly reduce the service quality of the network.Therefore,the related congestion control strategies of Machine Type Communication(MTC)uplink access have become the hot and difficult issues in current research.In this situation,this paper mainly considers the congestion control strategy to improve the access performance of communication terminals,and mainly studies the Access Class Barring(ACB)in 3GPP.The main contents include:First of all,this paper analyzed the research background and research status of MTC uplink access,summarized the MTC's business characteristics and current research directions,and reviewed the access network related congestion control strategy.Secondly,this paper considered the problem of traffic distribution for MTC terminal access in heterogeneous network scenarios.In order to solve the problem of network congestion caused by massive communication terminals,this paper modeled the terminals and base stations as a whole,and designed a strategy of ACB based on hierarchical game in heterogeneous scenarios.The evolutionary game is modeled on the terminal side.The replication dynamics is used as an evolutionary dynamic tool to demonstrate that evolutionary results eventually converge to Nash equilibrium,which ensures that each terminal is associated with an optimally functioning network.A non-cooperative game modeling method is used in the base station side,to ensure that the base station in the process of game gain maximization.The simulation results proved that the proposed scheme could effectively mitigate the delay of MTC terminal accessing the network and improve the network performance of heterogeneous networks.Finally,this paper considered the preamble resource allocation problem in random access.As the preamble resources are limited,how to effectively allocate resources is crucial to improve the network performance.Considering the problem of preamble resource allocation when both delay-sensitive and delay-tolerant terminals access the network at the same time,this paper designed a preamble resource allocation strategy based on the ACB mechanism.In this strategy,the preamble is divided into three sets,including delay-sensitive dedicated preamble,tolerance dedicated preamble and shared preamble.The ACB mechanism can directly and effectively limit the number of terminals applying for the preamble.The evolutionary game theory can adjust the proportion of delay-tolerant terminals' selection between dedicated preambles and shared preambles,that dynamically adjust the preamble resources distribution between two types of terminals.Simulation results proved that this scheme could effectively improve the success rate of preamble transmission.