Research On Admission Control Algorithms For LTE System

LTE(Long Term Evolution), as a major evolution direction of the mobile communicationsystem, becomes more and more widespreadly concerned for its high-speed, low-latency.UTRAN Long Term Evolution (LTE) architecture supports more flexible quality ofservice(QoS). The purpose of Admission Control (AC) is to control the trade-off between thenumber of bearers in the system and the QoS that they experience if admitted.One main work of this paper is to analyze the existing algorithms and do simulationevaluation. On the basis of thorough investigation for the AC algorithms published in recentten years, we have focused on simulation for the two representative algorithms in Matlab.Fractional Power Control (FPC) has been proposed as a QoS-aware AC for uplink LTE. Theidea is to estimate the required number of PRBs (Physical Resource Block) based on thepath-loss between the serving eNode B and the mobile. According to the statistics on thenumber of Resource Blocks (RBs) used in a recent period of time, a new cell loadmeasurement called as “AC based on Load” and the subsequent three mechanisms forpredicting the load increase of new bear has been proposed.The other main work of this paper is to seek more effective AC algorithm in performance.a new AC algorithm called “AC algorithm based on the filtering mechanism” has beenproposed. The idea comes from the “Injection Principle” in the communication system. Forthe busy cell lack of spectrum, in the short time many users apply for access competing forspectrum resources. Before making decision for the user access, we add the collection for thechannel quality characteristics of the new user requests, and in accordance with this the userwith better quality of communication channel is selected for access as well. If making sure thespectrum resource is occupied by the users with the better channel quality in the busy cell, wecan improve the utilization rate of resources, increase the number of online users, reduce theuser access rejection rate and increase the operating benefit.To evaluate the performance, we perform the simulation for the proposed AC algorithmcompared with a classic reference AC algorithm. It is shown that the proposed algorithmdosn’t only improve the QoS of the users connected to the network in the low busy cell, butalso reduces the blocking probability and increases the throughput in the high busy cell. Theresults of the simulation for the video users show that at20%unsatisfied user probability thecarried traffic gain of the proposed AC algorithm can be up to around24%over the referenceAC algorithm.