Performance Analysis Of Two-Hop-Relay Cellular Systems With Queueing Capability

Nowdays, communicationg technology has been growing very fast. A new technique emergesevery few years. Multihop relay network have been a very active area of research. Therefore,IEEE802.16Committee specifically established a department for Relay who is in charge ofproposing the criteria of Relay technology. Networks, built based on the Relay technology ismore inexpensive, convenient and advanced than that is built based on the variouscellulars.Incorporating the Relay technology into the conventional cell system, changes thetransmission mode between the base and mobile terminal: make single transmission line intomultiple lines. The change can reduce the transmission distance between the sender and thereceiver, increase the data transmission speeds, expand the area’ s coverage, improve the systemcapacity. Therefore, this networks meet more consumers need for high bit data rate.This paper firstly introduces some knowledge of the structure of WCDMA cellular systems,According to the distance from the base station distance, The coverage of base stations that thedistrict can be divided into high speed and low speed regions. However, due to the path loss andmultipath effect etc, a new call request arrives from low speed regions, can only be assigned to alow bit rate channel for data transmission. Some relay stations are placed at the boundary of thehigh and low speed regions in order to improve the average downlink transmission rate of thesystem, the call request from the low speed regions can have the high rate data transmission byrelay mode. However, after the introduction of the relay, the channel of the system will soon beassigned out, a new call request will be rejected immediately, so this article prent atwo-hop-relay WCDMA cellular system with queueing capability.Thus the channel of the basestation are assigned out, where a call can wait in the incoming buffer at the congested BaseTransceiver Station if no channel is immediately available, so as to greatly reduce the callblocking rate. but the length of the buffer queue will directly affect the system waiting time ofthe call, so the system call delay is also the focus of this article.First, in view of two types that are cellular relay system without queueing capability and withqueueing capability, we can build Markov state analysis model, and then analyze the analyticalmodel for the equation of state of the system.By the method of numerical calculation we canobtain performance assessment on the average downlink transmission rate of the system, thesystem call latency and system blocking rate.The results show that cellular relay system with queueing capability have lower average downlink transmission rate,most long call delay andlower call blocking rate than that without queueing capability.