| In all the B3G candidate program, Orthogonal Frequency Division Multiple Access (OFDMA) as the core technology of the wireless communication network become one of the competing current research focus. Due to the limited radio resources, only efficient Radio Resources Management (RRM) can ensure higher data transmission rate and spectrum efficiency in multi-user OFDMA system.As the layout and control of air interface resources, Radio Resources Management (RRM) is an important technology which can increase the system’s capacity. There are several means of RRM, and call admission control is the first step of RRM. The performance of admission control will influence the capability of entire system directly. The precondition to make a good call admission control strategy is a appropriate stochastic service model. Furthermore, the self-adaptive technology and the existence of several kinds of service make the demand for stochastic service model stricter.This paper models the call admission control of OFDMA system using stochastic Petri Net. For multi-services system, where voice service and FTP service are in existence simultaneously, admission control of carriers shared is modeled firstly. Then because voice service need stricter real time, so a higher priority and queuing management are given to voice users. Next, simulation results of Petri Net models are given and analyzed.In the second section, the corresponding Markov models are gotten, and through the analysis of stable state probability, we can get blocking probability’s academic value. Subsequently, we calculate the value that the probability of SNR<yth which is equal to the outage probability. In the end, by the simulation of MATLAB and the software TimeNet which is used to simulate Petri Net, we validate the models strictly, include blocking probability, outage probability, and throughput of system and so on. The results proved that the Petri Net models we bring forward are right completely; besides introducing Petri Net into the research of RRM of mobile communication system is feasible. |
