Research And Simulation On The QoS Mechanism Based On IEEE 802.16e Protocol

Nowdays, with the development of science and technology, particularly the rapid development of communication technology, the simple voice and SMS services can not meet the needs of daily life. IEEE 802.16e is an emerging broadband wireless access technology, which provides users with sufficient bandwidth, high transmission rate and multimedia services with high spectral efficiency, IEEE 802.16e solves"last a mile" communication needs. Quality of Service(QoS)requirements in IEEE 802.16e system is a very important and challenging problem. Although medium access (MAC) layer of IEEE 802.16e has QoS mechanisms, it does not suggest how to implement the QoS mechanism.so the QoS mechanism becomes a very popular research topic.Firstly, in this paper we generalize the background and development history of IEEE 802.16, and then analyze the IEEE 802.16e protocol model. QoS mechanism of MAC layer is the main part of this paper which describes the wired and wireless scheduling algorithms' theory and application scenarios. Based on the recent studies, The cross-layer design of the program should be suggested into original scheduling architecture, and a new cross-layer QoS scheduling architecture is proposed.The component modules of the new architecture are introduced simply. The MAC layer is combined with the physical layer's technology, and the uplink admission control and bandwidth allocation are researched in detail. The simple admission control technique is applied in this architecture which introduces grading upstream bandwidth allocation. In the first level scheduling, the original bandwidth allocation does not achieve the good fairness on the study of the previous scholars. Thereforce, we propose the improved Deficit Fair Packet Queuing scheduling algorithm(MDFPQ) in the first level scheduling to enhance the fairness of ths system, and we use the suitable wireless scheduling algorithms for a variety of queues in the second level scheduling.Based on the OPNET14.5's IEEE 802.16 model, the proposed scheduling architecture is implemented, and the simulation results should show the feasibility of this scheduling architecture. From the simulation results we can see that the proposed scheduling architecture improve bandwidth utilization and the system throughput, and lower the latency and provide QoS guarantees.