The Research Based On PFQ Packet Scheduling Algorithms

Recently with the explosive growth in network, there are more and more real-time applications.The best-effort service in traditional network cannot support QoS guarantee, so real-time application cannot be applied convenient. Since the QoS control mechanism is able to provide QoS guarantee for network, it becomes a key technique in high-speed network.Packet scheduling is a kind of measure for providing QoS guarantee and an important technique of QoS control mechanism. The research on wireline packet scheduling algorithms has become very mature. People have put forward many algorithms in packet communication based on GPS.The conventional scheduling algorithms in wireline network cannot be directly applied to wireless communication environments because of wireless-specific characteristics: bursty and location-dependent error. Taking into account the characteristics of wireless channel, wireless packet scheduling algorithms are submitted based on wireline packet scheduling algorithms.First, we make a summarize about wireline packet scheduling algorithms; Then, research a frame work used in PFQ algorithms and propose a kind of dynamic priority algorithm of VC; Next, introduce some important factors influencing the wireless channel and research the application of WF2Q in wireless environment; Finally, make a preliminary discussion on delay and bandwidth decoupling in PFQ algorithms.Doing a lot of simulation, the result show that the new priority algorithm has better flexible than the old one and the decouple algorithm can decrease the coupling of delay and bandwidth in some degree.