无线网络中实时业务的信道预留

Channel Reservation for Real-time Traffic in Wireless Network

随着无线数据服务的流行和多媒体应用需求的增长,需要无线网络能够为不同种类的业务提供有区别的服务质量(QoS),因此如何在无线网络中提供有区分和有保证的服务质量,成为一个非常重要的问题。论文提出了一种在IEEE802.11无线网络中为实时业务提供服务质量保证的有效方法,即通过修改介质访问控制(MAC)层的分布式协调功能(DCF),为实时数据预留信道。当一个节点竞争到信道后,可以连续向同一个目标节点发送多个实时数据帧,称作传送突发(TB,TransmissionBurst),即在一个TB中第一个数据帧将为实时业务预留信道,直到这个TB结束,这样实时业务将比其他业务占有更多的信道资源。仿真结果表明,该方法能够明显改进实时业务的吞吐率和延迟性能,提高无线网络的信道利用率,而且,对DCF的修改没有增加任何控制开销。

With the rapid growth in popularity of wireless data services and the increasing demand for multimedia applications,future wireless networks will provide services for heterogeneous classes of traffic with different quality of service（QoS） requirements.h is critical to develop new technologies for providing QoS differentiation and guarantees in wireless networks.In this paper,we propose an efficient method to provide QoS for real-time traffic in IEEE 802.11 wireless LANs.Our method is to reserve channel for real-time data through modifying the DCF（Distributed Coordination i Function） at MAC layer.Once a station has contended for the channel,it may transmit multiple real-time data frames continuously,named a TB（Transmission Burst）,to the same destination if they exists in the queue.That is to say the first data frame in a TB will reserves the channel for the real-time traffic until the end of the TB.So the real-time traffic may occupy more channel resource than other traffic.Our method can increase the channel utilization in IEEE 802.11 wireless LAN.The simulation results show that our method can improve the throughput and delay performance of real- time traffic remarkably.In addition,our method does not introduce any additional control overhead.