Fair Scheduling and Admission Control for Shared-Channel Wireless Packet Networks

摘要对于网页http://tesla.csl.uiuc.edu/~srikant/~wireless.html，由于无线媒体的两个独特特征：(A)突发信道错误和(B)依赖于位置的信道容量和错误，大多数现代有线公平调度算法不能有效地解决无线信道上的延迟和速率敏感分组流的公平调度。此外，在分组蜂窝网络中，基站通常为小区中的下行链路流和上行链路流执行分组调度任务；然而，基站对上行链路流的到达过程只有有限的了解。公平调度与接纳控制和信道测量密切相关，因为它们用于将信道容量的一小部分分配给基于每个流或其服务质量(Qos)要求的每个流。在这个方案中，我们将一起研究接纳控制和调度问题。大多数以前的工作都是在有线网络的背景下分别解决这两个问题，但这种方法不适用于无线网络。在线测量将与接纳控制、调度和速率自适应一起使用，以提供良好的服务质量性能。我们计划使用在线测量来估计描述信道状态的简单随机过程(如开关马尔可夫模型)的参数。离线测量将被用来验证和改进我们的预测算法，以及开发一个简单的信道模型，供在线测量算法使用。我们还将研究公平无线分组调度对媒体接入的影响，并开发一个有效的MAC协议来支持简单的速率和时延保证。最后，利用现有的测试床，我们将对本研究项目得出的算法进行评估。

Abstract for the web page http://tesla.csl.uiuc.edu/~srikant/~wireless.html Fair scheduling of delay and rate-sensitive packet flows over a wireless channel is not addressed effectively by most contemporary wireline fair scheduling algorithms because of two unique characteristics of wireless media: (a) bursty channel errors, and (b) location-dependent channel capacity and errors. Besides, in packet cellular networks, the base station typically performs the task of packet scheduling for both downlink and uplink flows in a cell; however a base station has only a limited knowledge of the arrival processes of uplink flows. Fair scheduling is closely connected to admission control and channel measurements since these are used to allocate a fraction of the channel's capacity to each flow based or its Quality-of-Service (QoS) requirements. In this proposal, we will study the problem of admission control and scheduling together. Most previous work has addressed these two problems separately in the context of wireline networks, but such an approach is not applicable to wireless networks. On-line measurements will be used along with admission control, scheduling and rate adaption to provide good QoS performance. We plan to use on-line measurements to estimate the parameters of simple stochastic processes (such as on-off Markov models) describing the channel state. Off-line measurements would be used to validate and refine our prediction algorithm as well as to develop a simple model for the channel which can used by the on-line measurement algorithm. We will also study the impact of fair wireless packet scheduling on medium access and develop an effective MAC protocol to support simple rate and delay guarantees. Finally, using existing testbeds, we will evaluate the algorithms that result from this research project.