Achieving MAC layer fairness in wireless packet networks
Achieving MAC layer fairness in wireless packet networks
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DOI：
10.1145/345910.345925
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发表时间：
2000-08
期刊：
影响因子：
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通讯作者：
T. Nandagopal;Tae-eun Kim;Xia Gao;V. Bharghavan
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文献类型：
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作者：
T. Nandagopal;Tae-eun Kim;Xia Gao;V. Bharghavan
为有线和分组蜂窝网络提出的链路层公平模型不能推广到共享信道无线网络，因为无线信道具有独特的特性，例如位置相关的竞争、优化信道利用率和实现公平性之间的固有冲突以及缺乏任何集中控制。在本文中，我们提出了一个通用分析框架，该框架捕获共享无线信道的独特特征，并允许通过每流效用函数的规范对一大类系统范围的公平模型进行建模。我们证明，只要每个节点执行旨在优化其本地效用函数的争用解决算法，就可以在没有明确的全局协调的情况下实现系统范围的公平性。我们提出了一种通用机制，用于将框架中给定的公平模型转换为相应的争用解决算法。使用这种转换，我们推导出用于在无线共享信道中实现比例公平的退避算法，并将该算法的公平性属性与理想的比例公平目标和最先进的基于退避的争用解决算法进行比较。我们相信，所提出的框架的两个方面，即通过本地效用函数指定任意公平模型的能力，以及响应给定效用函数自动生成本地竞争解决机制的能力，共同为未来共享信道无线网络中实现灵活的服务差异化提供了途径。
Link-layer fairness models that have been proposed for wireline and packet cellular networks cannot be generalized for shared channel wireless networks because of the unique characteristics of the wireless channel, such as location-dependent contention, inherent conflict between optimizing channel utilization and achieving fairness, and the absence of any centralized control. In this paper, we propose a general analytical framework that captures the unique characteristics of shared wireless channels and allows the modeling of a large class of system-wide fairness models via the specification of per-flow utility functions. We show that system-wide fairness can be achieved without explicit global coordination so long as each node executes a contention resolution algorithm that is designed to optimize its local utility function. We present a general mechanism for translating a given fairness model in our framework into a corresponding contention resolution algorithm. Using this translation, we derive the backoff algorithm for achieving proportional fairness in wireless shared channels, and compare the fairness properties of this algorithm with both the ideal proportional fairness objective, and state-of-the-art backoff-based contention resolution algorithms. We believe that the two aspects of the proposed framework, i.e. the ability to specify arbitrary fairness models via local utility functions, and the ability to automatically generate local contention resolution mechanisms in response to a given utility function, together provide the path for achieving flexible service differentiation in future shared channel wireless networks.