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arXiv 1104.2380cs.NI
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高效的分布式媒体接入

Efficient Distributed Medium Access

Devavrat Shah, Jinwoo Shin, Prasad Tetali

摘要:

考虑由图G=(V,E)表示的n个节点的无线网络,其中边(i,j)对i和j的传输彼此干扰的事实进行建模,即,i和j的同时传输变得不成功。因此,要求在每个时刻,一组非干扰节点(对应于G中的独立集)接入无线介质。为了有效地利用无线资源,需要对干扰节点之间的介质接入进行合理的仲裁。此外,为了实际使用,这种机制需要完全分布并且简单。作为本文的主要成果,我们提出了这样一种媒体接入算法。它是随机的,完全分布式的和简单的:每个节点尝试访问介质在每一个时间的概率是其本地信息的函数。我们建立的算法的效率表明,相应的网络马尔可夫链是积极的经常性,只要施加在网络上的需求可以支持的无线网络(使用任何算法)。在这个意义上,所提出的算法是最佳的利用无线资源。该算法不注意网络图结构,与Hastad-Leighton-Rogoff(STOC '87,SICOMP '96)的所谓的“多项式退避”算法形成对比,该算法被建立为对于完全图和二分图是最优的(Goldberg-MacKenzie(SODA '96,JCSS '99))。

英文摘要:

Consider a wireless network of n nodes represented by a graph G=(V, E) where an edge (i,j) models the fact that transmissions of i and j interfere with each other, i.e. simultaneous transmissions of i and j become unsuccessful. Hence it is required that at each time instance a set of non-interfering nodes (corresponding to an independent set in G) access the wireless medium. To utilize wireless resources efficiently, it is required to arbitrate the access of medium among interfering nodes properly. Moreover, to be of practical use, such a mechanism is required to be totally distributed as well as simple. As the main result of this paper, we provide such a medium access algorithm. It is randomized, totally distributed and simple: each node attempts to access medium at each time with probability that is a function of its local information. We establish efficiency of the algorithm by showing that the corresponding network Markov chain is positive recurrent as long as the demand imposed on the network can be supported by the wireless network (using any algorithm). In that sense, the proposed algorithm is optimal in terms of utilizing wireless resources. The algorithm is oblivious to the network graph structure, in contrast with the so-called `polynomial back-off' algorithm by Hastad-Leighton-Rogoff (STOC '87, SICOMP '96) that is established to be optimal for the complete graph and bipartite graphs (by Goldberg-MacKenzie (SODA '96, JCSS '99)).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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