Trading structure for randomness in wireless opportunistic routing
Trading structure for randomness in wireless opportunistic routing
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DOI：
10.1145/1282380.1282400
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发表时间：
2007-10
期刊：
影响因子：
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通讯作者：
Szymon Jakubczak;M. Jennings;S. Katti;D. Katabi
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文献类型：
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作者：
Szymon Jakubczak;M. Jennings;S. Katti;D. Katabi
机会路由是一种在无线链路损耗的情况下实现高吞吐量的最新技术。当前的机会主义路由协议Exor将MAC与路由捆绑在一起，对路由器访问介质施加了严格的时间表。尽管调度器提供了机会主义的收益，但它错过了802.11 MAC的一些固有功能。例如，它阻止了空间重用，从而可能未充分利用无线介质。它还消除了分层抽象，使协议不太容易扩展到其他流量类型，如组播。本文提出了一种MAC无关的机会路由协议MORE。More在转发之前随机混合数据包。这种随机性确保了侦听相同传输的路由器不会转发相同的数据包。因此，More不需要特殊的调度程序来协调路由器，可以直接在802.11上运行。在20个节点的无线测试床上的实验结果表明，More的单播吞吐量中值比Exor高22%，当有空间重用的机会时，单播吞吐量的增益比Exor高45%。对于多播，More的收益随着目的地数量的增加而增加，比Exor高35-200%。
Opportunistic routing is a recent technique that achieves high throughput in the face of lossy wireless links. The current opportunistic routing protocol, ExOR, ties the MAC with routing, imposing a strict schedule on routers' access to the medium. Although the scheduler delivers opportunistic gains, it misses some of the inherent features of the 802.11 MAC. For example, it prevents spatial reuse and thus may underutilize the wireless medium. It also eliminates the layering abstraction, making the protocol less amenable to extensions to alternate traffic types such as multicast. This paper presents MORE, a MAC-independent opportunistic routing protocol. MORE randomly mixes packets before forwarding them. This randomness ensures that routers that hear the same transmission do not forward the same packets. Thus, MORE needs no special scheduler to coordinate routers and can run directly on top of 802.11. Experimental results from a 20-node wireless testbed show that MORE's median unicast throughput is 22% higher than ExOR, and the gains rise to 45% over ExOR when there is a chance of spatial reuse. For multicast, MORE's gains increase with the number of destinations, and are 35-200% greater than ExOR.