Distributed Resource Sharing in Low-Latency Wireless Ad Hoc Networks

摘要

With the growing abundance of portable wireless communication devices, a challenging question that arises is whether one can efficiently harness the collective communication and computation power of these devices. In this paper, we investigate this question by studying a streaming application. Consider a network of N wireless nodes, each of power P, in which one or more nodes are interested in receiving a data stream from a fixed server node S. We ask whether distributed communication mechanisms exist to route media packets from S to the arbitrary but fixed receiver, such that 1) the average communication delay L is short, 2) the load is balanced, i.e., all nodes in the ensemble spend roughly the same amount of average power, and, more importantly, 3) power resources of all nodes are optimally shared, i.e., the lifetime of the network is comparable to an optimally designed network with L nodes whose total power is N ? P. We develop a theoretical framework for incorporation of random long range routes into wireless ad hoc networking protocols that can achieve such performance. Surprisingly, we show that wireless ad hoc routing algorithms, based on this framework, exist that can deliver this performance. The proposed solution is a randomized network structuring and packet routing framework whose communication latency is only L = O(log2 N) hops, on average, compared to O(?(N)) in nearest neighbor communications while distributing the power requirement almost equally over all nodes. Interestingly, all network formation and routing algorithms are completely decentralized, and the packets arriving at a node are routed randomly and independently, based only on the source and destination locations. The distributed nature of the algorithm allows it to be implemented within standard wireless ad hoc communication protocols and makes the proposed framework a compelling candidate for harnessing collective network resources in a truly large-scale wireless ad hoc networ-nking environment.