Joint Cooperation and Multi-Hopping Increase the Capacity of Wireless Networks
Abstract
Description
The problem of communication among nodes in an \emph{extended network} is considered, where radio power decay and interference are limiting factors. It has been shown previously that, with simple multi-hopping, the achievable total communication rate in such a network is at most $Θ(\sqrt{N})$. In this work, we study the benefit of node cooperation in conjunction with multi-hopping on the network capacity. We propose a multi-phase communication scheme, combining distributed MIMO transmission with multi-hop forwarding among clusters of nodes. We derive the network throughput of this communication scheme and determine the optimal cluster size. This provides a constructive lower bound on the network capacity. We first show that in \textit{regular networks} a rate of $ω(N^{2/3})$ can be achieved with transmission power scaling of $Θ(N^{\fracα{6}-{1/3}})$, where $α>2$ is the signal path-loss exponent. We further extend this result to \textit{random networks}, where we show a rate of $ω(N^{2/3}(\log{N})^{(2-α)/6})$ can be achieved with transmission power scaling of $Θ(N^{α/6-1/3}(\log{N})^{-(α-2)^2/6})$ in a random network with unit node density. In particular, as $α$ approaches 2, only constant transmission power is required. Finally, we study a random network with density $λ=Ω(\log{N})$ and show that a rate of $ω((λN)^{2/3})$ is achieved and the required power scales as $Θ(N^{α/6-1/3}/λ^{α/3-2/3})$.
11 pages; preliminary version in IEEE SECON 2008
11 pages; preliminary version in IEEE SECON 2008