Optimal and Suboptimal Routing Based on Partial CSI in Random Ad-hoc Networks

TL;DR

This paper derives the exact optimal routing strategy in random ad-hoc networks with partial channel information, providing a performance benchmark and proposing low-complexity schemes that perform nearly optimally.

Contribution

It presents the first exact optimal routing solution in Poisson-distributed ad-hoc networks with partial CSI, and introduces practical sub-optimal schemes with near-optimal performance.

Findings

Optimal routing maximizes a metric based on partial CSI and interference statistics.

Sub-optimal schemes with lower complexity perform close to the optimal.

Proposed schemes outperform other tested routing methods.

Abstract

In this paper we consider routing in random wireless-adhoc-networks (WANETs), where each node is equipped with a single antenna. Our analysis uses a proper model of the physical layer together with an abstraction of higher communication layers. We assume that the nodes are distributed according to a Poisson-point-process and consider routing schemes that select the next relay based on the geographical locations, the channel gains of its neighbor nodes and the statistical characterization of all other nodes. While many routing problems are formulated as optimization problems, the optimal distributed solution is rarely accessible. In this work, we present the exact optimal solution for the scenario analyzed. The optimal routing is given as a maximization of a routing metric which depends solely on the known partial channel state information (CSI) and includes an expectation with respect to the interference statistics. The optimal routing scheme is important because it gives an upper bound on the performance of any other routing scheme. We also present sub-optimal routing schemes that only use part of the available knowledge and require much lower computational complexity. Numerical results demonstrate that the performance of the low complexity schemes is close to optimal and outperforms other tested routing schemes.