Distributive routing & congestion control in wireless multihop ad hoc communication networks

TL;DR

This paper investigates routing and congestion control in wireless multihop ad hoc networks, analyzing traffic behavior and proposing a distributed method that enhances network capacity and robustness.

Contribution

It introduces a distributed routing and congestion control scheme based on local information exchange, improving network load capacity over shortest-path routing.

Findings

Scaling law of average delay depends on network topology

Distributed control increases critical network load

Analysis of congestion measures like delay and relaxation times

Abstract

Due to their inherent complexity, engineered wireless multihop ad hoc communication networks represent a technological challenge. Having no mastering infrastructure the nodes have to selforganize themselves in such a way that for example network connectivity, good data traffic performance and robustness are guaranteed. In this contribution the focus is on routing & congestion control. First, random data traffic along shortest path routes is studied by simulations as well as theoretical modeling. Measures of congestion like end-to-end time delay and relaxation times are given. A scaling law of the average time delay with respect to network size is revealed and found to depend on the underlying network topology. In the second step, a distributive routing & congestion control is proposed. Each node locally propagates its routing cost estimates and information about its congestion state to its neighbors, which then update their respective cost estimates. This allows for a flexible adaptation of end-to-end routes to the overall congestion state of the network. Compared to shortest-path routing, the critical network load is significantly increased.