Network Coding-Aware Queue Management for TCP Flows over Coded Wireless Networks

TL;DR

This paper proposes a network-coding aware queue management scheme to enhance TCP flow performance over coded wireless networks without altering TCP or MAC protocols.

Contribution

It introduces a distributed solution for network utility maximization and a novel queue management scheme that improves TCP performance in coded wireless networks.

Findings

NCAQM significantly improves TCP throughput.

The scheme operates without changes to TCP or MAC.

Simulation results validate the effectiveness of NCAQM.

Abstract

We are interested in unicast traffic over wireless networks that employ constructive inter-session network coding, including single-hop and multi-hop schemes. In this setting, TCP flows do not fully exploit the network coding opportunities due to their bursty behavior and due to the fact that TCP is agnostic to the underlying network coding. In order to improve the performance of TCP flows over coded wireless networks, we take the following steps. First, we formulate the problem as network utility maximization and we present a distributed solution. Second, mimicking the structure of the optimal solution, we propose a "network-coding aware" queue management scheme (NCAQM) at intermediate nodes; we make no changes to TCP or to the MAC protocol (802.11). We demonstrate, via simulation, that NCAQM significantly improves TCP performance compared to TCP over baseline schemes.