CANCAR – Congestion-Avoidance Network Coding-Aware Routing for Wireless Mesh Networks

Abstract

Network Coding (NC) is an approach recently investigated for increasing the network throughput and thus enhancing the performance of wireless mesh networks. The benefits of NC can further be improved when routing decisions are made with the awareness of coding capabilities and opportunities. Typically, the goal of such routing is to find and exploit routes with new coding opportunities and thus further increase the network throughput. As shown in this paper, in case of proactive routing the coding awareness along with the information of the measured traffic coding success can also be efficiently used to support the congestion avoidance and enable more encoded packets, thus indirectly further increasing the network throughput. To this end, a new proactive routing procedure called Congestion-Avoidance Network Coding-Aware Routing (CANCAR) is proposed. It detects the currently most highly-loaded node and prevents it from saturation by diverting some of the least coded traffic flows to alternative routes, thus achieving even higher coding gain by the remaining well-coded traffic flows on the node. The simulation results confirm that the proposed proactive routing procedure combined with the well-known COPE NC avoids network congestion and provides higher coding gains, thus achieving significantly higher throughput and enabling higher traffic loads both in a representative regular network topology as well as in two synthetically generated random network topologies.

Network and Traffic Design Aspects in Network-Coding-Enabled Wireless Networks

“…Th code selection that takes into account video-stream characteristics, such as the distortion values and the play-out deadlines of the video packets, was studied in [15]. The well-known and widely adopted COPE [10] has been under the spotlight, while so-called support mechanisms such as scheduling [21], queue management [7,16,17] and routing support [11,14,20] were used to bring about additional gains. Most of these support mechanisms can also be used with other opportunistic network-coding approaches, such as [3,8,19].…”