Cooperation at the network level

Cooperative Techniques in Wireless Networking have been developed mostly at the physical layer and are based on the notion of relaying and space-time codes. However, it is possible to also use the idea of cooperation at the MAC and Network layers in very simple ways that provide further performance improvements. We focus on the objective of stable throughput region which requires that delays are finite when packet arrivals are random and demonstrate how simple relaying can increase the region of arrival rates that can be accommodated with finite delays. The reasons for the improvement are subtle and suggest far-reaching ossibilities regarding “stable capacity regions”. Also, we consider another form of cooperative routing for the case of sensor networks and again demonstrate how cooperation can be thought of in a much broader sense than the one that has prevailed until now.