We have observed that cooperative communication holds considerable promise. Some of this promise is evidenced in the proposals examined in this topic. However, much remains to be done. For example, the proposals do not incorporate many of the ideas in topic 4.
It is tempting to argue that cooperation demands a complete redesign of the networking protocol stack. An abstract study might suggest that substantial benefits will be obtained by a tighter integration of the network layer with the MAC, link, and PHY layers. In particular, such an approach is likely to yield the greatest flexibility in optimizing the global use of wireless network resources.
However, this approach requires a significant expansion in the function of the network layer and more complex high-rate interfaces between PHY layer devices and network layer software. Demanding such a reconfiguration might well preclude the practical implementation of cooperative techniques. That is, requiring a more complex network layer represents a barrier to the adoption of cooperative wireless protocols. The practical value of cooperative communication is likely to depend on whether we can achieve the gains associated with cooperation without demanding more from the network layer.
