Abstract :
The concept of cooperation in wireless communication networks has drawn significant attention recently from both academia and industry as it can be effective in addressing the performance limitations of wireless networks due to user mobility and the scarcity of network resources. In this article, we aim to shed some light on potential benefits of such an approach and discuss its challenging issues. We focus on three cooperation scenarios, namely, cooperation to improve channel reliability through spatial diversity, cooperation to improve throughput through resource aggregation, and cooperation to achieve seamless service provision. Challenging issues which arise at different layers of the network protocol stack are discussed, with an emphasis on the medium access control, network, and transport layers. We also present some future research directions in this area.