A new wireless network medium access protocol based on cooperation

In this paper, we propose a new media access protocol for wireless networks, that due to its ability to resolve collisions can achieve high throughput. We view the wireless network as a spatially distributed antenna with antenna elements linked via the wireless channel. When there is a collision, the collided packets are saved in a buffer. In the slots following the collision, a set of nodes designated as nonregenerative relays retransmit the signal that they received during the collision slot. By processing the originally collided packets and the signals forwarded by the relays, the destination node can recover the original packets. The proposed scheme maintains the benefits of ALOHA systems, i.e., needs no scheduling overhead and is suitable for bursty sources, such as multimedia sources. It also offers the benefits of multi-antenna systems, i.e., spatial diversity while employing a single transmit/receive antenna at each node. Spatial diversity enables it to be robust to the wireless channel. The proposed approach achieves higher throughput and energy savings than existing techniques that allow for multiple packet reception.