Cooperative transmission for random access wireless networks

Abstract

We propose a new media access protocol for wireless networks, that through 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 relays, bounce off the signal 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 spatial diversity introduced via the cooperative relaying enables us to effectively deal with the wireless channel without any bandwidth expansion or additional antenna hardware. The proposed scheme offers the benefits of ALOHA systems in the sense that all nodes share access to media resources efficiently and without extra scheduling overhead, and enables efficient use of network power.