Design and performance of an enhanced IEEE802.11 MAC protocol for ad hoc networks

Ad hoc networks will be applied for coverage extension for existing wireless networks. Especially for upcoming WLAN hotspots this is a viable option to decrease installation costs. Unfortunately WLAN systems based on the IEEE802.11 standard lead to poor performance for such multihop networks. Therefore, we introduce a new MAC protocol for IEEE802.11 that needs only marginal changes in the standard, but offers high connectivity and high throughput values and advocates the use of a common signaling channel for the task of assigning channels among wireless terminals in an IEEE802.11a based ad hoc network is introduced. Our approach separates the RTS/CTS signaling from the data exchange. By means of this separation all wireless nodes are forced to listen to one domain, on which the channel assignment process takes place. After a four way RTS/CTS handshake, data transmission occurs on a dedicated channel. Due to this new scheme collisions are reduced. The common signaling channel helps also find the appropriate node for routing and achieves a high connectivity level among wireless nodes.