WSN02-6: RPMA: Receiver Prohibition Multiple Access for Collision-controlled Wireless Mesh Networks and Mobile Ad Hoc Networks

There are two main problems with the current paradigm for medium access control (MAC) in multihop wireless LANs, especially when quality of service (QoS) is required. The first is that it employs mandatory carrier sensing to avoid collisions, but such a transmitter- centric paradigm is vulnerable to the hidden terminal problem, and is inefficient in terms of spatial reuse especially when power controlled. The second is that it relies on RTS/CTS dialogues to mitigate the hidden terminal problem, but RTS/CTS messages are collision-prone and thus unreliable/ineffective for this purpose. In this paper, we propose a MAC scheme based on the receiver-centric paradigm called receiver prohibition multiple access (RPMA) with mixed-band busytone (MB) that can resolve the aforementioned problems. Advantages of RPMA-based protocols over IEEE 802.11/11e include collision freedom/controllability, higher energy efficiency, as well as being not vulnerable to collisions of RTS/CTS messages. Advantages of MB-based protocols over previous busytone protocols include the capability for interference prevention against CSMA or frequency-hopping devices that are not aware of busytone or MB. A resultant RPMA/MB protocol may be more complex and require additional hardware as compared to IEEE 802.11/11e, but it is expected to become feasible and competitive in cost with the advance of VLSI technology. Moreover, it can achieve the aforementioned advantages with backward compatibility to IEEE 802.11/11e, in the presence of other CSMA or frequency- hopping appliances.