Distributed collision-controlled MAC protocols without dialogues for mobile multihop networking and WLANS with crowded APs/MPs
Chi‐Hsiang Yeh · 2006
In this paper, we propose the carrier sense multiple access with binary countdown (CSMA/BC) scheme for medium access control (MAC) in WLANs with crowded access points (APs) or mesh points (MPs), as well as mobile multihop networks such as ad hoc networks and multi- hop WLANs. CSMA/BC is a special case of the multiple access collision prevention (MACP) paradigm with novel dual prohibition mechanism with sender-oriented competition, where RTS/CTS-type dialogues are not em- ployed. Contrast to dual prohibition multiple access (DPMA), which uti- lizes dual competition, CSMA/BC-based protocols do not require prior ar- rangements between the sender-receiver pair for simultaneous competition. Important advantages of CSMA/BC over the CSMA/IC scheme include power control capability, resolution to the prohibition-range exposed termi- nal problem, interference awareness, and feasible prohibition ranges. Ad- vantages of CSMA/BC over IEEE 802.11/11e-type protocols include colli- sion freedom/controllability, strong differentiation capability, interference awareness, better spatial reuse, as well as being not vulnerable to colli- sions of RTS/CTS messages. Also, suitably-designed CSMA/BC protocols only require single transceiver per node and can be made backwards com- patible to IEEE 802.11/11e, which are critical advantages over previous busytone-based MAC protocols. We propose various CSMA/BC extensions that have their respective advantages, including single-channel CSMA/BC. When synchronization is feasible, CSMA/BC protocols and their variants appear to be strong candidates for multiple access in multihop networks as well as conventional single-hop WLANs but with crowded APs.