Performance Characterization of CSMA/CA Adapted Multi-User MIMO Aware MAC in WLANs

To realize the multi-user Multiple Input Multiple Output (MIMO) advantage over WLANs, it requires significant changes in the MAC protocol. Either the dominant MAC protocol Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) needs to be replaced by a novel multi-user MIMO aware MAC protocol or it should be upgraded into multi-user MIMO aware CSMA/CA. Nevertheless, the simplest approach would be upgrading the CSMA/CA. Simple modifications in the control packets format and/or the channel access mechanism can upgrade CSMA/CA into simple, yet practicable, multi-user MIMO aware MAC protocol. By utilizing convenient changes, several modification approaches can be provisioned for this purpose. Hence, it is important to understand their performance benefits and trade-offs.