Cooperative channel operation MAC protocol for WLAN based indoor cognitive radio network systems

In this paper, we propose a new indoor cognitive radio network architecture that operates over a separated lower data rate band (ISM), which is mainly used for the common control information transmission, and multiple high speed data channel bands (UHF) at the same time. For cooperative indoor CR network operations, we have defined four procedures: network entry, normal channel operation, interface change, and handover operation. To solve a new hidden node problem due to the introduction of the CR into the WLAN, an incumbent node sensing information exchange mechanism among neighbor indoor CR APs is proposed as well. Simulation results show that our proposed system is able to deal with dynamics of resource availability of UHF band using cognitive technology effectively while keeping the high data rate transmission for the WLAN networks successfully.