Efficient utilisation of extended bandwidth in 802.11ac with and without overlapping basic service sets

The channel bonding proposed in IEEE 802.11ac has the potential to multiply the data rate. However, the backward compatibility with legacy 802.11 stations (STAs) and the overlapping basic service set (OBSS) problem make the available frequency resource severely under-utilised. The downlink (DL) approach (where the access point (AP) uses the available non-primary channels to transmit DL data to other 802.11ac STAs) and the relay (RL) approach (where the AP instructs some 802.11ac OBSS STAs to use the available nonprimary channels to transmit uplink data to a pre-designated RL) are proposed to improve the performance of 802.11ac by efficiently using the under-utilised spectrum. The simulation results show that the proposed scheme can mitigate the OBSS problem and obtain significantly better performance than the current media access control (MAC) protocol in the 801.11ac draft. In addition, the proposed approaches can work seamlessly with the 802.11ac protocol.