Efficient channel access scheme for multiuser parallel transmission under channel bonding in IEEE 802.11ac

Channel bonding proposed in IEEE 802.11ac has the potential to multiply the physical data rate with wider bandwidths. However, the backward compatibility with legacy 802.11 devices makes the available frequency resource severely underutilised. Furthermore, the design that allocates the entire extended bandwidth to a single user is very inefficient when the frame size is very small. In this study, the authors propose a novel channel access scheme, which has successfully mitigated these two problems by scheduling multiuser parallel transmission in both downlink and uplink. Simulation results show that the proposed scheme can improve the spectral efficiency of 801.11ac dramatically. In addition, same as the scheme in the 802.11ac draft, the proposed scheme guarantees the backward compatibility with legacy 802.11 devices, remains distributed and contention based and has the capability to multiply the physical data rates for 802.11ac devices.