Architecture and Scheduling Algorithm for a Multi-Channel Wireless Infrastructure Network with Diversity Management Layer

802.11a protocol provides 12 non-overlapping frequency bands, but the common wireless LAN usually only uses one channel. In this paper we propose a "super" Wi-Fi network architecture, which uses the multiple non-overlapping channels simultaneously to improve the total network band-width with minimum changes to the existing devices. To be compliable to the existing Wi-Fi network hardware and 802.11 protocols, a software based diversity management layer (DML) is introduced above the MAC layer to control and support the multi-channel. To minimize the total transmission time, a central scheduler is needed to decide how to allocate the stations’ requests into several simultaneous channels. Since the scheduling time is limited, we develop a Lagrangian relaxation based scheduling algorithm for this scheduling problem. The simulation results show that the algorithm is faster than Cplex and provides good sub-optimal solutions. We also propose a backup-resource method to further reduce the scheduling time when the number of stations in the system increases.