Design of a Hard Real-Time Guarantee Scheme for Dual Ad Hoc Mode IEEE 802.11 WLANs

摘要

This paper proposes and analyzes a message scheduling scheme and corresponding capacity allocation method for the distributed hard real-time communication on dual Wireless LANs. By making the superframe of one network precede that of the other by half, the dual network architecture can minimize the effect of deferred beacon and reduce the worst case waiting time by half. The effect of deferred beacon is formalized and then directly considered to decide polling schedule and capacity vector. Simulation results executed via ns-2 show that the proposed scheme improves the schedulability by 36 % for real-time messages and allocates 9 % more bandwidth to non-real-time messages by enhancing achievable throughput for the given stream sets, compared with the network whose bandwidth is just doubled.