Real-Time Support on IEEE 802.11 Wireless Ad-Hoc Networks: Reality vs. Theory

Mikyung KANG  Dong-In KANG  Jinwoo SUH 

Publication
IEICE TRANSACTIONS on Communications  Vol.E92-B  No.3  pp.737-744
Publication Date: 2009/03/01
Online ISSN: 1745-1345
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Ad Hoc and Mesh Networking for Next Generation Access Systems)
Category: 
Keyword: 
ad-hoc networks,  real-time scheduling scheme,  real bandwidth,  Wi-Fi,  IEEE 802.11 MAC, 

Full Text: PDF(1.1MB)

Summary: 
The usable throughput of an IEEE 802.11 system for an application is much less than the raw bandwidth. Although 802.11b has a theoretical maximum of 11 Mbps, more than half of the bandwidth is consumed by overhead leaving at most 5 Mbps of usable bandwidth. Considering this characteristic, this paper proposes and analyzes a real-time distributed scheduling scheme based on the existing IEEE 802.11 wireless ad-hoc networks, using USC/ISI's Power Aware Sensing Tracking and Analysis (PASTA) hardware platform. We compared the distributed real-time scheduling scheme with the real-time polling scheme to meet deadline, and compared a measured real bandwidth with a theoretical result. The theoretical and experimental results show that the distributed scheduling scheme can guarantee real-time traffic and enhances the performance up to 74% compared with polling scheme.