NDIS-based virtual polling algorithm of IEEE 802.11b for guaranteeing the real-time requirements

This paper focuses on the feasibility of IEEE 802.11b wireless LAN for real-time wireless industrial network. In general, it has been known that IEEE 802.11b is not suitable for industrial networking because its medium access control method is the contention-based CSMA/CA (carrier sensing multiple access with collision avoidance) that exhibits unstable performance under heavy traffic and unbounded delay distribution. As an attempt to circumvent the probabilistic nature, this paper presents an enhanced four-layer architecture using the network driver interface specification (NDIS) and a virtual polling algorithm. Also, the enhanced four-layer architecture´s performance is compared with that of conventional IEEE 802.11b. Based on the experimental results, it is found that the enhanced four-layer architecture for IEEE 802.11b is a very promising alternative for wireless industrial networking.