Dependability enhancement for IEEE 802.11 wireless LAN with redundancy techniques
Dongyan Chen, Shelly Garg, Chandra M. R. Kintala, Kishor Shridharbhai Trivedi · 2004
The presence of physical obstacles and radio interfer-ence results in the so called “shadow regions ” in wireless networks. When a mobile station roams into a shadow re-gion, it loses its network connectivity. In cellular networks, in order to minimize the connection unreliability, careful cell planning is required to prevent the occurrance of the shadow regions in the first place. In 802.11b/g wireless LANs, however, due to the limited frequency spectrum, it is not always possible to prevent a shadow region by adding another cell at a different frequency. Our contribution in this paper is to propose the alternate approach of tolerating the existence of “shadow regions ” as opposed to prevention in order to enhance the connection dependability. A redundant access point (AP) is placed in