Location sensing in enhanced IEEE 802.11e WLANs

Wireless local area networks (WLAN) represent one of the most important technological improvements in recent years. How to develop the location-aware applications for WLAN users, especially in an indoor environment is a challenging problem. Location sensing is a key technology to support location-aware applications. In this paper, we propose a location sensing technique for IEEE 802.11e supported WLANs, which doesn´t require any modification on MSs (Mobil Stations), and also very easy to deploy over the existing IEEE 802. 11e WLANs. Location sensors (reference tags) are introduced into the network and an enhanced medium access scheme based on IEEE 802.11e is designed correspondingly for accommodating and controlling the communication between the location sensors and the access points (AP), so that minimum amount of resource will be taken in the network for supporting the location sensing function and the quality of service (QoS) of other applications can still be controlled. It is shown in OPNET™ simulation results that by applying the Euclidean distance positioning algorithm, the overall MS positioning accuracy in the enhanced IEEE 802.11e WLANs can achieve 46.84% probability within 5 meters´ estimated error distance.