Resourceful association control in wireless mobile environment

Abstract

A user in IEEE 802.11(Wi-Fi) system must associate to a particular Access Point (AP) to communicate through the Internet. According to the current association method which is based on Receive Signal Strength Index(RSSI), the user first identify its convenient APs and associate with the strongest AP, excluding the fact whether that AP is overloaded or not. In current scenario, the wireless network is increasingly being connected to a wired backbone. This allows the AP's out of band communication among them and leaves opportunities for improved protocol design. As users are not always uniformly distributed in real time networks, some AP's goes through heavy load and some sits idle. In this paper we have tried to modify the existing system by introducing a novel WLAN network architecture that consists of a Master AP, connected to a wired backbone network which will periodically gather information about different subordinate APs connected to it. The coverage of Master AP is much greater so that it can cover the entire area of all other subordinate APs. The Master AP sends the beacon packet which contains the RSSI and existing load of subordinate AP/ APs, if the user is in coverage area of those subordinate AP/APs. This paper mainly concentrated on how the existing load of different subordinate APs will be calculated in Master AP. The existing beacon format (based on RSSI) is modified so that it can also send the existing load with the RSSI field to mobile nodes which are in the coverage of subordinate AP/APs. As a result, the nodes can make a proper judgment on which AP to connect, not only based on RSSI but also by checking the existing load of that AP. In our results we have shown that our proposed scheme performs better than RSSI and Least load first in several scenarios.