Efficient 802.11 Hand-off through Load Aware Channel Probing

In 802. 11 NLaN, Access Point (AP) and its associated mobile stations (MSs) forms a basic service set BSS. In such network a continuous service coverage with an acceptable throughput is highly desirable while the $\mathrm {M}\mathrm {S}s$ roam around the network. Limited size of WLAN BSSs with increased deployment results more transmission overlapping and frequent hand-offs. This significantly increases the delay. On the other hand, selection of appropriate target AP is another major issue as it crucially determines the obtained throughput. In this paper we propose a load aware channel probing (LACP) towards an efficient hand-off addressing these two issues simultaneously. Based on the accumulated load on the $\mathrm {A}\mathrm {P}s$ in range the proposed approach efficiently reduces the probe-count during hand-off by avoiding unnecessary channel probing and selects the appropriate destination AP. The objective is to reduce the hand-off delay and to enhance the obtained throughput. We first present a motivational example then develop an elegant algorithm. The novelty of the idea is established through extensive simulations. We have shown that the performance of the proposed approach is highly comparable to the other approaches from existing literature.