Advanced Handoff Mechanism for Delay Sensitive Applications in IEEE 802.11 Wireless LAN

When a Mobile Host (MH) moves out of the range of its current Basic Service Set (BSS), a request for handoff procedure will occur and then some delay associated with the handoff procedure, handoff delay, takes place. However, for the emerging multimedia streaming applications, delay sensitive applications, attention should be paid to the amount of this delay. In order to a fuller understanding of this issue, the handoff procedure is efficiently conducted by considering Quality of Service (QoS) requirements of the applications, particularly delay constraints. Thus, in this paper, we propose an advanced handoff mechanism, which is able to reduce the delay of discovering the candidate set as the next Access Points (APs), where this phase of the handoff procedure has been shown as the dominating factor of the total handoff delay. The simulations results show the effectiveness of our proposed mechanism in terms of the reduction of the total handoff delay, compared to the typical mechanism, while maintaining a satisfactory Received Signal Strength (RSS) to the applications.