Eliminating Handoff Latencies in 802.11 WLANs Using Multiple Radios: Applications, Experience, and Evaluation
Deployment of Voice-over IP (VoIP) and other real-time streaming applications has been somewhat limited in wireless LANs today, partially because of the high handoff latencies experienced by mobile users. The goal in this work is to eliminate handoff latency by exploiting the potential of multiple radios in WLAN devices. The proposed approach, called MultiScan, is implemented entirely on the client-side, and, unlike prior work, MultiScan requires neither changing the Access Points (APs), nor having knowledge of wireless network topology. MultiScan nodes rely on using their (potentially idle) second wireless interface to opportunistically scan and pre-associate with alternate APs and eventually seamlessly handoff ongoing connections.