Inter-domain WLAN handover management for Multi-homed Mobile Node

This document discusses inter-domain WLAN handover management for multi-homed mobile node (MN) in order to maintain Voice over IP (VoIP) quality during handover (HO). Switching a communication path from one Access Point (AP) to another in inter-domain WLANs is a critical challenge for real-time applications such as VoIP because communication quality during HO is more likely to be deteriorated. To maintain VoIP quality during HO, we need to solve many problems. In particular, in bidirectional communication such as VoIP, an AP becomes a bottleneck with the increase of VoIP calls. As a result, packets queued in the AP buffer may experience a large queuing delay or packet losses due to increase in queue length or buffer overflow, thereby causing the degradation of VoIP quality for the MNs side. To avoid this degradation, MNs need to appropriately and autonomously execute HO in response to the changes in wireless network condition, i.e., the deterioration of wireless link quality and the congestion state at the AP. We then propose an HO management considering all of frame retries, AP queue length, and transmission rate at an MN for maintaining VoIP quality during HO.