Providing handover with guaranteed QoS for realtime multimedia service such as VoIP, video/audio streaming, and video conferencing in wireless LAN is a challenging task. In this paper, we present a context-aware mobility management mechanism in wireless LAN, which can provide fast handover with guaranteed QoS for real-time multimedia service. To this end, the scanning period and the number of channels per scanning for handover are dynamically adapted to application context, so that both the degradation of application service quality and energy consumption are minimized simultaneously. The performance of the proposed mechanism is verified by the simulation. The simulation results show that the proposed mechanism is useful for the personalized network which is comprised of wireless LANs.

It is a challenging task to provide handover with guaranteed QoS for real-time multimedia service such as VoIP, video/audio streaming, and video conferencing in wireless LAN. This paper is aimed at presenting efficient layer 2 handover mechanism in wireless LAN, which can provide fast handover with guaranteed QoS for real-time multimedia service. In order to meet the above objective, the scanning period and the number of channels per scanning for handover are dynamically adapted to the types of applications and wireless networking environment, so that both the degradation of application service quality and signaling overhead are minimized simultaneously. We simulate proposed mechanism to verify the performance. The simulation results show that the proposed mechanism avoid service quality degradation and provide session connectivity.

Most previous research on MPLS/GMPLS recovery management has focused on efficient routing or signaling methods from single failures. However, multiple simultaneous failures may occur in large-scale complex virtual paths of MPLS/GMPLS networks. In this paper, we present a dynamic MPLS/GMPLS path management strategy in which the path recovery mechanism can rapidly find an optimal backup path which satisfies the resilience constraints under multiple link failure occurrences. We derived the conditions to test the existence of resilience-guaranteed backup path, and developed a decomposition theorem and backup path construction algorithm for the fast restoration of resilience-guaranteed backup paths, for the primary path with an arbitrary configuration. Finally, simulation results are presented to evaluate the performance of the proposed approach.

Recent advances in home network technology, combined with IP-based home appliances such as IPTV, can provide high-quality IP-based video conferencing service at relatively low cost. This paper presents SIP-based management architecture for large-scale home conferencing service using IPTV. In the proposed architecture, we extended the protocol stack of IPTV for the support of SIP-based signaling, and applied IPTV to large-scale home conferencing. High scalability of the proposed architecture is achieved by coordinated distributed conference control and media processing. The signaling procedures for the integrated control of IPTV have been designed in detail for SIP-based conferencing service. The performance of the proposed system has been evaluated by simulation. The simulation results show that the proposed architecture greatly improves scalability 1 .

Recent advances in broadband communication and computing technology have accelerated the proliferation of Internet protocol-based multimedia conferencing services in large-scale enterprises. Most of the research on session initial protocol (SIP)-based multimedia conferencing, however, has been limited in scalability due to the centralized management of conference control by a single server. In order to overcome this limitation, we have designed policy-based distributed management architecture for a large-scale enterprise conferencing service by extending the Internet Engineering Task Force's (IETF's) approach. The salient feature of the proposed management architecture is that in addition to the distribution of media processing, both participant membership control and authorization functions are dynamically distributed in accordance with the management policy in order to improve scalability. In order to implement these distributed management functions, we have extended both SIP and conference policy control protocols of the IETF. We also show the procedures for the distributed conference management using the extended SIP signaling methods. Finally, we have evaluated by simulation the performances of the proposed architecture in comparison with the centralized architecture of the IETF. The simulation results show that the proposed architecture greatly improves scalability.