[Show abstract][Hide abstract] ABSTRACT: The Proxy Mobile IPv6 (PMIPv6) have been widely studied as a mobility management protocol to effectively use the limited wireless resources. Recently, there have been some researches to apply PMIPv6 to multicasting, which is core technology of Internet broadcast system. However, PMIPv6 based multicasting has a problem in that it shows the disconnection of services during the handover because it does not solve the packet loss problem during binding and group joining procedure when handover occurs. Hence, we propose a new multicasting scheme which provides the seamless multicast service in PMIPv6 networks. The proposed scheme achieves lower latency than the existing scheme because it combines binding and group joining procedure, also it does not cause the packet losses due to the buffering. We present the simulation results which show that the proposed scheme achieves the loss-free and low latency through the NS-2 simulation.
[Show abstract][Hide abstract] ABSTRACT: In this paper, we present a proxy mobile IP based layer-3 handover scheme for mobile WiMAX based wireless mesh networks. Mobile WiMAX provides two types of layer-3 handover schemes: MIP based handover and PMIP based handover. MIP based handover incures the long handover latency because mobile nodes generate a lot of handover messages in wireless area. On the other hand, PMIP based handover decreases the handover latency by reducing the number of handover messages, because a mobile node does not participate in handover procedure. However, conventional PMIP based handover still has latency overhead, because of message exchanges between PBU and PBA after completing the layer-2 handover. Hence, we propose a new layer-3 handover method that does not bring about packet losses while achieving lower handover latency than conventional layer-3 handover scheme. Simulation results show that the proposed scheme achieves loss-free and low handover latency during the layer-3 handover.
[Show abstract][Hide abstract] ABSTRACT: Wireless Broadband Internet (WiBro) system that will be the first commercial and nationwide service is the Korean Wireless Broadband service based on IEEE 802.16e standard. Unlike the mobile communication networks based on the existing cellular system, the core networks of this system consist of IP based packet switching network that will be ultimately deployed by IP version 6 (IPv6) depending on the All-IP trend of the network evolution. In such IPv6 based Mobile Broadband Wireless Access (MBWA) system, articulated handover (HO) support between network layer and MAC layer is one of the most critical factors. On this view point, we propose a fast HO mechanism for efficient IPv6-mobility support based on the MAC layer HO signaling of WiBro specification. Through the NS-2 simulation results, we also show that our proposed mechanism achieves loss-free packet delivery without being mixed up and unnecessary latency during HO.
[Show abstract][Hide abstract] ABSTRACT: Wireless mesh networks have been studied as the next generation technology to solve problems of conventional wireless networks. Particularly, mobile WiMAX based wireless mesh networks are noticed due to many advantages. In this paper, we propose a layer-2 handover scheme for mobile WiMAX based wireless mesh networks. A layer-2 handover scheme based on mobile WiMAX causes many handover failures over mobile WiMAX based wireless mesh networks because it does not consider the characteristics of wireless mesh networks. The proposed scheme does not bring about packet losses achieving lower handover latency than a conventional handover scheme. Simulation results show that the proposed scheme achieves loss-free and low handover latency during the layer-2 handover.