International Journal of Communication Systems

In this work, we optimize the Patching-based multicast for video-on-demand (VoD) in wireless mesh networks by addressing two critical problems, namely, the Minimum Cost Multicast Tree (MCMT) problem and the Maximum Benefit Multicast Group (MBMG) problem at the network layer and the application layer respectively. We prove the MCMT problem is NP-hard and propose a fast greedy algorithm to accommodate the real time feature of the VoD application. We solve the MBMG problem by minimizing the communication of a Patching group in the entire wireless mesh networks. Copyright © 2009 John Wiley & Sons, Ltd.

In this paper, we introduce the Virtual Router abstraction to maintain communication links in a high mobility environment. A virtual router is a dynamically-created logical router that is associated with a particular geographical area and its routing functionality is provided by the physical nodes (i.e. mobile devices) currently within the geographical region served by the virtual router. In this environment, data packets are transmitted from a source node to a destination node over a series of virtual routers. Copyright © 2009 John Wiley & Sons, Ltd.

In this paper, we propose an extensible RFID management framework called SIP-based RFID management system (SRMS), which can support various RFID applications. To illustrate the extensibility of SRMS, we demonstrate two representative application scenarios: location management services and mobile RFID services. Compared with the existing RFID management frameworks, SRMS has advantages of service extensibility and reusability. Copyright © 2009 John Wiley & Sons, Ltd.

This paper develops a new analytical model to investigate the Quality-of-Service (QoS) performance metrics in Wireless Mesh Networks (WMNs) interconnecting multiple Wireless Local Area Networks (WLANs). The proposed model is then used to obtain the maximum achievable throughput, which is a key performance metric in wireless networks. Moreover, we utilize the model to evaluate the impact of communication locality on the network performance and investigate its effects on the optimization of integrated WLANs and multi-hop mesh networks. Copyright © 2009 John Wiley & Sons, Ltd.

This paper proposes an inter-domain handover scheme for Proxy Mobile IPv6 (PMIPv6) with a new network entity, called intermediate-mobile access gateway (iMAG) which is connected to both the home and the foreign domains. The proposed scheme is a proactive handover approach that performs the inter-domain L3 handover in advance before the inter-domain L2 handover while the Mobile Node (MN) is still connected to the iMAG in the home domain. Therefore, the proposed scheme enables the inter-domain handover latency to reduce as low as the intra-domain handover latency. Copyright © 2009 John Wiley & Sons, Ltd.

This paper proposes Access Router Information Protocol (ARIP), which performs a candidate access router discovery and a radio access network discovery in one protocol suite, to provide an efficient handover framework for MIPv6 and FMIPv6. ARIP is designed to cope with heterogeneous networks as well as homogeneous networks and to be closely coupled with FMIPv6 to provide the efficient handover performance. The performance evaluation of MIPv6, FMIPv6, and FMIPv6 with ARIP is performed in an actual network environment. Copyright © 2009 John Wiley & Sons, Ltd.

A set of proxy-assisted transmission schemes are proposed for layered-video streaming by integrating the proxy caching with reactive transmission schemes, peer-to-peer mesh networks and base station multicast capability. The optimal proxy prefix cache allocation is calculated for each transmission scheme to identify the cache layer and cache length of each video to minimize the aggregate transmission cost. Copyright © 2009 John Wiley & Sons, Ltd.

This paper investigates and develops a power-efficient node placement scheme (PENPS) in linear wireless multimedia sensor networks, which can minimize the average energy consumption per node and maximize the network lifetime. The analysis of PENPS and the comparison of performance with the equal-spaced placement scheme (EPS) show that PENPS scheme can significantly decrease the average energy consumption per node, which can prolong the lifetime of sensor nodes and sensor networks effectively. Copyright © 2010 John Wiley & Sons, Ltd.

This paper proposes two user authentication protocols for ubiquitous wireless sensor networks that are variations of a recent strong-password-based solution. The main aims of these schemes are to provide mutual authentication and user anonymity. They use one-way hash functions and XOR operations to achieve lower computational and communication overheads. In this paper, security evaluation of the proposed protocols was conducted. Comparing with the existing representative schemes, the proposed schemes are more robust and provide better security. Copyright © 2009 John Wiley & Sons, Ltd.

A decentralized clustering algorithm uses timers and a recursively updated probability to select nodes with more residual energy to become Cluster Head (CH) nodes and organize other nodes in the form of clusters over slotted time intervals. Each node initializes its probability of becoming a CH node using the distribution of Network Residual Energy (NRE) defined in its neighborhood area, which is proven to approximate the Gaussian distribution. The new clustering algorithm selects energy-rich CH nodes that reside in the center of every cluster area, and thus significantly prolongs the network lifetime. Copyright © 2010 John Wiley & Sons, Ltd.

In this paper we propose a CGA-based Authentication Route Optimization scheme (CARO) in mobile hotspots with heterogeneous networks. The proposed CARO protocol does not require the considerable computing costs to the MNN or a Correspondent Node (CN) and is more secure and efficient than the previous protocols. Copyright © 2010 John Wiley & Sons, Ltd.

This article proposes a mobile-initiated network-executed (MINE) SIP-based handover mechanism in IP multimedia subsystem over heterogeneous accesses. Handover decision is fully made by the mobile host (MH). When the MH decides to initiate a handover, it will send a SIP Publish message to trigger the mobility server (MS) to carry out the handover execution. With the network-executed design of the MINE, the MS can perform third-party registration for security re-association and third-party call control for session re-establishment in parallel. Copyright © 2010 John Wiley & Sons, Ltd.

In this paper, we present a methodology for the definition and application of profiles for mobile devices. The methodology, which follows appropriate recommendations by international institutes, is used to present the definition of profiles capable of supporting Personal Networking capabilities, while it is accompanied by the development of a mobile device based socializing service (‘Icebreaker’). Copyright © 2010 John Wiley & Sons, Ltd.