Supporting mobile Internet multimedia applications requires more than just the ability to maintain connectivity across subnet changes. We describe how the Session Initiation Protocol (SIP) can help provide terminal, personal, session and service mobility to applications ranging from Internet telephony to presence and instant messaging. We also briefly discuss application-layer mobility for streaming multimedia applications initiated by RTSP.

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Application-layer mobility using SIP

Next-generation wireless systems are envisioned to have an IP-based infrastructure with the support of heterogeneous access technologies. One of the research challenges for next generation all-IP-based wireless systems is the design of intelligent mobility management techniques that take advantage of IP-based technologies to achieve global roaming among various access technologies. Next-generation wireless systems call for the integration and interoperation of mobility management techniques in heterogeneous networks. In this article the current state of the art for mobility management in next-generation all-IP-based wireless systems is presented. The previously proposed solutions based on different layers are reviewed, and their qualitative comparisons are given. A new wireless network architecture for mobility management is introduced, and related open research issues are discussed in detail.

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A survey of mobility management in next-generation all-IP-based wireless systems

Mobile IP is the current standard for supporting macromobility of mobile hosts. However, in the case of micromobility support, there are several competing proposals. We present the design, implementation and performance evaluation of HAWAII (handoff-aware wireless access Internet infrastructure), a domain-based approach for supporting mobility. HAWAII uses specialized path setup schemes which install host-based forwarding entries in specific routers to support intra-domain micromobility. These path setup schemes deliver excellent performance by reducing mobility related disruption to user applications. Also, mobile hosts retain their network address while moving within the domain, simplifying quality-of-service (QoS) support. Furthermore, reliability is achieved through maintaining soft-state forwarding entries for the mobile hosts and leveraging fault detection mechanisms built in existing intra-domain routing protocols. HAWAII defaults to using Mobile IP for macromobility, thus providing a comprehensive solution for mobility support in wide-area wireless networks.

/pdf/hawaii-a-domain-based-approach-for-supporting-mobility-in-3g42k1k4sk.pdf

HAWAII: a domain-based approach for supporting mobility in wide-area wireless networks

/pdf/mobility-management-in-next-generation-all-ip-based-wireless-1oxeorxdms.pdf

Mobility Management in Next Generation All-IP Based Wireless Systems

Revolutionary drivers for 4G include a push toward universal wireless access and ubiquitous computing through seamless personal and terminal mobility. One of the major challenges for seamless mobility is the criterion of a vertical handoff protocol: a handoff protocol for users that move between different types of networks. Traditional operations for handoff detection policies, decision metrics, and radio link transfer are not able to adapt to dynamic handoff criteria or react to user inputs and changing network availabilities. Nor are they able to deliver context-aware services or ensure network interoperability. Thus, new techniques are needed to manage user mobility between different types of networks. This article presents a tutorial on the design and performance issues for vertical hand-off in an envisioned multinetwork fourth-generation environment. Various network architectures and technologies for 3G and beyond are described, including wireless LANs, cellular, satellite, and Mobile IP. Then the problem of vertical handoff is defined in the context of such a diverse network environment. Finally, research efforts to resolve the open problems are explored, including new techniques for dynamic handoff decision and detection algorithms and context-aware radio link transfer.

Vertical handoffs in fourth-generation multinetwork environments

Wireless access to Internet services will become typical, rather than the exception as it is today. Such a vision presents great demands on mobile networks. Mobile IP represents a simple and scalable global mobility solution but lacks the support for fast handoff control and paging found in cellular telephony networks. In contrast, second- and third-generation cellular systems offer seamless mobility support but are built on complex and costly connection-oriented networking infrastructure that lacks the inherent flexibility, robustness, and scalability found in IP networks. In this article we present cellular IP, a micro-mobility protocol that provides seamless mobility support in limited geographical areas. Cellular IP, which incorporates a number of important cellular system design principles such as paging in support of passive connectivity, is built on a foundation of IP forwarding, minimal signaling, and soft-state location management. We discuss the design, implementation, and evaluation of a cellular IP testbed developed at Columbia University over the past several years. Built on a simple, low-cost, plug-and-play systems paradigm, cellular IP software enables the construction of arbitrary-sized access networks scaling from picocellular to metropolitan area networks.

Design, implementation, and evaluation of cellular IP

A number of initiatives to add mobility to the Internet and packet data services to third generation cellular systems are being considered by emerging mobile service providers as possible candidate solutions for the delivery of IP data to mobile users. Both of these two candidates have a number of shortcomings, however. Mobile IP represents a simple and scalable global mobility solution but is not appropriate in support of fast and seamless handoff control. In contrast, third generation cellular systems offer smooth mobility support but are built on complex networking infrastructure that lacks the flexibility offered by IP-based solutions. In this paper we present an overview of cellular IP which represents a 'third way' combining the strengths of bath approaches without inheriting their weaknesses. Cellular IP combines the capability of cellular networks to provide smooth fast handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks.

An overview of cellular IP

In the context of the research in the IST project BRAIN, an in-depth study of the problem of IP mobility within the access network was performed. Mobility management was broken down to individual issues, which were separately analysed. Requirements, design goals, and recommendations for an ideal solution were proposed. Various existing proposals were considered against these requirements as a possible solution for the BRAIN access network. The outcome of this research activity was the proposal of a new IP mobility management protocol as a candidate solution for the BRAIN networks. This paper will present the functionalities of this BRAIN Candidate Mobility Protocol (BCMP). Furthermore the protocol was simulated, thus proving the correctness of its operation and its performance is evaluated through simulations. This paper will present qualitative and quantitative results of these simulations.

Evaluation of the BRAIN Candidate Mobility Management Protocol

The present invention relates to a session control unit (16) for use in a communication network (11 a) for providing wireless access to the Internet for mobile nodes (2). The communication network comprises one or several access routers (3) for wireless communication with mobile nodes and one or several anchor points (12 a) for routing data packets to and/or from the mobile nodes via the access routers. The session control unit is arranged to allocate a session identifier to a mobile node (2) requesting access to the network, select an anchor point (12 a) to route data packets to and/or from the mobile node, and communicate an IP-address associated with the selected anchor point to the access router communicating with the mobile node. The allocated session identifier is independent of the selected anchor point. The invention also relates to a method for providing session control to a communication network.

Arrangements and method in mobile internet communications systems

Neighbour discovery in communications networks is made possible by a node sending beacon packets which include information regarding the node. The beacon packets are sent at pseudo-random time and on pseudo-random frequencies.

Andras Valko

Papers

Design, implementation, and evaluation of cellular IP

An overview of cellular IP

Evaluation of the BRAIN Candidate Mobility Management Protocol

Arrangements and method in mobile internet communications systems

Neighbour discovery in a communications network