In current distributed systems, the notion of mobility is emerging in many forms and applications.

This paper describes current and proposed protocols for mobility management for public land mobile network (PLMN)-based networks, mobile Internet protocol (IP), wireless asynchronous transfer mode (ATM), and satellite networks. The integration of these networks will be discussed in the context of the next evolutionary step of wireless communication networks. First, a review is provided of location management algorithms for personal communication systems (PCS) implemented over a PLMN network. The latest protocol changes for location registration and handoff are investigated for Mobile IP, followed by a discussion of proposed protocols for wireless ATM and satellite networks. Finally, an outline of open problems to be addressed by the next generation of wireless network service is discussed

This paper describes current and proposed protocols for mobility management for PLMNbased networks, Mobile IP, Wireless ATM, and Satellite networks. The integration of these networks will be discussed in the context of the next evolutionary step of wireless communication networks. First, a review is provided of location management algorithms for PCS implemented over a PLMN network. The latest protocol changes for location registration and handoff are investigated for Mobile IP, followed by a discussion of proposed protocols for Wireless ATM and Satellite networks. Finally, an outline of open problems to be addresses by the next generation of wireless network service is discussed. Key Words: Mobility Management, Location Management, Paging, Handoff, IMT 2000, PLMN, PCS, PSTN, Mobile IP, Wireless ATM, Satellite This work was supported by DoD, National Security Agency under grant number MDA904-97-C-1105-0003. 1 Introduction The commercial proliferation of cellular voice and limited ...

In this paper, we propose an algorithm for optimizing the route of a connection that becomes suboptimal due to operations such as handoffs and location-based reroutes, for mobile ATM (asynchronous transfer mode) networks based on the PNNI (private network-to-network interface) standard. This algorithm uses hierarchical route information of the connection and summarized topology and loading information of the network to determine a "crossover node" such that adjusting the connection from that crossover node results in an optimally routed connection. We then apply this algorithm to the mobile location management problem. Location management schemes have been proposed in which an incoming call to a mobile is first routed to its home switch (based on summarized reachability data) and then rerouted to the mobile's current location. If we consider such rerouting a "first phase" of mobile connection setup, a "second phase" is required to optimize the paths of such rerouted connections. Such an approach is considered a two-phase mobile location/connection setup scheme. Alternatively, an incoming call to a mobile can be first routed to its home switch based on summarized reachability data, and then "cranked back" to an optimal crossover node before rerouting the connection to the mobile's current location. Such a scheme is a one-phase mobile location/connection setup scheme since it directly results in an optimal path. A comparative performance analysis of the oneand two-phase connection setup schemes is presented. Measures of comparison are call setup delay and the amount of network resources allocated to a connection. The maximum call setup delay (worst case call setup delay) is lower in the two-phase scheme, but the average call setup delay is lower in the one-phase scheme. T...

One of the issues in mobility management is to support handoff. When the mobile user moves from one location to another, the network should ensure that all ongoing connections are rerouted to another access point in a seamless manner. Part of our work focuses on connection rerouting due to inter-switch handoff in wireless ATM networks. Although fast local connection rerouting minimizes handoff delay, the end-to-end path after rerouting may become "suboptimal", which implies an inefficient use of network resources. Path optimization may be necessary afterwards. Our research begins with the following question: "How often should path optimization be performed?" To this end, we propose three path optimization schemes (namely: exponential, periodic, and Bernoulli), which are simple to implement. Closed-form solutions of the optimal operating point are derived for each scheme. We further investigate this problem and propose a stochastic model to determine the optimal time to initiate path o...

Abstract – Location management is important to effectively keep track of mobile terminals with reduced signal flows and database queries. Even though dynamic location management strategies are known to show good performance, we in this paper consider the static location management strategy which is easy to implement. A system with single home location register and pointer forwarding is assumed. A mobile terminal is assumed to have memory to store the IDs of visitor location registers (VLRs) each of which has the forwarding pointer to identify its current location. To obtain the registration point which minimizes the database access and signaling cost from the current time to the time of power-off probabilistic dynamic programming formulation is presented. A Selective Pointer Forwarding scheme is proposed which is based on one-step dynamic programming. The proposed location update scheme determines the least cost temporary VLR which point forwards the latest location of the mobile. The computational results show that the proposed scheme outperforms IS-41, pure Pointer Forwarding, and One-step Pointer Forwarding at the expense of small storage and a few computations at the mobile terminals.

This draft describes a specific problem encountered when using RSVP (Resource Reservation Protocol) over optimised routes in MIPv6 (Mobile IP Version 6). The address translation in the MIP's binding cache creates a mismatch between the flow-id of the packets sent from correspondent node to mobile node and the flow-id signalled by RSVP. We discuss several solutions to this problem: (1) By modifying RSVP at mobile and correspondent nodes to become aware of MIPv6 addressing, we provide a simple repair that allows RSVP flows to be established between the fixed network and mobiles; (2a) By adding optional objects to RSVP messages, a performance enhancement is proposed to make handovers smooth and seamless; (2b) A different technique with the same goal is called flow extension and it provides flows with fixed flow-ids from the correspondent node into the wireless access network at the expense of forwarding traffic inside the access network, whenever the mobile node moves. We conclude that ...

This draft describes a specific problem encountered when using RSVP (Resource Reservation Protocol) over optimised routes in MIPv6 (Mobile IP Version 6). The address translation in the MIP's binding cache creates a mismatch between the flow-id of the packets sent from correspondent node to mobile node and the flow-id signalled by RSVP. We discuss several solutions to this problem: (1) By modifying RSVP at mobile and correspondent nodes to become aware of MIPv6 addressing, we provide a simple repair that allows RSVP flows to be established between the fixed network and mobiles; (2a) By adding optional objects to RSVP messages, a performance enhancement is proposed to make handovers smooth and seamless; (2b) A different technique with the same goal is called flow extension and it provides flows with fixed flow-ids from the correspondent node into the wireless access network at the expense of forwarding traffic inside the access network, whenever the mobile node moves. We conclude that ...

Location management is one of the most important aspects in the realization of mobility in wireless networks. Following developments of ATM (Asynchronous Transfer Mode) technology, more core networks are becoming ATM-based. Therefore research into location management schemes for wireless networks with ATM cores is attracting more attention. In recent years several location management schemes have been proposed for classical wireless ATM networks, which have end-to-end native ATM connections. Most of these proposals assume that a wireless ATM network is built using End-user Mobile ATM Switches (EMAS). However, current ATM networks only consist of normal ATM switches that are not mobility enabled. In this paper, we present a location management scheme for hybrid wireless ATM networks, which have an ATM based core and IP based wireless tails. From a performance analysis, we show that the proposed scheme has better cost performance than the conventional GSM/IS-41 based location management scheme.