This paper presents a mobile tracking scheme that exploits the predictability of user mobility patterns in wireless PCS networks. Instead of the constant velocity fluid-flow or the random-walk mobility model, a more realistic Gauss-Markov model is introduced, where a mobile's velocity is correlated in time to a various degree. Based on the Gauss-Markov model, a mobile's future location is predicted by the network based on the information gathered from the mobile's last report of location and velocity. When a call is made, the network pages the destination mobile at and around the predicted location of the mobile and in the order of descending probability until the mobile is found. A mobile shares the same prediction information with the network and reports its new location whenever it reaches some threshold distance away from the predicted location. We describe an analytical framework to evaluate the cost of mobility management for the proposed predictive distance-based scheme. We then compare this cost against that of the regular, non-predictive distance-based scheme, which is obtained through simulations. Performance advantage of the proposed scheme is demonstrated under various mobility and call patterns, update cost, page cost, and frequencies of mobile location inspections.

https://www.comm.toronto.edu/%7Eliang/publications/Infocom99.pdf

Predictive distance-based mobility management for PCS networks

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.

http://www.cs.tcd.ie/~htewari/papers/ieee99.pdf

Mobility management in next-generation wireless systems

A mathematical formulation is developed for systematic tracking of the random movement of a mobile station in a cellular environment. It incorporates mobility parameters under the most generalized conditions, so that the model can be tailored to be applicable in most cellular environments. This mobility model is used to characterize different mobility-related traffic parameters in cellular systems. These include the distribution of the cell residence time of both new and handover calls, channel holding time, and the average number of handovers. It is shown that the cell residence time can be described by the generalized gamma distribution. It is also shown that the negative exponential distribution is a good approximation for describing the channel holding time.

/pdf/user-mobility-modeling-and-characterization-of-mobility-48lyhrywlr.pdf

User mobility modeling and characterization of mobility patterns

This paper introduces a mobility tracking mechanism that combines a movement-based location update policy with a selective paging scheme. Movement-based location update is selected for its simplicity. It does not require each mobile terminal to store information about the arrangement and the distance relationship of all cells. In fact, each mobile terminal only keeps a counter of the number of cells visited. A location update is performed when this counter exceeds a predefined threshold value. This scheme allows the dynamic selection of the movement threshold on a per-user basis. This is desirable as different users may have very different mobility patterns. Selective paging reduces the cost for locating a mobile terminal in the expense of an increase in the paging delay. We propose a selective paging scheme which significantly decreases the location tracking cost under a small increase in the allowable paging delay. We introduce an analytical model for the proposed location tracking mechanism which captures the mobility and the incoming call arrival patterns of each mobile terminal. Analytical results are provided to demonstrate the cost-effectiveness of the proposed scheme under various parameters.

https://ir.nctu.edu.tw:443/bitstream/11536/1122/1/A1996VE43600013.pdf

Movement-based location update and selective paging for PCS networks

Handoff is an essential element of cellular communications. Efficient handoff algorithms are a cost-effective way of enhancing the capacity and QoS of cellular systems. This article presents different aspects of handoff and discusses handoff related features of cellular systems. Several system deployment scenarios that dictate specific handoff requirements are illustrated. An account of handoff-related resource management tasks of cellular systems is given. Implementation of the handoff process is explained. Several mechanisms for evaluation of handoff-related system performance are described.

http://cs.tcd.ie/hitesh.tewari/papers/tripathi98.pdf

Handoff in cellular systems

A dynamic location area scheme is proposed for cellular networks, in which the size of location areas of a user is dynamically determined according to its current incoming call arrival rate and mobility as the signaling traffic in radio channels reaches the minimum. The protocols and algorithms of the proposed scheme are presented, and its performance is compared with that of the conventional system.

Dynamic location area management and performance analysis

A correct boundary condition of terminal mobility, called the biased sampling formula, is derived. The biased sampling formula is used in determining the speeds of cell-crossing terminals. Based on this formula, a different analysis approach with low computational complexity and high accuracy is proposed.

Priority handoff analysis

Handoff will become an increasingly important issue in mobile phone communications, especially in microcellular systems with the increase of handoff traffic between cells. Many approaches have been proposed for handoff analysis. In a previous analysis, it was assumed that the probability density function (pdf) of the speeds of cell-crossing terminals is the same as the pdf of the speeds of all terminals. In contrast to this assumption, we argue that both pdf's are unequal. The pdf of the speeds of cell-crossing terminals is given by a “biased sampling” formula. This boundary condition is used in our study and improves the accuracy of performance measures in handoff analysis. In previous work, a priority handoff system which has dedicated channels for handoff calls and uses a blocked call cleared (BCC) policy has been analyzed. In this paper, we use a different approach in performance analysis. The proposed approach has low computational complexity and high accuracy.

H. Xie

Papers

Dynamic location area management and performance analysis

Priority handoff analysis

Priority handoff analysis