An enhanced direction-based location update scheme for PCS networks

Mobile host (MH) has to be tracked in personal communication service (PCS) network, for which update and paging signals are required. The number of PCS network subscribers skyrocketed in recent years. To reuse channels over a distance, cell size is reduced and the number of cell crossing by user is becoming high. That makes optimal use of paging and update signal very important. In fact, most MH has unique movement profile, that contains the information of time, route, direction, etc., which is possible to learn and used to predict location. In this paper, we propose mobility pattern based location management scheme using the movement profile. Mobility pattern is learned and system will page only the restricted probable area. We compared the proposed scheme with distance-based location management. Improved cost saving is achieved.

Mobility management is an important aspect in LEO systems. In terrestrial wireless networks, the movement of the user triggers location updating and determines the paging scheme, while in LEO satellite systems, location updating and paging is mainly based on the movement of satellites. Terrestrial location management techniques must be altered to fit LEO systems. The paper introduces a modified movement-based location update and paging scheme in LEO networks. We propose the meta-cell concept, which includes two spot-beams of one satellite. First, we present a location management scheme based on the architecture with a meta-cell location area. Then, an analytical model is applied to formulate the cost of location updating and location paging for the movement and meta-cell based dynamic location update scheme. The comparison of performance between the meta-cell architecture method and the conventional signal-spot-cell architecture method is provided to demonstrate the cost-effectiveness and robustness of the proposed scheme under various parameters. To reduce the impact of meta-cell architecture on location paging cost, we present a forced location update strategy which is used in the case that the meta-cell includes two spot-beams from different satellites.

In Personal Communication Services (PCS) networks, mobile terminals (MT) are communicating frequently using variety of services. The increasing demands for diverse services dictate a high-quality framework for location management. To accomplish this objective, it is necessary to track MTs roving in the system within the time limit to deliver the services in timely manner. The expected reduction of the cell sizes due to transmission power concerns and for better frequency reuse in future PCS networks, and increasing speeds of MTs on the other hand, would cause a considerable signaling in the always updating (AU) strategy adopted in current PCS networks. Personalized location area (PLA) is an efficient way to reduce the location management cost by considering both the movement behavior of the individual users in the networks system and the system parameters. However, the PLA design problem is found to be NP-complete with high computation complexity. In this paper, we try to solve the problem by using the genetic algorithm (GA). Simulation results show that the location management cost of the designed PLAs by GA is significantly lower than that of the AU mechanism.

The distribution of the interservice time, which is the interval between the end of a call served and the start of the succedent call served by a portable, is a crucial parameter for modeling and cost analysis for location management in personal communication service (PCS) networks. The interservice time differs from the interarrival time due to the busy-line effect. However, in the literature, most of the cost analyses for location management were carried out by ignoring the busy-line effect, i.e., by identifying the interservice time with the interarrival time, because, so far, there is no analytical result for the interservice time distribution considering the busy-line effect. In this paper, we develop an analytical model to investigate the busy-line effect on the interservice time distribution. Closed-form analytical formulas for the interservice time are derived. A numerical study shows that a big discrepancy exists between the interarrival time and the interservice time. Based on the analytical results for the interservice time, the impact of the busy-line effect on modeling of portable movements in PCS networks is further evaluated. An analytical result for the distribution of the number of cell-boundary crossings during the interservice time is obtained. Both analytical results and numerical examples indicate that the busy-line effect has influence on the distribution of the number of cell-boundary crossings during the interservice time. Therefore, cost analysis for location management without considering the busy-line effect may lead to unreliable results. The results presented in this paper pave the way for modeling location management and portable movements in PCS networks.

On the problem of location update and terminal paging, many schemes using ring-paging strategies have been proposed. However, sequentially paging the rings surrounding the mobile user's last updated location may cause large paging cost. We propose a direction-based location update (DBLU) scheme using a line-paging strategy to reduce the paging cost. A moving direction identification mechanism using only simple computations detects the change of moving direction and updates the mobile's location. The numerical results show that our DBLU scheme achieves good performance when the paging cost is high.

Over the last decade there has been a rapid growth of wireless communication technology. Among numerous wireless network architectures, the personal communication services (PCS) networks and wireless local area networks (WLAN) have attracted lots of attention. One of the core functionalities in wireless networks is the location service that provides location information for subscriber services, emergency services, and various mobile networks internal operations. In this paper, an integrated location management mechanism is proposed for heterogeneous wireless networks that combine PCS networks and WLAN. Three major functionalities in the integrated location management scheme are the determination of the WLAN connectivity for a mobile terminal, the development of a local area location scheme for WLAN, and the location prediction module for PCS networks. This mechanism not only determines the location of a mobile client more precisely, but also reduces the cost of locating. The performance evaluation is conducted to demonstrate the effectiveness of the proposed mechanism for heterogeneous wireless networks.

The arrival of calls (i.e., new and handoff calls) in a personal communications services (PCS) network are modeled by a Markov arrival process (MAP) in which we allow correlation of the interarrival times among new calls, among handoff calls, as well as between these two kinds of calls. Each cell of the network consists of a finite number of channels and a buffer with finite size for handoff calls. There exist some channels among each cell which can be used by splitting the original rate into two channels with different rates if necessary when a handoff call arrives and finds all the channels busy. We obtain the stationary joint probability of number of calls in the cell and the phase of the arrival process, the blocking probability of a new call, the forced termination probability of a handoff call, and the mean dwell time of a handoff call in the buffer. Finally, we obtain the distribution and the mean of the cell's busy period, the distribution and the mean of the first time to split the cth channel, and some other interesting performance measures for the network. Some explicit results for special cases obtained by Lin et al. (see IEEE Trans. Vech. Technol., vol.45, no.1, p.122-30, 1996 and vol.43, no.3, p.704-12, 1994), Tekinary et al. (1992) and by Yoon et al. (1993) can also be directly obtained from the general conclusion. The results presented can provide guidelines for field data processing in PCS network design and performance evaluation.

There has been rapid growth an demand for mobile communications over the past few years that has led to intensive research and development of complex PCS (personal communication service) networks. Capacity planning and performance modeling are necessary to maintain a high quality of service to the mobile subscriber while minimizing the cost. Simulation is widely used in such studies, however, because these models are extremely time consuming to execute, only small-scale PCS networks have previously been simulated. In this paper, we examine the use of the Time Warp distributed simulation mechanism in simulating large scale (1024 or more cells) PCS networks. An object-oriented, distributed, discrete event simulator using Time Warp has been developed, and initial performance measurements completed. Speedups in the range of 2.8 to 7.8 using 8 Unix workstations have been obtained, enabling simulation runs that require 20 hours on a single workstation to be completed in only 3.5 hours.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Location management is one of the most important issues in the design of future cellular systems. It consists of two basic operations: location update and paging. The paging operation is dependent on the corresponding location update operation. The time based, movement based, and distance based location update schemes are three of the most popular dynamic location update schemes. It has been shown that the distance based scheme is more efficient than the movement based. However the distance between two cells is difficult to obtain. The author proposes a coordinate system which can be used to systematically assign IDs to the cells in a cellular system. With this cell ID assignment scheme, the distance between any two cells can be computed easily. Based on our distance computation scheme, a speed adaptive location update scheme is presented. It is shown that the speed adaptive location update scheme is a generalization of both time based and distance based schemes.

A movement-based location update (MBLU) scheme is effective and has low operation complexity. On the other hand, cellular networks use periodic LUs that are intrinsically time-based LUs (TBLUs) to detect the presence of a user equipment (UE) to avoid wasting network resources to deliver incoming calls to an abnormally detached UE. When implemented in a cellular network, the MBLU scheme must incorporate TBLUs to detect the UE presence. Thus, a hybrid-movement-based and time-based LU (HMTBLU) scheme arises naturally. Under the HMTBLU scheme, an LU occurs either when the movement threshold for MBLUs is reached or when the time threshold for TBLUs is reached. In this paper, we develop an embedded Markov chain approach to calculate the signaling cost of the HMTBLU scheme. We derive analytical formulas for the signaling cost and formulas useful for designing an optimal paging scheme. The accuracy of these formulas is validated through simulation. Based on these formulas, we conduct a numerical study to investigate the influence of various parameters on the signaling cost. The derived formulas can guide the implementation of the HMTBLU scheme in cellular networks, including Long-Term Evolution (LTE). Moreover, the developed mathematical approach can be applied to studying other LU schemes such as the LU scheme used in LTE.

Personal mobility and terminal mobility which are viable through wireless access to communication networks are the most fundamental goals of personal communication services (PCS). The technology needed for the wireless access in PCS networks is generally provided by the cellular networks and intelligent networks (IN). In cellular networks, the wireless mobile terminals (WMT) communicate with base stations (BS) which convey the messages among the WMTs and switching centers (SC). SCs and BSs are usually wired to the upper layers of the communication network. In this paper, we briefly review PCS and then propose an algorithm which determines the number of SCs and the BSs attached to the determined SCs in a network for which BS information together with the traffic requirements are given. While the algorithm produces these solutions, it also satisfies some constraints determined by the network designers such as the maximum capacities and the minimum utilization for the SCs.

This work deals with a design problem for a network of Personal Communication Services (PCS). The goal is to assign cells to switches in a PCS Network (PCSN) in an optimum manner so as to minimize the total cost which includes two types of cost, namely handoff cost between two adjacent cells, and cable cost between cells and switches. The design is to be optimized subject to the constraint that the call volume of each switch must not exceed its call handling capacity. In the literature, this problem has been conventionally formulated as an integer programming problem. However, because of the time complexity of the problem, the solution procedures are usually heuristic when the number of cells and switches are more. In this paper, we have proposed an assignment heuristic which is faster and much simpler than the existing algorithms. Despite its simplicity, experimental results show that it performs equally well in terms of solution quality, and, at the same time, it is faster than its predecessors. We present the algorithm as well as comparative results to justify our claim.

The paper proposes an integrated location management scheme, based on our previously proposed novel rule-based paging scheme (RBPS) for reducing the cost of terminal paging in a cellular wireless environment. We extend that scheme to propose a complete location management scheme. This requires application of RBPS together with a judicious movement based location update (LU) scheme. Numerical results show that the proposed integrated location management scheme, called RBPS*, not only attempts to resolve the issue of inherent tradeoff between the cost components, comprised of paging and LU cost, but also does reduce the total cost for location management compared to the other schemes. RBPS* significantly outperforms RBPS and the GSM-adopted blanket paging scheme along with movement based LU. When compared with the popular shortest distance first (SDF) scheme, results are again encouraging. The proposed scheme, RBPS*, is a generic one and can be deployed on-line. It has the potential for use in next generation wireless networks, irrespective of any standards.

With ever increased mobility in our dynamic society, the need for a low power portable handset and cost-effective access to a wide array of telecommunication network services has been recognized. A successfully deployed personal communication services (PCS) network will not only provide access to today's wire-line network services but also manage customer mobility seamlessly and transparently. In order to test this hypothesis and assess the capabilities of the state-of-the-art network technologies, a PCS technology trial network was established during the first half of 1993. The paper discusses the planning required and insights gained during the design, integration testing, establishing provisioning and fault isolation procedures phases of this multifaceted project. >

LOCATION MANAGEMENT AND COST PLANNING FOR PERSONAL COMMUNICATION SYSTEMS