Location Area Design for GEO Mobile Satellite System

Location management is the basis for ensuring service continuity in low earth orbit (LEO) satellite mobile communication systems. The dual mobility of LEO satellites and mobile users triggers frequent location update procedures, which will increase the network location management overhead and bring great challenges to network location management, especially in the mega satellite networks. In this paper, we propose a location management technology solution for mega satellite networks, including location management architecture, location area design, location update, and paging procedures. A medium earth orbit (MEO) satellite-assisted location management architecture is proposed to improve the efficiency of location management. It extends the location management control plane from the ground to space and adopts a distributed location management mechanism. A dual location area, including the satellite location area and user location area, is designed to balance the network location update and paging overhead. Based on the dual location area, we systematically design low-overhead location update and paging procedures. Simulation results have verified that the proposed location management technology solution can reduce the total location management overhead and delay by at least 45.8% and 20.8%, respectively.

In little more than two decades, communications satellite technology has gone from being revolutionary to commonplace, from an idea to world wide service. In both industrialized and developing countries, economic and social progress depends on improved telecommunications. Like other means of transport, telephones, computers, satellites and fiber optic cables and their proper interfaces are essential for moving commercial goods and services. Benefits of satellite communications should in the 1990's be extended to users in all parts of the world through the use of smaller, inexpensive and less sophisticated Earth stations for two way (voice and data), and one way (video, data) use. While earlier satellite systems have been designed and implemented using C and S band communications with satellites in geostationary orbits (GEO), K band communications using VSATs (Very Small Aperture Terminals) have enabled the communications across areas of the US and the world where extensive telecommunications networks did not exist and/or were not affordable. In addition, several systems have been proposed (being built) to provide for the global communication of the mobile users using clusters of smaller, less complex satellites in low Earth orbit (LEG) and medium Earth orbit (MEO). Mobile satellite systems are the future of the satellite communications technology applications. In this presentation, we will briefly summarize the status for satellite communications and then present a comparison of the enabling mobile satellite communications technologies and mobile satellite systems currently being developed. We will also review applications of these systems in public and commercial areas in this presentation. >

The scarce radio resources available to any cellular radio network have to be shared between its revenue-generating voice- and data-carrying services, and non-revenue-generating management services. One of these management services is location management, crucial for the network to keep track of the location of its subscribers and to connect their incoming calls. Location management consists of the two activities, paging and location updating, both of which are structured around a subdivision of the network service area called the location area (LA). The ways in which the service area is partitioned therefore has a direct impact on the amount of radio bandwidth that has to be spent on location management. However, paging and location updating share an antagonistic relationship, and finding the optimal LA partitioning that strikes a balance between the two is a challenging design problem. In this paper, the problem of finding the optimal LA partitioning of a cellular radio network service area in order to minimise the total location management signalling cost is addressed. The choice of the decision variables used in the mathematical programming model results in an objective function that is conceptually easy to understand and a solution method that is simple and straightforward.

Current and planned global mobile satellite systems (MSSs) are aimed mainly at serving voice, facsimile and low-bit-rate data services with rates of up to about 4.8 kbit/s. In the multimedia communication era, however, this channel rate, regardless of the use of GEO or LEO satellites, is too low to realize comfortable mobile computing for operations such as Internet access, e-mail, remote LAN access, image transmission, and videophone. This paper proposes a global mobile N-ISDN satellite communication (GMISC) system: a GEO satellite communication system offering the ISDN basic rate up to 144 kbit/s (2B+D) with notebook size user terminals and vehicular terminals to provide a comfortable nomadic communication environment. It also discusses satellite channel control techniques for the proposed GMISC system. It is clear that a layered satellite channel control scheme consisting of a master satellite channel controller and plural local satellite channel controllers that assign shared satellite channels within a country, is suitable for the proposed system.

Location management is a paramount issue in wireless mobile station communication systems to enable the terminals to continuously receive services when moving from one location to another. In this paper, we study the trends in the latest cellular wireless systems to page terminals, update location area and make handover decisions for a mobile station. Topics covered include static and dynamic location management, dynamic location areas and techniques, future location management developments, location tracking evolution and location management in 3G. It will be shown that location-area based location management methods designed around a profile or history-based direction information offer the best performance, in terms of location management cost, compared to all other alternative approaches while distance based schemes are to be the most efficient ones.

Experiments on mobile satellite communications are being carried out to determine if they are technically feasible for future domestic satellite services in the Experimental Mobile Satellite System project, which uses Engineering Test Satellite-V. Experimental ISDN (integrated services digital network) basic-rate communications services have also been offered for marine vehicles. The authors describe the configuration of an experimental system for maritime ISDN satellite communications, and the characteristics of ISDN basic-rate interface connections for the digital telephones, G4 facsimiles, and color video-phone terminals of terrestrial ISDN services. This experiment provided much information for designing future mobile satellite communications systems. Moreover, it indicates that forward error correction in a mobile satellite link with poor transmission quality is very effective at improving the communication quality of mobile satellite systems. >

Dynamic Channel Allocation (DCA) techniques permit a high resource utilization in cellular networks and are able to adapt themselves in the presence of rapid variations of traffic loads offered to the cells. Therefore, they are particularly suitable for Mobile Satellite Systems (MSSs). This paper compares the performance of several DCA solutions that are based on the evaluation of a cost function in terms of both quality of service parameters (i.e., blocking probabilities) and signaling load to be supported by the system. Both GEostationary Orbit (GEO) and Low Earth Orbit (LEO) MSSs have been considered. A particularly interesting DCA solution is proposed that tries to serve a new call attempt in a cell where no channel is available by means of a channel reconfiguration in an interfering cell. Handover requests that do not attain immediately service can be queued for a maximum time in order to enhance system performance.

Recently, engineers have focused on developing mobile satellite communications systems using GEO, MEO and LEO satellites. We are now studying an on-board antenna for future S-band mobile satellite communications using hand-held terminals. This antenna is carried on a GEO satellite, and consists of a large deployable mesh reflector and a primary feed using an active phased array. It has the advantage of beam forming flexibility. For example, when its radiation pattern changes due to an amplifier problem, we can obtain the desired pattern by adjusting the only excitation phase of the array feed. We first present the satellite antenna's configuration, then describe pattern correction by adjusting the excitation phase of the array feed.

As PCS networks aim to provide 'anytime-anywhere' cellular services, mobile terminals' (MTs) locations should be managed continuously. Location management (LM) includes two processes; registration and paging. Registration concerned with reporting MTs current locations, while, paging locates the callee MT. Both processes incur signalling cost across the wireless channel, which need to be reduced due to the scarcity of PCS wireless bandwidth. In spite of its minimal latency, blanket paging, used in current networks, wastes the network bandwidth. This paper aims to reduce the paging signalling cost under delay bounds. The paper contributions can be summarised as: 1) establishing a family of paging strategies under two proposed probability based LM strategies (PBLM and MPBLM); 2) introducing a novel topology for PCS registration area called the 'hot spot topology' (HST); 3) based on HST, another new LM strategy called 'flower based location management' (FBLM) is introduced. The proposed paging strategies substantially lower the signalling cost compared with the blanket one. Also, experimental results have shown that FBS dramatically reduce the signalling load (up to 80%) with a minimal increase in paging delay.

The features of two important application scenarios, supporting mobile switches with fixed end users and mobile switches with mobile users, are dramatically different from those of the traditional wired network structure. To exploit mobile switches, the location and configuration management of mobile switches is essential to handle the mobility and topology change of the wireless/mobile ATM network. In this paper we address the location management and configuration problems of mobile switches in an ATM network. We investigate several aspects of the location management problem including architecture to support switch mobility, mobile switch tracking, and mobile switch locating. We propose an approach that is based on the Private Network-Network Interface (PNNI) protocol. We extend the PNNI protocol to enable it to handle mobile switches. Moreover, we develop analytical models to determine the tracking and locating costs for mobile switches under the proposed scheme. The models illustrate the relation between total cost (tracking cost + locating cost) and peer group size. The models can be used to derive the optimal configuration for an ATM network with mobile switches.

Location management deals with how to track mobile users within the cellular network. It consists of two basic operations: location update and paging. The total location management cost is the sum of the location update cost and the paging cost. Location areas and reporting centers are two popular location management schemes. The motivation for the study is the observation that the location update cost difference between the reporting centers scheme and the location areas scheme is small whereas the paging cost in the reporting centers scheme is larger than that in the location areas scheme. The paper compares the performance of the location areas scheme and the reporting centers scheme under aggregate movement behavior mobility models by simulations. Simulation results show that the location areas scheme performs about the same as the reporting centers scheme in two extreme cases, that is, when a few cells or almost all cells are selected as the reporting cells. However, the location areas scheme outperforms the reporting centers scheme at the 100% confidence level with all call-to-mobility ratios when the reporting cells divide the whole service area into several regions.

In this paper, we provide the specification of a cloud-initiated Point-of-Interest (PoI) application, and illustrate its requirements for a convergence between IPv6 mobility management and Dedicated Short Range Communications (DSRC) geographic services. We propose to extend a flat IPv6 mobility management architecture with a new functional block, namely LIMME (Location & Infrastructure Mobility Management Entity), composed of three key functions: a Location Manager (LM) acting as location anchor point for cloud-based services, a Geographic Mobility Management (GMM) function acting as location proxy for the LM and handling IPv6 mobility, and an Infrastructure Node selector, which selects a route based on geographical data and local infrastructure node conditions. As a proof-of-concept, we implemented these extensions on the iTETRIS ITS simulation platform and illustrated their benefits in enhanced IPv6 mobility management and traffic offloading.

Traditional centralized approaches toward mobility management such as MIPv6 and its variants suffer because of the performance issues like single‐point failure, non‐optimal routing, low scalability, authentication latency, and signaling messages overhead of the mobility protocols. In this paper, we propose a novel network‐based Distributed Mobility and Authentication Mechanism (DMAM) to focus on these issues. DMAM decomposes centralized mobility functions into Home Address Allocation, mobility routing (MR), and location management (LM). A new entity is introduced in DMAM, called Location and Mobility Manager that distributes MR and LM among multiple routers to which mobile node can be attached. Furthermore, DMAM offers strong authentication mechanism based on symmetric cryptographic and collision‐free one‐way hash function. The performance of proposed scheme is analyzed and compared with existing approaches in terms of handover latency, handover blocking probability, packet loss, communication overhead, and computational cost. The conducted numerical results demonstrate that DMAM outperforms the existing approaches. Copyright © 2014 John Wiley & Sons, Ltd.

Some observations on using meta-heuristics for efficient location management in mobile computing networks

The growth in the number of users in mobile communications networks and the rise in the traffic generated by each user, are responsible for the increasing importance of mobility management. Within mobility management, Location Management makes sure that the roaming of the user within the coverage area is enabled. New strategies are being proposed to minimize the signaling costs involved in Location Management. In this paper we focus on user profile based algorithms and present new methods to calculate useful parameters for the estimation of the Location Management costs. In particular, we apply new algorithms to obtain the ?O?nparameters (useful in the calculation of the location update costs for different Location Management strategies), and we summarize our results in terms of practical guidelines for the networks designers in order to minimize signaling costs.