92,150 research outputs found

    Comparative Analysis of Location Management Schemes in Wireless ATM Networks

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    Mobility is the cornerstone of wireless networks. Supporting mobility requires some form of tracking to locate mobile terminals within the network. In the wireline ATM network, the terminal is fixed and the terminal is located by identifying the terminal and following the routing information provided at each switch along the path. As terminals become mobile, the path to the mobile becomes dynamic; the terminal and the path are no longer synonymous. Signalling traffic incurred in tracking mobile users and delivering enhanced services causes an additional load in the Wireless ATM (WArM) network. Efficient database and location management schemes are needed to meet the challenges from high density and mobility of users, and various service scenarios. In this thesis the three "natural" Location Management Strategies, i.e., Timer-Based, Location Area Based and Movement Based are studied and analysed for a W ATM network. The model used for depicting user motion and call arrival is Brownian motion with drift process and Poisson arrival process, respectively. The Timer-Based location management strategy is one in which the user updates its location periodically after an "optimum" interval of time. This optimum interval of time is based upon the user's mobility and call arrival characteristics and is therefore best suited for that particular mobile. In the Adaptive Location Area Based strategy, the user updates its location on each LA boundary crossing. The size of the LA changes according to the user' s mobility characteristics. The objective is to minimise the combined average signalling cost of both paging and registration for each individual mobile user such that the overall system-wide signalling cost for location tracking can be minimised

    Peer-assisted location authentication and access control for wireless networks

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    This paper presents the development and implementation of a location‐based, lightweight peer‐assisted authentication scheme for use in wireless networks. The notion of peer‐assisted authentication is based upon some target user equipment‐ (UE) seeking authentication and access to a network based upon its physical location. The target UE seeks authentication through the UE of peers in the same network. Compared with previous work, the approach in this paper does not rely on any cryptographic proofs from a central authentication infrastructure, thus avoiding complex infrastructure management. However, the peer‐assisted authentication consumes network channel resources which will impact on network performance. In this paper, we also present an access control algorithm for balancing the location authentication, network quality of service (QoS), network capacity and time delay. The results demonstrate that peer‐assisted authentication considering location authentication and system QoS through dynamic access control strategies can be effectively and efficiently implemented in a number of use cases

    Location Management Cost Reduction Using Adaptive Velocity-Movement Based Scheme In Personal Cellular Networks (Pcn)

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    Wireless personal communication networks (PCNs) consist of a fixed wireless network with nodes providing wireless coverage area and a large number of mobile terminals (MTs). These terminals are free to travel within the PCN coverage area without service interruption. Each terminal periodically reports its location to the network by a process called location update. When a call arrives for a particular mobile terminal, the network will determine the exact location of the destination terminal by a process called terminal paging. There are many schemes proposed which aim at reducing signaling costs and all these schemes were based on different assumptions and network parameters. Our objective is to study the updating and paging process of the MTs under different dynamic location management schemes, and to develop an adaptive scheme that caters for the ever-changing network parameters. In this thesis, a dynamic paging scheme is proposed and presented based on the semi-real time velocity information of an individual mobile user. This allows for more accurate prediction of the user location when a call arrives and therefore, reducing the cost of paging. The scheme is based on a basic scheme that was proposed in the open literature. Our new scheme results show that the newly proposed adaptive movement threshold and the adaptive velocity time unit schemes provide significant costs savings, compared to a benchmark system and the basic scheme, under different cell radius sizes and MT velocities broadly classified as high and low mobility systems

    ADAPTIVE PROFILE DRIVEN DATA CACHING AND PREFETCHING IN MOBILE ENVIRONMENT

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    This thesis describes a new method of calculating data priority by using adaptive mobile user and device profiles which change with user location, time of the day, available networks and data access history. The profiles are used for data prefetching, selection of most suitable wireless network and cache management on the mobile device in order to optimally utilize the device's storage capacity and available bandwidth. Some of the inherent characteristics of mobile devices due to user movements are – non-persistent connection, limited bandwidth and storage capacity, changes in mobile device's geographical location and connection (eg. connection can be from GPRS to WLAN to Bluetooth). New research is being carried out in making mobile devices work more efficiently by reducing and/or eliminating their limitations. The focus of this research is to propose, evaluate and test a new user profiling technique which specifically caters to the needs of the mobile device users who are required to access large amounts of data, possibly more than the device storage capability during the course of the day or week. This work involves the development of an intelligent user profiling system along with mobile device caching system which will first allocate weight (priority) to the different sets and subsets of the total given data based on user's location, user's appointment information, user's preferences, device capabilities and available networks. Then the profile will automatically change the data weights with user movements, history of cached data access and characteristics of available networks. The Adaptive User and Device Profiles were designed to handle broad range of the issues associated with: •Changing network types and conditions •Limited storage capacity and document type support of mobile devices •Changes in user data needs due to their movements at different times of the day Many research areas have been addressed through this research but the primary focus has remained on the following four core areas. The four core areas are : selecting the most suitable wireless network; allocating weights to different datasets & subsets by integrating user's movements; previously accessed data; time of the day with user appointment information and device capabilities

    MIRAI Architecture for Heterogeneous Network

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    One of the keywords that describe next-generation wireless communications is "seamless." As part of the e-Japan Plan promoted by the Japanese Government, the Multimedia Integrated Network by Radio Access Innovation project has as its goal the development of new technologies to enable seamless integration of various wireless access systems for practical use by 2005. This article describes a heterogeneous network architecture including a common tool, a common platform, and a common access. In particular, software-defined radio technologies are used to develop a multiservice user terminal to access different wireless networks. The common platform for various wireless networks is based on a wireless-supporting IPv6 network. A basic access network, separated from other wireless access networks, is used as a means for wireless system discovery, signaling, and paging. A proof-of-concept experimental demonstration system is available

    Mobility Management in beyond 3G-Environments

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    Beyond 3G-environments are typically defined as environments that integrate different wireless and fixed access network technologies. In this paper, we address IP based Mobility Management (MM) in beyond 3G-environments with a focus on wireless access networks, motivated by the current trend of WiFi, GPRS, and UMTS networks. The GPRS and UMTS networks provide countrywide network access, while the WiFi networks provide network access in local areas such as city centres and airports. As a result, mobile end-users can be always on-line and connected to their preferred network(s), these network preferences are typically stored in a user profile. For example, an end-user who wishes to be connected with highest bandwidth could be connected to a WiFi network when available and fall back to GPRS when moving outside the hotspot area.\ud In this paper, we consider a combination of MM for legacy services (like web browsing, telnet, etc.) using Mobile IP and multimedia services using SIP. We assume that the end-user makes use of multi-interface terminals with the capability of selecting one or more types of access networks\ud based on preferences. For multimedia sessions, like VoIP or streaming video, we distinguish between changes in network access when the end-user is in a session or not in a session. If the end-user is not in a session, he or she needs to be able to start new sessions and receive invitations for new sessions. If the end-user is in a session, the session needs to be handed over to the new access network as seamless as possible from the perspective of the end-user. We propose an integrated but flexible solution to these problems that facilitates MM with a customizable transparency to applications and end-users
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