An improved mobile tracking and location procedure for ATM-based PCNs

This paper presents a "flat" mobile location management scheme for personal communication networks (PCNs) with the goal of reducing both mobile tracking and locating costs. Mobile tracking costs are reduced by the use of one-level tracking for mobiles in their "home area", and a two-level tracking approach for mobiles visiting other areas. Mobile location costs are reduced by using an improved mobile location strategy, which requires a one-hop message exchange for mobiles in their home area, and a two-hop message exchange for mobiles visiting other areas. Analytical models are set up to analyze the performance of the flat scheme, and compare it with that of the other approaches. The measures of comparison used are the computation cost (database accesses), the communication cost (signaling messages), the average total cost, and the mobile location cost (call setup delay). For all these measures, the proposed flat scheme performs better than the location management scheme defined in the IS-41 standard. Results also show that for medium and high values of call-to-mobility ratio (>0.07, i.e., less than 14 moves per call), the flat scheme performs better than other approaches proposed in the literature.

Location management schemes are essentially based on users' mobility and incoming call rate characteristics. The network mobility process has to face strong antagonism between its two basic procedures: location update (or registration) and paging. The location update procedure allows the system to keep location knowledge more or less accurately in order to find the user in case of an incoming call, for example. Location registration also is used to bring the user's service profile near its location and allows the network to rapidly provide the user with services. The paging process achieved by the system consists of sending paging messages in all cells where the mobile terminal could be located. A detailed description of the means and techniques for user location management in present cellular networks is addressed.A network must retain information about the locations of endpoints in the network in order to route traffic to the correct destinations. Location tracking (also referred to as mobility tracking or mobility management) is the set of mechanisms by which location information is updated in response to endpoint mobility. In location tracking, it is important to differentiate between the identifier of an endpoint (i.e., what the endpoint is called) and its address (i.e., where the endpoint is located). Mechanisms for location tracking provide a time-varying mapping between the identifier and the address of each endpoint. Most location tracking mechanisms may be perceived as updating and querying a distributed database (the location database) of endpoint identifier-to-address mappings. In this context, location tracking has two components: (1) determining when and how a change in a location database entry should be initiated; and (2) organizing and maintaining the location database. In cellular networks, endpoint mobility within a cell is transparent to the network, and hence location tracking is only required when an endpoint moves from one cell to another. Location tracking typically consists of two operations: (1) updating (or registration), the process by which a mobile endpoint initiates a change in the location database according to its new location; and (2) finding (or paging), the process by which the network initiates a query for an endpoint's location (which also may result in an update to the location database). Most location tracking techniques use a combination of updating and finding in an effort to select the best trade-off between update overhead and delay incurred in finding. Specifically, updates are not usually sent every time an endpoint enters a new cell, but rather are sent according to a predefined strategy so that the finding operation can be restricted to a specific area. There is also a trade-off, analyzed formally between the update and paging costs.Location management methods are most adapted and widely used in current cellular networks, e.g., GSM, IS-54. IS-95, etc. The location management methods are broadly classified into two groups. The first group includes all methods based on algorithms and network architecture, mainly on the processing capabilities of the system. The second group contains the methods based on learning processes, which require the collection of statistics on subscribers' mobility behavior, for instance.

We propose an efficient location management algorithm for broadband personal communication networks (PCNs) which reduces the complexity of network signaling and delay due to database access when locating a portable station (PS). Previous works on updating and search algorithms for personal communications have concentrated on the access delay due to signaling network traffic only. But, with the advances in fiber optic technology, it will be possible to provide the capacity of signaling network on the order of several Mbps in broadband PCNs. Thus it may be more important to simplify the signaling procedure and reduce the number of database accesses for mobility management at the cost of some increase of signaling traffic. In the proposed algorithm, we first remove all visitor location registers (VLRs) in order to achieve the simplicity of signaling procedure. Thus, only home databases for mobility management are distributed in a global network, and each database keeps only the current locations of PSs initially registered in its management area. It can solve the problem of requiring an impractically large database in a centralized database structure by distributing home location registers (HLRs) while maintaining the simplicity of mobility management and reducing database loads. This algorithm has a simple signaling procedure, and reduces database operations when compared to hierarchical algorithms as network switching hierarchy increases or relocation and calling rate increase.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

To improve the local mobility performance of a wireless network, we present a new framework, namely Efficient Framework for Local Mobility (EFLoM). In EFLoM, we introduce three entities: Local Anchor Router (LAR), Wireless Access Gateway (WAG) and Mobile Node (MN). LAR is a router that is in charge of MN's IP mobility management. It keeps track of MN's movement, and delivers the MN's packets to its current location. AWAG is an access router that is responsible for managing the traffic flows within the same local mobility domain. In EFLoM, when Corresponding Node (CN) and MN connect to the same local mobility domain, packets are sent directly between CN and MN by WAG, without suffering sub-optimal routing problems. A MN is a mobile host which updates its data packets' header with its current location address before packets are sent out. To evaluate our new framework, we compare EFLoM with Hierarchical Mobile IPv6 Mobility Management (HMIPv6) [4] which is an existing protocol that has good performance for local mobility. Both analytical analysis and simulation result show that EFLoM can attain substantial improvements over HMIPv6 in terms of handover delay, end to end delay, traffic overhead, which therefore presents EFLoM as a new engineering alternative to existing MIPv6 based techniques.

The personal networks of listeners and nonlisteners to an entertainment-education radio soap opera in Tanzania are examined to determine the effects of interpersonal discussion of the soap opera's educational themes of family planning and HIV prevention. Listeners are more likely to discuss these two educational issues in their personal communication networks and are also more likely to have other listeners to the radio program in their personal communication networks. Respondents demonstrate a relatively high degree of homophily with their network partners and are more likely to discuss matters arising from the radio program with their network partners who are of similar tribal membership, religious affiliation, and gender, and those who are equally or more highly educated than themselves.

This paper presents a discussion of system design issues related to the development of next-generation multimedia personal communication networks (PCN). It is proposed that the baseline definition of emerging PCN systems be broadened to provide multimedia transport capabilities qualitatively similar to those offered by BISDN/ATM. A number of system-level design and technology selection issues are discussed. Specific topics considered include: multimedia PCN traffic handling requirements, service cost targets, system design criteria, choice of packet switching vs. circuit switching, strategies for ATM compatibility, media access control (MAC) selection, etc. The presentation is concluded with an outline of a dynamic TDMA based multimedia PCN system architecture consistent with the preceding discussion. Simulation based performance evaluation results are also given for such a dynamic TDMA PCN channel operating in example mixed voice/data traffic scenarios.

One of recent efforts for mobile computing in IETF is a network-based localized mobility management (NetLMM) approach. In the NetLMM approach Proxy Mobile IPv6 (PMIPv6) is one of proposed solutions to support a localized mobility management for a mobile node (MN). In PMIPv6, a PMIP client is a main entity responsible for sending messages on behalf of an MN whenever the MN hands off across access points (APs) within a local mobility domain (LMD). As multiple PMIP clients are configured in the LMD for redundancy and load balance concerns, a selection of PMIP client has to be carefully considered on the overall network performance. Thus, in this paper, we propose two distance-based PMIP client selection schemes - the nearest PMIP client selection scheme and the furthest PMIP client selection scheme. The proposed distance-based selection schemes, where an MN is registered via the nearest or the furthest PMIP client, announce the distance information of PMIP client, so that the PMIP selection is achieved by considering the distance between the PMIP client and the current attachment.

This paper is concerned with the development of a backbone network for a high capacity personal communication network (PCN). It is expected that some of the 1st generation PCNs will be implemented on the DCS1800, which is a GSM based standard. The present backbone network of the GSM system is based on a conventional centralised structure. The paper examines the efficiency of the current GSM backbone network using circuit switched input traffic for both full rate and half rate speech coders. Finally the paper proposes an ATM LAN/MAN based backbone network which removes some of the inefficiencies of the existing GSM backbone network and can efficiently handle new services.

Personal communication networks (PCN) have recently been put into operation in the UK. The PCN/DCS1800 is expected to be a very high capacity system because smaller cells are intended to be used. The data rate of 270 kbits/sec exceeds the reciprocal of the decay spread often measured in mobile radio environments. Hence PCN can be regarded as a wideband transmission system and therefore the frequency-selective fading behaviour of the radio channel cannot be ignored. This paper shows possible improvements that can be obtained if PCN systems employ 2-branch selection or equal gain diversity techniques. The diversity schemes implemented in this study are totally based on the received signal strength. The results show that, at a BER of 0.01, 2-branch selection diversity can provide a gain of 5-6 dB for the various channels specified for the DCS1800 system. A further 1 dB improvement can be obtained using equal-gain combining. >

Personal Communication Networks (PCNs) have become an important filed of activity and they are expected to play a fundamental role in next-generation telecommunication systems. In particular, the emerging personal communication services, such as portable computing, paging, personal e-mail, etc. have led to the need of an efficient integration of voice and data traffic in a same PCN by means of a suitable multiple-access scheme. This paper considers stability and optimization issues for the Packet Reservation Multiple Access (PRMA) protocol used for integrating voice and burst data traffic in a PCN. An important result here devised is that the optimized PRMA protocol permits to be achieved good performance even under heavy traffic load conditions.

LTE is an emerging wireless data communication technology to provide broadband ubiquitous Internet access. Femtocells are included in 3GPP since Release 8 to enhance the indoor network coverage and capacity. The main challenge of mobility management in hierarchical LTE structure is to guarantee efficient handover to or from/to/between Femtocells. This paper focuses, on different types of Handover and comparison performance between different decision algorithms. Furthermore, a speed based Handover algorithm for macro-femto scenario is proposed with simulation results

This study investigates the realistic conditions of ‘digital Korea’, especially as they are exemplified by the Samsung SDI scandal in South Korea. Samsung SDI, the world's largest plasma TV maker and a subsidiary of the Samsung Group, has fallen under suspicion due to using illegally cloned mobile phones to track the location data of some activist workers who tried to organise a union. The study stresses that this example of mobile tracking represents the shady side of mobile phone use created by management's excessive desire for labour control, and confirms that mobile tracking techniques make possible the spatial expansion of the scope of power. The spatial vocabulary of power is not totalitarian, but dispersed and nomadic in action, and resides in the space of ‘flows’ constructed by electronic impulses. This study discloses that, for private corporations, mobile tracking facilitates a form of efficient, invisible labour control over ‘targeted’ workers, even outside the workplace. It concludes that the control of labourers in Korea has been reinforced by the confluence of business interests, the under-developed political system and a societal lack of interest in privacy.

Two of the major challenges for next-generation mobile systems are to achieve seamless mobility management in next generation wireless networks and to manage resources efficiently given the exponential growth that mobile data traffic has experienced over the last few years. To track host mobility, the IETF has made important efforts to develop mobility management protocols such as Mobile IPv6 and Proxy Mobile IPv6. These protocols establish a tunnel to connect the mobile node with its correspondent node. The tunneling method provided by MPLS can be profitably used to take advantage of MPLS traffic engineering capabilities in order to achieve faster re-routing when a mobile node changes its point of attachment to the network. Moreover, in order to deal with increasing mobile traffic demand, mobility management network architectures are being redesigned towards a more distributed operation. Given these scenarios, service disruption during handoffs continues to cause excessive packet loss that needs minimizing in order to support quality of service requirements for emerging applications. In this paper, a qualitative and quantitative analyses of the most representative host-based and network-based mobility management approaches is presented, including recent distributed mobility management approaches.

In this paper, we study the scalability issues of SDNized wireless networks, specifically those relevant to mobility management. We study the improvements in handover delays: i) when a proposed proactive mobility management algorithm is implemented, ii) when the controller delegates partial control of mobility management to the forwarding entities. For the implementation of the proposed approaches on the OpenFlow network, the paper also suggests potential extensions to OpenFlow protocol. The contributed approaches are validated on a full scale demonstrator and results show that proactive outperforms reactive and the delegated control approach performs better than proactive for smaller topology sizes. Furthermore a proposal for LTE-X2 specific control delegation is discussed as use-case.

An advanced telecommunications system is provided for the recognizing of spoken commands over a cellular telephone (15), satellite telephone (14), or personal communications network (16). In the cellular application, for example, a Speech Recognition System (20) interconnects either internally with or as an external peripheral to a cellular telecommunications switch (12). The Speech Recognition System (20) includes an administrative subsystem (21), a call processing subsystem (23), a speaker-dependent recognition subsystem (25), a speaker-independent recognition subsystem (27), and a data storage subsystem (29). Pre-recorded instructional messages are stored in the memory of the call processing subsystem (23) for instructing a user on his or her progress in using the system. The speaker-independent recognition subsystem (27) allows the user to interact with the system employing non-user specific functions. User specific functions are controlled with the speaker-dependent recognition subsystem (25). User specific attributes collected by the recognition subsystems are stored in the data storage subsystem (29).