Showing papers on "Cellular network published in 1999"

Fair scheduling in wireless packet networks

Abstract: Fair scheduling of delay and rate-sensitive packet flows over a wireless channel is not addressed effectively by most contemporary wireline fair-scheduling algorithms because of two unique characteristics of wireless media: (1) bursty channel errors and (2) location-dependent channel capacity and errors. Besides, in packet cellular networks, the base station typically performs the task of packet scheduling for both downlink and uplink flows in a cell; however, a base station has only a limited knowledge of the arrival processes of uplink flows. We propose a new model for wireless fair-scheduling based on an adaptation of fluid fair queueing (FFQ) to handle location-dependent error bursts. We describe an ideal wireless fair-scheduling algorithm which provides a packetized implementation of the fluid mode, while assuming full knowledge of the current channel conditions. For this algorithm, we derive the worst-case throughput and delay bounds. Finally, we describe a practical wireless scheduling algorithm which approximates the ideal algorithm. Through simulations, we show that the algorithm achieves the desirable properties identified in the wireless FFQ model.

On-demand multipath routing for mobile ad hoc networks

Abstract: Mobile ad hoc networks are characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Design of efficient routing protocols in such networks is a challenging issue. A class of routing protocols called on-demand protocols has recently attracted attention because of their low routing overhead. The on-demand protocols depend on query floods to discover routes whenever a new route is needed. Such floods take up a substantial portion of network bandwidth. We focus on a particular on-demand protocol, called dynamic source routing, and show how intelligent use of multipath techniques can reduce the frequency of query floods. We develop an analytic modeling framework to determine the relative frequency of query floods for various techniques. Results show that while multipath routing is significantly better than single path routing, the performance advantage is small beyond a few paths and for long path lengths. It also shows that providing all intermediate nodes in the primary (shortest) route with alternative paths has a significantly better performance than providing only the source with alternate paths.

QoS routing in ad hoc wireless networks

Abstract: The emergence of nomadic applications have generated much interest in wireless network infrastructures that support real-time communications. We propose a bandwidth routing protocol for quality-of-service (QoS) support in a multihop mobile network. The QoS routing feature is important for a mobile network to interconnect wired networks with QoS support (e.g., ATM, Internet, etc.). The QoS routing protocol can also work in a stand-alone multihop mobile network for real-time applications. This QoS routing protocol contains end-to-end bandwidth calculation and bandwidth allocation. Under such a routing protocol, the source (or the ATM gateway) is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real-time applications. In addition, it enables more efficient call admission control. In the case of ATM interconnection, the bandwidth information can be used to carry out intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit (VC) service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine the system performance in various QoS traffic flows and mobility environments via simulation. Simulation results suggest distinct performance advantages of our protocol that calculates the bandwidth information. It is particularly useful in call admission control. Furthermore, "standby" routing enhances the performance in the mobile environment. Simulation experiments show this improvement.

A wireless hierarchical routing protocol with group mobility

Abstract: In this paper we present a hierarchical routing protocol in a large wireless, mobile network such as found in the automated battlefield or in extensive disaster recovery operations. Conventional routing does not scale well to network size. Likewise, conventional hierarchical routing cannot handle mobility efficiently. We propose a novel soft state wireless hierarchical routing protocol-Hierarchical State Routing (HSR). We distinguish between the "physical" routing hierarchy (dictated by geographical relationships between nodes) and "logical" hierarchy of subnets in which the members move as a group (e.g., company, brigade, battalion in the battlefield). HSR keeps track of logical subnet movements using home agent concepts akin to Mobile IP. A group mobility model is introduced and the performance of the HSR is evaluated through a detailed wireless simulation model.

Distributed and mobility-adaptive clustering for multimedia support in multi-hop wireless networks

Abstract: A distributed algorithm is presented that partitions the nodes of a fully mobile network (multi-hop network) into clusters, thus giving the network a hierarchical organization. The algorithm is proven to be adaptive to changes in the network topology due to nodes' mobility and to nodes addition/removal. A new weight-based mechanism is introduced for the efficient cluster formation/maintenance that allows the cluster organization to be configured for specific applications and adaptive to changes in the network status, not available in previous solutions. Specifically, new and flexible criteria are defined that allow the choice of the nodes that coordinate the clustering process based on mobility parameters and/or their current status. Simulation results are provided that demonstrate up to an 85% reduction on the communication overhead associated with the cluster maintenance with respect to techniques used in clustering algorithms previously proposed.

Effective bandwidth-based admission control for multiservice CDMA cellular networks

Abstract: We develop product form traffic models for single- and multiple-cell code-division multiple-access (CDMA) networks with multiple classes of mobile subscribers. The key feature of this development is the specification of a flexible call admission control procedure that details the numbers of mobiles of each class in each cell that the system operator should allow in order to maintain an acceptable quality of service. Effective bandwidth techniques from the analysis of statistical multiplexing at an asynchronous transfer mode (ATM) based broadband integrated services digital network (ISDN) link are used to give performance guarantees that overcome the variability in interference levels characteristic of CDMA cellular networks. The result is an admissible region bounded by a finite number of hyperplanes and a simple and efficient call admission policy. The CDMA mobile network, operating within the admissible region described, has a very similar form to a circuit-switched network operating with fixed routing. This similarity allows the existing traffic modeling techniques and network management strategies for general loss networks to be applied to CDMA mobile cellular networks. In particular, with standard assumptions on the call arrival processes and holding times, the stationary state distribution has a product form on the truncated state space defined by the call admission strategy.

Location system combining ranging measurements from GPS and cellular networks

Abstract: Methods and arrangements are provided for locating a mobile terminal (38) within a mobile telecommunications system. In certain embodiments, GPS ranging signals (14) and cellular base station (20) transmitted downlink signals are received by a mobile terminal, which is configured to determine its current location using a combination of these two types of ranging signals. In certain other embodiments, GPS ranging signals (14) are received by the mobile terminal (38), which is also configured to transmit uplink signals to cellular base stations (20). The current location of the mobile station is determined by fusing measured data from each of these different ranging signal transmissions. By combining the available resources of satellite and terrestrial (20) locating processes, the potential for locating a mobile terminal (38) is significantly increased.

Cell Planning for Wireless Communications

Abstract: From the Publisher: Obtain a more accurate analysis of radio propagation in cellular networks using the proven techniques described in this book. Cell Planning for Wireless Communications surveys the principle tools used in the planning of micro/pico cellular systems for personal communication networks. Engineers, researchers, consultants, and mobile communication graduate students learn how to use specific computer codes to perform a reliable analysis of the major aspects of micro/pico cellular design including propagation, fading estimation, mutual interference, cell geometry, teletraffic, and channel allocation. The book shows you how to improve the design of microcellular network systems by combining propagation models with topographical/morphological databases and ray-tracing acceleration techniques. The authors explain Physical Optic (PO), Geometrical Optic (GO), and the Uniform Theory of Diffraction (UTD) for the analysis of propagation in complex urban or indoor scenarios. The book also surveys select empirical propagation models. With over 100 illustrations, 300 equations, computer models and applications to PCS planning, a tutorial presentation of the application of UTD to wireless problems, and new ray tracing algorithms, you get all the information you need to compute propagation in micro/pico cells in one reference. Furthermore, the approaches presented may also be applied to macrocellular systems.

IP services over Bluetooth: leading the way to a new mobility

Abstract: We present protocol concepts for an extension of IP for mobility issues in Bluetooth networks. The protocol is called BLUEPAC IP, where BLUEPAC stands for "BLUEtooth Public ACcess". "Public access" means access to various kinds of information in public areas, e.g. airplane, train, hotel room, department store, museum. Bluetooth will reside in low-cost chips that provide wireless communication up to OSI Layer 2. By the end of this year many mobile devices, e.g. notebooks, PDAs, cell phones, will contain Bluetooth chips as a cable replacement. But Bluetooth is move powerful: with a suitable network protocol that inherits all aspects of IP, it will be possible to provide IP services over Bluetooth. BLUEPAC IP takes IP as a basis and additionally includes functionalities of mobile IP and cellular IP for local IP address assignment, routing issues and handoff support.

Mobile and Personal Communications in the 60 GHz Band: A Survey

Abstract: This paper intends to present a summary of the technical issues arising in the exploitation of the 60 GHz mm-wave band for mobile and personal communications. The most significant applications proposed so far are surveyed, with particular emphasis placed on recent experimentation about millimeter-wave propagation for road/railway transportation as well as indoor scenarios. As a case study, the capacity of a (micro-)cellular Code Division Multiple Access (CDMA) network in the 60-GHz band is also evaluated in detail.

System and method for informing network of terminal-based positioning method capabilities

Abstract: A telecommunications system and method is disclosed for allowing a cellular network to determine the optimum positioning method, having knowledge of all available network-based and terminal-based positioning methods. This can be accomplished by the Mobile Station (MS) sending to the Mobile Switching Center/Visitor Location Register (MSC/VLR) a list of terminal-based positioning methods that the MS is capable of performing. This list can, in turn, be forwarded to the Mobile Positioning Center (MPC) for determination of the optimum positioning method. For example, in a GSM network, the MS CLASSMARK information, which is sent to the MSC/VLR when the MS registers with the MSC/VLR, can be extended to include the MS's positioning capabilities.

Time division multiple access downlink personal communications system voice and data debit billing method

Abstract: A method and apparatus for full-duplex data communication in or for a wireless communications network, such as a cellular network, PCS network, or mobile satellite network, where a remote feature access control operation utilizes a switch to reserve and route selected voice channels or traffic channels in response to the remote feature access control operation. The method comprising the steps of: configuring a mobile switching center (MSC) to route the selected voice channels to a multi-port protocol converter (MPPC) for transmitting a selected data message on the selected voice channel. Transmitting the selected data message via the multi-port protocol converter on the selected voice channel via a data messaging channel during the remote feature access control operation. Then the selected data message is received at a communicator, which is communicatively linked to a reverse voice and/or digital traffic channel of the wireless network, thereby providing for both forward and reverse messaging on the wireless communications network. An apparatus is disclosed for data communication in or for a wireless communications network for transmitting and receiving both forward and reverse voice, traffic, and control channel messages utilizing the disclosed methodology.

On the teletraffic capacity of CDMA cellular networks

Abstract: The aim of this paper is to contribute to the understanding of the teletraffic behavior of code-division multiple-access (CDMA) cellular networks. In particular, we examine a technique to assess the reverse link traffic capacity and its sensitivity to various propagation and system parameters. We begin by discussing methods of characterizing interference from other users in the network. These methods are extremely important in the development of the traffic models. We begin with a review of several existing approaches to the problem of handling other-cell interference before presenting a novel characterization of the interference in the form of an analytic expression for the interference distribution function in the deterministic propagation environment. We then look at extending the capacity analyses that assume a fixed and equal number of users in every cell to handle the random nature of call arrivals and departures. The simplest way to do this is by modeling each cell of the network as an independent M/G/x/spl infin/ queue. This allows us to replace the deterministic number of users in each cell by an independent Poisson random variable for each cell. The resulting compound Poisson sums have some very nice properties that allow us to calculate an outage probability by analyzing a single random sum. This leads to a very efficient technique for assessing the reverse link traffic capacity of CDMA cellular networks.

Any network, any terminal, anywhere [cellular radio]

Abstract: In light of the current technology trends in the area of applications, wireless networks, and terminals, this article isolates a number of design requirements of future advanced mobile systems. We discuss research and standardization activities in the area of service support platforms and their corresponding application programming interfaces (API), where we especially focus on the wireless application protocol (WAP), Mobile Station Execution Environment (MExE), and HTTP-NG as candidates for the provision of mobile Internet services in cellular networks.

Wireless telecommunications system and method of operation providing users′ carrier selection in overlapping hetergenous networks

Abstract: An improved wireless telecommunication system enables a user to obtain communication services in overlapping wireless heterogeneous or homogeneous cellular networks at the most economical cost and bandwidth. A plurality of overlapping cellular networks includes a common command channel, a Central Selection Agency (CSA), a home location register, a visitor location register, and a user device positional location mechanism. In one embodiment the user device is equipped with a Global Positioning System (GPS) to determine its location. In placing a call, the user device broadcasts its ID, location and connection capability requirements on the common command channel. When a base station for the command channel bears the request, the CSA and the home location register for the user are informed. The CSA capability/requirements determine which network and base station selections are potential carriers for the call. Based on user preferences established by a profile stored in an accessible database, the CSA assigns a network and base station to handle the connection. The user device is informed and tunes to the appropriate network and protocols. For incoming calls, the calling party checks the home location register to determine the last known location. The user device is informed that a called is waiting. The user device selects the network and base station to receive the call in a fashion similar to that of placing the call. A call may be transferred from one network to a different network, the networks using different protocol. The user device may be programmed to change networks at random times to provide enhanced security for a call.

System and method for providing location services in parallel to existing services in general packet radio services architecture

Abstract: A telecommunications system and method is disclosed for enabling a General Packet Radio Service (GPRS) node, namely a Serving GPRS Support Node (SGSN) within a cellular network, to be able to handle requests for Location Services (LCS) for a GPRS mobile station (MS) in parallel to other existing transactions such as delivering short messages or engaging in session management activity, e.g., data call connection. A new LCS transaction type can be introduced in the Connection-Management (CM) sub-layer of GPRS in the SGSN and the GPRS MSs to handle requests for LCS in parallel to other offered services. LCS can be multiplexed together with other existing functions in GPRS by allocating a new Service Access Point Identifier (SAPI) to LCS within the Logical Link Control (LLC) sub-layer of the GPRS. Alternatively, when a common LLC SAPI is used between different CM-sublayer functions,then a different protocol discriminator (PD) can be allocated for LCS.

Combined power control and transmission rate selection in cellular networks

Abstract: Emerging multimedia services in cellular radio systems introduce a variable transmission rate, which raises the problem of controlling transmission rates in a spectrally efficient way. We formulate the problem into a combined power and rate control, for which we suggest two different algorithms. In the first one, we derive an algorithm applying the Lagrangian relaxation technique. In the other method, called selective power control we extend a fixed rate power control algorithm to solve the problem. Computational experiments carried out on a CDMA system indicate that the proposed algorithms give satisfying performance in terms of system throughput, outage probability and transmission power consumption.

Cdma transmission of packet-switched data

Abstract: A method for conveying packet data from a CDMA mobile station (40) to a GSM network (22), including communicating with a GSM service node to establish a data link from the mobile station (40) to the network (22) via a radio communications base station (32). The packet data are conveyed between the mobile station (40) and the base station (32) over a CDMA air interface and are then transferred over the link between the base station (32) and the network (22).

An efficient IF architecture for dual-mode GSM/W-CDMA receiver of a software radio

Abstract: Software radios have been widely studied as a solution to support multiple air interface standards in future wireless communications. In this paper, we present an efficient IF processing architecture for a dual-mode GSM/W-CDMA terminal based on the concept of software radio. Simplified digital mixer, high decimation rate filter and fractional frequency conversion techniques are adopted in this architecture to make it compatible with both GSM and W-CDMA. Simulation results show the performance of the architecture is suitable.

High data-rate packet communications for cellular networks using CDMA: algorithms and performance

Abstract: The advantages of code division multiple access (CDMA) for cellular voice have become well known, and IS-95-based systems have now been widely deployed. Attention is now focused on higher data-rate packet services for cellular systems. Although many packet multiple access schemes have been studied over the years, researchers have often studied single cell performance and ignored reuse. Moreover, direct sequence spread spectrum (DSSS) has been considered unsuitable for high data-rate packet multiple access since spreading limits the permitted data rates, DSSS requires large overhead (preambles) for acquisition and requires closed-loop power control. In this paper, we describe a scheme for high data-rate packet service using CDMA that addresses all of the above problems and has been standardized in Revision B of IS-95. A low rate fundamental code channel is maintained that eliminates the need for long preamble and provides closed-loop power control. Reuse is managed by the infrastructure through a "burst-level" admission control based on load and interference-level measurements at the base stations and mobiles. We report on the feasibility of such a burst-mode packet data service for cellular CDMA networks. The focus is not only on the performance of high data-rate users, but also on the impact on voice users sharing the CDMA band. We propose a multitiered performance analysis methodology consisting of a mix of static simulations, dynamic simulations at different time scales, and analytic methods to address the various feasibility issues: impact on coverage; capacity; power control; and effectiveness of burst admission algorithms. Based on the current study, we can conclude that the proposed approach is well suited for third-generation wideband CDMA systems being considered for standardization throughout the world.

An overview of cellular IP

Abstract: A number of initiatives to add mobility to the Internet and packet data services to third generation cellular systems are being considered by emerging mobile service providers as possible candidate solutions for the delivery of IP data to mobile users. Both of these two candidates have a number of shortcomings, however. Mobile IP represents a simple and scalable global mobility solution but is not appropriate in support of fast and seamless handoff control. In contrast, third generation cellular systems offer smooth mobility support but are built on complex networking infrastructure that lacks the flexibility offered by IP-based solutions. In this paper we present an overview of cellular IP which represents a 'third way' combining the strengths of bath approaches without inheriting their weaknesses. Cellular IP combines the capability of cellular networks to provide smooth fast handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks.

TD-SMS messaging gateway

Abstract: A gateway interface between the public switched telephone system (PSTN) and cellular network. The gateway interface provides a conversion function between the SMS text messaging protocol and TD device text messaging protocol. The conversion function includes appropriate queuing and timing features that allow the SMS and TD functions to communicate. In an embodiment of the invention, the method and apparatus is implemented as a stand-alone gateway. The gateway may be implemented anywhere there is access to the public switched telephone network (PSTN) and coverage by a cellular system having short messaging service (SMS) capability.

Radio Propagation in Cellular Networks

Abstract: From the Publisher: Radio Propagation in Cellular Networks delivers the most comprehensive description of propagation phenomena in urban, suburban, and rural environments to help you improve the efficiency of wireless communications systems. It is also the first book to consider the full algorithm for radio coverage prediction and cellular characteristic prediction to increase performance of radio and cellular map design. This thorough book helps wireless local loop, stationary and wireless system designers construct radio coverage maps, predict cellular characteristics in communications channels, design and split cellular maps, and predict cellular systems performance in complex, urban environments. This book includes analysis of free space propagation over regular and irregular terrain, reflection and diffraction by various obstacles, including hills, buildings, and trees, and well as the effects of scattering due to such obstacles and terrain. This is an essential sourcebook on radio propagation for wireless communication planners, designers and engineers, and it emphasizes behavior of waves in the UHF/L-frequency band throughout.

Method and apparatus for providing access of messages to multiple recipients in cellular networks

Abstract: A message accessing apparatus and method for providing access of select messages (voice or text) to multiple recipients in cellular networks. A network subscriber accesses a subscriber's mailbox which contains a message, by entering a voice messaging service address code and entering a personal access code. A temporary access code is then assigned to the selected message and the messaging service address code and temporary access code are transmitted to the intended recipients of the voice message to allow the intended recipients to access the selected message by contacting the voice messaging service and entering the temporary access code.

System and method for implementing positioning quality of service

Abstract: A telecommunications system and method is disclosed for allowing an application requesting positioning of a mobile terminal to indicate the quality of positioning information desired, e.g., timeliness, accuracy, etc. In addition, prior to performing the positioning, the cellular network can determine whether the quality of service requested can be achieved, and if so, return the positioning information along with a message indicating that the quality of service requested was achieved. However, if the quality of service requested cannot be achieved, a failure message is sent to the requesting application and the positioning is not performed.

Cellular mobile telephone network operation

Abstract: Where a call of one cellular telephone network has a cell of another network as neighbor, a dedicated control channel for a mobile station which is registered with the public network and whose subscriber has access privileges for the private network, carries neighboring cell data for the cell of the private network. Consequently, the mobile station (provides measurement reports for cells of both network and can be preferentially handed over to the cell of the private network by the public network.

Enhanced privacy and authentication for the global system for mobile communications

Abstract: The Global System for Mobile Communications (GSM) is widely recognized as the modern digital mobile network architecture. Increasing market demands point toward the relevancy of security-related issues in communications. The security requirements of mobile communications for the mobile users include: (1) the authentication of the mobile user and Visitor Location Register/Home Location Register; (2) the data confidentiality between mobile station and Visitor Location Register, and the data confidentiality between Visitor Location Register and Visitor Location Register/Home Location Register (VLR/HLR); (3) the location privacy of mobile user. However, GSM does not provide enough security functions to meet these requirements. We propose three improved methods to enhance the security, to reduce the storage space, to eliminate the sensitive information stored in VLR, and consequently to improve the performance of the system. Proposed methods include an improved authentication protocol for the mobile station, a data confidentiality protocol, and a location privacy protocol. The merit of the proposed methods is to improve but not to alter the existing architecture of the system. Furthermore, this study also performs computational and capacity analyses to evaluate the original GSM system and proposed approaches on a comparative basis.

System and method for accessing the internet in an internet protocol-based cellular network

Abstract: A telecommunications system and method is disclosed for transmitting and receiving short messages between a Mobile Station (MS) within an Internet Protocol (IP) based cellular network and a web site on the Internet. Each web site that the MS has access to contains an Application Program (AP). To retrieve the information, the MS within an IP-based cellular network originates a short message towards the AP associated with the web site using a pre-assigned E.164 number for the AP. When the short message reaches a Mobile Switching Center (MSC), an Application Manager (AM) within the MSC intercepts the short message and translates the E.164 number into an IP-address and port number for the AP. The AM extracts the data from the short-message, packs the data in an SMTP envelope and transmits it to the AP.

Implicit resource allocation in a communicaiton system

Abstract: In a communcations system, communications resources are allocated in a dynamic, 'as needed' fashion. No explicit signaling is needed to exchange information pertaining specifically to an allocated communications resource. Instead, resources are implicitly allocated by using one or more parameters known to both the radio access network and mobile station that are more or less unique to the mobile station. Such parameters are used to generate or address a communications resource for use by the mobile station. The parameters might, for example, be information readily acquired or communicated as a result of a synchronization procedure, a mobile station registration procedure, a mobile station access procedure, a paging procedure, etc. Example parameters may include a system frame number, a system identification, a radio access network identification, a base station identification, a cell identification, a mobile station-associated signature, an access reference number corresponding to the mobile station, a time instant when an acknowledgment message is received, etc.