By Topic

Selected Areas in Communications, IEEE Journal on

Issue 8 • Date Oct 1994

Filter Results

Displaying Results 1 - 14 of 14
  • A caching strategy to reduce network impacts of PCS

    Publication Year: 1994 , Page(s): 1434 - 1444
    Cited by:  Papers (89)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1020 KB)  

    We propose an auxiliary strategy, called per-user caching, for locating users who move from place to place while using Personal Communications Services (PCS). The caching strategy augments the basic location strategy proposed in existing standards such as GSM and IS-41, with the objective of reducing network signaling and database loads in exchange for increased CPU processing and memory costs. Since technology trends are driving the latter costs down, the auxiliary strategy will become increasingly attractive. The idea behind caching is to reuse the information about a called user's location for subsequent calls to that user, and is useful for those users who receive calls frequently relative to the rate at which they change registration areas. This idea attempts to exploit the spatial and temporal locality in calls received by users, similar to the idea of exploiting locality of file access in computer systems. We use a reference PCS architecture and the notion of a user's local call-to-mobility ratio (LCMR) to quantify the costs and benefits of using caching and classes of users for whom it would be beneficial. We also present two simple algorithms for estimating users' LCMR and the situation in which each is preferable. We show that under a variety of assumptions caching is likely to yield significant net benefits in terms of reduced signaling network traffic and database loads View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A topology transparent link activation protocol for mobile CDMA radio networks

    Publication Year: 1994 , Page(s): 1426 - 1433
    Cited by:  Papers (12)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB)  

    A topology transparent protocol for link activation in mobile CDMA networks is presented. The protocol resolves primary and secondary conflicts, and can easily be adapted to TDMA link activation, as well. The proposed protocol guarantees that each link will be successfully activated at least once in a frame without the need to adjust transmission schedules in mobile environments. Compared to other protocols with guaranteed delivery, the overhead due to the recomputation of transmission schedules is eliminated and, accordingly, transmissions need not be suspended for schedule reorganization. Furthermore, contrary to previously known protocols that adapt to mobility by schedule recomputation, the proposed solution is not subject to a potential catastrophic failure when the rate of topology changes exceeds the rate at which schedules can be readjusted. We prove the correctness and evaluate the efficiency of the new protocol by analytical methods View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A distributed paths migration scheme for IEEE 802.6 based personal communication networks

    Publication Year: 1994 , Page(s): 1415 - 1425
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (824 KB)  

    Wireless personal communications will be provided via the usage of microcells in urban areas. The current centralized architecture may be unsuitable with the increased processing load and handoff rate associated with microcells. Some distributed architectures based upon interconnected IEEE 802.6 MAN'S for wireless personal communications have been proposed recently. The IEEE 802.6 MAN is attractive since it also provides isochronous services which are quite suitable for voice communications. In such a network, a communication path between two mobile terminals may be inefficient due to the lack of better paths when the path is established or become inefficient due to the mobility of terminals, e.g., the path elongates and consumes too much isochronous channels. In this paper, a distributed paths migration scheme is proposed for the IEEE 802.6 based personal communication networks. This distributed scheme automatically recognizes inefficient paths and migrates them to better ones, if any. During the migration, the property of isochronous services is also preserved. The performance of this scheme is evaluated by simulations. Simulation results show that the proposed paths migration scheme dramatically reduces the number of isochronous channels consumed per path. As a result, the call blocking rate is reduced and the number of successful established paths is increased significantly View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Meeting QOS requirements in a cellular network with reuse partitioning

    Publication Year: 1994 , Page(s): 1389 - 1400
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1140 KB)  

    Reuse partitioning is a technique for providing more efficient spectrum reuse in cellular radio systems. A cell in such a system is divided into concentric zones, each associated with an overlaid cell plan. Calls that arise in the periphery of the cell have fewer channels in their availability than those arising close to the base station and therefore they experience higher blocking rates. In this paper we consider the problem of balancing uniformly the blocking probability throughout the cell offering a fair treatment to the whole area within the cell, by controlling the allocation to the different channel layers. A policy that minimizes the maximum blocking probability experienced at any location of the cell is identified and is shown to be of threshold type. The policy satisfies any achievable constraint on the blocking rate uniformly throughout the cell. An adaptive scheme that adjusts the threshold based on estimates of the blocking probabilities in the different zones of the cell is proposed. This scheme tracks the optimal threshold effectively without any knowledge of the traffic parameters. Simulation study shows that substantial capacity improvements are achieved by the application of the optimal channel assignment policy, over the uncontrolled system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Frequency-hopped ARQ for wireless network data services

    Publication Year: 1994 , Page(s): 1324 - 1337
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (888 KB)  

    The throughput efficiency and probability of undetected error of automatic-repeat-request (ARQ) protocols employing slow frequency hopping over Gilbert-Elliott (1960, 1963) fading channels are investigated. Throughput efficiency formulas for the three basic ARQ schemes, “stop-and-wait” (SW), “go-back-N” (GBN), and “selective-repeat” (SR), are obtained, and the improvement in throughput efficiency due to slow frequency hopping is examined. Results are also presented on the problem of determining the number of carriers used for frequency hopping so as to minimize the effect of fading channel memory and, therefore, optimize system performance. This work has application to TDMA architectures and packet data services for third generation wireless networks, where projected data service requirements call for error rates on the order of 10-9 , and the multiple service, multiple access environment demands that the delay for any service be minimized View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of a wireless MAC protocol with client-server traffic and capture

    Publication Year: 1994 , Page(s): 1299 - 1313
    Cited by:  Papers (17)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1156 KB)  

    We analyze an efficient medium access control (MAC) protocol for use in a single cell of a wireless local area network (LAN). A fixed frame structure with two periods is used; one period for making reservations using a slotted Aloha protocol and a second period for data transmission. The MAC protocol operates in a centralized manner in which a single station, the base station, accepts reservations (transmission or data requests) that are made by the remote stations, and then schedules the times in which they will transmit or receive data. We consider two different types of client-server traffic models, an open-loop and a closed-loop model. In the open-loop model, a remote station can generate reservation requests for the base station whether or not it has received a response from the base station. In the closed-loop case, the remote station waits for a response before generating a new request. The performance of the MAC protocol was analyzed exactly for both the open and closed-loop traffic models and for cases in which transmission errors and a mean-value type of radio capture model are included. In addition, different policies were considered for the transmission strategy that is used by the remote stations when they attempt to make reservations. We derive exact results for the mean throughput and waiting times as well as for the queue length distributions. We also derive an approximate Markov chain to treat a case in which a fixed-position capture model is used. Several types of behavior are illustrated through the use of numerical examples View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A retransmission scheme for circuit-mode data on wireless links

    Publication Year: 1994 , Page(s): 1338 - 1352
    Cited by:  Papers (21)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1156 KB)  

    The cellular radio link is characterized by deep fades leading to long error bursts (lasting hundreds of milliseconds). Data transmission over such links results in large packet error rates (in the range 10-3 to 10-1). We have designed a radio link protocol (RLP) to achieve high throughput on such links. The RLP is based on frequent, complete or partial feedback of the receiver state. Performance results for the US digital cellular TDMA standard show that the scheme can provide the equivalent of 9.6 kb/s service per full-rate TDMA channel above a carrier to interference ratio of 18 dB View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An architecture and methodology for mobile-executed handoff in cellular ATM networks

    Publication Year: 1994 , Page(s): 1365 - 1375
    Cited by:  Papers (238)  |  Patents (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1028 KB)  

    An architecture is presented for a high-speed cellular radio access network based on ATM transport technology. Central to this approach is a new concept known as the virtual connection tree which avoids the need to involve the network call processor for every cell handoff attempt. Such an approach can readily support a very high rate of handoffs, thereby enabling use of physically small radio cells to provide very high system capacity, but may occasionally cause the volume of traffic to be handled by one cell site to exceed that cell site's capacity. A simple analytical methodology is developed which can be used for admission control, the purpose of which is to limit the number of in-progress calls such that two new quality of service metrics (overload probability and average time in overload) can be kept suitably low. Finally, a general framework is presented for overall system organization and signaling View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • ATM-based transport architecture for multiservices wireless personal communication networks

    Publication Year: 1994 , Page(s): 1401 - 1414
    Cited by:  Papers (175)  |  Patents (26)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1136 KB)  

    This paper presents an ATM-based transport architecture for next-generation multiservices personal communication networks (PCN). Such “multimedia capable” integrated services wireless networks are motivated by an anticipated demand for wireless extensions to future broadband networks. An ATM compatible wireless network concept capable of supporting a mix of broadband ISDN services including constant bit-rate (CBR), variable bit-rate (VBR), and packet data transport is explored from an architectural viewpoint. The proposed system uses a hierarchical ATM switching network for interconnection of PCN microcells, each of which is serviced by high-speed, shared-access radio links based on ATM-compatible cell, relay principles. Design issues related to the physical (modulation), media access control (MAC), and data-link layers of the ATM-based radio link are discussed, and preliminary technical approaches are identified in each case. An example multiservice dynamic reservation (MDR) TDMA media access protocol is then considered in further detail, and simulation results are presented for an example voice/data scenario with a proportion of time-critical (i.e., multimedia) packet data. Time-of-expiry (TOE) based queue service disciplines are also investigated as a mechanism for improving the quality-of-service (QoS) in this scenario View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Call control and traffic transport for connection-oriented high speed wireless personal communications over metropolitan area networks

    Publication Year: 1994 , Page(s): 1376 - 1388
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1200 KB)  

    A distributed circuit-switched approach for supporting the deployment of high speed wireless personal communication services in urban areas through the interconnection of base stations via metropolitan area networks (MANs) is proposed. Broadband MANs minimize traffic congestion by dynamic sharing of link capacity and by serving as distributed switches for partitioning call control functions. While the DQDB protocol readily supports distributed packet-switching over the IEEE 802.6 MAN, isochronous traffic such as voice and video is best supported by circuit-switched connections. The authors present an enhanced bi-state pre-arbitrated (PA) transport mechanism, and associated call control and handoff management techniques, which enable distributed circuit-switching over the MAN. These capabilities are not currently addressed in the 802.6 standards. The bi-state PA transport mechanism facilitates statistical multiplexing of variable rate isochronous traffic sources. The network capacity is constrained by the call setup delay performance, and is analyzed by simulations. Alternative signaling architectures, involving different placements of call control network elements, are evaluated. The effects of erasure nodes, and close bus versus open bus architectures, are considered. The overlap inter-MAN call setup procedure is proposed to reduce delays. Different call handoff procedures are formulated according to the type of handoff and the resulting change in call connectivity. Most handoffs are intra-MAN, requiring simple procedures with short delays View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance of autonomous dynamic channel assignment and power control for TDMA/FDMA wireless access

    Publication Year: 1994 , Page(s): 1314 - 1323
    Cited by:  Papers (21)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (976 KB)  

    We combine autonomous algorithms for dynamic channel assignment (DCA) and power control in a TDMA/FDMA wireless system as a medium access control (MAC) protocol. The DCA algorithm determines paired radio channels that experience the least interference and are least likely to cause interference. The power control algorithm uses local estimations of signal to interference ratio (SIR) at a receiver to iteratively command power adjustment on the desired transmitter. A common control frequency, which is frame-synchronized among base stations, provides all necessary information for DCA without blind slots. Computer simulations are used to evaluate system performance. Results from computer simulations demonstrate good spectrum efficiency and robustness. Although studied under a specific set of parameters, this type of MAC protocol can be applied in different wireless communications environments View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Soft handoff extends CDMA cell coverage and increases reverse link capacity

    Publication Year: 1994 , Page(s): 1281 - 1288
    Cited by:  Papers (266)  |  Patents (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (576 KB)  

    The effect of handoff techniques on cell coverage and reverse link capacity is investigated for a spread spectrum CDMA system. It is shown that soft handoff increases both parameters significantly relative to conventional hard handoff View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Traffic models for wireless communication networks

    Publication Year: 1994 , Page(s): 1353 - 1364
    Cited by:  Papers (27)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1080 KB)  

    Introduces a deterministic fluid model and two stochastic traffic models for wireless networks. The setting is a highway with multiple entrances and exits. Vehicles are classified as calling or noncalling, depending upon whether or not they have calls in progress. The main interest is in the calling vehicles; but noncalling vehicles are important because they can become calling vehicles if they initiate (place or receive) a call. The deterministic model ignores the behavior of individual vehicles and treats them as a continuous fluid, whereas the stochastic traffic models consider the random behavior of each vehicle. However, all three models use the same two coupled partial differential equations (PDEs) or ordinary differential equations (ODEs) to describe the evolution of the system. The call density and call handoff rate (or their expected values in the stochastic models) are readily computable by solving these equations. Since no capacity constraints are imposed in the models, these computed quantities can be regarded as offered traffic loads. The models complement each other, because the fluid model can be extended to include additional features such as capacity constraints and the interdependence between velocity and vehicular density, while the stochastic traffic model can provide probability distributions. Numerical examples are presented to illustrate how the models can be used to investigate various aspects of time and space dynamics in wireless networks View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Capture and retransmission control in mobile radio

    Publication Year: 1994 , Page(s): 1289 - 1298
    Cited by:  Papers (125)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB)  

    We consider the slotted ALOHA protocol with capture, in a mobile communication environment, in the presence of Rayleigh fading and log-normal shadowing. The capture probabilities and their asymptotic value, as the number of colliding packets tends to infinity, are computed. A sufficient condition, under which this limit is positive, is identified and expressed in terms of the spatial distribution of the users. Also, various models for this latter distribution are discussed. These results help identify the region in which the system may achieve a positive stable throughput. Finally, a retransmission control scheme, that enhances the throughput, is considered, and the stability of the system is rigorously proven. We also show that the use of retransmission control is unavoidable if the network performance predicted in some recent literature is to be achieved View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Journal on Selected Areas in Communications focuses on all telecommunications, including telephone, telegraphy, facsimile, and point-to-point television, by electromagnetic propagation.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Muriel Médard
MIT