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Antennas and Propagation for Future Mobile Communications (Ref. No. 1998/219), IEE Colloquium on

Date 23 Feb 1998

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Displaying Results 1 - 14 of 14
  • The effect of sub-optimal base station positioning on the performance of a cellular network

    Page(s): 7/1 - 7/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    This paper discusses some aspects of self organisation in future cellular communications. In particular the effect sub-optimal base station positioning has on the overall interference level in the network. It is shown that the interference increases as the BS positioning error becomes more severe. The dropping probability becomes unacceptable as a the error increases. With the incorporation of a simple power control algorithm, the network's sensitivity to error in BS positioning is reduced and an improvement in the performance is achieved View full abstract»

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  • Characterising the radio propagation channel

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    Summary form only given. Optimising the designs of new cellular radio products requires a detailed understanding of the radio propagation characteristics of the transmission paths between mobiles or fixed subscriber terminals and base stations. The performance of a radio network in terms of coverage or capacity critically depends on factors such as path loss, multipath delay and angle spread and fading statistics. Detailed characterisation of these factors is very important in order to derive appropriate models of the propagation which can be used for more accurate prediction of radio link performance for product development and to determine the most effective deployment strategies for the RF network. This paper describes the upgrades made to the aperture analyser measurement facility (consisting of a base station receiver and a mobile transmitter which can be operated in a wideband channel sounding mode) and provides details of trials conducted in central London aimed at investigating the propagation phenomena for macrocellular and micro-cellular deployments in the 2 GHz band View full abstract»

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  • The STORMS project: an antennas and propagation perspective

    Page(s): 1/1 - 1/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    The article presents an overview of the functionality of the STORMS planning tool from an antennas and propagation perspective, with particular emphasis on novel integral equation methods used in propagation modelling. The STORMS prototype propagation tool is an advanced and versatile body of object oriented software. It provides the developer with an open environment facilitating the incorporation of new propagation models which can fully use any of a range of existing modules View full abstract»

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  • Indoor coverage requirements and solutions

    Page(s): 3/1 - 3/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (340 KB)  

    Mobile phones are already becoming a part of everyday life. Subscribers expect to be able to use their handsets everywhere. A key factor in the success of a cellular operator therefore is the ability to fulfil subscribers' expectations in terms of coverage. Hence, dedicated indoor coverage is required where the signal from outdoor cells is weak or where additional capacity is needed. Indoor coverage planning differs from its outdoor counterpart due to the large variety of building types and layouts combined with the constraint that the indoor cell must integrate seamlessly with the existing outdoor network. This paper discusses how in-building coverage generates new challenges for GSM operators, equipment manufacturers and network planners and how these are being addressed View full abstract»

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  • Efficient handover signalling for microcellular environments using packet access mechanism

    Page(s): 4/1 - 4/9
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    Future microcellular systems will require distributed network architecture and decentralised control to manage the large number of inter-cell handovers associated with the mobility of wireless terminals. Packet networks with autonomous routing and mobile initiated handovers represent the appropriate architecture for microcellular networks. A new handover strategy for microcellular environments is investigated. Handover signalling is diverted from the fixed part of the network to the air interface using PRMA++, the packet access mechanism proposed for operation within the RACE-ATDMA project for third generation wireless cellular networks. In this paper, handover delays in a GSM network are evaluated, using both fixed channel allocation (FCA) and dynamic channel allocation (DCA). The new strategy utilises the statistical multiplexing characteristic of the packet access mechanism to route handover signalling between current and candidate base stations (BS) via the radio interface instead of the public land mobile network (PLMN). Results show a faster handover procedure and improved spectral efficiency as compared to existing systems View full abstract»

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  • The use of adaptive antennas for cellular subscriber location experimental results

    Page(s): 11/1 - 11/7
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    This paper presents the results of an adaptive antenna measurement platform for PCS1800 frequency division duplex operation. A description of the measurement site in central London, UK is followed by a brief note on the data available and used for post-processing in this paper. Frequency division duplex operation is analysed in terms of the estimated peak-energy spectral energy density `look-direction' in the uplink and downlink channels and compared to the GPS estimated positions of a mobile transmitter View full abstract»

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  • A ray tracing approach to predicting indoor field distributions

    Page(s): 6/1 - 6/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (204 KB)  

    The last decade has seen an unprecedented growth in the use of mobile radio services both in the UK and overseas. This development has been aided by much research interest in the field of mobile telephony. The radio environment is unfortunately a complex and somewhat hostile one for application of broadband systems. The received signal typically arrives via many separate paths arising from reflections, diffraction, and scattering within the surrounding media. The area of mobile radio propagation modelling has been actively researched, providing many useful methods. This work can be broadly divided into two categories-simulation and predictive models. The simulation model initially assumes that there are measured data obtained from the environment. An attempt is then made to find a mathematical model which agrees with the measured data. This approach is very useful but it does have limitations. The model cannot easily be changed for different environments and involves further measurements. In this paper a ray tracing algorithm for the prediction of propagation characteristics in cordless applications is presented. It is suitable for the prediction of narrow-band indoor field distribution View full abstract»

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  • 5 GHz indoor channel characterization: measurements and models

    Page(s): 10/1 - 10/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    The advent of the HIPERLAN standard in Europe and the emergence of the U-NII bands in the USA allow the development of high bit-rate (>20Mbps) indoor wireless products at 5 GHz. The home is a fertile application ground for such technology. This has prompted the need to investigate the domestic indoor wireless propagation environment at 5 GHz. From measurements in houses, two empirical models were proposed to describe the path loss variation with distance throughout a house. Both models are based on the log-distance metric. One model is specific to individual rooms in a house whereas the other is a worst-case generalisation for all rooms on a floor View full abstract»

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  • TSUNAMI (II)-initial field trial results [macrocellular radio]

    Page(s): 9/1 - 9/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    The TSUNAMI (II) (Technology in Smart antennas for UNiversal Advanced Mobile Infrastructure-Part 2) project is on investigation into the application of adaptive antenna technology for use in future generation mobile communications systems. The key aims of the project are to study the complexity versus increase in system capacity and coverage extension that can be achieved over the existing, non-adaptive networks. This paper presents some of the initial results from the TSUNAMI (II) macrocellular field trials currently being performed or the Orange Testbed in Almondsbury, Bristol. Field trial results obtained using spatial reference beamforming (SRB) are presented along with tests performed with the calibration sub-system. The results of these tests demonstrate the successful integration and operation of the TSUNAMI (II) system View full abstract»

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  • An integrated deterministic urban/rural propagation model

    Page(s): 5/1 - 5/7
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    Cochannel interference is one of the major causes of signal quality degradation in a radio link, and the challenge to the cellular network planner is to deploy the network in a manner that maximises the carrier to interference ratio (C/I) for each cell. To this end, most network planners make use of computer propagation prediction models, which predict signal strength in the radio environment. This paper describes an integrated 3D model, which combines the key features from previous urban and rural models. The model considers full 3D off-axis scattered paths from building walls and terrain pixels. It further considers terrain and rooftop diffraction and combinations of off-axis diffracted and scattered paths. Predictions from the model are compared with narrowband measurements made in urban and rural environments. The importance of buildings and foliage is investigated, as is the accuracy improvement of the 3D analysis compared to the simpler 2D vertical plane approach View full abstract»

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  • Propagation activities in the Mobile VCE

    Page(s): 2/1 - 2/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (500 KB)  

    The Mobile VCE (Virtual Centre of Excellence in Mobile and Personal Communication) represents a new approach to collaborative research, permitting industry and academia to work together in partnership to innovate for the future of mobile radio systems. As part of the Mobile VCE, the Radio Environment Work Area will produce propagation measurements and models of parameters which have been little studied elsewhere, particularly within the mixed environments which are the key focus for this project. These will ultimately enable system designers to create innovative radio architectures to meet the needs of tomorrow's multi-service, multi-environment mobile radio users. This paper describes the propagation and channel modelling activities currently underway within the Mobile VCE View full abstract»

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  • IEE Colloquium on Antennas and Propagation for Future Mobile Communications (Ref. No.1998/219)

    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (124 KB)  

    The following topics were dealt with: STORMS project antennas and propagation perspective; mobile VCE; indoor coverage; microcellular handover signalling; integrated deterministic urban/rural model; ray tracing for indoor field distributions prediction; cellular network sub-optimal base station positioning; microcellular planning; TSUMANI II field trial results; 5 GHz channel characterisation; adaptive antennas for cellular subscribers location; spatial domain for high bit rate indoor communications; radio propagation channel View full abstract»

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  • Exploiting the spatial domain for high bit rate indoor communications

    Page(s): 12/1 - 12/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    The ACTS AWACS (ATM Wireless Access Communications Systems) project is considering the feasibility of supporting ATM compatible bit rates over the wireless bearer for low mobility terminals using directional antenna technology. The viability of directional antennas as an alternative to equalisation and multicarrier techniques is studied by employing pre-prototype hardware supplied by NTT Wireless Research Labs (Japan). This The paper presents the results of an investigation into the effects of spatial filtering on the performance of high bit rate wireless ATM systems. Various combinations of directional and omni antennas have been considered in a number of indoor environments. The scenarios studied range from short and long multipath variation (from a few centimetres to 25 m), LOS, partial-LOS and obstructed-LOS situations View full abstract»

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  • Microcellular planning based on information from the radio network

    Page(s): 8/1 - 8/8
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (620 KB)  

    This paper describes a novel approach to designing microcells in GSM radio networks. The proposed approach is based on a two-stage process. At the first stage, the most suitable location for a microcell is determined, while during the second stage the least interfered channel for the microcell is established. The novelty of the suggested method lies in the fact that information provided by the radio network as part of the standard GSM functionality is analysed to provide the optimum solution for these two tasks. Based on this approach microcells can be planned more accurately and more cost effectively than currently possible View full abstract»

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