CENTRE FOR COMMUNICATION SYSTEMS RESEARCH

CENTRE FOR COMMUNICATION SYSTEMS RESEARCH

2

ANNUAL REPORT

INDE

X

3


INTRODUCTION 5

Prestigious Highlights of 1997 6

Industrial Partners 7

Current Grants / Contracts 8

Current Research Topics 9

MOBILE COMMUNICATIONS

RESEARCH GROUP 10

1. Satellite Mobile Communications 10

2. Broadband Satellite Communications 14

3. Terrestrial Mobile Communications 15

4. Wireless LAN 18

MULTIMEDIA SYSTEMS

RESEARCH GROUP 19

1. Low Bit Rate Speech and Audio Coding 19

2. Image and Video Coding 20

3. Channel Coding 21

4. Modulation and Coding 22

COMMUNICATION NETWORKS

RESEARCH GROUP 23

1. ATM and Broadband Communications 23

2. Network and Service Management 25

3. Network Access and Interworking 25

4. Internet and ATM over Satellites 26

CCSR STAFF 28

PhD’s awarded 95-97 30

CCSR PUBLICATIONS LIST 31

1997 31

1996 34

1995 38

1997

Centre for Communication Systems Research

19

4

9 7

INRT

ODU

CTIO

N

5

INTRODUCTION

The Centre for Communication SystemsResearch was set up as an autonomousResearch Centre in 1996, within the School ofElectronic Engineering, IT and Mathematicsand now houses :

● 10 Academics

● 20 Research assistants

● 37 PhD Research students

● 6 Support staff

Our research is sub-divided into three research areas as follows:

Mobile Communicationsled by Dr Rahim Tafazolli

Multimedia Systemsled by Professor Ahmet Kondoz

Communication Networksled by Dr Zhili Sun pending arrival of Professor George Pavlou in 1998.

Our research concentrates on future communication systems for the next millennium. We are unique in our coverage of:

● Mobile and wireless communications

● Satellite communication systems

● Integration of communication systems

● Telecommunication management systems (TMN, CORBA, Java)

● Core network technologies (ATM, IP, Software telecommunications)

● Multimedia services and signals (speech, video and service)

● Networking (protocols, software, security)

● Enabling technologies (modulation, coding, signal processing, channel characterisation)

Overall, CCSR has over £4 million of ongoingspecialised research, funded in approximatelyequal ratios from the European Union (ACTS,ESPRIT), the EPSRC (a major research councilin the United Kingdom), and industry.

CCSR is a major player in the European Union,with fifteen ACTS and ESPRIT projects runningfrom 1998. These range from satellite systems,mobile communications, multimedia, IP andATM telecommunications management to newchips. Our European partners number aroundforty companies and universities.

In the UK, CCSR is a member of the two VirtualCentres of Excellence, in Mobile and PersonalCommunications and Multimedia Broadcasting.In addition we have major funding from EPSRCmanaged (ROPA, LINK, JREI) programmes andresponsive mode Grants. On the industrialfront, we now have twelve industrially-funded projects which cover UK, European, Japaneseand US industries.

CCSR is the UK’s largest and best knownresearch centre covering Mobile and SatelliteCommunication Systems, Multimedia andNetworking. On an annual basis we award several scholarships to study for a PhD andalmost constantly have vacancies for ResearchAssistants to work on our various contracts.

In addition to our research, CCSR is a majorcontributor to the Electronic EngineeringSchool’s one-year Masters courses in SatelliteCommunication Engineering, Mobile andSatellite Systems and Telematics. We also contribute one-week courses to the continuingeducation programme in the areas of SatelliteCommunications, Mobile Communications andTelecommunications.

We are progressively becoming more involvedin technology transfer and consultancy toindustry, by spinning off our intellectual property rights and technology and we arealways willing to talk to potential collaborators.

This Annual Report gives a summary of ourresearch as it was in 1997. Almost by definition things will have moved on by thetime you are reading this and it is worth checking our Web pages for updates.(http://www.ee.surrey.ac.uk/CCSR/)

Professor Barry G EvansDirector, CCSR December,1997

6

PRES

TIG

IOU

S HI

GHL

IGHT

S O

F 19

97

● Presentation of the Queen’s Anniversary Prize for Higher and Further Education 1996 for “Excellence in Satellite Communications & Engineering - Research & Teaching”.

● Being the first UK university to become one of the four finalists for the Royal Academy of Engineering’s Premier MacRobert Award 1997 for Engineering Excellence in Satellite Communications and Engineering.

● Commencement of the Mobile VCE Programme with £0.75M award to Surrey, supporting 4 RAs, and 2 studentships over three years.

● Award of two EPSRC ROPA grants based on collaboration with industry and Surrey’s only special equipment grant for a Multimedia Performance Test Bed.

● Award of one of the first Space-Foresight contracts with Matra Marconi Space to study Air Interface Aspects of Multimedia Satellite Systems.

● Award of a Technology Transfer contract with Toshiba (Japan) for SpeechStorage Technology.

● Involvement in sixteen bids for the EU third call for ACTS and the start of the first ESPRIT contract awarded with Siemens for ISDN chip architectures.

● Selected by the Cadence Group along with Berkeley, USA and Nan Yang University, Singapore in an International VCE for Communication Systems

● Appointment of new Racal Chair in Communication Network Management to Professor G Pavlou.

● Award of INMARSAT Chairman’s Prize to Dr Wei Zhao for work on “Terminal Locationand Positioning in a Dynamic Satellite Constellation”, representing the most outstanding research in an area commensurate with INMARSAT’s business.

ANNUAL REPORT 1997

PRESTIGIOUS HIGHLIGHTS OF 1997

INDU

STRI

ALPA

RTN

ERS

7

Industrial Partners

● VCE (Virtual Centre of Excellence) in:Mobile and Personal Communications: 5 Universities and 22 Industrial CompaniesDigital Broadcast and Multimedia Technology: 6 Universities and 12 Companies

● Acorn

● Airtel

● Alcatel Espace

● Alenia Spazio

● Algotel

● Aurigae SA

● BBC

● BT

● Cadence Design Group

● Cable & Wireless

● CET

● CISCO

● CNET France Telecom

● CRL

● CSELT

● Cellnet

● Dassault Electronique

● DLR

● Dolphin Communications

● Ericsson

● Ericsson OMC

● European Partnership Contracts

● ACTS: SECOMS, SINUS, THESEUS

● ESPRIT: COPARIS

● Fundacion Airtel

● Fujitsu

● Hitachi

● Hewlett Packard

● Hughes Network Systems

● IBM

● Italtel

● INMARSAT

● ICO Global

● Intracom

● Iona Technologies

● Laben Spa

● Lucent Technologies

● L3S Conseil

● Société de la Bourse Français

● Matra Marconi Space (France)

● Matra Marconi Space (UK)

● Matsushita

● Mitsubishi

● Mobile Systems International

● Motorola

● NDS

● NERA

● Nokia

● Nortel

● Nova Telespazio

● NTT

● NTL Cable Telecoms

● One2One

● Orange

● Philips

● Quotient

● Racal

● Roke Manor Research

● Samsung

● Siemens AG

● Simoco

● Sintef T & I

● Société de la Bourse de Valeurs Mobilières de Bruxelles

● Space Bel

● Space Engineering Spa

● Space Helas

● Symbionics

● Telenor

● Texas Instruments

● TNO

● Toshiba

● Vodafone


8

CURR

ENT

GRA

NTS

/ CO

NTR

ACTS

Current Grants/Contracts

EPSRC

● Source and Channel Coding forMobile Multimedia

● Wireless ATM LAN

● User Terminal Positioning in Non-GEO Satellite Systems

● Migration to 3rd Generation Personal Communication Systems

● Variable Bit Rate Time Envelope Vocoder Using Source Dependent Rate Switching

● Study of Scintillation Applicable to Design of Satellite Communication Systems

● Global Integrated Personal Satellite Environment

● Multimedia Testbed for Audio Visual Communications

● Low Complexity Soft Decision Trellis Decoding of Block Codes

● Call Admission Control for Multimedia CDMA

● Multilayer Scaleable Audio & Speech Coding for 3rd Generation Systems

● GSM Network Optimisation

INDUSTRIAL

● Indoor Propagation Factors at 17-20 GHz and 60 GHz

● High Quality Speech Codecs for Premium Communications Services

● VCE in Mobile & Personal Communications

● Satellite Wideband Air-Interface Design (SWAID)

● Ad-Hoc Computer Networking

● Software Radio

● Indoor Propagation Measurements at 17 & 60 GHz

EUROPEAN

● SECOMS-Satellite EHF Communications for Mobile Multimedia Services-EU ACTS 2

● SINUS-Satellite Integration into Network forUMTS-EU ACTS 2

● ASSET-Advanced Satellite Switching End-end Trials-EU ACTS 3

● ACCORD-AdvanCed aCts brOadband joined tRials and Demonstrations-EU ACTS 3

● SUMO-Satellite UMTS Multimedia service trials Over integrated Testbeds- EU ACTS 3

● WISDOM-Wideband Satellite DemonstrationOf Multimedia-EU ACTS 3

● SORT-SOftware Radio Technology-EU ACTS 3

● FlowThru ACTS 3

● IACI-Internet and ATM Convergence and Integration of Ipv6 with resource reservationof ATM

● MIAMI-Management of the Information Infrastructure

● VITAL-Validation of Integrated Telecommunication Architectures for the Long-term

● REFORM-Resource and Fault restORation and Management close integration of control and management.

● COPARIS - Common Physical Access for ISDN Systems

● THESEUS - Terminal at High Speed for European Stock Exchange Users

9


CURR

ENT

RESE

ARCH

TO

PICS

Current Research Topics

MOBILE COMMUNICATION

SYSTEMS

● Terrestrial and Satellite Mobile Systems

● Narrow band and broad band systems

● Networking, services, terminals, antennas & propagation

● Wireless LAN/cordless/mobile/satellite

● CDMA - Multi-user detectors, call admissioncontrol, power control, synchronisation, coded-CDMA, overlapped CDMA

● TDMA - equalisation

● Ad-hoc networking

● Genetic algorithm

● Integration cellular/cordless/satellite systems

● Traffic modelling for multimedia

● Integration cellular/cordless/satellite systems

● Packet communication in mobile networks - GPRS etc

● Band sharing CDMA/TDMA

● Satellite constellation studies and QoS

● Mobile satellite - mobility management and neworking - resource management

● Satellite air-interface TDMA studies

● Mobile satellite channel modellingand simulators

● On-Board processing architectures

● Broadband satellite - ATM/IP networking

● Antennas - Intelligent base station and handhelds - Dual mode satellite/cellullar

● Propagation - Indoor up to 60 GHz, Satellite up to 30 GHz, macro + micro cells deterministic and physical statistical modelling, cell planning tools

● Intelligent micro/pico cells

MULTIMEDIA & DSP

● Speech coding

● Joint speech and channel coding

● Image coding and compression

● Error resilient coding for images

● Performance analysis for speech and multimedia systems

● RS/Trellis/Soft decoding and turbo coding

● Cryptography for Multimedia Communications

● Higher level modulation and joint modulation/coding

● DSP applications and implementations

● On-Board Satellite DSP and Processing

COMMUNICATION NETWORKS

● Broadband service/traffic characterisation

● Performance assessment of Multimedia over ATM

● ATM over satellite and satellite networking

● IP over GEO Satellite and LEO/MEOSatellite Constellations

● Traffic management and congestioncontrol in ATM

● Optimisation of TCP/IP over ATM

● Integrated services in INTERNE - Multimediaand Multicasting

● Network & Service Management using object, orientation, TMN and TINA

● Multimedia service control using IN and TINA

● Future integrated Telecom Architectures

● Network security

10

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

● Breakthrough in Blind Search Algorithms-Genetic Algorithm

● Fast, Adaptive, low complexity MultiUser Detector for CDMA

● Fast, Frequency Planning Optimisation Algorithm

● Network Dimensioning Technique for Multimedia mobile Systems

● Mobility Management Technique for Wireless ATM

● Novel Media Access Technique for Wireless ATM

● Quality of Service Provisioning for Wireless ATM

● Novel CDMA Multiple Access Schemefor UMTS

● New code Synchronisation and tracking Technique for packet CDMA

● New Mobility Management Techniquefor GSM

● New Satellite Constellation Design

● New Handover for HCS algorithms

● Novel Mobility Management Techniquefor Satellite-PCS

● Four Novel Multiple access protocols for integrated DATA+Voice in GSM/GPRS

● New adaptive and predictive power control technique for CDMA

● New call admission control for load balancing in CDMA

● New mobile terminal positioning technique for satellite systems

● New in-call handover scheme between satellite and cellular systems

● Full network integration between cordless and cellular systems

● Novel call-handling and routing in non-Geostationary satellite mobile systems

● Novel intelligent (terrestrial-satellite) mobileterminal antenna

● New physical statistical propagation modelsfor terrestrial and satellite coverage prediction

● High capacity indoor-outdoor radio architectures using intelligent antennas

Achievements

Description

1 Satellite Mobile Communications

1.1 Network architecture and signalling investigation for GSM

and satellite integration

This work concerns research into the possibility of integrating GSM networks into dynamic constellation mobile satellite networks. The satellite constellation considered representative MEO (e.g., ICO), LEO (such as Iridium and Globalstar).

The work has been divided into several areas

● Design satellite radio link frame structure and logical channels

● Identify various inter-connection schemes between GSM network entities (MSC, VLR, HLR and GMSC) and satellite network entities (GMSSC, MSSC, LES and SVLR). The inter-connection reuses as much as possible of already existing GSM signalling interface (A, B, C, D, E and G interface).

● Design signalling procedures between dual-mode terminal and network (GSM or satellite)for various services in the integrated system.

Aims

To research Global Universal Multimedia Personal Communication Systems integrated with cordless, cellular and satellite mobile components. To develop novel and practical techniques for the establishment and enhancement of personal communication networks and services for future publicand private systems.

MOBILE COMMUNICATIONS RESEARCH GROUP

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

11


1.2 Satellite Integration into Networks for UMTS Services

A laboratory test-bed has been set up for performance experiments in satellite-UMTS environment and the laboratory demonstration will be performed in the test-bed. Entities being produced in theproject: S-UMTS dual-mode terminal, satellite FES, satellite constellation+satellite propagationchannel emulator, terrestrial radio link simulator, fixed network (only a switch) and a test-bed controller.

1.3 Non-GEO Mobility Management and Resource Management

The aim of this work was to determine the optimum location area definition and size for a given S-PCN system that would produce the minimum mobility related signalling on the air interface. This involved analysing layer two paging and location update signalling.

Key outcomes:

1 Intelligent Paging Strategies and new Location area definitions which result in minimisation of in-call handovers between FES (Gateways) and optimum call routing.

2 Handover solution between satellite and terrestrial cellular system. The techniques resulting from this work have been tested and optimised for ICO, Iridium and Globalstar Constellations.

1.4 S-PCN satellite availability in urban areas

Satellite blockage caused by buildings will result in a loss of service from an S-PCN system. Some ofthe 1st generation systems employ satellite diversity to overcome blockage. To evaluate the behaviour of the two satellite channels fish eye images of typical urban areas were taken. The images were transformed to obtain shadowing statistics.

The fish-eye images can also reveal how similar the two satellite channels behave based on the elevation and azimuth angles difference between the two satellites.

1 Example urban fish eye image

12

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

The data from a large number of fish eye images have been applied to several 1st generation constellations to reveal statistics on, service availability, highest and second highest satellite visibility,and overall correlation of blockage between the two highest satellites in urban areas.

1.5 Non-GEO Stationary Satellite Constellation Design

The aim of this work was to design a non-GEO satellite constellation as the satellite component ofUMTS. Several demands and restrictions where initially placed on the constellation structure and coverage properties. Firstly to be competitive the orbit had to have fewer satellites than current 1stgeneration S-PCN proposals. At the time this limit was 66 satellites (Iridium). In order to minimisedelay and power requirements the use of a LEO orbit was preferred, while avoiding the Van Allenradiation belts. In order to increase the availability of service and quality of service the constellationshould provide dual satellite visibility at a minimum elevation angle of 15 degrees. The dual satellite diversity was restricted to the latitude range of +/- 70 degrees.

The requirements from the constellation lead to the use of an inclined LEO orbit. An altitude of1626km was selected. This orbit height provides a repetitive ground track by compensating the altitude to account for the precession of the Right Angle of the Ascending Node due to the earthbulge affect. An inclination angle of 54 degrees was found to provide a good trade off between double coverage at the equator and coverage at higher latitudes. The number of satellites used was64. The satellites are arranged in 8 planes with 8 satellites in each. A phasing angle between eachplane of 39.375 degrees resulted in the best dual satellite visibility. Given that the orbit provides continuous dual satellite visibility the constellation was called Deligo which is Latin for ‘I Choose’.

1.6 Band Sharing between Non-Geostationary Satellite-PCNs

The first generation satellite PCNs are to operate at L-band for uplink and S-band for downlink to provide world wide services. However, the scarcity of free spectrum, together with the bandwidthrequirements means that S-PCNs will have to share these bands with each other. In order to evaluatethis complex sharing scenario, an Interference Simulation Program has been developed to model thedynamic satellite constellations (DSC) and to evaluate interference between such non-geostationaryMSS and investigate techniques/criteria to make such bandsharing possible.

0 20 40 60 80 100 120 140 160 180-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

Cor

rela

tion

coef

ficie

nt

Sat. 30&30deg, w=dm/2=10mSat. 30&45deg, w=dm/2=10mSat. 30&30deg, dm=5m, w=15mSat. 30&45deg, dm=5m, w=15m

Theoretical Prediction of Satellite Diversity Correlation

Azimuth Separation (degrees)

Azimuth Separation (degrees)

The figures below show how the correlation of blockage coefficient varies with different satellite elevation and azimuth angle differences and how it can be predicted using a theoretical approach.

13


MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

● Stand-by state (Handover, Diversity,synchronisation and time advance mechanisms)

● Optimisation of frame structure for packet switching

● Error correction and re-transmission strategies

● Power control

● Random access protocol design

1.8 UMTS Satellite Channel Emulation

Bringing together a number of the threads of the research is an EU ACTS project SINUS, which isinvestigating the air-interface of the satellite part of the UMTS as well as producing a demonstratorair-interface system and a satellite channel emulator. The latter is a project within Surrey and uses the channel data at L/S band from the propagation campaign that has been converted to models for any elevation angle and environment. Also builtinto the channel emulation are the orbit dynamics of LEO/MEO and the interface paths for satellitesand mobile users from the system. The emulation will allow a simulation of any run forLEO/MEO/GEOs and allow the prototype air interface to be tested and evaluated.

1.9 Antennas and Propagation

1.9.1 Propagation Measurements and Analysis include:

● Satellite PCN measurements, narrow-band and wide-band at L,S,X bands simultaneously, forthcoming narrow-band at 20 and 30GHz. Measurements made in 5 environments and elevation angles from 30 to 80 degrees using helicopters.

● Physical-statistical models of Satellite PCN, providing attenuation statistics and time-series generation based on statistical measures of the building environment and deterministic knowledge of satellite constellations.

● Analysis, simulation and modelling of scintillation effects for fixed satellite systems at 12.5, 20 and30 GHz. Includes diurnal variations, time series generation and scintillation countermeasures using adaptive modulation schemes.

Physical-statistical model of mobile satellite propagation in built-up areas

1.7 Multiple Access Schemes

TDMA and CDMA and various hybrids are currently being investigated. Among these, the packetswitched protocols for support of mixed services are also being investigated. We are also researchingon the suitability of GPRS (General Packet Radio Services) and in particular the optimisation of thefollowing schemes for packet S-PCN:

14

● Advanced CDMA Receiver Architectures for Satellite Multimedia Communication

● Call Handling for ATM Over Satellite

● Congestion Control Techniques

● ATM on-board satellite

● Resource management and bandwidth reservation mechanisms

● Channel Coding Schemes

● Network optimisation

● Propagation measurements and channel characterisations for all the environment categories at Ka band

2.0 Other research areas related to broadband satellite

communications are as follows:

A number of projects are being undertaken in the Broadband Multimedia Satellite area. These are concerned with Multimedia Services above the 64-144 kb/s region dealt with in UMTS studies andreach up to 2-100 Mb/s. An EU ACTS project, SECOMS, forms much of the effort and this is looking at delivery of Multimedia to lap-top, and palm-top terminals at Ka-band and ehf respectively from a GEO satellite. Another project, GIPSE, is looking at new and hybrid constellationsfor such delivery. The work involves both air-interface studies in which synchronous CDMA is a feature together with advanced modulation and channel coding as well as networking issues such asATM modification for both the satellite traffic and control planes, resource and bandwidth management and congestion control. In addition work on on-board-processing including on-boardATM switching and switch management as well as efficient digital implementation of on-boardequipment. Particular topics are:

Prediction of radiation from a satellite-mobile handset in close proximity to the human head

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

● Design of Wire quadrifilar helix antennas. Compact fractional-turn designs forS-PCN handsets.

● Printed quadrifilar helix antennas for easy manufacture, small size and robustness. Analysis package created using Integral Equation / Method of Moments.

● Intelligent handset antennas for multiband, multimode operation in terrestrial and satellite systems. Incorporates adaptive matching and polarisation and pattern diversity. Such antennas are a key component of future softwareradio technology.

● Noise calculations for satellite PCN handsets. Includes the effects of sky and building noise, together with shadowing and satellite constellation statistics. Leads to calculation of effective statistical G/T, andpermits specification and optimisation of antenna radiation patterns.

● Rapid electromagnetic simulation for both antenna and propagation modeling using Finite Difference Time Domain simulators. Rapid, simple 2D simulator and efficient parallel 3D simulators produced. Used to calculate the interaction of S-PCN antennas and the human body.

1.9.2 Antennas:

cm

cm

dB

15


3.0 Terrestrial Mobile Communications

3.1 Optimization of GSM network

The work has concentrated on reduction of signalling traffic and database transactions within theGSM network. A novel location tracking method has been proposed and evaluated both analyticallyand through simulations. The proposed technique has resulted in substantial reductions in DB accessand a reduction of total network signalling load under most operating conditions.

A distributed mobility management scheme is also proposed that can also result in significantreductions in signalling traffic compared with the existing GSM scheme. Evaluation and application ofoptimization algorithms ( NN, GA and SA ) to the problem of optimal location area partitioning within cellular networks have been extensively researched. The aim is to reduce the signalling traffic overthe air-interface through optimal design of LAs and support of “personal location areas” concept.

3.2 Cordless-Cellular interworking in the context of

migration to UMTS

Identification of an alternative registration method in the combined system according to the similarityand dissimilarity of air-interface and network and also the level of integration or interworking. This will consider the deployments of new technologies such as IN concept in the system.

Possible System architecture for Broadband Satellite Communications based on ATM

System architecture

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

● Support of both personal mobility and terminal mobility for dual-mode user

● Service mobility (service migration todifferent elements) for dual-mode user

● Seamless handover & roaming between Cordless/Cellular using DECT and GSM as example systems and satellite coverage for multi-mode terminals

● Handover optimization in hierarchicalcell architecture

● Identification of a location updating procedure

● Identification of paging strategy

● Identification of call routing strategy

● Signalling load evaluation

● Multi-mode terminal functionality

16

● network independence

● seamless roaming

● capacity

● upgradeability

● General analysis

● Statistical upper bound study

● Performance comparison of 15 RRA protocols against each other

● Performance optimisation through dynamic contention mechanisms

● Guidelines for RRA protocols in cellular design

● Three different hybrid multi-access protocols based on TDMA/CDMA, DTDMA/CDMA, PRMA/CDMA

● Link quality control procedures

3.3 Software Telecommunication

This aims to investigate the applications of new software technologies such as Mobile and IntelligentAgents JAVA and CORBA for realisation of future software telecommunications scenarios. Such techniques could change the conventional management mechanism and offer more intelligence, flexibility and robustness, contributing to a suitable platform for open communicationsystem infrastructure.

In particular we are investigating design and specification of software radio based terminals and basestations. The resulting flexibility and re-configurability of a software based communication systemwill enhance service provision, help realise VHE concepts and bring about capacity and coverageimprovements. Other benefits include :

3.4 Packet Communications

The following areas are being extensively investigated:

3.4.1 Reservation Random Access (RRA) Protocols

3.4.3 Aggregate Finite-Source Modelling for

Multimedia Communication

Systems Dimensioning

An aggregate source model is proposed by which the whole multi-service queuing system can bemodelled with a mono-service M/G/c/N/FCFS queuing system.

3.5 Frequency Planning

We have developed an automatic frequency planning & optimisation tool, based on the Genetic Algorithm.

The novelty of this work lies in optimisation of Initialisation and Objective Function which togethermakes the GA convergence rate extremely fast so that the algorithm can also be used on the fly in anoperating system for fast Dynamic Channel Allocation (DCA). Another aspect of this tool is theenhanced stability for GA, a feature which makes GA now suitable for such applications.

3.6 Multi-User Detection for CDMA

The work on Genetic algorithms is now extended and optimised for joint-detection for both S-CDMAand A-CDMA. The technique has been compared with Convention Detector (Single User Detector) aswell as Multi-Stage Detectors (MSD) with 10 stages. The single user bound is achievable and because of fast convergence rate, it is highly adaptable tofast channel changes due to fading and channel loading. The current work on GA is reduction of theimplementation complexity whilst keeping the performance. In parallel we are also investigatingNeural Network based Joint Detectors for CDMA.

3.4.2 Hybrid Multiple Access Protocols Communications

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

17

● Acquisition and Tracking particularly for packet CDMA

● Interference Analysis CDMA

● Cellular System Modelling currently configured for GSM and can be changedfor CDMA

● OFDM/MC-CDMA/Call Admission Control

● Predictive and adaptive power control schemes

● Channel Estimation Techniques

● Amplifiers for UMTS

● End-to-end modelling and performance of UTRA

● Advanced RAKE receivers

● Interference cancellation inCDMA / TDMA overlay

● Overlapped carrier CDMA


3.7 Propagation

1. Multiple Edge Diffraction: Fast, accurate calculation of multiple edge and multiple cylinderdiffraction, using deterministic numerical techniques. Applications: Urban / suburban area coverage and reuse prediction, terrain diffraction for point-to-point links.

2. Modelling and measurement of spatial and angular shadowing correlation for macrocells and picocells. Application to sectorisation, adaptive antennas, power control etc.

3. Measurement and statistical modelling of time-variant fading for line-of-sight links. Rapid time variant fading occurs due to vehicle and foliage motion combined with multiple scattering effects, as well as atmospheric and precipitation effects. These can lead to very rapid fading, having significant impact on performance and optimum system design. Applications include wireless local loop, MVDS and BRAN systems. Models allow prediction and simulation of time-variant effects for performance prediction and modem design.

4. Path loss models for direct mode mobile communications, such as TETRA. Physical-statistical models for picocell prediction, combining semi-deterministic path loss prediction with statistical prediction of spatially correlated shadowing effects.

5. Intelligent picocells, using intelligent antenna technology to provide high capacity indoor coveragesolutions with distributed processing for plug-and-play, modular operation. Incorporates aspects of distributed antennas, diversity, optimum combining / beamforming, dynamic channel allocationand equalisation.

Measurement and predictions of Field Strength in an Indoor Environment at 17GHz -colours indicate

path loss values in decibels

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

0 1 2 3 4 5 60

2

4

6

8

10

12

metre

met

re

1

Received Field Strength [dB]

0 1 2 3 4 5 60

2

4

6

8

10

12

metre

met

re

Field Strength, module n: 1 at floor: 3

1

130

120

110

100

90

80

70

60

18

● an extension of HIPERLAN specifications to support optimally ATM traffic,

● the definition of an ATDMA based multiple access, introducing traffic policing on the air-interface

● a technique for modifying NNI specifications to support mobility in a wide area ATM network with wireless access points

● the design of an OFDM based transmission path for the ATM WLAN with variable channel coding rate.

● Vector Network Analyser up to 26.5 GHz

● Spectrum Analyser up to 75 GHz

● Power Meter up to 40 GHz

● Signal Generator up to 75 GHz

● Digital Storage Oscilloscope with 500 MHz bandwidth

4.0 Wireless LAN

New challenges associated with the mobile stations that are being addressed, such as location management, registration (including authentication and network security) and handover implementation.

4.1 Mobility management and Call control in a

wireless ATM LAN

Investigation of suitable MAC and DLC layers is being taken place. The HIPERLAN and IEEE 802.11MAC layers have been tested using both an analytical and a simulation model. Delay and throughputdeficiencies led to the development of a novel TDMA based MAC layer with better performance char-acteristics.

4.2 Ad-Hoc Computer Networking

Most of the work, in wireless LAN has been concentrated on star topology configurations. Thisresearch is on distributed wireless computer networking, researching on Dynamic Routing algorithmsfor a wide range of mobility for the terminals, and implications on TCP layer and mobile IP, as well asmultiple access techniques for guaranteeing QoS.

4.3 Antenna & Propagation

1 Space-time channel modelling for adaptive antenna systems operated in indoor/outdoor environments at 2 and 5GHz. Four-channel measurement system under construction to measure correlations in space and time.

2. Measurement of propagation at 17 & 60GHz using remote controlled platform. Measurements in modern and Victorian office buildings, including indoor-outdoor and building-building scenarios. Leading to accurate physical-statistical prediction techniques.

3. Simultaneous Propagation Measurements at 17 & 60 GHz using a remote controlled mobile platform. Measurements in a variety of buildings from the Victorian-era to modern day, including indoor to outdoor and building to building scenarios. Leading to accurate physical-statistical prediction techniques.

4. Intelligent picocells, using intelligent antenna technology to provide high capacity indoor coveragesolutions with distributed processing for plug-and-play, modular operation. Incorporates aspects of distributed antennas, diversity, optimum combining / beamforming, dynamic channel allocationand equalisation. Rapid electromagnetic simulation for both antenna and propagation modelling using Finite Difference Time Domain simulators. Rapid, simple 2D simulator and efficient parallel 3D simulators produced.

6. CCSR has a modern specially equippped Radio Frequency Laboratory, featuring the following key test and measurement capabilities:

MO

BILE

CO

MM

UN

ICAT

ION

S RE

SEAR

CHG

ROU

P

MU

LTIM

EDIA

SYST

EMS

RESE

ARCH

GRO

UP

19

MULTIMEDIA SYSTEMS RESEARCH GROUP

Aims

The main research activities of the group are in the area of low and very low bit rate speech and video compression algorithms with improved error robustness and efficient channel coding, encryption and water marking techniques as well as new modulation and coding schemes and the DSP and ASIC implementation of satellite OBP.

Achievements

Description

1 Low Bit Rate Speech and Audio Coding

1.1 Split-Band LPC Vocoder

The aim of this project is to develop a new type of low bit rate speech coder. By assuming that thespectrum of the speech is voiced for the low frequencies and unvoiced for the high frequencies, thiscoder gives a very high quality even at very low bit rates. Different versions, at 2.4 kbit/s, 4.0 kbit/s,5.5 kbit/s and 6.2 kbit/s, have been developed. They give better speech quality than the full-rate GSM standard, which makes them suitable for mobile applications.

1.2 Wideband SB-LPC Vocoder

An advantage of a wideband speech (sampled at 16 KHz) over a narrowband speech(sampled at 8KHz) is that it sounds more natural and pleasant to human ear. This is due to the better preservationof the speech dynamics during the higher sampling process. Therefore, the ultimate goal of thisproject is to develop a wideband LPC vocoder which, when quantised, should operate at the rate ofaround 8.5 kbit/s. This coder uses a split-band voicing technique which has proved successful at verylow bit rates. Current results promise a high-quality speech coder ready to compete in the marketwith other wideband coders.


● Development and implementation of the AUDETEL codec which is currently undergoing acceptance tests being conducted by the ITC.

● Development of two new speech codec algorithms

● Pulsed Residual Linear coding for bit rates of 4.8 kbit/s and over

● Time Envelope Vocoding for rates from 1.2 to 2.4 kbit/s

● Development of a novel lossy multiplexing technique for thin route telephony

● Demonstration of the novel concept of source-aided channel decoding for increased error control performance for speech codecs

● Improvements to the error robustness and lost information recovery of ITU H.261 and H.263 video codecs.

● Development and performance study of an error resilience algorithm for H.263 and its comparison with other techniques found in the literature such as EREC

● Two-way decodable entropy coding for MPEG-4.

● Adaptation of MPEG-4 applications for satellite and terrestrial (indoor/outdoor) environments.

● New Turbo code implementations

● New applications and implementationsof RS codes

● Reduced complexity on board satelliteVLSI demultiplexers

20

MU

LTIM

EDIA

SYST

EMS

RESE

ARCH

GRO

UP

1.3 Low Bit Rate Speech Coder Based on CELP Coder

The coder is applied to encode the narrow band speech signal (4 KHz) and decode the widebandspeech signal (8 KHz) at the receiving end. This will enhance hi-fidelity and the naturalness of thespeech. The ultimate aim is to achieve the decoded speech signal which sounds more pleasant thanthe original one.

1.4 Low Bit Rate Audio Coding

Applications involving digital transmission and/or storage of high quality audio signals, such asDigital Audio Broadcasting and Multimedia, require low bit rates. The research area of digital audiocoding is currently developing a time-domain scheme which achieves 1 bit/sample compression. Theoverall bit rate will of course depend on the sampling frequency of the analog audio. Our presentwork has been concentrated on the sampling rate of 16 KHz producing a very interesting bit rate of 16kbit/s. The project employs CELP (Code Excited Linear Prediction) coding algorithm and noise masking techniques so as to achieve good quality at the low bit rate. The audio quality produced at 16 kbit/s is very acceptable for low bit rate applications and has already created significant interestfrom the industry.

2 Image and Video Coding

2.1 Reduced Resolution Updating

For fixed-rate video coding, a sudden increase in the amount of bits generated by the codec, causedby short-term changes in the video content, is undesirable as this will increase the time delay. By reducing the resolution in each dimension by half, the amount of bits spent on coding the motion-compensated difference signal will be reduced greatly. Fixed bit-rate variable frame-rate controller will be used.

2.2 Object Detection and Rate/Quality Optimisation in

MPEG-4 Video coder

To take advantage of the content-based functionalities provided by MPEG-4, the scene must besearched for the contour of the enclosed VOPs. MPEG-4 does not explicitly specify any technique forthe detection of objects in the video scene. The door is left open for researchers to combine theirefforts in order to incorporate an efficient object detection algorithm for the alpha plane encoding.This project aims at providing an algorithm for an efficient and low-complexity detection of the objectborders. On the other hand, the project examines the efficiency of binary shape coding defined byMPEG-4 and aims at optimising the quality against the bit rate generated by the alpha plane encoder.

2.3 Source and Channel Coding for Mobile

Multimedia Communications

In this project, the performance and robustness of H.263 and H.261 were compared and focus hasbeen made on the study of the error sensitivity of various video parameters in H.263. Furthermore,the error resilience aspects of the coder were examined and a set of several error resiliencetechniques have been implemented on H.263 to enhance its performance in error-proneenvironments. A novel error resilience algorithm has been developed and its performance was compared to that of the techniques found in the literature such as EREC. Two-way decoding and RVLCwere applied on H.263 to mitigate the effect of channel errors on the video quality.

Quality Improvement with an Error/Rate Control Mechanism Using Feedback

MU

LTIM

EDIA

SYST

EMS

RESE

ARCH

GRO

UP

21

2.4 Video Coding Algorithm for Wireless ATM Networks

This project aims at improving the transport of video intended for video conferencing applications.The H.263 low bit rate algorithm is to be modified for transport over wireless ATM channels. The project involves modification of the syntax of H.263 in order to adapt it to the mobile environment. Modifications include both source and channel level with prospects of channel assisted decoding.

3 Channel Coding

3.1 Trellis Decoding of Cyclic Block Codes

This project extends previous work in which it was found that Reed Solomon codes could use softdecisions from the demodulator to give performance and complexity comparable with convolutionalcodes on the AWGN channel. Methods being investigated include representation of the codes asbinary codes, development of sequential decoding methods and trellis re-ordering techniques.Appropriate metrics for a range of channel conditions will also be investigated.


Quality Improvement Using Two-Way Decoding and Reversible Codewords

H.263 EREC Frames on Wireless ATM Networks

3.2 Algebraic Decoding of Cyclic Block Codes

Methods using the algebraic properties of block codes have speed advantages and can be adapted forsoft decision decoding. Investigation of an algorithm proposed by Dorsch showed that it was moresuited to binary than to multilevel codes, however other methods investigated have produced impressive results. An extension of the Kasami algorithm is shown to have significant computationaladvantages over Minimum Weight Decoding and a novel method based on re-ordering and errortrapping provides low complexity decoding of Reed Solomon codes.

● Definition of a method for certifying images from digital cameras.

● Development of a low-complexity method for encryption of compressed imagesand video.

● Development of source key distribution schemes for subscription broadcast services using smart card controlled set top boxes.

● Development of methods for hiding cipher text.

3.3 Cryptography for Images and Video

A range of issues are being investigated to resolve specific requirements of applications involvingimages and video. Achievements include:

22

4 Modulation and Coding

4.1 Turbo Coded Modulation for Fading Channels

We are aiming at creating error robust coded modulation schemes for fading channels using theturbo coding scheme. In particular, we are investigating the characteristics and suitability of variousconstituent encoders in the appropriate channel conditions.

4.2 Ground-Satellite Optical Communications

We are studying system design/analysis of ground-satellite optical communication links, aimed atderiving well-defined guidelines with necessary tools in the form of graphs, tables, algorithms, simulation models etc. We have been concentrating on the issues which are not common with opticalintersatellite links, namely atmospheric propagation. Atmospheric turbulence causes fluctuations inamplitude and phase of an optical beam propagating through it. We are planning to conduct opticalturbulence measurements based on the analysis of bi-dimentional spatiotemporal spectra of stellar light in collaboration with the Communications Research Laboratory in Japan.

Performance of our low-complexity Turbo Coding Scheme

MU

LTIM

EDIA

SYST

EMS

RESE

ARCH

GRO

UP

● Development of a combination of set partitioning techniques, a novel expanded rotated detector and a multistage decoding method allowing Reed Solomon codes to be applied with hard decision demodulation.

● Performance across a range of channel conditions comparable with, or better than, other trellis coded and block coded modulations.

● Development of techniques for reduction of peak-to-mean power ratio in OFDM.

● Development of concatenated RS-RS codingschemes for multilevel modulations on OFDM.

4.4 Development of Algorithms for ASIC Implementation of

DVB .0QPSK Demodulator

This project has been undertaken in conjunction with industry, in order to develop synchronisationalgorithms for a QPSK demodulator for the reception of signals conforming to the ETSI DVB-S stan-dard, Digital Video Broadcasting via satellite. The DVB standards renders the symbol rate completelyunspecified, and hence imposes tremendous difficulties in terms of aliasing-avoidance in thesampling process due to the variable bandwidth, symbol rate and automatic frequency control.

4.3 Robust Coded Modulations

The objective of this project was to develop bandwidth-efficient coded modulations that would berobust across a range of channel conditions. Achievements include:

COM

MU

NIC

ATIO

NN

ETW

ORK

SRE

SEAR

CHG

ROU

P

23

● To study ATM and INTERNET for satellite and terrestrial systems supporting broadband communications and multimedia services.

● To study Network and Service Management using Object-Oriented TMN andTINA principles

● Design and implementation of protocols stacks with security solutions for accessing to Paris and Brussels Stock Exchanges.

● Study and Development of “system-on-chip” solution for future ISDN switch and internetworing technology.

● Validation of Integrated Architectures based on the emerging CORBA/TINA framework for integrated multimedia services and network management.

● Study of Mobile Intelligent Agents Management and examines applicability of MIAs to TMN / TINA.

● Investigation of Internet and ATM Convergence and Integration IPv6 with resource reservation over ATM, pan-European trials.

● Developed and refined an integrated voice and data multiple access scheme for a VSATsatellite network

● Developed a new and efficient traffic controlmechanism for ATM

● Demonstrated and tested the interconnection of LANs via an ATM satellite link


Aims

Achievements

Description

1.0 ATM and Broadband Communications

1.1 THESEUS (Terminal at High Speed for European

Stock Exchange Users)

The objective of this project is to develop a terminal that will be a key component of an open systemand able to meet the telecommunication needs of the future European capital market. The projectaims to develop a universal terminal that will use low-level ATM properties to encapsulate data units,whatever the application layers maybe, and to display information exchanged between several stockexchanges on a single screen, through appropriate multi-windowing software. A representative sample of European stock exchanges are co-operating actively on the project fromproject definition through to the validation and analysis of the demonstration results.

1.2 TCP/IP over ATM

TCP/IP is the most widely used protocol in the computer communications area. Although it has beenused globally in LAN/MAN/WAN environments for years, it is not optimised for high-speed networkssuch as ATM. The Communication Networks Research Group is carrying out experiments to test theperformance of TCP/IP over ATM and to find ways to optimise it so that current applications can makeuse of the high-speed networks such as ATM.

COMMUNICATION NETWORKS RESEARCH GROUP

2.0 Network and Service Management

2.1 VITAL

This project concerns Validation of Integrated Telecommunication Architectures for the Long-term andValidation of the emerging TINA framework for integrated multimedia services and service/networkmanagement. We are mainly involved in ATM resource configuration and connection control throughthe management plane.

2.2 REFORM

It is to study Resource and Fault restORation and Management Close integration of control and management, ATM-F PNNI signalling integrates VPC recovery, ATM network management based onCORBA/TINA principles. Our involvement is in ATM VPC configuration, planning activities and algorithms for dynamic bandwidth (re-distribution).

2.3 FlowThru

This project is a Trial Integration of the results of the VITAL, REFORM and PROSPECT projects integrated TINA-based multimedia service management with both TMN and TINA-based ATM network management. This work is mainly relevant to the VITAL, REFORM project plus ATM accounting management issues.

24

COM

MU

NIC

ATIO

NN

ETW

ORK

SRE

SEAR

CHG

ROU

P

● User plane: To provide end-to-end security services where the ATM network passes the user information (ATM cell payload) without any security processing

● Control and management planes: To protectsignalling and management messages using public-key systems and timestamps

● Public-key distribution: Between end systems and network nodes as well as between network nodes

● Parallel ciphering: To provide fast encryption techniques suitable for ATM highdata rate services

1.3 Security Systems for ATM Networks

We have research in security system requirements to protect user, control and management planes in ATM networks. Specific areas of interest are:

THESEUS Main Architecture

COM

MU

NIC

ATIO

NN

ETW

ORK

SRE

SEAR

CHG

ROU

P

25

2.4 MIAMI

Concerns Mobile Intelligent Agents in the Management of the Information Infrastructure andExamines applicability of MIAs to TMN / TINA. It uses the OMG CORBA emerging mobile code solution involvement in ATM QoS management issues

3.0 Network Access and Interworking

3.1 COPARIS (Common Physical Access Chip for ISDN Systems)

In order to stimulate the growth in the ISDN market, the ESPRIT COPARIS project will develop anapplication-specific embedded processor capable of implementing a large subset of the existing ISDNline interface standards. This will be the forerunner of a generation of advanced telecommunicationsprocessors using OMI subsystems that can be extended into a range of future applications. As anexample, it will allow the production of ISDN home PBXs with a cost of about 50% compared totoday’s equivalent products.

3.2 IthACI

Will study Internet and ATM Convergence and Integration IPv6 with resource reservation over ATM,pan-European trials. CISCO is involved in the development of IP/ATM QoS management.

3.3 Integrated Service VSAT Satellite Access Protocol

There is an increasing demand for VSAT networks that can provide integrated voice and data services. This explores and develops VSAT protocols that can best meet these requirements.Using analytical and simulation methods, we have studied the performance of a variety of candidateaccess schemes that could be used in this scenario such as Reservation Aloha, Selective-Reject Aloha,Selective-Reject Aloha FCFS with Reservations, and Multiple Channel CRA. We have looked at theproblems that the introduction of packetised speech introduces to the system and ways to deal withthem. We have looked at voice/data integration at two levels: Firstly, by using a combination of voicechannels and data channels and optimising the way we allocate these with respect to the availabletraffic, and secondly, by taking advantage of the silences in the voice channels and transmitting datapackets during the longer silence intervals.


Internal COPARIS Architecture

26

COM

MU

NIC

ATIO

NN

ETW

ORK

SRE

SEAR

CHG

ROU

P

4.0 Internet and ATM over Satellites

4.1 CATALYST

The CATALYST project tested satellite technology in relation to the terrestrial Integrated BroadbandCommunications (IBC) network. We analysed end-to-end system communications for client-to-serverarchitectures across Asynchronous Transfer Mode (ATM) links and satellite relays, interconnectingEthernet, DQDB and FDDI networks. The project demonstrated the world’s first ATM connection viasatellite at Nanteer, in Paris. This showed the capability of ATM via satellite to support interactiveimages, joint viewing, multimedia communications and network file systems.

4.2 Internet and B-ISDN via Satellite

The aim of this project is to investigate efficiency of the ATM and Internet protocols including the nextgeneration of IP (IPv6) that would enable communication satellites to offer Internet and B-ISDN services. The research concerns satellite network architectures, protocol performance and optimisation and simulation prototype and validation.

4.3 Satellite Constellations

Low-earth orbiting (LEO) satellite constellations offer the possibility of full world-wide wirelessnetworking, better support for high latitudes than provided by Geo-stationary Earth Orbit (GEO)satellites, and with decreased time delay over GEO.Ensuring seamless interworking with existing ground-based networks raises complex networkingissues, as does attempting to model the performance of a network based on a rapidly-changing LEO satellite constellation or considering guaranteed-quality multimedia services over such a constellation. We are researching network topologies and simulation techniques to better understand these problems.

COM

MU

NIC

ATIO

NN

ETW

ORK

SRE

SEAR

CHG

ROU

P

27


● Security protocol efficiency to prevent long delays and bandwidth consumption.

● Mutual and unilateral authenticationbetween the satellite-user and satellite network using public-key cryptosystems.

● Data encryption using a secret-key algorithm.

● Access control

4.4 Security Systems for Satellite Networks

Security system requirements to improve the data and voice services provided by satellite networks.Specific areas of interest are:

28

CCSR

STA

FF

● DirectorProfessor Barry G Evans, BSc, PhD (Leeds), FEng, FIEE, SMIEEE, FRSA

● Deputy DirectorProfessor Ahmet M Kondoz, BSc (Birm), MSc (Essex), PhD (Sur), CEng, MIEE, MIEEE,(Head of Multimedia SystemsResearch Group)

● Academic StaffMs Frances Coakley, BSc, MSc (Manc), C.Eng, MIEE, MIEEE, (Senior Lecturer)

Mr Tony Jeans, MA (Camb), MSc (S’ton), (Senior Lecturer)

Dr Abdul H. Sadka, BSc (AUB), MSc (METU), PhD (Surrey), (Lecturer)

Dr Simon Saunders, BSc (Brunel), PhD (Brunel) AMIEE, MIEEE (Lecturer)

Dr Zhili Sun, BSc(China) PhD (Lanc), (Lecturer, Acting Head of Communication Networks Research Group)

Dr Peter Sweeney, MA (Oxon), PhD (Camb),(Senior Lecturer)

Dr Rahim Tafazolli, BSc (Bath), MSc (Lond), PhD (Surrey), MIEE, MIEEE, (Reader)Head of Mobile Communications Research Group)

● Technical & Financial AdministratorMr David Brock (MSc Surrey,C. Eng.MIEE)

● Computing OfficersMr John Hibbitt

Mr Adam Kirby

● Technician

Mr Terry Roberts

● PA to Director/Centre Secretary

Mrs Moira Cook

● Financial Assistant

Mrs Stephanie Evans

● Secretary to Research Groups

Mrs Lakshmi Chennell

● Research Fellows/Assistants (PhD subjects where applicable)

Mr Andreas-Albertos Agius

(Dual mode antenna for SPCN handheld terminals)

Mr Costas Apostolas(Study for multiple access schemes for ATMwireless LANs)

Dr Bachir Belloul

Dr Haitham Cruickshank

Mr Shahram Ghaheri Niri

(Integration between cordless and cellular systems)

Mr Cheng Jinwu

Mr Chris Meenan

(Mobility management in SPCN)

Mr Ioannis Mertzanis

(Networking aspects & QoS provisioning formobile satellite multimedia services)

Mr Tolga Ors

(Traffic management and control over ATM via satellite networks)

Mr Heng Pan

(Satellite communications management)

Dr Martin Parks

Dr Haidar Radi

Mr Tony Sammut

(Resource management for satellite SPCN)

Dr Riaz Suddle

Mr Payam Taaghol

(Power control for CDMA)

Mr Pouya Taaghol

(Wireless packet communications)

Mr Seiamak Vahid

(Optimisation of GSM networks)

Mr Cyril Valadon

(Advanced CDMA receivers for satellite multimedia communication systems)

Miss Greet Verelst

(Satellite on-board processing for multimedia communications)

Mr Stephane Villette

(High quality low bit rate speech coding)

Dr Stephan Wesemeyer

CCSR STAFF

CCSR

STA

FF

29


Mr Saied Abedi

(Multi-user Detection)

Mr Dionisis Adamopoulos

(Design and management of telematic services - the case for Greece)

Mr George Aggelou

(Ad Hoc wireless networking)

Mr Bilal Ahmed

(Ka Band channel for satellite mobilemultimedia services)

Mr Thumrongrat Amornraksa

(Cryptography for multimedia communications)

Mr Ilias Andrikopoulos

(Optimising TCP/IP over ATM networks)

Mr Mehrdad Ardebilipour

(Code Synchronisation for pocket CDMA)

Mr M. Hafeez Aziz

(Band sharing between CDMA based CDMA)

Mr Damon Birch

(CDMA for satellite broadband communications)

Mr Yotsapak Chotikapong

(TCP/IP over ATM via satellite constellations)

Mr David Cooper

(Communications using Mains for transmission)

Mr Nikolaos Dimitriou

(CDMA for multimedia)

Mr Kjetil Fagervik

(Interactive decoding techniques)

Ms Bin Fan

(Call handling for ATM via satellite)

Miss Maria Farrugia

(Audio and speech signalling)

Mr Mauro Fiacco

(Intelligent picocells using optimum combining)

Mr Hai Pang Ho

(Soft decision decoding of Reed-Solomon codes)

Mr Jong-Ok Joo

(Optimisation of ATM switch on -board satellite for multimedia)

Mr Stephen Leach

(Optimum control of hand portable terminalantennas for mobile communications)

Mr Teck Hock Kweh

(Improved Quality Block-Based Low Bit RateVideo Coding)

Mr Klaus Moessner

(Software radio)

Mr K Narenthiran

(Mobile satellite communications)

Mr Min-Seok Oh

(Binary Reed-Solomon decoder formulti-channels)

Mr John Paffett

(Interference avoidance techniques)

Mr Philip Psiloinis

(Video conferencing for wireless ATM networks)

Mr George Sfikas

(Call handling and mobility managementfor satellite SPCN)

Mr Chana Sriratanaban

(Low bit rate speech coding)

Mr Milos Stefanovic

(Low bit rate speech coding)

Mr Stavros Stavrou

(The accuracy of mobile propagationmeasurements)

Mr Nhong Suvannapattana

(Interaction of satellite mobile hand-held with human body)

Mr Rajan Thiruvathirai

(Software radio)

Mr Constantinos Tzaras

(Physical modelling of mobile propagation)

Mr Lloyd Wood

(Multicast over satellite constellations)

Mr Len Woodhead

(Coded modulations)

Mr Yusuf Yenice

(System design/analysis of ground-satellite optical communications)

Research Students (PhD subjects)

30

CCSR

STA

FF

Cullen C J,“Network and signalling Aspects of SatellitePersonal Communication Networks”,March 1995.

Danesfahani G R,“A study in Optimising a MulticarrierDemultiplexer Demodulator (MCDD) forOn-Board Processing (OBP) Satellites”, April 1995.

Eryurtlu M O F, “New Approaches in Low Bit Rate Image &Video Coding”, June 1995.

Hadjitheodosiou M,“Performance Optimisation of Multiple AccessProtocols for Multi-Service VSAT Networks”,June 1995.

Tafazolli Rahim, “Multiple Access Protocols for ThirdGeneration Cellular Mobile/Personal Communication Systems”, February 1996.

Suddle Riaz,“Speech Coding in Private and BroadcastNetworks”, March 1996.

Qi Ronggang,“Multicarrier Demultiplexing and VLSIImplementation for Processing SatelliteCommunication Systems”, July 1996.

Finean B,“The Role of Mobile Satellite Systems inFPLMTS”, September 1996.

He Xiaoping,“The Signalling System in Satellite - PersonalCommunication Networks”, November 1996.

Parks Martin,“Wideband Propagation ChannelCharacterisation Applicable to Mobile SatelliteSystems at L- and S- Bands”, December 1996.

Smith Christopher,“Quality of Service Issues in Digital MobileTechnology”, December 1996.

Atkinson Ian,“Advanced Linear Predictive SpeechCompression at 3.0 kbit/sec and below”,February 1997.

Black Alastair,“Analysis by Synthesis Coding of Narrowbandand Wideband Speech at Medium Bit Rates”,May 1997.

Yaghmaie Khashayar,“Waveform Interpolation Based Low Bit RateSpeech Coding”, June 1997.

Tateesh Said,“Multi-Rate Source and Channel Coding forCDMA-Based Mobile Communications”,September 1997.

Sadka Abdul H,“Error Control Strategies in Block-TransformVideo Coders in Multimedia Communications”,September 1997.

Zhao Wei,“Handover Techniques and Network IntegrationBetween GSM and Satellite MobileCommunication System”, September 1997.

Husni Emir,“Robust Reed Solomon Coded MPSKModulation”, November 1997

Lee Joohee,“CDMA Overlapped Carrier Allocation Schemesfor Cellular Mobile Communications”.November 1997.

Awarded PhDs

Chronological list of awarded PhDs in CCSR over the last 3 years:

Visiting Students

Mr Adrian Cortier

Mr Safak Dogan

Mr Claude Oesteges

Mr Jiangfeng Li

PUBL

ICAT

ION

S

31


CONFERENCE PAPERS

Agius A A , Saunders S R, Evans B G,“Antenna Design For The ICO HandheldTerminal.” International Conference OnAntennas & Propagation (ICAP 1997). IEE,Herriot Watt University, Edinburgh, UK.14-18 April 1997.

Agius A A, Saunders S R, Evans B G,“The Design of Specifications for Satellite PCNHandheld Antennas.” Vehicular TechnologyConference (VIC) 1997, IEEE, Arizona, USA. 4-7May 1997.

Agius A A, Saunders S R, “Intelligent Antennas for Mobile Handsets”, 1st Surrey Symposium on Intelligent AntennaTechnology for Mobile Communications, 28th to 29th August 1997, University of Surrey.

Ahmed B, Buonomo S, Otung I E,“Simulation of 20 Ghz narrow Band MobilePropagation Data Using N-States MarkovChannelModelling Approach.” 10thInternational Conference on Antenna andPropagation, Edinburgh, UK, 14-17 April 1997.

Apostolas C, Tafazolli R,“Dynamic TDMA scheme with Traffic Policingfor ATM Wireless LAN” 9th TyrrhenianInternational Workshop on DigitalCommunications, Lerici, Italy, 7-10thSeptember 1997.

Atkinson I, Yeldener S, Kondoz A,“High Quality Split Band LPC VocoderOperating At Low Bit Rates.” InternationalConference on Acoustics, Speech and SignalProcessing (ICASSP) Munich, Germany, 21April 1997.

Aziz H, Tafazolli R, Evans B G, “Comparison of Total System Capacity forBand Sharing between CDMA based non-Geostationary Satellite-PCNs underImperfect Power Control Systems” IEEE 47thAnnual International Vehicular TechnologyConference (VTC 97) Phoenix, USA, 4-7thMay 1997.

Belloul B, Saunders S, Evans B G,“Diurnal variability of scintillation intensity on a moderate elevation Earth-satellite path at 12.5,20 and 30 Ghz” COST 255, Brussels, 27-29October 1997.

Buracchini E, Melis B, Romano G, Taagho lP,“SINUS Air Interface Overview” 3rd ACTSMobile Communication Summit, Aalborg,Denmark, 7-10 October 1997.

Cruickshank H S,“Securing User, Control and ManagementPlanes In ATM Networks.” SingaporeInternational Conference On Networks 1997(SICON 97). Singapore, 14-17 April 1997.

Fagervik K, Jeans T G,“A Polar Automatic Frequency ControlAlgorithm for Low Signalto Noise Ratios.”Norsig 199, IEEE Norway Section, Tromso,Norway, May 1997.

Fiacco M, Saunders S R, Evans B G,“Design & Simulation of Intelligent Picocells”,1st Surrey Symposium on Intelligent AntennaTechnology for Mobile Communications, 28thto 29th August 1997, University of Surrey.

Ho H P, Sweeney P,“Extended Kasami Algorithm” 6th IMAInternational Conference on Crytography andCoding, Cirencester, December 1997.

Husni E, Sweeney P,“Robust Block Coded MPSK Modulation for theGaussian and a Rayleigh Fading Channel”IMSC’97, Pasadena California, USA, June 1997.

Husni E, Sweeney P, “Robust Block CodedMPSK Modulation” 4th InternationalSymposium on Communication Theory andApplications, Ambleside, July 1997.

Husni E, Sweeney P,“Robust Reed Solomon Coded MPSKModulation” 6th IMA International Conferenceon Cryptography and Coding, Cirencester,December 1997.

Koudelka O, Maral G, Cruickshank H, Collard J,“Network integration via MEO/LEOsatellites-The COST 253 action” IEE Colloquiumon EU’s initiatives in satellite communications-fixed and broadcast, London, 9th May 1997.

Lee J, Tafazolli R, and Evans B G,

”Erlang capacity of OC-CDMA imperfect powercontrol”, IEE Eletronics Letters, pp. 259-261,13th Feb vol 33, no 4, 1997

Meenan C, Tafazolli R, Evans B G,“Mobility Management and its Impact On CallRouting in Dynamic Satellite PersonalCommunication Networks.” InternationalMobile Satellite Conference, Pasadena, USA,June 1997.

PUBLICATIONS

Alphabetical list of conference and journal publications by researchers in CCSR over the last 3 years.

CCSR PUBLICATIONS LIST FOR 1997

32

PUBL

ICAT

ION

S

Meenan C, Tafazolli R, Evans B G,

“Intelligent Paging Schemes for Non-GeoSatellite Personal Communication Networks.”Vehicular Technology Conference 1997,IEEEPhoenix Arizona, USA, 4-7th May 1997.


“New Mobility Management And Call Routing Protocols For Dynamic Satellite PersonalCommunication Networks.” Integration of Satellite Terrestrial PCS, IEE London, April 1997.

Meenan C, Tafazolli R, Evans B G,“Intelligent Paging in Dynamic SatellitePersonal Communication Networks.”International Mobile Satellite 1997, Pasadena,USA, 19 June 1997.

Meenan C, Tafazolli R, Evans B G,“Mobility Management and its Impact On CallRouting in Dynamic Satellite PersonalCommunication Networks.” InternationalMobile Satellite Conference, Pasadena, USA,June 1997.

Mertzanis I, Tafazolli R, Evans B G,

“Protocol Architecture Scenarios for Satelliteand B-ISDN Network Integration” 3rd Ka-BandUtilisation Conference, Sorento, Italy,September 1997.

Mertzanis I, Fan B, Tafazolli R, Evans B G,

“Signalling and Protocol Schemes for SECOMS, the ACTS European project” FourthEuropean Conference on Satellite Communications (ECSC-4), Italy, 18-20November 1997.


“Connection Admission Control Strategy andRouting Considerations in Multimedia (Non-Geo) Satellite Networks”, IEEE 47th AnnualInternational Vehicular Technology Conference,Phoenix, USA, May 4-7th 1997.


“Performance Issues and Modelling of Mobile Executed Handoffs in Multi-Spotbeam DynamicSatellite Networks using ATM Multiplexing”,IEE, Colloquium London, UK, February 1997.

Ors T, Sun Z, Evans B G,

“A Meshed VSAT Satellite NetworkArchitecture using an On-Board ATM Switch”,IEEE International Performance, Computing andCommunications Conference 1997, Phoenix-Arizona, USA, 5-7th February 1997.

Parks M A N, Saunders S R, Evans B G,

“Wideband Characterisation and Modelling ofthe Mobile Satellite Propagation Channel at L- and S- Bands.” Tenth InternationalConference on Antennas and Propagation,Edinburgh, 14 April 1997.(Proceedings vol.2 pp. 239-243)

Rautiola K, Tolonen M, Taaghol P, Tafazolli R,

Evans B G,

“Design of the Satellite Radio ChannelEmulator for Real-Time Demonstrations inSINUS” 3rd ACTS Mobile CommunicationSummit, Aalborg, Denmark, 7-10 October 1997.

Sadka A H, Eryurtlu F, Kondoz A M,

“Modified H.263 video coding algorithm formobile multimedia communications”, 2ndErlangen Symposium on advances in digitalimage communications, Erlangen, Germany,April 1997.

Samarakoon M I, Honary B, Sweeney P,

“Secure file transmission over multi-user networking environments” 4th InternationalSymposium on Communication Theory and Applications, Ambleside, July 1997.

Sammut A, Mertzanis I, Tafazolli R, Evans B G,

“A Global Integrated Personal SatelliteMultimedia Environment (GIPSE):Communications for the Next Millenium.” Proceedings of the Third Ka Band UtilizationConference, Sorrento, Italy, pp 429-434, 15 September 1997.

Sammut A, Mertzanis I, Tafazolli R, Evans B G,

“A Global Integrated Personal SatelliteMultimedia Environment (GIPSE)” FourthEuropean Conference on SatelliteCommunication (ECSC-4), pp 11-15, Rome,Italy, 18-20 November 1997.

Saunders S R, Evans B G,

“A Physical-Statistical Model for Land MobileSatellite Propagation In Built-Up Areas”, 10thInternational Conference on Antennas and Propagation, pp 2.44-2.47 14 th to 17th April1997, Edinburgh.

Sweeney P, Honary B,

“Security and Information Representation forthe Niederreiter Public Key Cryptosystem” 4thInternational Symposium on CommunicationTheory and Applications, Ambleside, July 1997.

Taaghol P, Tafazolli R, Evans B G,

“Performance Evaluation of an Adaptive PowerControl Scheme in Measurement Based S-PCNChannel” IMSC’97, Pasadena, California, USA,16-18 June 1997.

Taaghol P, Tafazolli R,

“Correlation Model for Shadow Fading in land-Mobile satellite System”, IEE Eletronics Letter,17th July 1997 Vol.33 No.15, pp.1287-1289

Taaghol Pouya, Tafazolli R, Evans B G,

“On the Reservation Multiple Access Protocolsfor Future Mobile Communication Systems”IEEE 47th Annual International VehicularTechnology Conference, Phoenix, USA, 5-7thMay 1997.


“An Air Interface Solution for General PacketRadio Service (GPRS) for GSM/DCS” IEEE 47thAnnual International Vehicular TechnologyConference, Phoenix, USA, 4-7th May 1997.

Tateesh S, Atungsiri S, Kondoz A M,

“Link Adaptation to Channel Interference UsingMulti-rate Source and Channel Coding forCDMA Mobile Communications.” InternationalConference on Acoustics, Speech and SignalProcessing (ICASSP) Munich, Germany, April 1997.

PUBL

ICAT

ION

S

33


Andrikopoulos I, Ors T, Matijasevic M,

Leitold H, Posch R,

“TCP throughput measurements within hetero-geneous ATM local area networks” ATMNetworks:Performance Modelling and Analysis,Vol.III, Chapman and Hall, London.

Cruickshank H,

“Securing user, control and managementplanes in ATM networks”, National Universityof Singapore, May 97.

Valadon C, Tafazolli R, Evans B G,

“On Channel Coding for Satellite MultimediaSystems with a Synchronous CDMA AccessScheme.” International Mobile SatelliteConference’97, Pasadena California, USA, 16-18June 1997.

Valadon C, Taaghol P, Tafazolli R, Evans B G,

“Design and Dimensioning of a CDMARegenerative Payload for the SECOMSSystem” 4th European Conference on SatelliteCommunications, Rome, Italy, 18-20 November1997.


“Link Design and Dimensioning of CDMA, theAlternative Multiple Access in SECOMS” 3rdKa-Band Utilization Conference, Sorrento, Italy,15-18 September 1997.


“SECOMS CDMA Link Dimensioning” 3rdACTS Mobile Communications Summit,Aalborg, Denmark, 7-10 October 1997.

Villette S, Stefanovic M, Atkinson I,

Kondoz AM,

“High Quality Split Band LPC Vocoder and itsFixed Point Real Time Implementation”Eurospeech ‘97, Vol.3, pp 1243-1246, Rhodes,Greece, 22-25 September 1997.

Apostolas C, Sfikas G, Tafazolli R,

“The UK LINK- PCP Approach to the WirelessATM System“, Accepted for publication in IEEECommunications Magazine , Special Issue onWireless ATM, October 1997

Amornraksa T, Sweeney P, Honary B,

“Protecting the integrity of a sequence ofimages.”IEE Electronics Letters, Vol 33, Part 19,pp 1617-1618, September 1997.

Atungsiri S A, Tateesh S, Kondoz A M,

“Multirate Coding for Mobile CommunicationsLink Adaptation.”IEE Proceedings OnCommunication, Vol. 144, Part 3, pp 211-216,June 1997.

Eryurtlu F, Sadka A H, Kondoz A M,

“Error Robustness Improvement of VideoCodecs with Two-way Decodable Codes” IEEElectronics Letters, Vol.33, No.1, pp 41-43,January 1997.

Hadjitheodosiou M H, Evans B G, Coakley F,

“Next generation multiservice VSAT networks”IEE Electronics & Communication EngineeringJournal, Vol.9 No.3, June 1997.

Kweh T H, Eryurtlu F, Kondoz A M,

“Closed – Loop Motion Compensation forVideo Coding Standards.” IEE Proceedings –Visual Image Signal Process, Vol 144,Part 4, pp227-232, August 1997.

Lee J, Tafazolli R, Evans B G,

“Erlang Capacity of OC-CDMA with imperfectPower Control” IEE Electronics Letters, Vol 33, No 4, pp. 259-261, 13 February 1997.


“Error Resilience Improvement for Block-Transform Video Coders” IEE Proc. VISP,Vol.144 No.6, December 1997.”,


“Improved Performance H.263 under ErroneousTransmission Conditions” IEE ElectronicsLetters, Vol.33 No.2, pp 122-124, January 1997.

Sun Z, Ors T, Evans B G,

“ATM-over Satellite demonstration of broad-band network interconnection” Special Issue inComputer Communications Journal, ElsevierScience Publications.

Taaghol P, Tafazolli R,

“Correlation Model for Shadow Fading in Land-Mobile Satellite Systems” IEE ElectronicsLetters, Vol.33, No.15, pp 1287-1289, 17 July 1997.

X.He,Tafazolli R, Evans BG,

”Priority-based Random Access Schemes for S-PCN“, IEE Electronics Letter,Vol.33 No.1, pp 25-27, 2 January 1997

Zhao W, Tafazolli R, Evans BG,

”Inter-Network Handover PerformanceAnalysis in a GSM-Satellite Integrated MobileCommunication System”, IEEE Journal ofSelected Communications (JSAC) Special Issueon Mobile Networks October 1997.

JOURNAL PAPERS

SEPARATE PUBLICATIONS

34

Agius A A, Mahmoud M, Tafazolli R, Evans, B G,

“QuadrafilarHelical Antennas for a HandheldTerminal in Satellite Personal CommunicationNetworks (SPCN)” 5th Intl.Conf. on Satellite Systems for Mobile Com. &Navigation, IEE May 1996

Agius A A , Saunders S R , Evans B G,

“Quadrifilar Helical Antenna (QHAI)Characteristics Of A Proposed Wire AntennaFor An SPCN Handheld Terminal.” InternationalWorkshop On Mobile Communications ‘96,Greece, 19-21 September 1996.

Andrikopoulos I, Ors T, Jones S P W,

“Throughput Measurements for TCP/IP overAAL 5 in ATM LANs”, Twelfth UK Computerand Telecommunications PerformanceEngineering Workshop, University ofEdinburgh, UK, 12th September 96.

Andrikopoulos I, Ors T, Matijasevic, Leitold H,

Jones S P W, Posch R,

“TCP/IP Throughput Performance Evaluationfor ATM Local Area Networks” 4th IFIPWorkshop on Performance Modelling andEvaluation of ATM Networks. W. Yorkshire,UK

Apostolas C, Tafazolli R, Evans B G,

“Comparison Between Elimination Yield Non-Pre-Emptive Priority Multiple Access (EY-NPMA) and Dynamic TDMA(DTDMA)”Proceedings for PIMRC ‘96, Taipei,Taiwan 1996.

Aziz H,

“Effect of Total System Capacity due toImperfect Power Control for Band sharingbetween CDMA based Non-GeostationarySatellite-PCNs”, The Seventh IEEE InternationalSymposium on Personal, Indoor and MobileRadio Communications (PIMRC 96), Taiwan,Taipei, 15-18th October 1996.

Coakley F P, Hadjitheodosiou M,

“Networking with VSATS from Low Bit Rate Systems to ATM Service Provision” AIAAConference, USA. February 1996.

Cruickshank H, Sun Z, Velentzas S,

A Proposal for Security Services in ATM Networks.Fourth Workshop on PerformanceModelling and Evaluation of ATM Networks. Ilkley,W. Yorkshire. July 1996.

Qi R, Coakley F P, Evans B G,

“Low Complexity and Low Power Consumption Design for OBP Multicarrier DEMUX VLSI,”16th AIAA International CommunicationsSatellite Systems Conference, Washington, DC,USA, February 25-29, 1996.


“A Reconfigurable Multistage Multicarrier DEMUX Architecture,” the 5th InternationalWorkshop on Digital Signal ProcessingTechniques Applied to Space Communications,Barcelona, Spain, September 25-27, 1996.


“A Novel Pure Systolic Linear Phase FIR forHigh speedApplications,” the 7th InternationalConference on Signal Processing Applications& Technology, Boston, Massachusetts, USA,October 7-10, 1996.


“Optimization of Complex Binary Tree FilterBank Structure Using Multirate Signal FlowGraph Transformation,” the IEEE International Conference on Communication Systems,Singapore, November 25-29, 1996.


“Source and Channel Coding for Mobile Multimedia Communications” COST 237Workshop on Multimedia Telecommunicationsfor Applications.25th November 1996.Barcelona, Spain.


CONFERENCE PAPERS

PUBL

ICAT

ION

S


Ors T, Hadjitheodosiou M H, Sun Z, Evans B G,

“ATM over VSAT networks using traditionalbent-pipe or on-board processing Satellites”ATM Networks:Performance Modelling andAnalysis, Vol.III, Chapman and Hall, London.

Ors T, Sun Z, Evans B G,

“A Meshed VSAT Satellite NetworkArchitecture Using An On-board ATM Switch.”IEEE Int . Performance, Computing andCommunications Conference 1997. IEEE, USA,1997

Taaghol P, Tafazolli R, Evans B G,

“Performance Evaluation of an Adaptive Power Control Scheme in Measurement Based S-PCNChannel” IMSC’97, Pasadena California, USA, 16-18 June 1997.


“Link Adaptation To Channel Interference UsingMulti-rate Source and Channel Coding ForCDMA Mobile Communications.” Proceedingsof International Conference on Acoustics,Speech and Signal Processing (ICASSP) IEEE,Munich, Germany, April 1997.

35


Sadka A H, Eryurtlu F, Kondoz A M, Evans B G,

“Performance Comparison of ITU H.261 andH.263 Video Coding Algorithms for PacketSwitched Networks” Intl. Conference onTelecommunications. Istanbul, Turkey. April 1996.


“Aspects of error resilience for Block-BasedVideo Coders for Multimedia Communications”,IEE Colloquium on the future of MobileMultimedia Communications, Savoy Place,London UK, December 1996.

Saunders S, Evans B G,

“The Spatial Correlation of Shadow Fading InMacrocellular Mobile Radio Systems”Proceedings IEE Colloquium on PropagationAspects of Future Mobile Systems, IEE London25 October 1996.

Saunders S, Thomas H,

“Control of Microcellular Re-use statistics usingdirectional antennas in the presence of scatter-ing” 46th IEEE Vehicular Technology SocietyConference, April 28th May - 1st June 1996.Vol 3. pp 1685-1689.

Sfikas G, Tafazolli R, Evans BG,

“Hands-off Considerations in a Wireless ATMEnvironment”, International Workshop onMobile Communications (IWMC), Thessaloniki,Greece, 19th Sept 1996.

Sfikas G, Tafazolli R, Evans B G,

“ATM Cell Transmission over the IEEE 802.11Wireless MAC Protocol.” Personal, Indoor andMobile Radio Communications PIMRC ‘96Taiwan 1996.

Shin S K, Sweeney P,

“Evaluation of Efficient Trellis Methods for SoftDecision Decoding of Reed Solomon Codes”IEE Proceedings -Commun., Vol 143 No. 2 pp61-67, April 1996.

Sun Z, Ors T, Cruickshank H, Evans B G,

“Implementation of ATM over satellite forbroadband services” IEE Colloquium on ATMover Satellite, London, UK, 27 November 1996.

Sun Z, Cruickshank H, Evans B G,

“Theseus Broadband Networks for EuropeanStock Exchange and Users.” IEEE ICCS/ISPACS96, Singapore, November 1996


“Burst Reservation Multiple Access Techniquesfor the GSM/DCS and DECT Systems.” 7th IEEEInternational Symposium on Personal,Indoorand Mobile Communications, Taiwan.October 1996.


“Performance Optimisation of PacketReservation Multiple Access Through NovelPermission Probability Strategies.” IEEColloquia on Networking Aspect of RadioComms. Systems. London, pp 8/1-8/5, March 1996

Tafazolli R, Evans B G,

“Wide Area Mobility for DECT.” Globecom ‘96London, UK. November 1996

Tafazolli R, Evans B G,

“Interworking and Integration of the InmarsatStandard-M with the Pan-European GSMSystem.” International Mobile SatelliteConference, Pasadena, CA, June 1993.


“Link Adaptive Multi-rate Coding VerificationSystem for CDMA Mobile Communications”1996 IEEE Global TelecommunicationsConference GLOBECOM, London UK,November 1996.


“Link Adaptive Multi-rate Coding VerificationSystem for CDMA Mobile Communications”Proceedings for 1996 IEEE GlobalTelecommunications Conference GLOBECOM,London UK, November 1996.

Yaghmaie K, Kondoz A M, Atungsiri S,

“Prototype Waveform Interpolation of OriginalSpeech” 3rd Communication NetworksSymposium. Manchester, UK July 1996.

Yaghmaie K, Kondoz A M, Atungsiri S,

“Prototype Waveform Interolation of OriginalSpeech” Proceedings for 3rd CommunicationNetworks Symposium. Manchester, UK July1996.

Zhao W, Tafazolli R, Evans B G,

“Inter Networking Signalling Load Analysis forGSM - Satellite Integration” EMPS ‘96, Rome, October 1996

Zhao W, Tafazolli R, Evans B G,

“Inter-Network Signalling Load Analysis forGSM Satellite Integration.” Proceedings of theSecond European Workshop on Mobile/PersonalSatcoms. (EMPS ‘96) UK 1996.

Cruickshank H S,

“A Security System for Satellite Networks” IEEConference on Satellite Systems for MobileCommunications and Navigation. London, UK.13 -15 May 1996.

Ghaheri Niri S, Tafazolli R, Evans B G,

“Wide Area Mobility for DECT.” Globecom ‘96IEEE Global Telecommunications ConferenceProceedings. London, UK November 1996.

PUBL

ICAT

ION

S

36

Ghaheri Niri S, Tafazolli R, Evans B G,

“Third Generation Personal CommunicationsNetwork a Candidate Network for DIS” 15thDIS Conference/Workshop on theInteroperability of Distributed InteractiveSimulations. Orlando September 1996

He X, Tafazolli R, Evans B G,

“Paging signalling in Non-GEO Satellite Mobile Systems” Fifth International Conference on“Satellite Systems for Mobile Communicationsand Navigation”, London, May 1996.


“Call Processing Functions in the IntegratedSatellite and GSM System” IEEE 46th VehicularTechnology Conference, Atlanta, USA, May1996.


“An Optimised Signalling Architecture for aMEO/ICO Satellite System” AIAA 16thInternational Communications SatelliteSystems Conference, Washington DC, USA,February 1996.

Husni E, Sweeney P,

“Block Coded M-PSK Modulation Using ReedSolomon Codes” Fifth ESA InternationalWorkshop on Digital Signal ProcessingTechniques Applied to Space Communications.Barcelona, Spain, September 1996.

Losquadro G, Jahn A, Lutz E, Paraboni A,

Taaghol P, Tartara G, Evans B G,

“SECOMS Demonstrators for BroadbandMobile Satellite Links at Ka and EHF Bands”,2nd ACTS Mobile Communications Summit,Granada, Spain, November 1996.


“Capacity of the Overlapped Carriers Schemein FD/FDS-CDMA” ISSSTA ‘96, Mainz,Germany. September 1996.

Marinelli M, Perez-Leal R, Taaghol P,

“SECOMS Satellite Characteristics for MobileMultimedia Services”, ACTS MobileCommunications Summit, Granada, Spain, 27-29 November 1996.


“A Low Earth Orbit Satellite Constellation ForPersonal Communication Networks” XXVthGeneral Assembly of the International Union ofRadio Science(URSI), Lille, France, August1996.

Ors T, Jones S P W,

“Congestion Control for ABR Services in ATMLANS” 8th IEEE Workshop on Lans and MANs.Potsdam, Germany 25th August 1996.

Ors T, Sun Z, Jones S P W,

“ATM Networking with VSATs” 4th IFIPWorkshop on Performance Modelling andEvaluation of ATM Networks, Ilkley, UK. July1996.

Ors T, Jones S P W,

“An Adaptive Congestion Control Scheme ForNetworks Using Advanced BufferManagement.” IEEE Int. Conference OnCommunication Systems(ICCS). Singapore,Nov.1996.

Ors T, Jones S P W,

“Congestion Control For ABR Services In ATMLANS.” Eighth IEEE Workshop On Local AndMetropolitan Area Networks. Potsdam,Germany, Aug 1996.

Ors T, Jones S P W,

“Traffic management for ATM Local AreaNetworks using a Combined Preventive/ReactiveControl Mechanism”, International Conferenceon Telecommunications 96, Bogazici,University, Istanbul, March 96.

Otung I E, Evans B G,

“Impact of Scintillation Fading on Satellite EHFCommunications for Multimedia MobileServices.” 2nd KA Band Utilization Conference,Florence, Italy, September 1996.

Otung I E, Saunders S, Mahmoud M S,

Parks M, Ahmed B,

“Radio Propagation and Antennas Research atSurrey” 4th CEPIT Workshop. Florence, ItalySeptember 1996

Otung I E,

Comparative Evaluation of Rain andScintillation Fading on Low-availability Ka-/EHFbands VSAT Satellite Systems. IEEE Africon ‘96University of Stellenbosch, South Africa.September 1996.

Otung I E, Mahmoud M S,

“Statistics of Scintillation and the Structure ofAtmospheric Turbulence.” XXVth GeneralAssembly of the International Union of RadioScience (URSI) Lille, France, August 1996.


“Role of Tropospheric Scintilations in SatelliteCommunication Systems at Ka-bandFrequencies and Beyond.” XXVth General Assembly of the International Union of RadioScience (URSI). Lille, France. August 1996.

Parks M A N, Saunders S, Evans B G,

“A Widespread Channel Model Applicable toMobile Satellite Systems at L- and S-band” IEEColloquium On Propagation Aspects Of FutureMobile Systems, IEE Savoy Place, London,25 October 1996


“Carrier to Multipath Characterisation andPrediction for Mobile Satellite Systems” EMPS‘96 . Rome. 8-10th October 1996

PUBL

ICAT

ION

S

37


JOURNAL PAPERS

Black A W, Kondoz A M, Evans B G,

“Improved Pulsed Residual Excited LinearPrediction: A New Excitation for CELP BasedSpeech Coders” IEE Electronics Letters. Vol32Part 6 p520-521, March 1996.

Dyer C, Sims A, Underwood C,

“Measurements of the Sea Environment from Sea Level to GEO using the Cream and CredoExperiments” IEE Transactions on Nuclear Science, Volume 43, Part 2. pp383 to 402 April 1996.

Fagervik K, Jeans T G,

“Low Complexity Bit By Bit Soft OutputDemodulator.” IEE Electronics Letters, Vol 32,Part 11, pp. 985-987, May 1996.

Guntch A, Tafazolli R, Giancristofaro D,

Argenti F, Menolascino R,

“Integrating GSM with new Satellite Systems”,Mobile Communications International,Issue 31, pp62-65, May 1996.

Kweh T H, Eryurtlu F, Kondoz A M,

“Rate control algorithm for block-basedvariable rate video encoders” IEE ElectronicsLetters, Vol.32, No.14, pp 1277-1278, July 1996.


“Effect of Adjacent Carrier Interference on SNRUnder the Overlapping Carrier AllocationScheme in FD/DS-CDMA” IEE ElectronicsLetters Vol.32, No. 3 p171-172, February 1996.

Otung I E,

“Prediction Of Tropospheric Amplitude On ASatellite Link .” IEEE Transactions On AntennasAnd Propagation, Vol.44, Part. 12, pp. 1600-1608. December 1996.

Otung I E,

“Scintillation Fade and Enhancement Durationon a 20 GHz Satellite Downlink” IEE


“Practical Considerations for BandpassSampling,”IEE Electronics Letters, Vol. 32,No.20, September 1996.


“Tropospheric Scintillation and the Influence ofWave Polarisation” IEE Electronics Letters, Vol32 Part 4, p307-308 February 1996


“Rate Control Feedback Mechanism for PacketVideo Networks” IEE Electronics Letters, Vol.32part 8. p716 to 717. April 1996.

Saunders S, Evans B G,

“Physical Model of Shadowing Probability forLand Mobile Satellite Propagation”, IEE Electronics Letters, Vol 32, Part 17, pp 1548-1589, 15 August 1996.

Shah A, Atungsiri S, Kondoz A M, Evans B G,

“Lossy Multiplexing of Low Bit Rate Speech inThin Route Telephony.” IEE Electronics Letters,Vol.32, Part 2. p 95-97. January 1996.


“Evaluation of Efficient Trellis Methods for SoftDecision Decoding of Reed-Solomon Codes”IEE Proceedings - Communications, Vol.143,Part 2 p61-67. April 1996.Letters. Vol 32 Pt 1 pp65 - 67 January 1996.

Smith C J, Kondoz A M, Gaskell P S ,

Evans B G ,

“Subjective performance evaluation oftandemed full-rate GSM/ADPCM voice codecs”International Conference onTelecommunications, Istanbul, Turkey, pp 140-143, April 1996.


“A Wideband Channel Model Applicable to Mobile Satellite Systems at L- and S- band” IEEColloquium on Propagation Aspects of futureMobile Systems - Proceedings. IEE SavoyPlace, UK. October 1996.

Parks M A N, Butt G, Buonomo S, Evans B G,

“Wideband Propagation Measurements andResults at L and S-Bands for Personal andMobile Satellite Communications” FifthInternational Conference on Satellite Systemsfor Mobile Communications and Navigation,IEE Savoy Place, London. May 1996


“Satellite Personal Communication ChannelCharacterisation at L and S-bands” FirstCommunication Conference, Muscat. May 1996


“Simultaneous Wideband PropagationMeasurements Applicable to Mobile SatelliteCommunication Systems at L and S-Bands”16th International CommunicationSatellite Systems Conference, AIAA. February1996.

PUBL

ICAT

ION

S

38

Agius A, Mahmoud M S,

“A Simple World Wide Teleradiology System”TELEMED ‘95 International Conference onTelemedicine and Telecave Medicine in theSuperhighway. Heathrow, London 8-9November 1995.

Allery M N, Price H E, Ward J W,

da Silva Curiel R A,

“Low Earth Orbit Microsatellites for DataCommunications Using Small Terminals.”Proceedings to 10th IEE InternationalConference on Digital SatelliteCommunications, Vol 2, pp. 457-465, Brighton,May 1995.

Apostolas C, Tafazolli R, Evans B G,

“Wireless ATM LAN.” Proceedings to 6th IEEE International Symposium on Personal,Indoor & Mobile Communications (PIMRC’95),pp. 773-777, Toronto, Canada, September 1995.

Atkinson I A, Kondoz A M, Evans B G,

“Time Envelope LP Vocoder: A New CodingTechnique at Very Low Bit-Rates.” Proceedingsto EUROSPEECH ‘95, pp. 241-244, Madrid,September 1995.


“Time Envelope Vocoder, A Natural SoundingSpeech Coding Algorithm Operating at 1.6KBits/Sec.” Fifth IEE Conference onTelecommunications, IEE, Brighton, 26-29March 1995.


CONFERENCE PAPERS


Cruickshank H,

“Implementation of ATM over SatelliteBroadband Services” IEE Professional GroupE9. Nov 96.

Ors T, Jones S P W,

“An Adaptive Congestion Control Scheme ForNetworks Using Advanced BufferManagement.” IEEE Int. Conference OnCommunication Systems (ICCS). Singapore,Nov.1996.

Ors T, Jones S P W,

“Traffic management for ATM Local AreaNetworks using a combinedPreventive/Reactive Control Mechanism”,International Conference on Telecommunications 96, Bogazici, University,Istanbul, March 96.

Qi Rongang, Coakley F, Evans B G,

“Optimisation of Complex Binary Tree Filter Bank Structure using multirate signalFlow Graph”, Conference Proceedings, IEEEICCS/ISPACS 96, Singapore, Nov 96.

Smith C J, Black A W, Kondoz A M,

“Improved Spectrum Efficiency by SourceCompression”, Microwaves and RF 96Conference Proceedings, Nexus Media Ltd,London 96.

Sun, Z, Cruickshank H, Evans B G,

“Theseus - Broadband Networks for EuropeanStock Exchange and Users” IEEE InternationalConference on Communication Systems,Singapore, 25-29 November 1996.

Sun Z, Ors T, Evans B G,

”Interconnection Of Broadband Islands ViaSatellite Experiments on the Race II CatalystProject”, Transport Protocols For High - SpeedBroadband Networks Workshop, Globecom 96,22 November 1996.

Sun Z, Ors T, Cruickshank H, Evans B G,

“Implementation of ATM over Satellite forBroadband Services” IEE Colloquium on ATMover Satellite, London, 27th November 1996.

PUBL

ICAT

ION

S

JOURNAL PAPERS


“Impact of multi-rate source and channel coding on long term fading in CDMA mobilecommunication systems” InternationalConference on Telecommunications, Istanbul,Turkey, pp 750-753, April 1996.

Yeldener S, Kondoz A M, Evans B G,

“Perceptually based modelling of excitation spectrum for the applications of multi-band LPCspeech coding” International Conference onTelecommunications, Istanbul, Turkey, pp 148-151, April 1996.

Zhao W, Tafazolli R, Evans BG,

“A Combined Handover Algorithm for DynamicSatellite Constellations“, IEE Electronics Letters,Vol 32, No.7, pp.622-624, 28 March 1996.

39

Atungsiri S A, Kondoz A M, Evans B G,

“Comparative Study of Two CELP Codecs forEnhanced Full Rate GSM Applications.”Proceedings to EUROSPEECH ‘95, pp. 703-706,Spain, September 1995.

Bjelajac B, Cohen M, Fantacci R, Huggins G,

Sammut A,

“Dynamic Channel Allocation Schemes forSatellite UMTS.” Proceedings to RACE Mobile Telecommunications Summit, Vol 2, pp. 313-318, Cascais, Portugal, November 1995.

Black A, Atkinson I, Kondoz A M,

Evans B G,

“High Quality 14.2kb/s Wideband Speech Coder”. EUROSPEECH ‘95, Madrid,September 1995.

Black A, Atkinson I, Kondoz A M,

Evans B G,

“High Quality 14.1kb/s Wideband Speech Coder.” Proceedings to EUROSPEECH‘95, pp. 45-48, Madrid, September 1995.

Black A, Kondoz A M, Evans B G,

“High Quality Low Delay Wideband SpeechCoding at 16KBits/Sec.” 2nd Int. Workshop onMobile Multimedia Communications, HewlettPackard, Bristol University, 11 April 1995.

Butt G, Parks M A N, Evans B G,

“Narrowband and Wideband Characterisationof Satellite Mobile/PCN Channel.” IMSC’95,Ottawa, Canada, June 1995.


“Measurements & Modelling of WirelessChannel for Satellite Mobile/PersonalCommunication Systems.” 10th Int. Conf. onDigital Satellite Communications, IEE, Brighton,May 1995.


“Modelling the Mobile Satellite Channel forCommunication System Design.” Int. Conf. onAntennas & Propagation, IEE, The Netherlands,April 1995.


“Modelling the Mobile Satellite Channel forCommunication System Design.” Int. Conf. onAntennas & Propagation, IEE, The Netherlands,April 1995.


“Channel Models for Mobile/Personal Satellite Communication Systems.” Proceedings of 1stEuropean Workshop on Mobile/PersonalSatcoms, EMPS’95, pp. 251-262, London, 1995.

Coakley F P, Yim W H,

“A Hybrid CDMA Scheme and DemodulatorStructure for Ka-Band Operation.”10th Int.Conf. on Digital Satellite Communications,Brighton, 15 May 1995.

Coakley F P, Malinowski P,

“Fault Tolerant On-Board Switches for ATM.”10th Int. Conf. on Digital SatelliteCommunications, Brighton, 15 May 1995.

Cullen C, Sammut A, Tafazolli R,

Evans B G,

“Networking & Signalling Aspects of a Satellite Personal CommunicationsNetwork.” Proceedings of the 1st European Workshop on Mobile/Personal Satcoms,EMPS’95, pp. 202-222, London, 1995.

Danesfahani G R, Jeans T G,

“Self-Noise Cancellation of the ModifiedMueller and Müller Algorithm.” 3rd Int.Symposium on Communication Theory andApplications, IEEE, Ambleside, July 1995.

Eryurtlu F, Kondoz A M, Evans B G,

“Predictive Entropy Coding of Gain-Shape VQ Parameters.” Proceedings for 1995 Int.Conf. on Acoustics, Speech & Signal Processing, pp. 2515-2518, Detroit, May 1995.

Eryurtlu F, Sadka A H, Atungsiri S, Kondoz A

M, Evans B G,

“Integrated Speech and Video Coding forMobile Audio-Visual Communications.” 2ndInt. Workshop on Mobile MultimediaCommunications,pp 93-97, Hewlett-Packard,Bristol University, 11 April 1995.

Evans B G, Zhao W, Tafazolli R,

“Interworking Procedures Between Cellular Networks & Satellite Systems.” Proceedings ofthe 1st European Workshop on Mobile/PersonalSatcoms, EMPS’95, pp. 123-141, London, 1995.

Hadjitheodosiou M H, Coakley F P,

“Adaptive Multiple Access Protocols for VSATsProviding Voice/Data Services & ATMInterconnection.” 10th Int. Conf. on DigitalSatellite Communication Networks Symposium(IEEE) Manchester 1995Communications, IEE,Brighton, May 1995


“Study of CRP and Capture Probability inSlotted Aloha RACH of NGEO SatelliteSystem.” IMSC ‘95, Ottawa, Canada, June1995.

Ho H P, Sweeney P,“Soft Decision Decoding of Reed SolomonCodes using the Dorsch Algorithm”,Proceedings of 5th IMAConference on Codingand Cryptography, December 1995.

Mahmoud M S, Evans B G,

“Radiowave Amplitude Scintillation &Applications to Remote Sensing of theAtmosphere.” 12th UK National Radio ScienceColloquium, London, July 1995.


PUBL

ICAT

ION

S

40

JOURNAL PAPERS


“Pitch Detection of Speech Signals Using Segmented Autocorrelation.” IEE ElectronicsLetters, Vol 31, Part 7, pp. 533-535, March 1995.

Atkinson I A , Kondoz A M, Evans B G,

“1.6kbits/sec LP Vocoder Using TimeEnvelope.” IEE Electronics Letters, Vol 31, Part 7, pp. 517-519, March 1995.


“Time Envelope Vocoder A New LP Based Coding Strategy for Use at Bit Rates of 2.4kb/sand Below.” IEE Journal on Selected Areas inCommunications, IEE, Vol 13, Part 2, pp. 449-457, February 1995.

Danesfahani G R, Jeans T G,

“Optimisation of Modified Mueller and MullerAlgorithm.” IEE Electronics Letters, Vol. 31,Part 13, pp. 1032-1033, June 1995.

Eryurtlu M O F, Kondoz A M, Evans B G,

“Very Low Bit Rate Segmentation Based VideoCoding using Contour and Texture Prediction.”IEE Proceedings - Vision, Image & SignalProcessing, Vol 142, No. 5, pp. 253-261,October 1995.

Eryurtlu M O F, Atungsiri S A, Kondoz A M,

Evans B G,

“Entropy Coding of ITU G.728 SpeechParameters for Low Bit Rate AudiovisualCommunications.” IEE Electronics Letters, Vol.31, Part 15, pp. 1213-1215, July 1995.

Kondoz A M,

“Pulse Residual Excited Linear Prediction.” IEEProc. in Vision, Image & Signal.Processing, Vol.142, Part 2, pp. 105-110, March 1995.

Kondoz A M, Horos J, Evans B G,

Suddle M R,

“Pulsed Residual Excited Linear Prediction.”Proc. of Vision, Image and Signal Processing,IEE, Vol 142, Part 2, pp. 105-110, April 1995.

Meenan C, Sammut A, Tafazolli R, Evans B G,

“Deligo: Repetitive Ground Track 100% Dual-Diversity LEO Satellite Constellation for S-PCN.” IEE Electronics Letters, Vol. 31, Part17, pp. 1407-1408, August 1995.

Ors T, Jones S P W,

“Performance Optimization of ATM InputControl using Multiple leaky-Buckets” ThirdIFIP Workshop on Performance Modelling andEvaluation of ATM Networks. (IFIP) YorkshireJuly 1995.

Ors T, Jones S P W,

“Congestion Control for ATM LANs usingReactive and Preventive Control” SecondCommunication Networks Symposium (IEEE)Manchester July, 1995.


“Data Processing Techniques in RadiowavePropagation.” 12th UK National Radio ScienceColloquium,London, July 1995.

Otung I E, Mahmoud M S, Norbury J R,

“Observations of Ka-Band Tropospheric Scintillation on a Moderate-Elevation Earth-Space Path.” 12th UK National Radio Science Colloquium, London, July 1995.

Otung I E, Goddard J W F,

“Radiowave Amplitude Scintillation inPrecipitation-filled Random Media.”Proceedings to the “Progress inElectromagnetics Research Symposium”(PIERS), pp. 532, Seattle, USA, July 1995.


“Differential Amplitude Scintillation in a Ka-Band Satellite Link.” Int. Conf. on Antennas& Propagation, IEE, The Netherlands, April 1995.

Otung I E, Subramaniam R, Willis M J,

Mahmoud M S,

“Rain Attenuation Statistics of Ka-Band Earth-Space Path.” Int. Conf. on Antennas &Propagation, IEE, The Netherlands, April 1995.

Otung I E, Mahmoud M S, Evans B G,

“Radiowave Amplitude Scintillation & Applications to Remote Sensing of theAtmosphere.” 12th UK National Radio Science Colloquium, London, July 1995.

Parks M, Butt G, Evans B G,

“Propagation Aspects in Satellite Mobile/PCNSystem Design.” Proceedings to RACE MobileTelecommunications Summit, Vol 2, pp. 535-541, Cascais, Portugal, November 1995.


Evans B G,

“A Method for Controlling the Bit Rate of an H.261 Video Stream forMultimedia Communications.” 2nd Communication Networks Symposium,Manchester, July 1995.


Evans B G,

“Packetisation of Speech and Video Signals for MultimediaCommunications.” Int. Conf. on Multimedia Communications: The Information Age, SCSEurope BVBA, Southampton, April 1995.

PUBL

ICAT

ION

S

41

Otung I E,

“New Equations for the Terminal Velocity ofPrecipitation Droplets in a StandardAtmosphere”Journal of Electromagnetic Wavesand Applications Vol.9. Part 10. 1995pp 1241 - 1247.


“Radiowave Amplitude Scintillation Intensity:Olympus Satellite Measurements & EmpiricalModel.” IEE Electronics Letters, Vol 31, Part 21,pp. 1873-1874, October 1995.


“Short Term Distribution of AmplitudeScintillation on a Satellite Link.” IEEElectronics Letters, Vol. 31, Part 16, pp. 1328-1329, August 1995.

Otung I E, Mahmoud M S, Evans B G,

“ Dual Frequency Scintillation Measurement for Remote Sensing” IEE Electronics Letters,Volume 31, Part 23, Pages 1972-1973.9 November 1995.


“Short Term Distribution of AmplitudeScintillation on a Satellite Link.” IEEElectronics Letters, Vol. 31, Part 16, pp. 1328-1329, August 1995.

Shin S K, Atungsiri S A, Kondoz A M,

Evans B G,

“Trellis Decoding of Reed-Solomon Codes inLow Bit Rate Speech Communications.” IEEElectronics Letters, Vol. 31, Part 16, pp.1331-1332, August 1995.


“Efficient Sequential Decoder for ReedSolomon Codes.” International Journal onElectronics, Vol. 79, Part 1, pp. 1-6, July 1995.

Sun Z, Coakley F P, Evans B G,

“Satellite ATM for Broadband ISDN.”Telecommunication Systems, Vol. 4, pp. 119-131, April 1995.

Sweeney P,

“Cyclic Block Codes Definable over MultipleFinite Fields”, IEE Electronics Letters, Vol 3 No.5 pp 344-346, 2 March 1995.


PUBL

ICAT

ION

S

42 NOTES


School of Electronic Engineering, Information Technology & MathematicsUniversity of Surrey, Guildford GU2 5XH UKTel: +44 (0)1483 259800Fax: +44 (0)1483 259504E-mail: [email protected]://www.ee.surrey.ac.uk/CCSR/

Documents

CENTRE FOR COMMUNICATION SYSTEMS RESEARCH