annual report 1998 - university of surrey · alliance with ericsson in mobile ... reform-resource...
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ANNUAL REPORT 1998
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ANNUAL REPORT
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CENTRE FOR COMMUNICATION SYSTEMS RESEARCH
INTRODUCTION 5
Prestigious Highlights of 1998 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 16
3. Terrestrial Mobile Communications 18
4. Wireless LAN 22
MULTIMEDIA SYSTEMS
RESEARCH GROUP 24
1. Speech and Audio Coding 24
2. Image and Video Coding 26
3. Modulation and Channel Coding 26
4. Packet Communication 27
5. Transcoding, Enhancement etc 27
COMMUNICATION NETWORKS
RESEARCH GROUP 29
1. ATM and Broadband Communications 29
2. Network and Service Control and Management 30
3. Internet Technologies 33
4. Network Access 34
5. Integrated Satellite Networking 34
CCSR STAFF 36
CCSR RESEARCH STUDENTS 37
PhDs AWARDED 38
CCSR PUBLICATIONS 39
1998 39
1997 43
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INTRODUCTION
CCSR is a Research Centre within the School ofElectronic Engineering, Information Technologyand Mathematics (EEITM) at the University ofSurrey. The EE section of the School is one ofthe largest in the UK and one of only five, 5* (excellent) research rated departments in theUK. The Research Centre, CCSR, is one of fiveCentres in EEITM and houses around 100researchers. (10 academics, 28 research assistants, 48 PhD students, 8 visitors and 6 support staff). It is the largest academicCommunication Systems Research Centre inthe UK and comprises research groups inMobile and Satellite Systems, MultimediaCommunications and CommunicationsNetworks.
Research covers the
following areas:
● Mobile and Wireless Communications
● Satellite Communications - mobileand broadband
● Integration and Convergence of Communications Systems
● Core Network Techniques (TMN,TINA, Corba)
● Multimedia Services and Signals -Speech and Video
● Networking Features (Protocols, Software Agents, Security)
● Enabling Technologies (Modulation,Coding, Signal Processing and Channel Characterisation)
Current research funding is around £4M and issplit between European Union Projects (15currently running), Research Council Grantsand projects funded from Industry in the UK,Europe, USA and Far East.
CCSR is a core member of both of the UK’s firsttwo Virtual Centres of Excellence in Mobile andPersonal Communications Systems and DigitalMultimedia Broadcasting. It is the largest academic contributor in the UK to EUCommunications projects and has formedmajor global research alliances with Ericsson,Lucent Technologies, Alcatel, Matra and Nortel.In 1998 CCSR was awarded the UK Departmentof Trade and Industry First Prize in Engineeringfor Partnerships between Academiaand Industry.
In addition to our prestigious research, CCSRis a major contributor to the School’s one yearMasters Course in Satellite CommunicationsEngineering, Mobile and Satellite Systems,Mobile and Personal Communications andTelematics. CCSR also contributes one-weekcourses to the Continuing EducationProgramme in areas such as Satellite andMobile Communications, TelecommunicationsNetworks, Digital Signal Processing, CDMATechnology etc.
Our Technology Transfer Consultancy area isalso building up rapidly and enables us tospin-off our intellectual property. Licensingagreements on Speech Coder Software, DigitalSignal Processing algorithms and networkingsoftware are in place and we are planningmajor new initiatives in third generationmobile products.
Further details of the individual researchprojects, staff and publications can befound on our Web Site:(http://www.ee.surrey.ac.uk/CCSR/)
Professor Barry G EvansDirector, CCSR
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● The DTI President‘s Partnership Prize 1998to CCSR in recognition of success in building partnerships with Industry
● Alliance with Ericsson in Mobile Communications which sees CCSR joining its global University Partnership as the only UK University to be funded in this way
● ETSI AMR Competition: CCSR submitted a speech and channel coder for the full and half rate AMR GSM system and achieved the best result in the half rate and third overall out of 11 candidates
● Bin Fan and Tolga Ors were the joint winners of the INMARSAT Council Chairman‘s Prize 1998 for papers written on their PhD research The prizes were awarded on the basis of innovation, relevance to mobile satellite service development and practical implementation
● The IEE Council awarded the1996/1997 IERE Benefactors Premium to Professor Ahmet Kondoz for a paper entitled ’Closed-loop motion compensation for video coding standards‘
● Six PhD students each won £1000 from Industry for Research Excellence. The prizeswere awarded by INMARSAT, Marconi Communications, Nokia, NTL, Racal Research and Vodafone
ANNUAL REPORT 1998
PRESTIGIOUS HIGHLIGHTS OF 1998
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Industrial Partners
● VCE (Virtual Centre of Excellence) in Mobile and Personal Communications: 5 universitiesand 22 industrial companies Digital Broadcast and Multimedia Technology:6 Universities and 12 Companies
● Airtel
● Alcatel Espace
● Alenia Spazio
● Algorex
● Aurigae SA
● BBC
● BT
● Cadence Design Group
● Cable & Wireless
● CET
● CISCO
● CNET France Telecom
● CRL
● CSELT
● Cellnet
● Dassault Electronique
● DLR
● Dolphin Communications
● Ericsson
● Ericsson Limited
● 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
● Matra Marconi Space (France)
● Matra Marconi Space (UK)
● Matsushita
● Mitsubishi
● Mobile Systems International
● Motorola
● NDS
● NERA
● Nokia
● Nortel
● Noval Telespazio
● NTT
● NTL Cable Telecoms
● One2one
● Orange
● Philips
● Quotient
● Racal
● Roke Manor Research
● Samsung
● Siemens AG
● Simoco
● Sintel T & I
● Societe de la Bourse de ValeursMobilieres de Bruxelles
● Societe de la Bourse Francais
● Space Bel
● Space Engineering Spa
● Space Helas
● Symbionics
● Telenor
● Texas Instruments
● TNO
● Toshiba
● Vodafone
CENTRE FOR COMMUNICATION SYSTEMS RESEARCH
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Current Grants/Contracts
GRANTS
● Source and Channel Coding for Mobile Multimedia
● Migration to 3rd Generation Personal Communication Systems
● Variable Bit Rate Time Envelope Vocoder Using Source Dependent Rate Switching
● Global Integrated Personal Satellite Environment (GIPSE)
● 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
● Mobile Radio Antenna Platform (JREI)
● DIGIPLAN (LINK)
● DICTION
● CDMA - MUD
● Channel Emulator (JREI)
INDUSTRIAL CONTRACTS
● Indoor Propagation Factors at 17-20 GHz and 60 GHz
● RCA Modelling/Indoor MeasurementsTestbed
● VCE in Mobile & Personal Communications
● VCE in Multimedia and Digital Broadcasting
● Satellite Wideband Air-Interface Design (SWAID)
● Satellite Handset Antennas
● Software Radio
● Satellite UMTS Architecture
● Satellite UMTS Air Interface Study
● Modelling and Propagation for Indoor Communications
● Indoor Propagation Measurement
● Small Antennas for Handsets
EUROPEAN UNION
● SECOMS-Satellite EHF Communications for Mobile Multimedia Services-EU ACTS2
● SINUS-Satellite Integration into Network forUMTS-EU ACTS2
● ASSET-Advanced Satellite Switching End-end Trials-EU ACTS3
● ACCORD-AdvanCed aCts brOadband joined tRials and Demonstrations-EU ACTS3
● 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 ACTS 2
● MIAMI-Management of the Information Infrastructure ACTS 2
● VITAL-Validation of Integrated Telecommunication Architectures for the Long-term ACTS 2
● REFORM-Resource and Fault restORation and Management close integration ofcontrol and management. ACTS 2
● COPARIS - Common Physical Access for ISDN Systems - ESPRIT
● THESEUS - Terminal at High Speed for European Stock Exchange Users
● ITHACI - Internet and the ATM: experiments and enhancements for conveyance and integration - ACTS 3
● BISANTE - Broadband Integrated Satellite Network Traffic Evaluation - ESPRIT -ACTS 3
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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
● Traffic modelling for multimedia
● Integration cellular/cordless/satellitesystems
● Packet communication in mobilenetworks - GPRS etc
● Band sharing CDMA/TDMA
● Satellite constellation studies and QoS
● Mobile satellite networking - mobility management and resource management
● Satellite air-interface CDMA studies
● Mobile satellite channel modelling andsimulation
● On-Board processing architectures
● Broadband satellite - ATM/IP networking
● Antennas - Intelligent base station and handhelds - Dual mode satellite/cellular
● 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 andmultimedia systems
● RS/Trellis/Soft decoding and Turbo coding
● Cryptography for Multimedia Communications
● Higher level modulation and jointmodulation/coding
● DSP applications and implementations
● On-Board Satellite DSP and Processing
COMMUNICATIONS NETWORKS
● Broadband service/traffic characterisation
● Performance assessment of Multimedia over ATM
● ATM over satellite and satellite networking
● IP over GEO Satellite and LEO/MEO SatelliteConstellations
● Traffic management and congestion control 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 INand TINA
● Future integrated Telecom Architectures
● Network security
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● Breakthrough in Blind Search Algorithms-Genetic Algorithms
● Fast, Adaptive, low complexity MultiUserDetector for W-CDMA
● Fast, Frequency Planning OptimisationAlgorithm
● Network Dimensioning Technique forMultimedia, Mixed Mobile Systems
● Mobility Management Technique forWireless ATM
● Novel Media Access Technique for MobileMultimedia
● Quality of Service Provisioning for MobileMultimedia
● Novel CDMA Multiple Access Scheme forUMTS
● New and Fast Code Synchronisation andTracking Scheme for packet CDMA
● New Mobility Management & LocationTechnique for GSM/UMTS
● New Satellite Constellation Designs forSatellite UMTS
● Novel Mobility Management Technique forSatellite-UMTS and S-PCN
● Four Novel Multiple access protocols forintegrated DATA/Voice in GSM/GPRS
● New adaptive & predictive power controltechnique for W-CDMA
● New call admission control for loadbalancing in Multimedia W-CDMA
● Soft-handover performance optimisation forUMTS
● New handover algorithm for HCS
● New mobile terminal positioning techniquefor Satellite-UMTS
● New in-call handover scheme betweensatellite and cellular UMTS segments
● Full network integration between cordlessand cellular systems
● Novel call-handling and routing in non-Geostationary satellite mobile systems
● Novel dual-mode (terrestrial-satellite)mobile terminal antenna
● Rapid, Uniform Computation of MultipleKnife-edge Diffraction
● Intelligent quadrifilar helix antennas
● Software radio architecture developments
Research Aims
To research Global Universal Multimedia Personal Communication Systems, an integrated systemwith cordless, cellular and satellite mobile components. The aim is to develop novel practicaltechniques for the establishment and enhancement of personal communication networks andservices for future public and private systems.
Major Achievements
MOBILE COMMUNICATIONS RESEARCH GROUP
Research Areas
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 the GSM network into various dynamicconstellation mobile satellite networks. The satellite constellations considered are representative ofMEO (e.g., ICO), LEO (such as Iridium and Globalstar).
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1.2 Mobility Management in Non-GEO Satellite Communications
The aim of this work is to determine the optimum location area definition and size for a given S-PCNsystem that would result in the minimum mobility related signalling on the air interface. This involvesanalysing layer two paging and location update signalling.
Key outcomes
The techniques resulting from this work have been tested and optimised for ICO, Iridium andGlobalstar constellations. Currently the techniques are being optimised for S-UMTS, with muchimproved and simpler mobile terminal positioning algorithm.
1.3 Non-GEO Satellite Constellation Design
The aim of this work is to search for new constellations of satellites that will provide coverage withimproved visibility and availability for multimedia services. Existing LEO and MEO orbits provide forspeech services outside urban areas but in the next generation of satellite systems, eg. for satelliteUMTS and into broadband services the availabilities must be much higher. Effects of radiationenvironment spacecraft control and lifetime are features of this choice of orbit. With CDMA in mind,good diversity performance is also essential.
Current work has produced a new constellation (called DELIGO) which is an inclined LEO orbit at analtitude of 1626 Km which gives dual diversity with ± 70° latitude range. The inclination of 54° providesgood trade-off between double coverage at the equator and coverage of higher latitudes. Thepopulation is 64 satellites (8 in each of 8 planes) with a phase between planes of 39.4°.
● Identification of various inter-connectionschemes between GSM network entities(MSC, VLR, HLR and GMSC) and satellitenetwork entities (GMSSC, MSSC, LES andSVLR) which reuses as much as possible ofthe already existing GSM signallinginterface (A, B, C, D, E and G interface)
● Design of the satellite radio link framestructure and logical channels
● Design of signalling procedures betweendual-mode terminals and the network (GSMor satellite) for various services in theintegrated system
The work has been divided into several areas
● Intelligent Paging Strategies and newLocation area definitions which results inminimisation of in-call handovers betweenFES (Gateways), and optimum call routing
● Handover solutions between satellite andterrestrial cellular system
Deligo Satellite Diversity Performance Deligo Mean Elevation Statistics
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1.4 Band Sharing between Non-GEO Satellite-PCNs
The first generation satellite PCNs are to operate at L-band for uplink and S-band for downlink toprovide world wide services. However, the scarcity of free spectrum, together with the bandwidthrequirements means that S-PCNs will have to share these bands. In order to evaluate this complexsharing scenario an Interference Simulation Program has been developed to model the dynamicsatellite constellations (DSC) and to evaluate interference between such non-geostationary MSSand investigate techniques/criteria to make such a bandsharing a possibility.
1.5 Resource Management for Mobile Satellite Systems
Resource management studies include both Radio Resource Management and MobilityManagement Related Signalling Optimisation for non-geostationary satellite constellations (S-PCN and S-UMTS). In the first area the efficiency of channel allocation (CA) algorithms applied toMEO constellations is investigated with a view to the implementation of flexible traffic-adaptivedynamic channel allocation (DCA) algorithms using the predictability of satellite positions andcoverage characteristics. Real-time high-speed inter-Ground Station signalling is used tomaintain the integrity of the allocations and fast stochastic optimisation processes (GeneticAlgorithms) are proposed to make the allocations. Signalling optimisation studies for S-PCNhave analysed the trade-offs in the mobility management task, comparing the variation of thepaging signalling load with the complexity and accuracy of the user location updating task.Furthermore, the effect on the network signalling load of the establishment of gateway controlzones, or GSM-like location areas, which enable users to be associated with a known gatewaywithout frequent updates has been studied.
1.6 Multiple Access Schemes
TDMA and CDMA and their hybrids are currently being investigated. Among these, the packetswitched protocols for support of mixed services are also being investigated. We are alsoresearching the suitability of GPRS (General Packet Radio Services) and in particular theoptimisation of the following schemes for packet S-PCN:
● Stand-by state (Handover, diversity,synchronisation and time advancemechanisms)
● Optimisation of frame structures forpacket switching
● Error correction and re-transmissionstrategies
● Power control
● Random access protocol design
1.7 Propagation Measurements and Analysis of the Satellite Channel
Both narrowband and wideband measurements have been made at L, S & X bands using ahelicopter at the transmitter and a fully instrumented van with receiver which is driven aroundfive different selected areas. Currently Ka band (20/30 GHz) measurements are also beingmade.
Data is used to produced models of the satellite channel for real time emulation (see 1.10) aswell as for creating physical-statistical models (see 1.9).
Satellite fixed link modelling, in particular for scintillation at 12.5, 20 and 30 GHz has also taken place.
1.8 S-PCN Service Availability in Urban Areas
Satellite blockage caused by buildings will result in a loss of service from an S-PCN system.Some of the first generation systems employ satellite diversity to overcome blockage. To evaluate the behaviour of the two satellite channels, fish eye images of typical urban areaswere taken, and such images were transformed to obtain shadowing statistics for use in theSatellite channel model.
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The fish-eye images can also reveal how similar the two satellite channels behave based on theelevation and azimuth angles difference between the two satellites. In this way we are able to showhow the correlation of blockage coefficient varies with different satellite elevation and azimuth angledifferences.
The data from a large number of fish-eye images have been applied to several first generationconstellations to reveal statistics on service availability, highest and second highest satellite visibility,and overall correlation of blockage between the two highest satellites in all types of environments.
1.9 Mobile Satellite Propagation Modelling using physical-statistical
methods
Using physical-statistical modelling techniques, new models of signal variation in mobile satellitesystems have been developed. These permit accurate generation of received signal time-series forsingle and multiple satellites using statistical measures of the building environment and deterministicknowledge of satellite constellations. Aspects of these models have been included in new ITU-Rinternational recommendations.
Example Urban Fish Eye Image
Comparison of the Physical-Statistical Model and Measurements
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1.10 UMTS Satellite System Emulator
Bringing together a number of threads of the research is an EU ACTS project SINUS, whichinvestigates the air-interface, system and network performance of S-UMTS. In Surrey, a UMTSSatellite System Emulator has been developed which uses the channel data at L/S band from thepropagation campaign that has been converted to models for any elevation angle and operatingenvironment. Also built into the emulator are the orbit dynamics of LEO/MEO, satellite diversity,mobility management and positioning of the mobile users. The emulator will allow a simulation ofany run for LEO/MEO/GEOs and allow prototype air-interface and terminals to be tested andevaluated.
1.11 Antennas for Land Mobile Satellite Handheld Terminals
CCSR researchers have enhanced the state-of-the-art in understanding of the quadrifilar helix antenna(QHA) which is the most appropriate standard antenna configuration for mobile satellite handheldterminals. The figure shows scaled-up models of the QHA, created for detailed investigation of theantenna’s current distribution, which helped to verify new moment-method code dedicated to QHAdesign. This has complemented work on the basic modal characteristics of the QHA and enhanceddesign and analysis procedures. These procedures include the impact of satellite elevation statistics,user handling of the terminal and the propagation environment. Commercial contracts on the designof QHA dedicated to particular mobile satellite systems have yielded designs with excellentperformance in terms of size, bandwidth and radiation pattern.
New structures, providing similar performance to the QHA but with improved performance in reducedvolume are also under investigation.
Scale model quadrifilar helix antennas
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Real-time Satellite Channel Emulation
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1.12 Interaction between handset antennas and the human head
The interaction between radiating systems and the human body is an area of intense current interest.Research work at CCSR focuses on the impact of the human body on the radiation performance of thehandset, using a combination of analytical and numerical techniques. The numerical work uses thetransmission line method (TLM) and a custom-developed parallel code based on the finite-differencetime-domain (FDTD) approach. Good agreement between simulations and measurements has beenobtained, and the knowledge gained has been used to create antenna configurations which cangreatly reduce specific absorption rates and minimise the impact of the human head.
1.13 The Intelligent Quadrifilar Helix Antenna and Depolarisation
Measurements
The intelligent quadrifilar helix antenna (I-QHA) builds on the basic work on the QHA. It has beeninvented, developed and patented by CCSR researchers within the Mobile Virtual Centre of Excellenceproject. It provides for terrestrial and satellite operation from a compact antenna, together withsignificant diversity gain and the ability to substantially reduce specific absorption rates within thehuman head. The equipment shown below was used to measure the effects of depolarisation andthe potential for intelligent antennas at the handset. An access platform was used to simulate thesatellite transmitting location and the trolley contains all the receive and data acquisition system forsix independent receivers. The results showed significant depolarisation in regions of reasonablydeep shadow and, by weighting the four elements of the I-QHA for maximum gain, a diversity gain of10 or 11 dB can be obtained over the standard quadrifilar.
1.14 G/T for Mobile Satellite Handheld Terminals
The noise at the terminals of a satellite handheld depends on the sky and the surrounding buildingnoise all shaped by the constellation statistics of the satellite; using the previously mentioned rainfallshading measurements and satellite constellation statistics, a tool has been developed to provideeffective statistical noise and hence G/T calculations for handheld antennas in different environments.
Intelligent Quadrifilar Helix Antenna and Measurement Equipment
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Effective Statistical G/T
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2. Broadband Satellite Communications
A number of projects are currently being undertaken in the area of Broadband Multimedia satellitecommunications. These are concerned with Multimedia services above 64-144 kb/s region dealt with inS-UMTS studies and reach up to 2-155 Mb/s. Three EU ACTS projects, SECOMS, ASSET and WISDOM,form much of the effort and they are looking at different network aspects and configurations for thedelivery of Multimedia services to laptops, palmtop terminals at Ka and EHF respectively from GEOand MEO satellites. The work involves air-interface studies in which synchronous CDMA is a featurewith advanced modulation and channel coding as well as networking issues such as ATM modificationin both the satellite traffic and control planes, resource and bandwidth management and congestioncontrol. The BNSC-Foresight funded project SWAID, in collaboration with UK Matra-Marconi,concentrates research mainly on multiple access schemes, modulation formats and channel codingand their optimisation for satellite broadband services, taking into account the satellite payloadtechnology constraints. Particular topics are:
● Study on the resource management andtraffic control functions and their distributionbetween the space and the ground segmentassuming a regenerative payload, multi-spotbeam antennas and on-board ATM ‘like’switching/queuing capabilities
● Proposed a S-ATM system model that couldbe used in the future high data ratemultimedia satellite telecommunicationnetworks
● Definition of the most promisingcommunication platform for the futurebroadband satellite communicationssystems with the highest level of integrationwith the fixed B-ISDN and other terrestrialnetworks
● Advanced CDMA Receiver Architectures
● Call Handling for ATM Over Satellite
● ATM switch dimensioning on-board satellite
● Resource management and bandwidthreservation mechanisms
● Channel Coding Schemes
● Network optimisation
● Propagation measurements and channelcharacterisations for all the environmentcategories at Ka band
● Congestion Control Techniques
2.1 Satellite-ATM
Many broadband satellite systems have proposed advanced on-board satellite switching in order tomake full use of the advantages that ATM technology can offer. However, due to the space segmentconstraints a full ATM switch on-board satellite is not foreseen. Some of the resource managementand control functions are placed on the ground segment; i.e. the connection admission control andcall control functions. As a result, the on-board satellite processing requirements are reduced only tothe ATM traffic management and where applicable the up-link resource allocation. The mainachievements in this research area are as follows:
Satellite and B-ISDN integration
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Possible System Architecture for Broadband Satellite Communications based on ATM
Resource management and control functional block diagram of a S-ATM
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● Performance evaluation of the future S-ATMbroadband networks and development ofnew means for network dimensioning thattake into account multimedia trafficcharacteristics
● Propose new algorithms for wirelessGoS/QoS provisioning that need to beadopted in future broadband multimediasatellite networks
● Development of a new methodology for theABR capacity estimation and the CACstrategy that needs to be adopted in S-ATMsystems
● Investigation of the bandwidth reservationtechniques and their performance that couldbe used in a non-GEO multi-rate, multi-service class environment has beenconducted
● A new approach for creating service classesaccording to the user defined performancecriteria has been developed and itsperformance has been evaluated bothanalytically and by simulation means
System Dimensioning and Simulation Results
Connection Admission Control and Wireless GoS/QoS Provisioning
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3. Terrestrial Mobile Communications
3.1 Optimization of the GSM network
The work has concentrated on the reduction of signalling traffic and database transactions within aGSM network. A novel location tracking method has been proposed and evaluated both analyticallyand via simulation. The proposed technique has resulted in substantial reductions in database 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 of optimization algorithms ( NN, GA and SA ) to the problem of optimallocation area partitioning within cellular networks have also been extensively researched. The aimhas been to reduce the signalling traffic over the air-interface through optimal design and support of“personal location areas”.
3.2 Cordless-Cellular interworking in the context of migration to UMTS
This project investigates the networking problems associated with hierarchical cellular structures withspecial reference to integrated cordless-cellular interworking in the intial stages. The work isextended to investigate overlayed cells of different sizes in the third generation scenario.
A range of topics are under investigation as follows:
● Support of both personal mobility andterminal mobility for dual-mode user
● Service mobility (service migration todifferent elements) for dual-mode user
● Seamless handover & roaming betweenCordless/Cellular using DECT and GSM asexample systems and satellite coverage formulti-mode terminals
● Identification of paging strategy
● Identification of a location updatingprocedure
● Handover optimization in hierarchical cellarchitecture
● Identification of call routing strategy
● Signalling load evaluation
● Multi-mode terminal functionality
2.2 Broadband Satellite Air Interface Design
Within the ACTS-SECOMS (Satellite EHF Communications for Mobile Multimedia Services) andBNSC-SWAID (Satellite Wideband Air Interface Design) projects, the issues related to the air interfacedesign for future broadband satellite communication systems have been investigated. An in-depthcomparison between CDMA and TDMA access schemes has been performed and a new systemdimensioning approach for CDMA has been derived. Using this new technique, based on evolutionarytheory and genetic algorithms, it was shown that CDMA could provide a better spectral efficiencythan TDMA. Moreover, work on new techniques reducing the complexity of CDMA on-boardprocessing proved that the implementation of regenerative CDMA payloads is within currenttechnological limits. Future broadband satellite systems will have to provide BER values significantlylower than first generation S-PCN. Hence, the performance of powerful coding schemes suitable tomultimedia services has been assessed. A wide range of possible schemes, including convolutionalcoding, trellis-coded modulations, multilevel trellis coded modulations, turbo codes and concatenatedcoding schemes, have been considered. Finally, the implementation of adaptive modulation andcoding schemes to overcome the penalising effect of rain attenuation has been investigated. It wasshown that by matching the coding spectral and power efficiency to the channel conditions, themargins required for the link dimensioning could be reduced.
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In our approach, a common Network Architecture for the support of software radio terminals basedon CORBA middleware and using the facilities of a Universal Control Channel (UCCH) is defined. TheUCCH framework is then used to facilitate inter system/network roaming and Over the Air softwareReload (OTAR). Software downloading may be defined as “the process of introducing newprogramme code into the Software Defined Radio”. There are basically three types of software thatmay be down-loaded. These are DSP algorithms, protocols and application software, and thesoftware download mechanism can be based on any one or combinations of OTAR (Over The AirReload), smart cards, or fixed network connection.
3.3 Software Telecommunications
The motivation for research into software-based telecommunications is the rapid introduction andimplementation of new services, support of global roaming and access to different cellular systems viathe same terminal. The Virtual Home Environment (VHE) provision i.e. familiar user interfaceindependent of access network, support of interoperability between services and systems andapplication distributions is driving this new scenario on which the fourth generation mobile system willbe based.
Our research activities in this area, are focused on service provision mechanisms and enablingtechnologies and address the requirements on the higher-layer protocols (at both the mobile terminaland the access points) as well as programming interfaces to facilitate introduction, modification andlong-term support of protocol/application software modules.
Configuration of a Mobile Software Telecommunication System
UCCH Architecture in a Distributed Mobile Environment
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Open Programming Interfaces concern the specification of Application Programming Interface andopen protocol programming interfaces will enable third party service/content providers to deliverfunctionally-enhanced implementations for protocols (i.e. even single layers) and applicationsoftware. This will also simplify protocol (and application) re-configuration.
APIs hide complexity by abstracting lower level functionality and leave space to improve functionalitywithin the layers. A Java platform has been selected for our object implementation and developmentsin Java provide a platform-independent programming language and framework (VM), offering codeportability and scalability all based upon object oriented design methodologies.
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Aggregate Traffic Modelling for Multimedia Mobile Communication
Systems Dimensioning
A new aggregate traffic scheme has been found which is simple to model and provides very accurateresults for dimensioning of any mobile system such as UMTS which supports a hybrid of circuit andpacket switched services. The novelty of the technique lies in the simplicity of implementation whilstproviding a mechanism to dimension the available capacity for each service category individually.The technique is an alternative multiservice solution to the Erlang-B approach which is only suitablefor circuit switched homogeneous services.
3.5 Frequency Planning
An automatic frequency planning & optimisation tool, based on Genetic Algorithm has beendeveloped for more optimum planning of cellular networks.
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.
3.4 Packet Mobile Communications
The following areas are being extensively investigated:
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Reservation Random Access (RRA)
Protocols
● General analysis
● Statistical upper bound study
● Performance comparison of 15 RRA protocolsagainst each other
● Performance optimisation through dynamiccontention mechanisms
● Guidelines for RRA protocols in cellulardesign
Hybrid Multiple Access Protocols
Communications
● Three different hybrid multi-access protocolsbased on TDMA/CDMA, DTDMA/CDMA,PRMA/CDMA
● Link quality control procedures
● Optimised load/GoS balancing betweenGPRS/GSM
● Aggregate Traffic Modelling for MultimediaMobile Communication SystemsDimensioning
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Other CDMA related research
● Acquisition and Tracking particularly forpacket CDMA
● Interference Analysis CDMA
● Cellular System Modelling currentlyconfigured for GSM and can be changedfor CDMA
● OFDM/MC-CDMA
● Call Admission Control for UMTS
● Predictive and adaptive power controlschemes for UMTS
● Channel Estimation Techniques Amplifiersfor UMTS
● End-to-end modelling and performance ofUTRA
● Advanced RAKE receivers
● Interference cancellation in CDMA / TDMAoverlay
● Overlapped carrier CDMA
3.7 Multiple Diffraction Modelling for Cell Planning
The key propagation mechanism which affects the coverage of terrestrial fixed links, digital broadcastsystems and macrocells is multiple diffraction over terrain and building rooftops. CCSR has creatednew methods of predicting multiple edge and multiple cylinder diffraction, using deterministicnumerical techniques. These methods permit accurate computations over many tens of obstructionswith a user-definable trade-off between accuracy and computation speed. The results are uniformlyvalid over a wide range of obstacle configurations, overcoming limitations in existing semi-empiricalmodels such as those by Deygout, Causebrook and Giovanelli. Models have also been developedwhich permit inclusion of diffraction both over and around obstacles, improving the accuracy ofrepresentation of the real world.
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 the Conventional Detector (single UserDetector) as well as Multi-Stage Detectors (MSD) with 10 stages. The single user bound is achievableand because of the fast convergence rate, the scheme is highly adaptable to fast channel changes dueto fading and channel loading. The current work on GA is the reduction of the implementationcomplexity whilst monitoring a high quality of performance. In parallel we are also investigatingNeural Network based Joint Detectors for CDMA.
The following figures illustrated some of the simulation results for S-CDMA.
Cumulative BER versus SNR for S-CDMA MUD m-sequence is employed, Length=15, 10 users are
transmitting with the different powers. CD: Conventional Detector, MSD: Multi-stage Detector,
GMD: Genetic Multi-user Detector
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4 Wireless LAN/Indoor Mobile Communications
4.1 Mobility management and Call control in a wireless ATM LAN
Investigation of suitable MAC and DLC layers has taken place. The HIPERLAN and IEEE 802.11 MAClayers 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 improved performancecharacteristics.
Current work addresses new challenges, associated with the mobile such as location management,registration (including authentication and network security) and handover implementation.
Other areas of work in this area are:
● an extension of HIPERLAN specifications tosupport optimally ATM traffic
● the definition of an ATDMA based multipleaccess introducing traffic policing on the air-interface
● techniques for modifying NNI specificationsto support mobility in a wide area ATMnetwork with wireless access points
● design of a OFDM based transmission pathfor the ATM WLAN with variable channelcoding rate
(a) (b)
Inclusion of diffraction around obstacles: (a) Geometry for two truncated apertures,
(b) Signal predictions
3.8 Software Radio Technology (for base stations and user terminals)
The software radio concept permits the creation of flexible multi-standard adaptive terminals withoutthe need for multiple set of analogue or digital hardware. As a partner in the European SORT(SOftware Radio Technology) project, CCSR is helping to solve the challenges created by suchterminals in terms of the need to process large quantities of data in near-real time. One approach tothis processing is the use of reconfigurable hardware processing solutions, such as fieldprogrammable gate arrays (FPGA). CCSR will host the SORT demonstration and will analyse itsperformance relative to standard terminal solutions. See http://www.ee.surrey.ac.uk/CCSR/ACTS/Sort/
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The work is being partly funded by the DigiPlan project, in collaboration with the BBC and CellularDesign Services Ltd (see http://www.ee.surrey.ac.uk/CCSR/LINK/DigiPlan/ for more information).
(a) (b)
Multiple diffraction model performance: (a) Prediction accuracy, (b) Reduction of
computation time
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4.2 Ad-Hoc Wireless Networking
Most of the work in wireless LANs has been concentrated on a star topology configuration. Thisresearch is concerned with distributed mobile networking, researching on Dynamic Routingalgorithms for a wide range of mobility of the terminals, and implications on TCP layer and mobile IP,as well as multiple access techniques for guaranteeing QoS. The work is now extended to mobilitymanagement between ad hoc sub-networks and cellular systems.
4.3 Indoor and Indoor/Outdoor Propagation at 2 GHz and 5 GHz
Detailed propagation measurements of multiple spatially separated channels at 2GHz and 5GHz havebeen performed in a range of environments representative of future mobile cellular deploymentsinside and around buildings (see below). The measurements are being used to derive new models ofindoor and indoor-outdoor propagation, enabling more accurate cellular system design. They are alsobeing used as the foundation for optimising the intelligent picocell radio architecture (see section 4.4)
(a) (b)
Measurements of indoor propagation at 2 and 5GHz (a) Robotic measurement platform,
(b) measurement system
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4.4 Intelligent Picocells
Research work continues on the novel intelligent picocell concept, which uses intelligent antennatechnology to provide high capacity indoor coverage solutions with distributed processing for plug-and-play, modular operation. The result is a set of personalised ‘islands’ of capacity which track eachuser and permit channel reuse on a massively dense scale, provided the channel characteristics areproperly exploited. Incorporates aspects of distributed antennas, diversity, optimum combining /beamforming, dynamic channel allocation and equalisation.
Intelligent Picocells
More information about the Mobile Communications Research Group activities and its Researchcan be found at the following web address:
http://www.ee.surrey.ac.uk/CCSR/Mobile/
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MULTIMEDIA SYSTEMS RESEARCH GROUP
Aims
The main research area of the group is in compression and coding of speech/audio and videoservices, communication aspects of speech/audio and video such as efficient error resilientpacketisation, secure crypto systems, low complexity error-correcting decoders, speech and videointegration and the related signal processing issues such as acoustic and line echo cancellation withback ground ambient noise suppression.
Achievements
Description
1. Speech and Audio Coding
1.1 Low Bit Rate Audio Coding
The aim is to develop an audio compression algorithm operating at 1 bit/sample, suitable for bothspeech and music signals (16 kHz bandwidth). The signal spectrum is split into bands which areencoded separately using backward-adaptive linear prediction analysis. The quantisation isperformed using a low complexity pulse-generated excitation structure. The coder is bandwidth
● AMR candidate submission to ETSI which came amongst the best.
● Development of multi-rate source andchannel coding scheme for robust speechtransmission. Lowest rate of this coder is 1.2kb/s.
● Filed the SB-LPC speech coding patents which created worldwide interest.
● Technology transfer deal with TOSHIBA for digital answering machines.
● Completed Speech/Audio and Videotestbeds.
● LINK initiative in DICTION which is involved with enhancing the TV soundsfor hard-of-hearing.
● Modified EFR codec for speech over GPRS.
● Very low bit rate audio coding based on Pulse-Excited LPC.
● IERE Benefactors Premium Award for the best paper in 1997/98 for “Closed-Loop Motion Compensation for Video Coding Standards”.
● Protocols for key distribution in smart card applications and for copyright protection.
● Bit-oriented low complexity trellis decoders for RS codes.
● Low complexity soft output block decoders for high performance iterative decoding of Reed Solomon product codes.
● Implementation of an MPEG4-H.263 bidirectional transcoder.
● Design of novel MPEG4 multi-rate motion and shape coders.
● Applying high-efficiency turbo codes on error-prone video streams travelling overchannels with various and time-varyingconditions.
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1.2 Low Bit Rate Speech Coding Below 4 kbit/s
Split-Band LPC (SB-LPC) Vocoder gives high quality speech at 4kb/s. The objective of this project isto develop a speech coding algorithm which overcomes the problems SB-LPC coder suffers at bitrates below 4kb/s. The factors under investigation are accurate segmentation of frames, improvedspeech modelling and efficient coding of the model parameters.
1.3 Split-Band LPC Vocoder
The aim of this project is to develop a new type of low bit rate speech coders. By assuming thatthe spectrum of the speech is voiced for the low frequencies and unvoiced for the highfrequencies, this coder gives a very high quality even at very low bit rates.
Different versions, at 2.4 kb/s, 4.0 kb/s, 5.5 and 6.2 kb/s , have been developed. They give betterspeech quality than the full-rate GSM standard, which makes them suitable for mobile applications.
1.4 Source Dependent Variable Rate Speech Coding below 2.6 Kbit/s
This work addresses the need for high quality, very low bit rate speech compression algorithmsthat can be utilised in many forthcoming multimedia applications. The proposed speech codec is avariable rate system based on the adaptive source-driven frame length scheme. The maximumspeech compression is achieved for the long-term steady-state speech and non-speech (silence andunvoiced) conditions. In addition, shorter frame sizes are used to code those difficult-to-modelspeech transitions, thus improving the overall perceptual quality when compared with traditionalfixed rate schemes. This codec may be used for implementing various voice communicationsystems, such as Voice Store and Forward systems and digital answering machines, or to augmentlow bit rate integrated digital packet networks.
1.5 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 wide bandspeech signal (8 kHz) on 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 present thanthe original one.
scaleable, producing bit rates of 16, 24 and 32kbit/s. Improved output quality can be achieved byemploying multi-layer embedded quantisation at the expense of higher bit rates scaling up to64kbit/s. The coder offers low algorithmic delay and good output quality, when compared toexisting standards.
Scaleable Audio Coding Block Diagram
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2. Image and Video Coding
2.1 Adaptive Multi-Rate Error Protection For Video Coding
Over A Mobile Channel
Developments in mobile phone technology have made it possible to produce systems that allowmobile video-phones to be introduced. However, due to the highly variable nature of mobilechannels, it is necessary to vary the amount of error protection to maintain the best possible picturequality. Such a protection scheme requires a method of measuring the channel conditions to enablea decision to be made as to the amount and type of protection that should be used. The efficiency ofthe scheme may also be enhanced by prioritising the data, so that the data which is most importantfor received picture quality is given the greatest protection.
2.2 Model-Based Video Coding
In order to achieve lower bit rates without losing content, superfluous information must befound and eliminated. 3D-objects, in particular human faces, can be described once and thencemanipulated with action units applied to key points, thus achieving even further reduction. A criticalissue is to locate and identify the object which requires a certain amount of artificial intelligence.
3. Modulation and Channel Coding
3.1 Turbo Coded Modulation for Fading Channels
We are to create error robust coding modulation schemes for fading channels using the Turbo codingscheme. In particular, we are investigating the characteristics and suitability of various constituentencoders in the appropriate channel conditions. We have experimented with concatenated schemese.g. inner Turbo codes and outer Reed-Solomon codes and the performance was quite impressiveshowing a BER of 10E-10 at Eb/No <2 dB. We applied Turbo codes on H.263 compressed videostreams to evaluate their performance in video communications. The figure below shows that Turbocoded H.263 streams led to a better objective quality at 2 different error patterns than H.263 streamscoded with the same encoding parameters and protected with RS and Convolutional Codes.
3.2 Coding for OFDM
This project aims at:
The project has been undertaken in conjunction with industry.
● Reducing bit error rate for givenchannel conditions by using forwarderror correction coding.
● Reducing Peak-to-rms power levels inthe OFDM signal.
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4. Packet Communication
4.1 Multimedia Communications over Mobile Packet Networks
This project aims to develop strategies which will allow for voice and video communications overthe new mobile packet networks being standardised, and in particular, GPRS (General Packet RadioService) and EDGE (Enhanced Data Rates for GSM Evolution). Research carried out at CCSR andLucent Technologies has shown the viability of transmitting real-time voice over GPRS networks,providing perceptual speech quality comparable to that obtained using the Enhanced Full Rate codecover GSM ciruit-switched networks. Current research aims at extending the methodologies developedfor the provision of real-time services over GPRS to be able to provide multiparty audio-visualcommunications over EDGE and GPRS networks within the framework provided by the H.323standard for multimedia communications. Issues being investigated include the performance oferror-resilient video codecs over mobile radio channels, the integration of radio-link adaptationschemes with source-rate adaptive codecs, and delay and complexity issues when carrying outmulti-party conferencing.
4.2 Video Coding Algorithm for Wireless ATM Networks
This project aims at improving the transport of Video intended for videoconferencing applications. TheH.263 low bit rate algorithm is to be modified for transport over wireless ATM channels. The projectinvolves 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.
5. Transcoding, Enhancement etc.
5.1 Transcoding between MPEG-4 and H.263 for Linking of
Asymmetric Networks
Both MPEG-4 and H.263 are the very low bit rate video communications standards. H.263 has beenin operation for the few recent years, and is designed to operate on existing telephone networkswith a bit rate less than or equal to 64 kb/s. On the other hand, after the public release of MPEG-4
in January 1999, it is mainly used in mobile-wireless and satellite communications environmentscomprising very low transmission rates. Since the conventional telephone networks will continue todominate our lives for at least the next thirty-forty years, the interconnection of these two videostandards operating on two asymmetric networks has already been a key issue. Therefore, thisproject aims at investigating the key issues of transcoding mechanism, implementing a fullyoperational transcoder in both directions and optimising it. Here, the main goals of transcoding thosetwo standards are to avoid cascaded decoding and re-encoding processes whilst maintaining theQuality of Service, and reducing the processing power and its time delay for delay sensitiveapplications like video communications.
Transcoding of MPEG-4 and H.263
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5.4 Digitally Improving the Clarity of Television Narrative for
Hard-of-Hearing Viewers (DICTION) - A LINK Broadcast Technology
Programme Project
A significant proportion of the elderly population suffers from the reduced ability to distinguishbetween foreground dialogue and background music or sound effects in television programmes. TheDICTION project proposes to explore some new ideas in speech processing technology to establishwhether they are able to enhance the intelligibility of speech at the television receiver, when it hasbeen detrimentally affected by background sounds. The objective is to develop a prototype speechenhancer which will have been proven under controlled conditions with elderly and hard-of-hearingviewers, to increase the intelligibility of speech. The work on speech enhancing and coding in thiscollaborative project is carried out exclusively by the Multimedia Research Group at the Centre ForCommunication Systems Research.
More information about Multimedia Systems Research activities and research teams can befound at the following web address:
http://www.ee.surrey.ac.uk/CCSR/Multimedia/
5.2 Ground-satellite Optical Communications
We are studying system design/analysis issues of ground-satellite optical communication links,aimed at deriving well-defined guidelines together with necessary tools in the form of graphs,tables, algorithms, simulation models etc. We have been concentrating on the issues which are notcommon with optical intersatellite links, namely atmospheric propagation. Atmospheric turbulencecauses fluctuations of the refractive index of air, which in turn produces fluctuations in amplitudeand phase of an optical beam propagating through it. We are planning to conduct opticalturbulence measurements based on the analysis of bidimentional spatiotemporal spectra of stellarlight in colloboration with Japanese Communications Research Laboratory.
5.3 Trellis Decoding of Binary Version Reed-Solomon Codes
Although error control codes are often useful for only a narrow range of channel conditions, it isdifficult to specify the codes as part of a Standard. This project will address the problem bydeveloping new methods of decoding, allowing a specific code to be used and the decoding methodchosen according to channel conditions. Reed-Solomon codes are multi-level block codes useful formany applications. They are efficient in terms of the redundancy needed for a given degree of errorcorrection, and they are particularly good in burst error conditions and in low bit error rates. In
addition, if viable soft decision decoding methods were available, it would be possible to improvethe performance across the whole range of channel conditions. RS codes would then be highlysuitable for specification as part of evolving standards.
Recent work at Surrey has shown the reduced complexity trellis based methods are viable for somerelatively simple RS codes and can give performance and complexity comparable with standardconvolution codes at 10-5 BER in Gaussian conditions. If we are based on structural features forextending the methods to more powerful codes, the extension to other channel conditions can beachieved by adapting the metrics.
Tasks:
● Address problems of decomposing multilevel codes into binary codes and the automaticproduction of a binary form of the trellis for Gaussian conditions. Evaluate performance andcomplexity for longer codes up to 255 over GF(256)
● Analyse optimum method and metrics for simple bursty channel model and then apply todecoding of a range of RS codes. Analyse performance and complexity
● Implement and quantify performance and complexity for a range of codes across a range ofconditions. Identify the basic decoder architectures required and the detailed means ofadaptation to channel conditions
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Aims
The main research activities of the networks research group cover the areas of BroadbandCommunications, Internet Technologies and Network and Service Control and Management.
These areas are investigated in both terrestrial and satellite networks.
Achievements
Description
1. ATM and Broadband Communications
1.1 Traffic Management for ATM networks
A traffic management framework is needed in order to provide QoS differentiation for end-to-endcommunication in ATM networks. Real-time traffic management methods that are simple to implementare required. We have been investigating scheduling and buffer management methods that can meetthe individual QoS requirements of each service class. Research has also been carried out onadmission control and policing functions within the traffic management framework. Theoreticalanalysis and simulations have been used to optimise and dimension the network so that an optimumthroughput is achieved after taking fairness and the priority of each service class into account.
COMMUNICATION NETWORKS RESEARCH GROUP
● Designed and implemented a secureprotocol for broadband access to European stock exchanges.
● Studied and developed a “system-on-chip” solution for future ISDN switch andinternetworking technology.
● Examined the issues of IP Multicast and Quality of Service over satelliteconstellation networks.
● Demonstrated that fault and performance management for ATM can result in resilient connectivity services with very highavailability.
● Designed and implemented a combined adaptive and random reservation MACprotocol to guarantee Quality of Service for ATM over satellite links.
● Validated the emerging TINA architecture through the development of sophisticated multi-media, multi-party services withintegrated control and management.
● Devised a methodology for the design and development of telematic services thattargets a TINA environment.
● Conducted experiments and simulations that investigated the performance of TCP/IP over the ATM UBR and GFR services for both terrestrial and satellite environments.
● Developed a novel and efficient trafficcontrol mechanism for ATM.
● Investigated the assembly of integratedservice and network management systems through reusable components, withminimal customisation.
● Developed solutions for performancemanagement using mobile intelligent agent technologies which minimise management traffic on the managed network.
● Investigated the emerging Multi-Protocol Label Switching (MPLS) approach forcoexistence of IP and ATM, researching intoQuality of Service and resourcemanagement schemes.
1.2 THESEUS
The objective of the THESEUS (Terminal at High Speed for European Stock Exchange Users) ACTSproject was to develop a stock trading terminal with broadband communications capabilities thatprovides access to all the European stock exchanges through terrestrial and satellite links. Thisterminal can put into practice the EC directives concerning the opening of the European capital marketand enable brokers to trade not only with their national stock exchange but also with all the Europeanstock exchanges. THESEUS has performed three successful demonstrations to the EuropeanCommission. The first demonstration was conducted in January 1998, using European ATM national
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hosts access facilities (through the JAMES project). A second demonstration for secure stock tradingusing security keys and digital signatures was conducted in April 1998. Finally, a satellitedemonstration (through the VANTAGE project) was conducted in July 1998, between a remoteTHESEUS terminal located in Rome and the Paris stock exchange.
1.3 TCP/IP over ATM
The Transmission Control Protocol/Internet Protocol (TCP/IP) has become the most widely-usedprotocol stack in computer communications, being the core protocol suite for the global Internet.Networking solutions which use high-speed ATM as the underlying transport technology for IP-basedcommunications are of particular interest, since the wide range of TCP/IP applications can then beused transparently over ATM without modifications.
Tests have been conducted using our ATM LAN testbed to assess the overall performance of TCP/IPover ATM. The ATM Forum has recently defined a Guaranteed Frame Rate (GFR) Service, able toprovide minimum throughput guarantees to non real-time, and research is being carried out into thedesign and implementation of enhanced GFR mechanisms.
1.4 Security Systems for ATM Networks
We have been doing research in order to secure the user, control and management planes in ATMnetworks. Our work complies with emerging solutions in the ATM Forum. In the user plane we aim toprovide protocols for end-to-end security with mutual authentication of end-systems, digitalsignatures and data encryption. These protocols permit future enhancements with new securityalgorithms and also allow non-encrypted data exchange. In the control plane, we have beenexamining the use of public keys, timestamps and digital signatures to authenticate signallingmessages. Security of the ATM management plane is still under investigation.
2. Network and Service Control and Management
2.1 VITAL
The VITAL (Validation of Integrated Telecommunication Architectures for the Long-term) ACTS projectaims to validate the emerging Telecommunications Information Networking Architecture (TINA) as thevehicle for providing future advanced telecommunications services. TINA brings together IntelligentNetwork (IN) and Telecommunications Management Network (TMN) concepts, using an object-orientedDistributed Processing Environment (DPE) which supports both signalling and management interactions.
The VITAL project has designed and implemented an Open Distributed Telecommunications Architecture(ODTA) which extends and validates the TINA concepts. Various advanced services have beenimplemented using this architecture, including multi-media, multi-party and mobility service features.The core application is a tele-training application that includes multi-media conferencing and distributedslide presentation facilities.
These services were demonstrated in a pan-European environment by connecting ATM islands inBelgium, Italy, Spain and Portugal through the JAMES European ATM infrastructure. Our researchcontribution concentrated in configuration management and ATM call- and connection control throughdistributed object interactions.
THESEUS - one interface to trade on may stock exchanges
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2.2 REFORM
The REFORM (REsource and Fault restORation and Management in ATM) ACTS project investigatesfault and resource management in ATM networks through close interaction between the control andmanagement planes. While resource and routing management in ATM has been studied in differentcontexts, the problems of availability and performance have been tackled in isolation. REFORM takesan integrated approach, in which the network is dimensioned and provisioned with spare capacity todeal with faults, while at the same time a bandwidth- and routing-management system supervises thenetwork and tries to optimise the use of network resources. The control plane is based on object-oriented signalling while the management plane follows the TINA Network Resource Architectureprinciples.
The REFORM system is based on an experimental ATM testbed, based in Basel, Switzerland, that wasprovided by the EXPERT project. Since these switches are relatively open, control and managementfunctionality has been added, resulting in a REFORM “node” with interfaces based on the CommonObject Request Broker Architecture (CORBA). Faults are first detected and recovered from in thecontrol plane, with the management plane being informed in order to reconfigure the network over aless stringent timescale. The management plane addresses virtual path planning and design,bandwidth allocation, and manipulation of route priorities for load balancing.
Our involvement concentrated on aspects of configuration and performance management. Wedesigned and implemented an ATM network map application similar in concept and design to a TMNconfiguration Operations System (OS). We also designed the hierarchical Network ResourceMonitoring (NRM) subsystem and provided generic metric-monitor objects in CORBA as part of thatsubsystem.
2.3 FlowThru
The FlowThru ACTS project aims to provide a service and network management system integratingmanagement applications that originate from previous ACTS projects such as VITAL, REFORM andProspect.
In this case, integration brings together aspects of order handling for service access, network planning,configuration management, Quality of Service management, problem handling and accounting processes.There is an automated flow of management information from the service level down through the networkand element management levels to the network elements supporting the services.
Cost-effective performance & availability under normal & fault conditions
Flow Thru integrates previous ACTS projects and provides results for other work
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The FlowThru system follows state-of-the-art techniques in describing reusable components, such asusing the Unified Modelling Language (UML) and emerging technologies for plug-and-playdistributed systems such as the Object Management Group (OMG) component model. The variousapplications are brought together through customisation but without having been developed to forman integrated system in the first place. The project follows the Tele-Management Forum’s (TMF)decomposition of business processes, covering aspects of fulfilment (order handling, planning andprovisioning), assurance (QoS management, problem handling) and billing (charging, invoicing).
Our involvement in the project focuses on the fulfilment part, concentrating on components for ATMconfiguration and connection management.
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2.4 MIAMI
The MIAMI (Mobile Intelligent Agents in the Management of the Information Infrastructure) ACTSproject aims to investigate the benefits gained from agent mobility and intelligence in the context oftelecommunications network and service management, information services and electroniccommerce. The project will develop agent-based solutions for managing telecommunication networksand providing advanced communication and information services. These solutions will bedemonstrated in a pan-European test-bed.
The communication service to be provided is an Active Virtual Pipe (AVP). This is an extension of theconcept of leased lines or Virtual Private Networks, in the sense that the service can be customisedand be dynamically controlled by the service user. This customisation is achieved through mobileintelligent agents, which the user sends to be executed in the provider’s domain. The advancedinformation service which is built using the AVP is a Virtual Enterprise, which is dynamically formedamong interested parties through agent negotiations. A mobile agent platform which supportssemantically-rich agent interactions is used.
We are driving the performance management aspects of the AVP service. In particular, we areconcentrating on providing facilities for metric monitoring and summarisation which are flexible, canbe customised through user-built algorithms and can result in agents migrating to network elementsto perform monitoring tasks without incurring significant management traffic.
2.5 Methodology for Telematic Service Development
In recent years, the Open Service Architecture (OSA) and the Telecommunications InformationNetworking Architecture (TINA) have attempted to define frameworks for supporting advancedtelecommunication services. These result in a set of generic re-usable components for service controland management. On the other hand, every newly-conceived service needs to be decomposed intofunctionality that can be mapped onto existing components where possible, while identifyingcomponents that need to be customised and new components that need to be developed.
How agents and applications fit together
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This project looks into a methodology that guides the service designer, who begins from the servicedescription, in mapping the service onto components of a particular service architecture. Themethodology describes both the set of steps to be followed and the specification languages, toolsand techniques to describe the system at various stages and from various viewpoints. Though themethodology is general enough, it is validated through examples that target a TINA environment.
3. Internet Technologies
3.1 IthACI
The overall scope of the IthACI (Internet and the ATM: Experiments and Enhancements forConvergence and Integration) ACTS project is to evaluate and contribute to the different technologiesthat together permit the efficient transport of IP traffic over a public or a private ATM backbonenetwork. IthACI investigates and enhances methods for the efficient integration of IP and ATMnetwork technologies. It focuses on fast layer-two forwarding methods for IP traffic, based aroundlabelled flow mechanisms. The main goal is to improve the performance of the Internet by combiningMPLS (Multi-Protocol Label Switching) techniques with added-on enhancements for multicast, Qualityof Service support, resource management and mobility in multicast environments.
In addition, IthACI will critically assess emerging solutions, perform incremental development onexisting solutions addressing specific feature enhancements, and make recommendations forimplementations, based upon observations of conducted experiments and analysis.
To validate its approach, IthACI will establish three trial islands located in Belgium, Greece, andGermany, where each island will use and enhance a different MPLS solution over ATM. The mainMPLS technologies used are tag switching from Cisco, IPSOFACTO from NEC and YALSA from AlcatelBell.
Our involvement in the project is focused on QoS provision and Resource Management.
3.2 TCP/IP in Mobile Satellite Networks
It is expected that the volume of Internet traffic carried over satellite networks will continue to grow.The number of mobile users running TCP/IP applications is increasing as wireless services aredeployed, and satellite support for those mobile users is expected to grow as a market.
This project aims to study the performance of TCP/IP over networks utilising low-earth-orbiting (LEO)satellites, in order to provide enhancements to the TCP congestion control mechanisms that willbenefit the satellite environment. The effects of user mobility and satellite multiple accessmechanisms on the performance of TCP/IP traffic are also investigated.
3.3 IP Multicast over Satellite
Supporting IP Multicast over LEO satellites poses difficulties not encountered in the broadcast-friendly nature of traditional GEO satellites. Use of an ATM infrastructure makes multicast supportdifficult, as ATM-based multicast is currently both less advanced and less flexible than IP Multicast.We are investigating use of IP routing on-board satellites in order to support IP Multicast, whileexamining how an ATM infrastructure can still be used to support non-IP traffic and provide classes ofservice. This involves integrating IP routing and ATM functionality using MPLS (Multi-Protocol LabelSwitching).
3.4 Differentiated Services
The Differentiated Services Quality of Service model is gaining increasing popularity in the Internetcommunity in comparison to the Integrated Services model, especially in wide area networks (WANs)where scalability is a major issue. We are conducting simulations in order to evaluate the variousarchitectural components of the framework in terms of efficiency, simplicity and scalability. We arealso trying to investigate how a differentiated services network can be dimensioned and managed interms of bandwidth distribution and routing strategies in order to optimise resource utilisation andmeet the demands of the various classes of service.
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4. Network Access
4.1 COPARIS
In order to stimulate growth in the ISDN market, the ESPRIT COPARIS (Common Physical Access Chipfor ISDN Systems) project is developing an application-specific embedded processor chip capable ofimplementing a large subset of the existing ISDN line interface standards. This will be the forerunnerof a generation of advanced telecommunications processors using OMI subsystems that can beextended into a range of future applications. As an example of the benefits COPARIS will provide, itwill allow the production of ISDN home PBXs with a cost of about 50% compared to today’sequivalent products.
The project will develop an evaluation board using the chip with interfaces for Ethernet, UniversalSerial Bus (USB) and ISDN Primary Rate Interface (PRI). Our primary tasks include the design andimplementation of the ISDN PRI as well as the development of an application system for ISDN &Internet Protocol integration.
4.2 Integrated Services Satellite Access Protocol
The combination of various multimedia services generates a heterogeneous mix of traffic. Integratingand carrying this traffic mixture while providing appropriate quality of service (QoS) to the variousapplications is a difficult problem not yet solved for satellite networks.
We have analysed and simulated the performance of a variety of candidate media access control(MAC) schemes in the satellite environment, and have proposed an adaptive protocol that attempts toprovide good performance under a wide range of conditions and loads for a combination of traffictypes and service categories.
5. Integrated Satellite Networking
5.1 BISANTE
The BISANTE (Broadband Integrated Satellite Network Traffic Evaluation) ESPRIT project aims tosupport network and service providers in management of their services and capacity planning of theirresources, by providing them with a simulation methodology realised in a workbench.
In order to design or to dimension networks, it is necessary to study the characteristics of the trafficthat the networks will carry. On the other hand, the characteristics of multimedia services traffic are notyet well-known. The network can affect the services as the user-perceived Quality of Service maychange due to varying network conditions, but how services are affected is not clearly understood.
BISANTE aims to develop a knowledge base of user profiles, to characterise and model broadbandterrestrial, mobile and satellite networks and to build a workbench which will be able to mapuser/application characteristics in order to determine the end-to-end QoS that can be supported over satellite networks.
Internal COPARIS architecture
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5.2 Internet and ATM via Satellite
Future satellite networks will use satellites with on-board processing and packet-routing or cell-switching capabilities to provide IP or ATM-based networking. Statistically multiplexing the trafficover the air interface for maximum bandwidth utilisation and on-board resource management shiftsissues that were previously solely the concern of the ground segment to the space segment. Trafficand control mechanisms regulating the uplink and downlink traffic become onboard functions.
We have created a framework to provide end-to-end QoS for multiple service classes bydifferentiating services according to their QoS requirements.
5.3 Traffic and Congestion Control for Satellite Networks
In broadband multimedia satellite networks, it becomes necessary to multiplex bursty streams oftraffic with differing Quality of Service (QoS) requirements in order to maximise the overall utilisationof the satellite link bandwidth. Providing the desired QoS for each service in a multi-serviceenvironment is a major challenge.
The design of suitable traffic and congestion control algorithms is an important task to ensure thesuccess of a QoS provisioned satellite network. We are developing and optimising traffic andcongestion control mechanisms for satellite networks which can provide to users the required QoS.
5.4 Satellite Constellations
Low-Earth-Orbiting (LEO) satellite constellations offer the possibility of fully global wirelessnetworking, with better support for high latitudes, decreased delay, and more network capacity thansystems based around geostationary (GEO) satellites.
Ensuring seamless interworking with existing ground-based networks raises complex networkingissues for these LEO networks, as does evaluating the performance of a network that has a mobileand rapidly moving geometry. We are investigating simulation and protocol-based approaches toexamining this, with an emphasis on supporting multicast and Quality of Service (QoS).
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More information about Communication Networks Research activities andresearch team can be found at the following web address:
http://www.ee.surrey.ac.uk/CCSR/Networks/
Proposed Teledesic and Skybridge constellations rendered using SaVi
(SaVi is the Satellite Visualisation package from the Geometry Centre)
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● DIRECTOR, CCSR and DEAN OF
ENGINEERING RESEARCH, UniS
Professor Barry G Evans, BSc, PhD (Leeds), FREng, CEng, FIEE, SMIEEE, FRSA
● DEPUTY DIRECTOR, CCSR
Professor Ahmet M Kondoz, BSc (Birm), MSc (Essex), PhD (Sur), CEng, MIEE, MESCA, MIEEE, (Head of Multimedia Systems Research Group)
● ACADEMIC STAFF
Mr Tony Jeans, (Camb), MSc (Soton), (Senior Lecturer)
Professor George Pavlou, MSc (Lond), PhD (Lond), MIEE, MIEEE, (Racal Professor of Information Technology), (Head of Communication Networks Research Group)
Dr Abdul H. Sadka, BSc (AUB), MSC (METU), PhD (Sur), MIEEE, (Lecturer)
Dr Simon Saunders, BSc (Brunel), PhD (Brunel) AMIEE, MIEEE (Senior Lecturer)
Dr Zhili Sun, BSc (China), PhD (Lanc) (Lecturer)
Dr Peter Sweeney, MA (Oxon), PhD (Camb), (Senior Lecturer)
Mr Payam Taaghol, BEng (Lond), AMIEE, MIEEE, (Lecturer)
Dr Rahim Tafazolli, BSc (Bath), MSc (Lond), PhD (Sur), MIEE, CEng, MIEEE, (Reader, Head of Mobile Communications Research Group)
● SUPPORT STAFF
FINANCIAL & TECHNICAL ADMINISTRATOR
Mr David Brock, MSc (Sur), CEng, MIEE
COMPUTING OFFICERS
Mr John HibbittMr Adam Kirby
PA TO DIRECTOR/CENTRE SECRETARY
Mrs Moira Macmillan
FINANCIAL ASSISTANT
Mrs Stephanie Evans
RESEARCH GROUP SECRETARY
Mrs Lakshmi Chennell
TECHNICIAN
Mr Terry Roberts
● RESEARCH FELLOWS
(PhD subjects where applicable)
Mr Saied Abedi(Multi-user detection)
Mr Andreas-Albertos Agius(Dual mode antenna for SPCNhandheld terminals)
Mr Ilias Andrikopoulos(Optimising TCP/IP over ATM networks)
Mr Mohammed Hafeez Aziz(Band sharing between CDMA based SPCN)
Dr Bachir BelloulMr Christos BohorisDr David BurgessDr Haitham CruickshankDr Zhong FanMr Mauro Fiacco
(Intelligent picocells using optimumcombining)
Mr Shahram Ghaheri Niri(Integration between cordless and cellular systems)
Mr Enric JaenMr Arouggou JbiraDr Guanghong LuMr Ioannis Mertzanis
(Networking aspects and QoS provisioning for mobile satellite multimedia services)
Mr Tolga Ors(Traffic management and control over ATM via satellite networks)
Mr Philip Psiloinis(Video conferencing for wirelessATM networks)
Mr Yusep Rosmansyah(Turbo and iterative coding forCDMA systems)
Mr Tony Sammut(Resource management for satellite SPCN)
Mr George Sfikas(Call handling and mobility management in wireless LANs)
Mr Stavros Stavrou(The accuracy of mobile propagationmanagements)
Mr Milos Stefanovic(Low bit rate speech coding)
Mr Costantinos Tzaras(Physical modelling of mobile propagation)
Mr Seiamak Vahid(Optimisation of GSM networks)
Mr Cyril Valadon(Advanced CDMA receivers for satellitemultimedia communication systems)
Mr Stephane Villette(High quality low bit rate speech coding)
CCSR STAFF
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Mr George Aggelou(Dynamic Routing and QoS Support in Mobile Ad-Hoc Networks)
Mr Bilal Ahmed(Ka Band Channel Modeling for Satellite Mobile and Multimedia Services)
Mr Ruben Alvarez(Mobile Terminal Position Determination in Dynamic Satellite WCDMA Networks)
Mr Thumrongrat Amornraksa (Cryptography for Multimedia Communications)
Mr Alejandro Aragon(Mobile Radio Propagation Measurement Techniques)
Mr Mehrdad Ardebilipour(Synchronisation on Mobile Channel)
Mr Kar Ann Chew(Handover and Routing: MIP & RSVP)
Mr Yotsapak Chotikapong(Performance Improvement for TCP/IP over ATM via Satellite Constellations)
Mr Nikolaos Dimitriou(Call Admission Control for Multimedia CDMA)
Mr Safak Dogan(Video Transcoding for Heterogenous Multimedia Networks)
Mr Walter Dos Santos(Mobility Management on Satellite ATM Communication Systems)
Mr Dan Erichsen(Very Low Bit Rate Video Coding)
Mr Simon Fabri(Speech and Video Communications over Mobile Packet Networks)
Ms Bin Fan(Call Handling for ATM via Satellite)
Ms Maria Farrugia(Audio and Speech Signalling)
Ms Maria Gkizeli(Service Availability and QoS of Mobile Satellite Systems)
Mr Suji Gunaratne(Power Control for CDMA)
Mr Jong-Ok Joo(Congestion Control in ATM On-Board Satellite System for Multimedia Services)
Mr Nilantha Katugampala
(Narrow Band Speech Coding Below 4kb/s)
Mr Stephen Leach(Optimum Control of Hand Portable Terminal Antennas for Mobile Communications)
Mr Tarek Mahmoud(Low-delay Video Communications Over Internet)
Mr Dimitrios Mavrakis(Optical Techniques for High Bit Rate Communications)
Mr Klaus Moessner(Reconfigurable Mobile Communication Networks)
Mr K Narenthiran(Non-GEO Satellite Constellation and Signalling in Mobility Management)
Mr Min-Seok Oh(Low Complexity Decoding using Bit-level Soft Decision for RS Codes)
Mr Abdus Samad Owadally(Modeling of Propagation Over Irregular Terrain)
Mr Jonathan Rodriguez(Advanced CDMA Receiver)
Mr Chana Sriratanaban(Low Bit Rate Speech Coding)
Mr Abhaya Sumanasena(Evaluation and Optimisation of Air Interface for S-UMTS)
Mr Panomporn Suvannapattana(The Interaction Between Mobile Satellite Handset Antennas and the Human Body)
Mr Rajan Thiruvathirai(Software Radio)
Mr Panos Trimintzios(Bandwidth and Routing Management for ATM and IP)
Mr Lloyd Wood(Multicast Over Satellite Constellation Networks)
Mr Stewart Worrall(Adaptive Multirate Video and Channel Coding)
Mr Yusuf Yenice(Counter Measures to the Effects of Atmospheric Turbulence on Ground-Satellite Optical Communications)
Research Students (PhD subjects)
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Atkinson Ian, “Advanced Linear PredictiveSpeech Compression at 3.0 kbit/sec andbelow”, February 1997.
Black Alastair, “Analysis by Synthesis Codingof Narrowband and Wideband Speech atMedium Bit Rates”, May 1997.
Yaghmaie Khashayar, “WaveformInterpolation Based Low Bit Rate SpeechCoding”, June 1997.
Tateesh Said, “Multi-Rate Source andChannel Coding for CDMA-Based MobileCommunications”, September 1997.
Sadka Abdul H, “Error Control Strategies inBlock-Transform Video Coders in MultimediaCommunications”, September 1997.
Zhao Wei, “Handover Techniques andNetwork Integration Between GSM andSatellite Mobile Communication System”,September 1997.
Husni Emir, “Robust Reed Solomon CodedMPSK Modulation”, November 1997.
Lee Joohee, “CDMA Overlapped CarrierAllocation Schemes for Cellular MobileCommunications”, November 1997.
Komisarczuk Peter, “The Performance of theTelecommunication Information NetworkingArchitecture applied to Internet ProtocolService Provision”, February 1998.
Asadullah Shah, “An Intelligent MultiplexerArchitecture for Thin Route Communications”,March 1998.
Apostolas Costas, “Multiple Access Controland Mobility Management for ATM WirelessLAN”, March 1998.
Christopher Meenan, “Advanced MobilityManagement Techniques for Satellite MobileCommunication Networks”, May 1998.
Kjetil Fagervik, “Iterative Decoding ofConcatenated Codes”, September 1998.
Teck Hock Kweh, “Improved Quality Block-Based Low Bit Rate Video Coding”, September1998.
Hai Pang Ho, “Low Complexity Decoding ofCyclic Codes”, October 1998.
Awarded PhDs
Chronological list of awarded PhDs in CCSR over the last 2 years
Mrs Shyamalie Thilakawardana
Mr Xinjie Yang
Mr Yong Duk Cho
Mr Jung Hwan Lee
Mr Christoph Degen
Visiting Students
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CONFERENCE PAPERS
Aggelou G, Tafazolli R, “Wireless Ad Hoc onDemand Routing (WAODR) Protocol.” ACTS ’98Mobile Telecommunications Summit, Rhodes,Greece, 3rd June 1998.
Agius A A, Saunders S R, “Prediction ofDownlink Effective Statistical G/T in SatellitePCN Handsetsî Vehicular TechnologyConference ë98, 18th May 1998, Ottawa,Canada.
Agius A A, Leach S, Suvannapattana P,Saunders S R, “Intelligent Handset AntennaResearch Within Mobile VCE.” 2nd IntelligentAntenna Symposium, University of Surrey,Guildford, Surrey, 9th July 1998.
Amornraksa T, Sweeney P, “KeyDistribution Scheme for One WayBroadcasting.” 5th International Conference onMathematics in Communications, University ofLoughborough, 15th - 17th December 1998.
Apostolas C, Sfikas G, Tafazolli R,“Wireless ATM LAN”, ACTS MobileCommunication Summit ‘98, 8th June 1998,Rhodes, Greece.
Belloul B, Saunders S R, Evans B G,“Radiometer Based Prediction of ScintillationsIntensity in Earth-Satellite Links.” 5th COST 255Meeting, Vigo, Spain, 27th May 1998.
Chan Y, Sadka A H, Kondoz A M, “Multi-Rate Variable Quality Motion Coder for MPEG-4Video.” IMA International Conference onMathematics in Communications,Loughboroug, December 1998.
Chu V Y Y, Sweeney P, Paffett J,Sweeting M N, “Characterising ErrorSequences of the Low Earth Orbit SatelliteChannel and Optimisation with Hybrid ARQSchemes.” Globecom ë98, Sydney, Australia,November 1998.
Dogan S, Sadka A H, Kondoz A M,“Tandeming/Transcoding Issues BetweenMPEG-4 and H.263.” 3rd European Workshopon Mobile/Personal Satcoms, 4th to 5thNovember 1998, Venice, Italy.
Fagervik K, Jeans T G, “Turbo CodedModulation Using High Rate Binary and Non-Binary Block Codes”, 1st InternationalSymposium on Communication Systems andDigital Signal Processing, 6th April 1998,Sheffield Hallam University, Sheffield.
Fagervik K, Jeans T G, “Performance ofInterleaved Concatenated Convolutional andReed-Solomon Codes Using Soft-In/Soft-OutDecoding Algorithms”, 1st InternationalSymposium on Communication Systems andDigital Signal Processing, 6th April 1998,Sheffield Hallam University, Sheffield.
Fan B, Tafazolli R, Evans B G, “Performanceof Semi-Permanent Call Set-Up Protocol in S-PCN.” 3rd European Workshop onMobile/Personal Satcoms, 4th to 5th November1998, Venice, Italy.
Fan B, Tafazolli R, Evans B G, “A FullyIntegrated Air Interface Signalling and Protocolfor ATM via Satellite.” 4th Ka-BAND UtilisationConference, 2nd to 3rd November 1998, Venice,Italy.
Farrugia M, Jbira A, Kondoz A M, “Pulse-Excited LPC for Wideband Speech and AudioCoding.” IEE Colloquium, Audio and MusicTechnology: The Challenge of Creative DSP,Savoy Place, 18th November 1998.
Fiacco M, Saunders S R, “Physical-statisticalIndoor Propagation Modelling”, IEE Colloquiumon “Broadband Digital Radio:The Challenge ofThe Radio Environment”, 19th May 1998.
Ghaheri-Niri S, Tafazolli R, “Cordless-Cellular Network for Third Generation MobileCommunications System.” IEE Colloquium onPersonal Communications in the 21stCentury(II), London, February 1998.
Ghaheri-Niri S, Tafazolli R, “Cordless-Cellular Inter-System Handover Optimisation.”VTC ë98 Conference, Ottawa, Canada, May1998.
Ghaheri-Niri S, Tafazolli R, “CordlessCellular Integration for Third GenerationPersonal Communication Systems.” VTC ë98Conference, Ottawa, Canada, May 1998.
PUBLICATIONS
Alphabetical list of conference and journal publications produced by CCSR
researchers over the last 2 years.
CCSR PUBLICATIONS 1998
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Ghaheri-Niri S, Taaghol P, Tafazolli R,Barbieri M, Gobbi R, Dinis M, Luediger H,“ACCORD: A new ACTS initiative todemonstrate a feasible Global MobileBroadband Communication System throughJoint-trials.” 3rd ACTS Mobile CommunicationSummit, Rhodes, Greece, June 1998.
Ghaheri-Niri S, Tafazolli R, “Signallingtraffic Impacts in Cordless-Cellular IntegratedSystem.” PIMRC ’98, Boston, USA, September1998.Ho H P, Sweeney P, Paffett J,“Extended Kasami Algorithm for CyclicCodes.”Globecom ë98, Sydney, Australia, 8-12th November 1998.
Liotta A, Knight G, Pavlou G, “ModellingNetwork and System Monitoring Over theInternet Using Mobile Agents”, Proceedings ofthe IEEE/IFIP Network Operations andManagement Symposium (NOMS í98) Vol 2, pp300-312, February 1998.
Meenan C, Parks M, Tafazolli R, Evans B G,“Availability of 1st Generation SatellitePersonal Communication Network Service inUrban Environments” IEEE VehicularTechnology Conference, May 1998, Canada.
Mertzanis I, Tafazolli R, Evans B G, “A NewApproach for Radio Resource Management InMultimedia Dynamic Satellite Networks”17thAIAA Conference, 23rd February 1998,Yokohama, Japan.
Mertzanis I, Sammut A, Tafazolli R, Evans B G,“Network Aspects of Dynamic SatelliteMultimedia Systems: An Overview of COST-252Activities.” 1st Joint COST 252/259 Workshop,21st April 1998, Bradford, U.K.
Mertzanis I, Priscolli F D, Matziale V,Poddx V, Fan B, Tafazolli R, “SECOMSInterworking Scenarios and Interconnectionwith B-ISDN.” 3rd ACTS MobileCommunications Summit 1998, 8th June 1998,Rhodes, Greece.
Mertzanis I, Tafazolli R, Evans B G,“Service Mapping and Radio ResourceManagement in Multimedia Non-GEO SatelliteNetworks.” COST 252, 7th ManagementCommittee Meeting, 28th September 1998,Lisbon, Portugal.
Mertzanis I, Sfikas G, Tafazolli R, Evans B G,“Satellite-ATM Networking and CallPerformance Evaluation for MultimediaBroadband Services.” 4th Ka-Band UtilizationConference, 2nd November 1998, Venice, Italy.
Oh M S, Sweeney P, “Bit-Level Soft DecisionSequential Decoding for Reed SolomonCodes.” Workshop on Coding andCryptography, Paris, France, 11th to 14thJanuary 1998.
Ors T, Sun Z, Evans B G, “Analysis of a MACProtocol to Guarantee QoS for ATM overSatellite.” International Conference onCommunications, Atlanta, Georgia, USA, 7thJune 1998.
Ors T, Sun Z, Evans B G, “Analysis of anAdaptive Random/Reservation MAC protocolfor ATM over Satellite.” VTC ë98, Ottawa,Canada, 18th May 1998.
Ors T, Sun Z, Evans B G, “An AdaptiveRandom-Reservation MAC Protocol toguarantee QoS for ATM over Satellite.” 4thInternational Conference on BroadbandCommunications, Stuttgart, Germany, April1998.
Ors T, Sun Z, Evans B G, “A MAC Protocolfor ATM over Satellite.” 6th IEE Conference onTelecommunications, Edinburgh, U.K, 29thMarch 1998.
Ors T, Evans B G, “Multiple Access Protocolsfor ATM over Low Earth Orbit Satellites.” 1stJoint COST 252/259 Workshop, Bradford, U.K,21st April 1998.
Pavlou G, Liotta A, Abbi P, Ceri S,“CMIS/P++:Extensions to CMIS/P for IncreasedExpressiveness and Efficiency in theManipulation of Management Information.”Infocom ë98, March 1998.
Radi H, Fiacco M, Parks M.A.N, SaundersS R, “Simultaneous Indoor PropagationMeasurements at 17 and 60GHz for WirelessLocal Area Networks”, 48th IEEE InternationalVehicular Technology Conference, Ottawa,Canada, 18th - 21st May 1998.
Saunders S, Nix A, Jones S, Aghvami H,“Propagation Aspects of the Mobile VCE” IEEColloquium on “Antennas & Propagation forFuture Mobile Systems”, IEE ref. no. 1998/219,23rd February 1998.
Sfikas G, Apostolas C, Tafazolli R,“Location Management Issues in Wireless ATMNetworks”, ICT ë98, 22nd June 1998, PortoCarras, Greece.
Sfikas G, Apostolas C, Tafazolli R, “PowerSaving Mode of Operation in the WATM MACProtocol.” ICATM ë98, IEEE COMSOC, Colmar,France, 22nd June 1998.
Sweeney P, Husni E M, “A Reed SolomonCoded Approach to Robust.” InternationalConference for Prof. P.G Farrell, Lancaster,January 1998.
Taaghol P, Tafazolli R, “Multimedia TrafficModelling for Finite Population QueuingSystems”, 1st Conference on Mathematics inCommunications, University of Loughborough,December 1998.
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Taaghol Pouya, Tafazolli R, “AggregateFinite-Source Modelling for MultimediaCommunication Systems” 48th AnnualVehicular Technology Conference (VTCí98)18thMay 1998, Ottawa, Canada.
Taaghol Pouya, Taaghol P, Tafazolli R,“Burst Reservation CDMA Protocol for MixedServices S-PCS” 48th Annual VehicularTechnology Conference(VTCí98)18th May 1998,Ottawa, Canada.
Taaghol Pouya, Tafazolli R, “GPRS forMobile Satellite Communication Systems” 17thAIAA International Communications SatelliteSystems Conference, 23-27th February 1998,Yokohama, Japan.Tafazolli R, Meenan C,Evans B G, “Mobility and ResourceManagement for S-PCN and Integration withTerrestrial Mobile Networks.” 3rd EuropeanWorkshop on Mobile/Personal Satcoms, 4th to5th November 1998, Venice, Italy.
Tzaras C, Saunders S R, Evans B G, “APhysical-Statistical Propagation Model ForDiversity in Mobile Satellite PCN”, IEEEVehicular Technology Conference, VTCí98, 18thMay 1998, Ottawa, Canada.
Valadon C, Tafazolli R, Evans B G,“Efficient Channel Coding Techniques forSatellite Robic Multimedia Systems UsingSynchronous CDMA” 17th AIAA InternationalCommunications Satellite Systems Conference,23rd February 1998 Yokohama, Japan.
Valadon C, Tafazolli R, “A Fast AdaptiveMultiuser Detector for DS-CDMACommunications Based on an Artificial NeuralNetwork Architecture.” 5th InternationalSymposium on Spread-Spectrum Techniquesand Applications, Sun-City, South Africa, 2ndSeptember 1998.
Valadon C, Dimitriou N, Tafazolli R, Evans BG, “Performance Comparison between TCM andMTCM for Multimedia Satellite Systems UsingSynchronous CDMA.” COST 252 7TH MCMMeeting, Lisbon, Portugal, 28th September 1998.
Valadon C, Verelst G, Taaghol P, TafazolliR, Evans B G, “A New Approach to theDesign and Dimensioning of CDMARegenerative Payloads.” 4th Ka-BANDUtilisation Conference, 2nd to 3rd November1998, Venice, Italy.
Valadon C, Mertzanis I, Huggins G,Tafazolli R, Evans B G, “Air Interface Designfor the Provision of Multimedia Services toCompact User Terminals: The SWAID Project.”4th Ka-BAND Utilisation Conference, 2nd to 3rdNovember 1998, Venice, Italy.
Valadon C, Dimitriou, Tafazolli R, Evans B G,“Performance Comparison of TCM DesignCriterion for Mobile Multimedia SatelliteSystems Using Synchronous-CDMA”,Proceedings of the 5th InternationalSymposium on Spread Spectrum Techniques &Applications (ISSSTA í98), pp 23-27, Sun City,South Africa, 2-4 September 1998.
Velentzas S, Cruickshank H, Sun Z,Pavlou G, “Security Mechanisms for ATMPONS.” 6th IFIP Workshop on PerformanceModelling and Evaluation of ATM Networks,Iekley, West Yorkshire, 20th to 22nd July 1998.
Widiawan A K, Sammut A, Evans B G,“Interbeam Handover in LEO SatelliteSystems.” 3rd European Workshop onMobile/Personal Satcoms, 4th to 5th November1998, Venice, Italy.
Wood L, “Multicast in SatelliteConstellations”, Cost 253 Meeting, 27thMarch 1998, Brussels.
Wood L, Cruickshank H, Sun Z,“Supporting Group Applications Via SatelliteConstellations with Multicast.” 6th IEEConference on Telecommunications, London,1998.
Yenice Y, Evans B G, “Adaptive Beam-SizeControl for Ground to Satellite LaserCommunications.” Free Space LaserCommunication Technologies X, San Jose,California, 27th January 1998.
JOURNAL PAPERS
Agius A A, Saunders S R, “EffectiveStatistical G/T (ESGUT): A ParameterDescribing The Performance for non-GEOSatellite Systems.” Electronics Letter, Vol.34,Part 19, pp 1814 to 1816, 17th September 1998.
Belloul B, Saunders S R, Evans B G,“Prediction of Scintillation Intensity from Sky-Noise Temperature in Earth-Satellite Links”, IEEElectronics Letters, 1998.
Cruickshank H, THESEUS - Terminal Accessto Broadband Networks for European StockExchange.” 1998 IEE Electronics &Communications Engineering Journal, Vol 10,Part 6, pp 289 to 296, December.
Danesfahani G R, Jeans T G, “ApproximatelyJitter-Free Tracking Performance of GardnerTiming Error Detection Algorithm.” Daneshvar,Scientific Research Journal of Shahed University,Vol.5, No 18, pp 11-14, December 1998.
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Ghaheri-Niri S, Tafazolli R, “Handover inHierarchical Cell Architecture”, IEE Proceedingson Communications.
Guoan B, Evans B G, “Hardware Structurefor Walsh-Hadamard Transforms.” IEEElectronics Letters, Vol 34, Part 21, pp 2005 to2006, 15th October 1998.
Ho H P, Sweeney P, “Low ComplexityDecoding of Cyclic Codes Using an ExtendedKasami Algorithm” Electronic Letters, Vol 34,Part 8, pp 756-757, 16th April 1998.
Ho H P, Sweeney P, “Cover Positions andDecoding Complexity of Golay Codes using anExtended Kasami Algorithm.” IEEECommunications Letters, Vol 2, Part 12, pp 1 to3, December 1998.
Lee J, Tafazolli R, Evans B G, “Performanceof Hybrid OCA-FD/CDMA for Cellular MobileCommunications.” IEE Proc. Communication,Vol 145, Part 5, pp 363 to 369, 5th October1998.
Otung I E, Al-Nuaimi M O, Evans B G,“Extracting Scintillations from Satellite BeaconPropagation Data.” IEEE Antennas &Propagation, Vol 46, Part 10, pp 1580-1581,October 1998.
Pavlou G, Festor O, “ManagementInformation Model Engineering.” Journal ofNetwork & System Management, Vol 6, Part 3,pp 236 to 243, September 1998.
Pavlou G, Liotta A, Abbi P, Ceri S,“CMIS/P++: Extensions to CMIS/P for IncreasedExpressiveness and Efficiency in theManipulation of Management Information.”IEEE Network-Special Issue on NetworkManagement, Vol 12, Part 5, pp 2 to 12,October 1998.
Pavlou G, Griffin D, “An EvolutionaryApproach Towards the Future Integration of INand TMN”, Journal of InteroperableCommunication Networks, Special Issue onTelecommunication Services Engineering, Vol 1,No 1, pp 1-16, Baltzer Science Publishers, 1998
Shin S K, Atungsiri S A, Kondoz A M,Evans B G, “Source-aided Trellis Decoding forMobile Communication Channels” InternationalJournal of Electronics, Vol 84 No 1, pp 3-7,January 1998.
Sun Z, Ors T, Evans B G, “ATM-Over-Satellite Demonstration of Broadband NetworkInterconnection.” Computer Communications,Vol. 21, pp 1090 - 1101, 1998.
Valadon C, Tafazolli R, Evans B G,“Multilevel Trellis-Coded Modulations forMobile Multimedia Satellite Systems UsingSynchronous CDMA.” International Journal ofSatellite Communications, Vol 16, Part 1, pp 59to 76, February 1998.
Wesemeyer S, Sweeney P, “SuboptimalSoft-Decision Decoding for Some RS-Codes.”Electronics Letters, Vol 34, Part 10, pp 983 to984, 14th May 1998.
Wesemeyer S, “On the Automorphism Groupof Various Goppa Codes.” IEEE Transactions ofInformation Theory, Vol 44, Part 2, pp 630 to643, March 1998.
Widiawan A K, Sammut A, Evans B G,“Interbeam Handover in LEO SatelliteSystems” International Journal of SatelliteCommunications, Vol 16, Part 5, pp 209 - 217,September 1998.
Yenice, Y E, Evans B G, Aruga T,“Experimental Evidence For NegativeExponential Distribution of Intensity in aGround-to-Satellite Optical Link.” ElectronicsLetters, Vol 34, Part 15, pp 1512 to 1513, 23rdJuly 1998.
Zhao W, Tafazolli R, Evans B G, “MobileTerminal Positioning technique for DynamicSatellite Constellations.” International Journalof Satellite Communications, Vol. 16, pp 77 -85, 27th January 1998.
SEPARATE PUBLICATIONS
Black A W, Kondoz A M, “High Quality LowDelay Wideband Speech Coding at 16kb/s.”Insights into Mobile MultimediaCommunications, Signal Processing and itsApplications, pp 271 - 283, Academic Press.
Eryurtlu F, Sadka A H, Kondoz A M,“Integrated Speech and Video Coding forMobile Audiovisual Communications.” Insightsinto Mobile Multimedia Communications,Signal Processing and its Applications, pp 381-394, Academic Press, 1998.
Liotta A, Knight G, Pavlou G, “ModellingNetwork and System Monitoring Over theInternet Using Mobile Agents”, Proceedings ofthe IEEE/IFIP Network Operations andManagement Symposium (NOMS í98) Vol 2, pp300-312, ISBN 0-7803-43514, February 1998.
Ors T, Sun Z, Evans B G, “An AdaptiveRandom-Reservation MAC Protocol toguarantee QoS for ATM over Satellite.”Broadband Communications: The future ofTelecommunications, Vol.I, pp 107 - 119,Chapman & Hall.
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Ors T, Sun Z, Evans B G, “Analysis of anAdaptive Random/Reservation MAC protocolfor ATM over Satellite.” VTC ë98 ConferenceRecord, Vol.II, pp 1523 -1528, IEEE, USA, 1998.
Ors T, Sun Z, Evans B G, “A MAC Protocolfor ATM over Satellite.” 6th IEE Conference onTelecommunications, Conference PublicationNo.451, pp 185 - 190, IEE, London, 1998.
Pavlou G, Liotta A, Knight G, “ModellingNetwork and System Monitoring over theInternet Using Mobile Agents.” Proceedings ofthe IEEE/IFIP Network Operations andManagement Symposium, pp 300 to 312,February 1998.
Sadka A H, Eryurtlu F, Kondoz A M,“Aspects of Error Resilience for Block-basedVideo Coders in Multimedia Communications.”Insights into Mobile MultimediaCommunications, Signal Processing and itsApplications, pp 431 - 443, Academic Press.
Wood L, Cruickshank H, Sun Z,“Supporting Group Applications via SatelliteConstellations with Multicast”, 6th IEEConference on Telecommunications, Heriou-Watt University, Edinburgh, 29th March 1998.
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. 14-18April 1997.
Agius A A, Saunders S R, Evans B G, “TheDesign of Specifications for Satellite PCNHandheld Antennas.” Vehicular TechnologyConference (VIC) 1997, IEEE, Arizona, USA. 4-7May 1997.
Agius A A, Saunders S R, “IntelligentAntennas for Mobile Handsets”, 1st SurreySymposium on Intelligent Antenna Technologyfor Mobile Communications, 28th to 29thAugust 1997, University of Surrey.
Ahmed B, Buonomo S, Otung I E,“Simulation of 20 Ghz narrow Band MobilePropagation Data Using N-States MarkovChannel Modelling Approach.” 10thInternational Conference on Antenna andPropagation, Edinburgh, UK, 14-17 April 1997.
Apostolas C, Tafazolli R, “Dynamic TDMAscheme with Traffic Policing for ATM WirelessLAN” 9th Tyrrhenian International Workshopon Digital Communications, Lerici, Italy, 7-10thSeptember 1997.
Atkinson I, Yeldener S, Kondoz A, “HighQuality Split Band LPC Vocoder Operating AtLow Bit Rates.” International Conference onAcoustics, Speech and Signal Processing(ICASSP) Munich, Germany, 21 April 1997.
Aziz H, Tafazolli R, Evans B G,“Comparison of Total System Capacity forBand Sharing between CDMA based non-Geostationary Satellite-PCNs under ImperfectPower Control Systems” IEEE 47th AnnualInternational Vehicular Technology Conference(VTC 97) Phoenix, USA, 4-7th May 1997.
Belloul B, Saunders S, Evans B G, “Diurnalvariability of scintillation intensity on amoderate elevation Earth-satellite path at 12.5,20 and 30 Ghz” COST 255, Brussels, 27-29October 1997.
Buracchini E, Melis B, Romano G, Taaghol P,“SINUS Air Interface Overview” 3rd ACTSMobile Communication Summit, Aalborg,Denmark, 7-10 October 1997.
Cruickshank H S, “Securing User, Controland Management Planes In ATM Networks.”Singapore International Conference OnNetworks 1997 (SICON 97) . Singapore, 14-17April 1997.
Fagervik K, Jeans T G, “A Polar AutomaticFrequency Control Algorithm for Low Signal toNoise Ratios.” Norsig 199, IEEE NorwaySection, 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 KasamiAlgorithm” 6th IMA International Conferenceon Crytography and Coding, Cirencester,December 1997.
Husni E, Sweeney P, “Robust Block CodedMPSK Modulation for the Gaussian and aRayleigh Fading Channel” IMSCí97, PasadenaCalifornia, 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 SolomonCoded MPSK Modulation” 6th IMAInternational Conference on Cryptography andCoding, Cirencester, December 1997.
CCSR PUBLICATIONS 1997
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Koudelka O, Maral G, Cruickshank H,Collard J, “Network integration via MEO/LEOsatellites-The COST 253 action” IEE Colloquiumon EUís initiatives in satellite communications-fixed and broadcast, London, 9th May 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.
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,“Intelligent Paging Schemes for Non-GeoSatellite Personal Communication Networks.”Vehicular Technology Conference 1997,IEEEPhoenix Arizona, USA, 4-7th May 1997.
Meenan C, Tafazolli R, Evans B G, “NewMobility Management And Call RoutingProtocols For Dynamic Satellite PersonalCommunication Networks.” Integration ofSatellite Terrestrial PCS, IEE London, April1997.
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 forSECOMS, the ACTS European project” FourthEuropean Conference on SatelliteCommunications (ECSC-4), Italy, 18-20November 1997.
Mertzanis I, Tafazolli R, Evans B G,“Connection Admission Control Strategy andRouting Considerations in Multimedia (Non-Geo) Satellite Networks”, IEEE 47th AnnualInternational Vehicular Technology Conference,Phoenix, USA, May 4-7th 1997.
Mertzanis I, Tafazolli R, Evans B G,“Performance Issues and Modelling of MobileExecuted Handoffs in Multi-Spotbeam DynamicSatellite Networks using ATM Multiplexing”,IEE, Colloquium London, UK, February 1997.
Ors T, Sun Z, Evans B G, “A Meshed VSATSatellite Network Architecture using an On-Board ATM Switch”, IEEE InternationalPerformance, Computing and CommunicationsConference 1997, Phoenix-Arizona, USA, 5-7thFebruary 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 International Conferenceon Antennas and Propagation, Edinburgh, 14April 1997.(Proceedings vol.2 pp. 239-243)
Rautiola K, Tolonen M, Taaghol P, TafazolliR, Evans B G, “Design of the Satellite RadioChannel Emulator for Real-TimeDemonstrations in SINUS” 3rd ACTS MobileCommunication Summit, Aalborg, Denmark, 7-10 October 1997.
Sadka A H, Eryurtlu F, Kondoz A M,“Modiried 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-usernetworking environments” 4th InternationalSymposium on Communication Theory andApplications, 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, 15September 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 Mobile SatellitePropagation In Built-Up Areas”, 10thInternational Conference on Antennas andPropagation, pp 2.44-2.47 14 th to 17th April1997, Edinburgh.
Sweeney P, Honary B, “Security andInformation Representation for the NiederreiterPublic Key Cryptosystem” 4th InternationalSymposium on Communication Theory andApplications, Ambleside, July 1997.
Taaghol P, Tafazolli R, Evans B G,“Performance Evaluation of an Adaptive PowerControl Scheme in Measurement Based S-PCNChannel” IMSCí97, Pasadena, California, USA,16-18 June 1997.
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JOURNAL PAPERS
Amornraksa T, Sweeney P, Honary B,“Protecting the integrity of a sequence ofimages.”Electronics Letters, Vol 33, Part 19, pp1617-1618, 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, “ErrorRobustness Improvement of Video Codecs withTwo-way Decodable Codes” IEE ElectronicsLetters, 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 for Video CodingStandards.” IEE Proceedings – Visual ImageSignal Process, Vol 144, Part 4, pp 227-232,August 1997.
Lee J, Tafazolli R,Evans B G, “ErlangCapacity of OC-CDMA with imperfect PowerControl” Electronics Letters, Vol.33, pp. 259-261, 13th February 1997.
Sadka A H, Eryurtlu F, Kondoz A M, “ErrorResilience Improvement for Block-TransformVideo Coders” IEE Proc. VISP, Vol.144 No.6,December 1997.”,
Sadka A H, Eryurtlu F, Kondoz A M,“Improved Performance H.263 under ErroneousTransmission Conditions” IEE ElectronicsLetters, Vol.33 No.2, pp 122-124, January 1997.Sfikas G, Apostolas C, Tafazolli R, “TheU.K. LINK-PCP Approach to the Wireless ATMSystem” IEEE Communications magazine,November1997.
Sun Z, Ors T, Evans B G, “ATM-over Satellitedemonstration of broadband networkinterconnection” Special Issue in ComputerCommunications Journal, Elsevier SciencePublications.
Taaghol P, Tafazolli R, “Correlation Modelfor Shadow Fading in Land-Mobile SatelliteSystems” IEE Electronics Letters, Vol.33, No.15,pp 1287-1289, July 1997.
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Taaghol Pouya, Tafazolli R, Evans B G, “Onthe Reservation Multiple Access Protocols forFuture Mobile Communication Systems” IEEE47th Annual International Vehicular TechnologyConference, Phoenix, USA, 5-7th May 1997.
Taaghol Pouya, Tafazolli R, Evans B G, “AnAir Interface Solution for General Packet RadioService (GPRS) for GSM/DCS” IEEE 47thAnnual International Vehicular TechnologyConference, Phoenix, USA, 4-7th May 1997.
Tateesh S, Atungsiri S, Kondoz A M, “LinkAdaptation to Channel Interference Using Multi-rateSource and Channel Coding for CDMA MobileCommunications.” International Conference onAcoustics, Speech and Signal Processing (ICASSP)Munich, Germany, April 1997.
Valadon C, Tafazolli R, Evans B G, “OnChannel Coding for Satellite MultimediaSystems with a Synchronous CDMA AccessScheme.” International Mobile SatelliteConferenceí97, Pasadena California, USA, 16-18
June 1997.Valadon C, Taaghol P, Evans B G, Tafazolli R,“Design and Dimensioning of a CDMARegenerative Payload for the SECOMS System” 4thEuropean Conference on Satellite Communications,Rome, Italy, 18-20 November 1997.
Valadon C, Taaghol P, Tafazolli R, Evans B G,“Link Design and Dimensioning of CDMA, theAlternative Multiple Access in SECOMS” 3rdKa-Band Utilization Conference, Sorrento, Italy,15-18 September 1997.
Valadon C, Taaghol P, Tafazolli R, Evans B G,“SECOMS CDMA Link Dimensioning” 3rdACTS Mobile Communications Summit,Aalborg, Denmark, 7-10 October 1997.
Villette S, Stefanovic M, Atkinson I,Kondoz A M, “High Quality Split Band LPCVocoder and its Fixed Point Real TimeImplementation” Eurospeech ’97, Vol.3, pp 1243-1246, Rhodos, Greece, 22-25 September 1997.
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SEPARATE PUBLICATIONS
Andrikopoulos I, Ors T, Matijasevic M,Leitold H, Posch R, “TCP throughputmeasurements within heterogeneous ATMlocal area networks” ATM Networks:Performance Modelling and Analysis, Vol.III,Chapman and Hall, London.
Cruickshank H, “Securing user, control andmanagement planes in ATM networks”,National University of Singapore, May 97.
Ors T, Hadjitheodosiou M H, Sun Z, Evans B G, “ATM over VSAT networks usingtraditional bent-pipe or on-board processingSatellites” ATM Networks:PerformanceModelling and Analysis, Vol.III, Chapman andHall, London.
Ors T, Sun Z, Evans B G, “A Meshed VSATSatellite Network Architecture Using An On-board ATM Switch.” IEEE Int . Performance,Computing And Communications Conference1997. IEEE, USA, 1997
Taaghol P, Tafazolli R, Evans B G,“Performance Evaluation of an Adaptive PowerControl Scheme in Measurement Based S-PCNChannel” IMSCí97, Pasadena California, USA,16-18 June 1997.
Tateesh S, Atungsiri S, Kondoz A M, “LinkAdaptation 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.
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School of Electronic Engineering, Information Technology & MathematicsUniversity of Surrey, Guildford GU2 5XH UKTel: +44 (0) 1483 87 6010Fax: +44 (0) 1483 87 6011E-mail: [email protected]://www.ee.surrey.ac.uk/CCSR/