RA5a: Structure,environment and staffing policy1. DEPARTMENTAL RESEARCH POLICY, STRUCTURE AND FUTURE PLANS
Research in the Department of Electronic Systems Engineering focuses on novel telecommunications, network infrastructure and multimedia services. Notable achievements since 1996 are summarised in the Table below, and confirm that both the volume and level of research are substantially improved. We are particularly proud of our research productivity, achieving high journal and conference publication rates in relation to research expenditure. Future research definition is indicated by current grants of £4.3m, including grants of more than £2.8m awarded in the last year. Electronics is a key strategic development area for the University, which has committed SRIF funding of £3.7m supported by £1.25m from the University itself and our industrial partners to build the first phase of a new building for the Department (linked to Computer Science and Psychology) within the next 3 years.
The three research groups (Communication Networks, Electronics, Multimedia and Vision) of the last RAE have evolved into the four groups (Photonics, Audio and Video Networking, Multimedia Architectures and Applications, and RF Engineering and Propagation) detailed below. The Department’s research vitality has been enhanced by 10 new academic staff over the last 3 years (including 3 full-time and 2 part-time senior staff from the Physics Department). The 5 new appointees to Essex (bold italics in the following sections) have already demonstrated their potential through successful EPSRC research applications, publications and research staff/student supervision.
Departmental research planning and strategy is managed by our Research Policy Committee (RPC), comprising the Director of Research, Head of Department, and Heads of Research Groups. New academic staff benefit from the experience of a research uncle operating in tandem with a probationary supervisor. Our Industrial Advisory Committee provides external guidance to RPC while Industrial Visiting Professors and Fellows are associated with individual research groups. Sabbatical entitlement at Essex is generous, and all research-active staff take one year in seven as study leave to focus full-time on research, often in collaboration with industry. Research students and staff are critical to the Department’s research output; we maintain high standards both in the performance we expect (through comprehensive progress monitoring), and in the stimulating and supportive research environment we provide which attracts applicants worldwide. Four prizes/awards have been won by our research students in recent IEE national competitions and at EPSRC PREP conferences.
2. PHOTONICS RESEARCH GROUP
2.2 The Optical Transmission Systems Laboratory, led by Shamim Siddiqui, focuses on understanding and measuring the fundamental characteristics of fibre, with the aim of maximising transmission capacity. Studies involve polarisation and its effect on transmission, and dispersion compensation techniques and their application to 40 Gb/s soliton transmission. Achievements include the first fully polarisation-sensitive optical time domain reflectometer, a major objective of the RAE96 plan. This work provided the first real understanding of polarisation mode dispersion (PMD) in spun fibres and led to a new technique for fibre design (J. of Lightwave Technology, 1998). A novel method for PMD compensation, based on these studies, has resulted in 2 patents. Since 1996, research on the access network has commenced (Stuart Walker). An EPSRC/Fujitsu project has investigated the application of arrayed-waveguides to access networking. These devices can form the basis of a low cost network and are of great interest to manufacturers; this work has been extensively reported. Collaboration with the University of Bristol and HP involves the study of low-cost high-speed transmission over multimode fibre for Ethernet networking. 10 Gb/s transmission over 300 m of multimode fibre has recently been demonstrated, far exceeding other reported results.
2.3 The Lasers and Nonlinear Optics Laboratory, led by Mike Adams, is concerned primarily with semiconductor devices, but also includes Rodney Loudon’s work on quantum effects associated with the propagation of light in absorbing or amplifying media. In the semiconductor device area recent major achievements include the derivation of a theoretical understanding of the temperature dependence of threshold current in long-wavelength vertical cavity surface emitting lasers (VCSELS) and the derivation of design rules for room-temperature operation. The first demonstration of all-optical switching by absorptive and dispersive non-linearities in a single laser diode was reported, together with a complete characterisation of optical (and electrical) switching and wavelength conversion in a Side Injection Light-Controlled Bistable Laser Diode (SILC-BLD).
2.4 Optoelectronic Materials and Devices Laboratory. The main activity, led by Naci Balkan, involves the study of hot electrons and instabilities in semiconductors. The Laboratory's work includes Brian Ridley’s research on the transport and opto-electronic properties of GaN and related compounds. A major achievement has been the development of a series of unique light emitting and lasing devices (HELLISH) which utilise hot electron transport parallel to heterojunction layers. These devices can perform light logic functions and operate both in the 850 nm and 1.5 mm wavelength ranges (by suitable choice of material). This work, started at Essex, has now been taken up by a number of other universities in Germany, Turkey and Holland. NASA AMES Research Centre has also expressed interest in the device concept. The laboratory also reported the first UK based experimental work on GaInAsN/GaAs quantum well structures for applications in 1.3 mm uncooled lasers.
2.5 The High-Speed Optoelectronics Laboratory, led by Anthony Vickers, involves the development and use of electro-optic sampling and electrical autocorrelation techniques for measuring sub-picosecond events. The focus on high-speed photodetectors includes work on novel devices such as the Back-Gated Metal-Semiconductor-Metal (BG-MSM) detector. A major achievement (resulting in a patent) has been the development of a technique for accurately positioning optical pulse trains (generated by a gain switched DFB) by manipulation of the drive currents. This is applicable to measuring events on a fast time scale and also to the interleaving of several optical sources for high bit rate communication systems. Devices based on the use of quantum confined stark effect and heterojunction barriers are being investigated as wide (20 mm) tunable lasers. A paper reporting these results won the SPIE best paper award in 1998.
2.6 Future Plans: The group's future emphasis will be on information networks, incorporating optical switching, transmission and advanced devices. Work on optical packet switching in the Photonics Networks Laboratory has demonstrated the major issues to be addressed to enable multi-terabit operation. Such throughputs require radically different technical approaches, and identifying these will be the main goal: all-optical processing, for example, is an area of planned collaboration with the LNLO Lab. This research has been greatly enhanced by the appointment of Dimitra Simeonidou from Alcatel. She now has 2 EPSRC and 1 EU grants to her name, plus numerous publications, and has been instrumental in establishing the start-up company Ilotron. The Optical Transmission Systems Laboratory will continue work on establishing the polarisation propagation properties of solitons, and the investigation of the dispersion compensating potential of Polarisation Shift Keying and Differential Polarisation Shift Keying. The aim is a system capable of correcting for large amounts of both chromatic and polarisation mode dispersion simultaneously. Access research will focus on high-speed low cost Ethernet. Future plans in the Lasers and Nonlinear Optics Laboratory involve novel mechanisms for ultra-fast all-optical switching (including spintronics) and non-linearities in semiconductor optical amplifiers, and further research into fundamental aspects of noise. Work will also investigate the roles of quantum effects in optical devices and evaluate the advantages they can provide in optical information processing. Activities in the Optoelectronic Materials and Devices Laboratory will focus on GaInAsN devices with emphasis on 1.3 mm operation and on resonant cavity photodetectors (together with the HSO Lab). Fundamental studies will investigate the hot electron properties in FETs using GaN with application to high power FETs. The High-Speed Optoelectronics Laboratory will extend its research on high-speed measurements through the study of resonant cavity enhanced detectors with the objective of detecting 1 ps pulses.
3. AUDIO AND VIDEO NETWORKING RESEARCH GROUP
Audio and Video Networks Laboratory: Prof Mohammed Ghanbari, Prof Don Pearson,6 ac staff; 1.85 res staff and 2 vacancies; 8.5 FTE res students; 24 res degrees awarded over RAE period; res expenditure of £1064k over RAE period; current res grants held £650k; 67 int. journal papers and 131 int. conf. papers published between Jan 1996 and Dec 2000.
Dr Tim Dennis, Dr Martin Reed, Dr John Woods.
Audio Engineering Laboratory: Prof Malcolm Hawksford, Dr Martin Reed.
The Audio and Video Networking Group has a worldwide reputation for research into the presentation and coding of broadcast and interactive television and multimedia services, and high-quality audio engineering. Immersive technologies investigated have included super-high definition video, stereo, motion, and spatial audio, while there has also been extensive research on very low bitrate services for applications such as mobile videotelephony and video transcoding. The group was one of 6 academic sites selected by industry as core members of the Virtual Centre of Excellence in Digital Broadcasting and Multimedia (DVCE).
3.1 Inspiration for many activities in the Audio and Video Networking Laboratory comes from Ghanbari’s pioneering work on layered video coding, for which he was recently elected FIEEE. This is now known as SNR scalability in standard video codecs such as MPEG-2, MPEG-4 and H.263+, and has impacted on ATM networks by defining the cell loss priority level. Ghanbari has also made fundamental contributions in cell-loss concealment and motion compensation using warping, which is now known as SPRITE coding in MPEG-4. His current research on video transcoding aims to reduce network congestion in applications of video over IP/ATM, and is the subject of several international patents. Ghanbari and Pearson also contributed to the recently-completed EU Tapestries project, and its predecessor Mosaic (with the Department of Psychology) on the evaluation of compressed picture quality. Ghanbari has since been one of 10 contributors world-wide to submit findings to the Video Quality Experts Group (VQEG). The work of the laboratory on Mosaic/Tapestries has had a major impact in defining video quality assessment methods for digital television through ITU-R recommendation 500, and academic recognition through the award of the IEE A H Reeves Prize 1996 and an invited keynote address at IEEE ICASSP.
3.2 Malcolm Hawksford has been internationally recognised for innovative high-quality multi-channel audio systems design since he established the Audio Engineering Laboratory in the 1980s. Within the current RAE period he, Bob Stuart and Hiro Negishi (respectively a visiting Fellow and visiting Professor) founded the Acoustic Renaissance for Audio (http://www.meridian.co.uk/ara/), which strongly influenced the technical standards for the new DVD-Audio format. The laboratory also originated the concept of perceptual models for subjective evaluation of audio codecs, for telecoms and multimedia applications. This work has recently been commercialised by BT Labs, as a company (Psy Technics) led by the two PhD students who conducted the original research with Malcolm and Rob Massara (Design Automation Laboratory). High accuracy digital and active loudspeaker designs are another continuing theme, which has recently been applied in immersive spatial audio, telepresence and networked audio (in collaboration with Martin Reed and others in the AVN lab). This work led to the award of the Audio Engineering Society's Publication Prize 2000 for the best journal paper of 1997/1998, to an invited consultancy with NXT plc, which is applying it to distributed mode loudspeakers, and to Malcolm’s appointment as Chairman of the international AES Technical Committee on high-resolution audio. The laboratory continues to produce able young researchers, with two recent PhD students achieving national IEE prizes/awards at EPSRC PREP conferences.
3.3 Future Plans: The group plans to extend its internationally recognised activity in layered video and multimedia coding to a wide range of networks, such as IP, ATM and mobile, and to new high quality immersive audio and multimedia services. To support these developments, the group has video transcoders, an ATM LAN and switches, and IP routers connecting it to the East Anglian LeaNet network comprising BT and the Universities of Essex, Cambridge and UCL. LeaNet is being used to carry out quality-of-service related experimental research and subjective evaluation on future high-performance and low-bandwidth audio and video applications. The group has recently been awarded a £263k grant from BT to carry out real-time experiments on coding and transmission of high quality video over IP through the LeaNet link to UCL. In anticipation of Don Pearson’s retirement, two new appointments were made in Oct 1998 and Sept 1999. Martin Reed and John Woods have both already obtained EPSRC research funding; Reed is investigating transmission of audio over IP, and Wood is working on optimisation of multimedia services over IP networks.
4. MULTIMEDIA ARCHITECTURES AND APPLICATIONS RESEARCH GROUP
Multimedia Architectures Laboratory: Prof Andy Downton, Dr Martin Fleury, Dr Steve Sangwine.4 ac staff; 3.2 res staff +2 vacancies; 6 FTE res students; 7 res degrees awarded over RAE period; res expenditure of £537k over RAE period; current res grants held £797k; 30 int. journal papers and 68 int. conf. papers published between Jan 1996 and Dec 2000.
VASE Laboratory: Dr Adrian Clark
4.1 The Multimedia Architectures Laboratory has established a unique design approach for parallel and distributed embedded applications, which is now being extended into the rapidly emerging area of hardware-software co-design. The successful conclusion of an EPSRC research contract (£265k) on design tools for embedded parallel applications has led to publication of the first book providing a comprehensive design method for embedded parallel systems (Martin Fleury and Andy Downton, Wiley, New York, March 2001) and has led to EPSRC, industry and MoD-funded projects on hardware/software co-design tools for parallel and distributed architectures. Anticipated applications range from networked mobile consumer information appliances through to intelligent distributed signal-tracking systems for defence. The laboratory also continues to be a UK leader in document and handwriting recognition, and has recently, with the Natural History Museum, established new bioinformatics research in distributed and networked archive document conversion. This work is key to making legacy biological archives available on line for assessing biodiversity and environmental change.
4.2 The Vision and Synthetic Environments (VASE Laboratory), led by Adrian Clark, is one of two main academic centres of expertise for wearable computing in the UK. An accurate position-finding system for wearable computing has been developed, while Sulawesi, an innovative multi-modal user interface framework for wearable computing, has been downloaded by about 100 other researchers. Other research explores the boundary between computer vision and virtual reality, through projects on shared virtual environments using IP multicasting, hyperspectral data processing, and augmented reality. Image analysis and rendering techniques have recently been combined to achieve what is believed to be the first fully 3D facial recognition system, in conjunction with Essex Police. New grant awards involve combining computer vision and virtual reality as a pilot aid for improved safety in civil aircraft (EPSRC, £177k), and performance characteristics in computer vision (EU funded, with the University of Manchester and KTH Sweden).
5. RF ENGINEERING AND PROPAGATION RESEARCH GROUP
RF Engineering and Communication Laboratory: Prof Dariush Mirshekar, Prof Ravi Mazumdar (p-t).
Propagation Laboratory: Prof Anthony Holt, Dr David Bebbington.
Design Automation Laboratory: Prof Rob Massara, Mr Bob Mack.
5.1 ac staff; 3 res staff; 4.5 FTE res students; 17 res degrees awarded over RAE period; res expenditure of £1080k over RAE period; current res grants held £520k; 39 int. journal papers and 75 int. conf. papers published between Jan 1996 and Dec 2000.
The RF Engineering and Propagation Group is primarily concerned with theoretical research and its applications in foundation areas of communications and provides theoretical support to the other groups. Topics include electro-magnetics, CAD tools for mixed-signal and RF circuits, communication theory and atmospheric microwave propagation. A particular strength of the group is its interaction with industry through collaborative research and consultancy.
5.1 Research in the RF Engineering and Communication Laboratory, led by Dariush Mirshekar, concerns the spectral domain technique for microwave integrated circuit analysis and design. This technique forms the core of commercial CAD tools, e.g. Sonnet (USA) and Linmic (Germany), used extensively for the design of microwave integrated circuits. EPSRC/BT projects have enabled extension of the approach to solve the complex scattering problems in antennas, MMICs, and the electromagnetic detection of flaws in metals. A major new area of study, RF filter miniaturisation for future mobile systems, funded through EPSRC (ROPA) and Nokia, has led to a patent application. Ravi Mazumdar has developed fundamental theory for the performance analysis of Quality of Service in broadband networks, a parameter of great importance in network design. One publication on this topic was a finalist for best paper award at the IEEE Infocom98 Conf., San Francisco, USA.
5.2 The Design Automation Laboratory, led by Rob Massara, focuses on novel CAD tools and environments for use in the synthesis of high-performance analogue and mixed-signal integrated circuits (ICs) in mobile communication devices. The laboratory works closely with industry. An important example has been the EPSRC project on the development of an artificial-intelligence-based silicon-level layout tool involved close collaboration with Fujitsu Microelectronics (UK) Ltd. The work provided a pioneering study into the automation of analogue IC layout, resulting in a paper awarded the IEE’s 1997 Ambrose Fleming Premium. Fujitsu now fully funds a further major research project. Another EPSRC collaborative project involved the University of Central England, Ericsson and Cadence. This addressed the architectural-level design analogue ICs and produced a novel multi-level approach to circuit and system optimisation; this was rated a ‘Very Significant Contribution’ by EPSRC.
5.3 The Propagation Laboratory, led by Anthony Holt and David Bebbington, studies electromagnetic scattering and propagation, especially applied to weather monitoring. The Laboratory has participated in two major EU projects during the review period: DARTH (for which Anthony Holt was coordinator) and EuroTRMM. A particular achievement has been the analytical formalism for polarimetric synthetic aperture radar (SAR) systems in remote sensing. This work has resulted in a request by the Office of Naval Research for a monograph. The use of dual-wavelength fixed microwave links for measurement of path-averaged rainfall is currently being tested in the field with NERC/Industry support. This is being extended under a new EU project (MANTISSA) to mountain valleys liable to flash flooding. The propagation expertise has been successfully applied to understanding polarization effects in long-haul optical fibre links enabling the characterisation of fibre twist from the backscattered signal (J. Opt. Soc. of America, Dec 2000) .
5.4 Future Plans: In the RF and CAD areas emphasis is on enhancing channel performance and spectrum use, together with greater integration and miniaturisation. The focus is on compact RF filters, topologies and resonators with the aim of size reduction and on multi-frequency antennas for future mobile systems. In the Design Automation Laboratory the increasing complexity of circuits requires novel circuit design and layout automation, enabling convergence with the RF Engineering and Communication Laboratory which provides the techniques to analyse and optimise layouts. In the Propagation Laboratory activities will focus on the integration of radar and numerical weather predictors with remote sensing observations to build a more accurate meteorological model.
Copyright 2002 - HEFCE, SHEFC, ELWa, DEL
Last updated 17 October 2003