David Heatley

David Heatley
University of Suffolk | UC Suffolk · Engineering Arts Science & Technology (EAST)

PhD, MIET, C.Eng

About

82
Publications
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624
Citations

Publications

Publications (82)
Article
The need and drive for sustainable development have never been greater. This creates demand for radical ways to improve efficiency and resource productivity. This paper describes how integrating the Internet of Things (IoT), Big Data and Cloud computing creates a recipe for driving sustainable development and growth. Issues and challenges associate...
Patent
Full-text available
A system for use in installation of blown fiber for detecting a signal indicative of presence of at least one of a gas flow or an optical fiber at a remote location, comprising a gas vibration detector configured to acoustically couple with an installation duct through which the signal can travel after its generation at the remote location, and a p...
Patent
Full-text available
A device for use with a conduit having a first conduit end and a conduit second end, into which conduit a cable can be installed using a flow of air into the first conduit end, the device being suitable for confirming that the air is flowing out from the second conduit end. In an embodiment, the device includes a housing, means to enable connection...
Conference Paper
Full-text available
Like many others we have found most microCT software excellent for analytical work on both micro and nano-CT scans but less capable for real-time 3-D image reconstructions. Many users therefore resort to using 3rd party 3D viewing software. However that approach can incur prohibitively high per-user licence costs and the software may not be as user...
Conference Paper
Full-text available
Designed to run on a standard laptop or desktop computer, disect delivers a highly cost effective viewing solution for radiology images that can be operated anywhere and utilises the existing IT infrastructure. When run on our bespoke workstation disect delivers the ultimate viewing experience. It is perfectly suited to in-theatre procedures, singl...
Conference Paper
Full-text available
Micro-CT scanning is widely used, particularly in medicine, but has rarely been applied to insects. The technique has great potential for providing fine-resolution images of the internal organs of living specimens. We have established the technique in an entomological context using young adult male desert locusts, Schistocerca gregaria. We chose th...
Chapter
Look around today and you will see numerous examples of pervasive information. These range from the popular pastime of ‘Googling on the net’, which is highly informal and (in principle) open to everyone, through to dedicated search engines and databases with password protected access that support major organisations in specialist closed application...
Conference Paper
Full-text available
This paper discusses the results obtained from a sensor network installed in a person’s home as part of a twelve month Telecare trial. The aim of the trial was to unobtrusively collect data to detect changes in a person’s daily activity (washing, eating, watching television etc.) around a home, using a low power/cost sensor network. A number of dif...
Conference Paper
Full-text available
This Paper defines and explains ‘Telecare in the Home’. It enumerates the number of people in the UK likely to need such a service and the potential financial savings from the Healthcare Budget made possible by this modern technology. The successive Generations of Telecare (1st, 2nd and 3rd) are explained and demonstrated. Detailed examples in curr...
Conference Paper
Full-text available
Radiology departments in many parts of Africa cannot afford to purchase expensive PACS systems. One of us (BAS) is a South African Radiologist currently working in the UK but involved in the African Organisation for Research and Training in Cancer (AORTIC) whose aim is to promote cancer awareness throughout Africa. BAS hopes to make a meaningful ra...
Conference Paper
Full-text available
ABSTRACT: This paper describes a new DICOM viewing system designed around a laptop/desktop computer which can be operated anywhere and can readily interconnect clinicians at different locations. The system delivers a potentially cost effective solution through its simple yet high performance implementation, and by exploiting the existing IT facilit...
Conference Paper
Full-text available
This paper describes a new DICOM viewing system designed around a laptop/desktop computer which can be operated anywhere and can readily interconnect clinicians at different locations. The system delivers a potentially cost effective solution through its simple yet high performance implementation, and by exploiting the existing IT facilities availa...
Chapter
The inescapable fact that people are living longer today than ever before means that the number of elderly people needing care or medical treatment has never been higher. In response to this there is a growing trend to place the elderly and infirm in residential homes or in sheltered accommodation, where they live in a protective environment while...
Conference Paper
Full-text available
The ability to remotely monitor the well-being of individuals is fundamental to the well-being demonstrator being developed within the NWTM (Next Wave Technologies & Markets) Care in the Community Centre, details of which are described elsewhere in these conference proceedings. A variety of new sensing methodologies are being developed and evaluate...
Conference Paper
Full-text available
Our group previously presented the development and trials of a laptop-based 3D DICOM viewer for single-site MDT cancer meetings where high-end viewing facilities are unavailable (Gut 2004 Suppl III A79). We showed that a suitable low-cost laptop, running our software, reproduces the image quality and 3D manipulation features of high-end workstation...
Article
Full-text available
Continuous monitoring of well being is one of a number of new schemes under development that promise to reduce the UK's health care bill and ease the burden on carers and support organisations. Fundamental to its widespread adoption is the deployment of low-cost sensor networks in residential, sheltered and community settings. These networks must b...
Conference Paper
Full-text available
With an ageing population, a growing shortage of care workers and rising care costs, tele-care is becoming increasingly important as an effective means of managing these trends and maintaining a quality of service. Of particular interest is the continuous monitoring of peoples’ well being in their normal setting, from which the onset of ill health...
Article
Full-text available
In the paper “Tele-endoscopy: influence of data compression, bandwidth and simulated impairments on the usability of real time digital video endoscopy transmissions for medical applications” by T Rabenstein et al, published in the September 2002 issue of Endoscopy (Vol 34, pp 703-710), the authors present their view that tele-endoscopy (i.e., conve...
Conference Paper
Picture a dealing room in any of the world's finance centres in which dealers conduct their business at desks that intelligently work 'with' them rather than merely 'for' them. Desks that give dealers and the finance institutions they represent a vital business edge. Desks that integrate the voice, data and video technologies and services that deal...
Conference Paper
Full-text available
Optical wireless has languished in the shadow of radio primarily because of its limited range, despite the promise of a significantly greater bandwidth. There has been much development on radio systems and the new Bluetooth architecture holds much promise. This, coupled with the fact that the capacity of commercial optical wireless systems has not...
Article
Full-text available
In this article we present a broad review of the field of Optical Wireless, from early experiments through to the high performance systems of today. Emphasis is placed on understanding the benefits and limitations of optical wireless, all of which ultimately define the applications. A variety of systems are examined, each incorporating a different...
Article
Full-text available
We present a broad review of the optical wireless field, from early experiments through to today's high-performance systems. Emphasis is placed on understanding the benefits and limitations of optical wireless, all of which ultimately define the applications. A variety of systems are examined, each incorporating a different technological solution t...
Conference Paper
Full-text available
Today's microwave line-of-sight systems benefit from a century of advances following the landmark achievements of Marconi and his peers. Consequently they deliver a performance close to the theoretical maximum and are now in widespread use. Although the history of optical line-of-sight systems spans a similar period (e.g., Alexander Graham Bell's p...
Article
Full-text available
Picture a dealing room in any of the world''s finance centres in which dealers conduct their business at desks that intelligently work with them rather than merely for them. Desks that give dealers and the finance institutions they represent a vital business edge. Desks that integrate the voice, data and video technologies and services that dealers...
Article
This paper considers the design and performance of a tuned front-end receiver for use in a free-space optical video systems system. The use of front-end tuning is advantageous as it enables large area optical collectors to be employed, it reduces receiver noise and it eliminates the problematic L.F. emissions that emanate from typical lighting sour...
Article
Full-text available
The convergence of computing and telecommunications is changing lives, mostly those of the young. New developments will benefit everyone and see intuitive interfaces allowing anyone to fully reap the benefits of IT. For the immobile, travel substitution will make it easier to shop, see friends, consult a doctor or bank manager, or simply keep menta...
Article
Full-text available
The first world is moving towards higher concentrations of older people and fewer carers. Just 20 years ago there were 30 potential carers for each person needing care. By 2010 this will have reduced to only three potential carers. National economies will not be able to sustain the levels of care enjoyed to date and a potential crisis looms. Fortun...
Article
Twenty years ago, there were thirty potential carers for each person needing care. By 2010, the will be reduced to only three potential carers. National economies will not be able to sustain the levels of care enjoyed to date and a potential crisis forecast has changed. In particular, these advances have spawned the means of caring through informat...
Chapter
Optical fibre transmission systems have now largely replaced their copper forebears. This has been achieved by overlaying the copper pair and coaxial systems with optical fibre, thereby realising vastly increased repeater spacing, smaller cable size, increased capacity and reliability, and orders of magnitude reduction in costs. Despite these radic...
Book
Telecommunications today is in the midst of far-reaching changes due to rapid development of new technologies, services and social evolution. This is the first book to model the process of change in telecommunications, including all of the relevant factors. The approach is practical and responsible, based on hard facts and tested models. It deals w...
Article
The optical-fibre amplifier is geared on changing telecommunications on a broadrange of operational and application fronts. Often cited as the major advances of this technology include simplifications in repeater hardware, the opening up of the latent fibre bandwidth, and the enormous increase in cable capacity. The optical-fibre amplifier will bri...
Article
Full-text available
The optical fiber amplifier will bring about network transparency and reductions in manning levels, interface problems, software and operating costs, while improving reliability and performance. It is in the area of economics that optical transparency affords a unique opportunity. What is generally not recognized is that there is a raft of hidden b...
Article
Full-text available
The stage is now conducive for a paradigm shift in telecommunications. For numerous countries, new technologies are offering the prospect of realizing an all-optical communications between all users, for instance, optical transparency. The optical transparent network will soon be underway as long distance undersea and inland cable systems containin...
Article
Full-text available
Optical fibre has replaced copper on point-to-point long distance lines on a one-for-one basis, with system and network designs scaled directly from our copper experience. However, fibre has introduced radical changes in almost every system parameter including repeater spacings, power feed requirements, EMC, human interdiction, multiplex equipment,...
Article
Full-text available
BTTJ Special Issue on “Future Telecommunication Systems & Networks”. Extract of the foreword by the editors, Peter Cochrane and David Heatley. Since the invention of the electric telegraph, generations of engineers have concerned themselves with the modelling of systems and networks. Their goal has been, and continues to be, the gaining of fundam...
Chapter
Optical fibre transmission systems offer a number of important advantages over metallic cable systems, advantages which are vital to present day telecommunication networks. For example, the ~40,000GHz bandwidth of a typical optical fibre is at least 4 orders of magnitude broader than that of a good quality coaxial cable. This is clearly a major ben...
Conference Paper
Full-text available
A system for mapping, in real time, the three dimensional path of a medical endoscope is described. The system, which may be used with existing endoscopes, generates weak magnetic fields (~10 μT) within the patient which are detected in the endoscope by an array of miniature magnetic field sensors. The signals from the sensors are processed by a sp...
Conference Paper
Full-text available
Telecommunications in the UK is almost unique in the Western World with 100% availability of ISDN service, digital transmission and switching of all trunk circuits and direct customer dialling facilities to all regions of the UK and over 129 countries. British industry today enjoys access to more wide band (2 Mbit/s and above) circuits than the res...
Article
Full-text available
Optical technology is already the dominant carrier of global information. It is also central to the realisation of future networks which have the capabilities demanded by society. For example, essentially unlimited bandwidth to convey services of any kind, full transparency that allows terminal-only upgrades in capacity, and flexible routeing of ch...
Conference Paper
Full-text available
The widespread introduction of optical fibre transmission, digital switching, and the ISDN, has opened a route to new telecoms services which exploit combinations of voice, image, text and data for telemedicine applications now possible over switched circuits at acceptable quality and cost. However, the full potential of the low cost bandwidth made...
Conference Paper
Full-text available
The authors describe a selection of telepresence systems and services that are currently being investigated and developed. Each can be fully realised with present day technology, and most can operate, albeit at a reduced service level, over the existing network. The authors draw attention to their potential and likely importance in future telecommu...
Article
A novel system is described which images in three dimensions, the total configuration of a colonoscope without the use of conventional radiological techniques. A low intensity magnetic field is used in conjunction with a miniature inductive sensor. The system intrinsically safe and it is potentially inexpensive and capable of being used in a normal...
Conference Paper
This article compares the performance of several optical receiver configurations optimized for 10 GHz bandwidth: (1) PIN/lossy matched pre-amplifier; (2) feedback amplifier; and (3) distributed pre-amplifier. For this purpose a new technique was developed in order to perform circuit optimization taking into account all the important circuit charact...
Article
Today we see a telecommunications network transformed by optical fibre. Over 55% of all international communication is now carried by fibre, and in the UK over 80% of all long lines traffic. Operating costs have been reduced by orders of magnitude since the 1970's with bit rates up to 2.4Gbit/s and an expectation of 10Gbit/s within the next 10 year...
Conference Paper
The choice of modulation format on the optical carrier in a fibre communication system is a principal factor in realising a high performance bandwidth-efficient system at an acceptable cost. In this context Pulse Time Modulation (PTM) techniques represent an attractive alternative to purely digital or analogue methods. This paper reviews theoretica...
Conference Paper
One of the most impressive features of optical fibre system development is the fact that in a period of less than 15 years they have emerged to become the dominant global bit transport mechanism. For example, the UK currently has >80% of all its long haul traffic conveyed by fibre systems, whilst internationally the total is now >55%. The prime rea...
Conference Paper
Optical fibre is now the dominant transport medium for long distance telecommunications. In the UK over 80% of all long distance traffic is conveyed by fibre systems, while internationally the total exceeds 55% (Fig 1). Optical fibre has also significantly reduced the number of regenerators required on terrestrial and undersea cable routes, and in...
Conference Paper
Exploiting the features of optical fibres to directly supercede the established copper cable network of point-to-point links has already realised operational cost savings well beyond the initial investment for the new plant. The paper considers what further gains may yet be realised with the introduction of more economic multiplexing schemes, optic...
Article
A pin-HEMT receiver for multi-Gbit/s heterodyne detection systems is described. The receiver uses discrete, packaged devices and a simple hybrid construction to achieve a bandwidth of 10 GHz and a noise level not exceeding 13.5 pA/ square root (Hz). A sensitivity of -32.5 dBm is demonstrated at 4 Gbit/s using CP-FSK over 100 km of conventional sing...
Article
The last decade has witnessed the progressive replacement and capacity upgrade of copper cable point-to-point links by optical fibre systems. Repeater spacings have increased more than ten-fold; traffic demand has increased to absorb the available capacity; transmission costs have fallen and very significant savings have been achieved. Optical tech...
Conference Paper
Optical fibre systems which operate in the multi-Gbit/s regime or utilise microwave subcarriers require low noise receivers with bandwidths spanning many GHz. Such receivers may be realised with hybrid circuits using discrete devices mounted on microstrip or coplanar substrates. The paper shows that the microstrip approach takes advantage of a broa...
Conference Paper
Progress on coherent optical communication systems is reviewed with particular reference to their readiness for deployment in the field. The basic technology is discussed, together with the state of development of key system components. Performance comparisons are drawn between coherent and intensity modulated systems employing optical preamplifier...
Conference Paper
A broadband optical receiver suitable for coherent system applications is described. The simple hybrid construction utilises commercial devices throughout and comprises a single InGaAs PIN followed by a low noise HEMT amplifier in a high impedance configuration. The measured 3 dB bandwidth is 10 GHz, with substantially flat magnitude and group dela...
Conference Paper
A broadband optical receiver using discrete commercial devices is described. The design comprises an InGaAs PIN detector followed by a three stage, high impedance amplifier employing HEMT’s interconnected by impedance matching networks. The measured 3dB bandwidth is 10GHz which is suitable for a variety of broadband optical transmission application...
Conference Paper
A packaged semiconductor laser pre-amplified receiver (LaserPIN) has been developed for use in long haul and wavelength selective systems at a data rate of 2.4Gbit/s. This receiver has two major advantages over other types of receiver at high data rates. First, the receiver has a sensitivity of -36dBm at 2.4Gbit/s (BER = 10^-9 at 2^7-1 PRBS) which...
Article
The sensitivity of an ultra-broadband optical receiver, built using discrete commercial components, was improved by 13.4 dB giving -32.4 dBm at 5 Gbit/s, by employing an erbium doped fibre preamplifier. Results also showed a maximum sensitivity variation of 2.1 dB over a 30 nm wavelength range.
Article
Full-text available
An ultra-broadband optical receiver using discrete, commercial devices is described. The design comprises a GaInAs PIN detector followed by a three-stage, high-impedance amplifier employing HEMTs interconnected by impedance-matching networks. All devices are mounted on a standard soft substrate. The measured 3 dB bandwidth is nearly 10 GHz, and rec...
Conference Paper
FM subcarrier schemes are shown to give a significant sensitivity advantage over AM subcarrier schemes in optical fibre video transmission systems, however, their channel multiplexing capacity within a given receiver bandwidth is about one third that of the AM schemes. Direct detection FM is shown to give a better sensitivity and channel multiplexi...
Conference Paper
Semiconductor laser preamplified (LA-PIN) optical receivers utilise a PIN receiver and a semiconductor laser preamplifier to achieve better sensitivities and gain bandwidth products than those of APD receivers. This paper compares the performance of a selection of LA-PIN receivers at bit rates up to 8 Gbit/s relative to APD designs
Article
The PTAT-1 transatlantic undersea cable system is due to be laid during the summer of 1989. This paper describes the design and performance of the optical receiver developed and manufactured by British Telecom Research Laboratories (BTRL) for this system.
Thesis
Available from UMI in association with The British Library. Requires signed TDF. This dissertation is primarily concerned with the optical receiver sensitivity achieveable by a broad selection of analogue modulation schemes, each of which is applicable to the distribution of video signals over optical fibres. The receiver sensitivities of certain d...
Article
The development of low loss optical fibre and reliable opto-electronic devices has led in recent years to the installation of a new generation of undersea communication links – optical fibre systems. Compared with their metallic counterparts, optical systems afford significantly greater transmission capacities and repeater spacings, the combined ef...
Conference Paper
The operating principles and performance of waveguide Mach-Zehnder frequency translators suitable for use in coherent optical fibre systems are described. The performance of a coherent optical fibre system transmitting analogue colour video signals and employing a Mach-Zehnder electro-optic waveguide device as a double sideband suppressed carrier f...
Conference Paper
The design and receiver sensitivity of a novel heterodyne detection system is examined for the transmission at baseband of a single analogue colour video signal. By using optical frequency modulation a receiver sensitivity of -70.3dBm is achieved after transmission over 30km of cabled monomode fibre at a wavelength of 1.523um. This is 21.2dB better...
Conference Paper
The receiver sensitivity and wavelength multiplexing properties of heterodyne detection are examined for analogue video transmission using optical amplitude, phase or frequency modulation. Optical frequency modulation gives the greatest theoretical receiver sensitivity at -68.8dBm, with -67.3dBm demonstrated. Optical amplitude modulation gives the...
Article
The design and receiver sensitivity of a heterodyne detection system using analogue optical frequency modulation is examined for the transmission of a single baseband colour video signal. After transmission over 30 km of cabled monomode fibre, receiver sensitivity was measured to be ¿70.3 dBm for a 53 dB unified weighted video SNR.
Article
Full-text available
PFM demodulation which relies on the generation of one pulse per PFM signal period is compared with demodulation which generates two pulses per period. The dual pulse approach is shown to give an SNR advantage of up to 7 dB for the same input conditions, but the two methods give SNRs which converge when used to demodulate FM.
Conference Paper
ASK, FSK and PSK receiver sensitivities using heterodyne detection are compared with direct detection counterparts for single channel video transmission using a PFM sub-carrier. Depending on modulation configuration and IF detection, receiver sensitivities 7-14dB greater than direct detection are predicted, with 8-11dB demonstrated. Optical fibre v...
Article
Analogue video transmission over a tandem connection of optical fibre systems is examined. A simple mathematical model is presented which relates section length and fibre attenuation to route length and video SNR at the final receiver. The model takes account of any analogue modulation format and applies to direct and coherent detection.
Article
625-line colour video transmission over 61 km of cabled monomode fibre at 1.523 ¿m is reported. PFM with 2-PSK heterodyne detection gives a receiver sensitivity of ¿53.4 dBm at 50 dB video SNR, which is 5.2 dB from the shot noise limit and 8.4 dB better than direct detection. Alternative modulation configurations are discussed.
Conference Paper
Video transmission over optical fibres using Pulse Width, Frequency or Position Modulation is examined. Demodulated video signal-to-noise ratios are compared for an integrating receiver front-end. Pulse Frequency Modulation is shown to display the greatest receiver sensitivity and hence transmission range.
Conference Paper
Optical fibre local networks offer potential for the large scale distribution of visual services to customers, requiring few repeaters between terminal stations. The favoured transmission format is likely to be digital but the high cost of video codecs may prohibit its use in the local network during early development phases. An alternative scheme...
Conference Paper
A versatile optical communication system has been developed at British Telecom Research Laboratories which offers a transparent baseband channel capable of supporting analogue video or digital data signals, or some combination of both. The system employs Pulse Frequency Modulation to provide a transparent channel of 10MHz bandwidth and is capable o...
Article
Unrepeatered transmission of 625-line colour video signals using PFM over monomode optical fibre is reported. The results show that a received video signal/noise ratio better than 53 dB unified weighted was achieved over 68 km of fibre at 1.3 ¿m and 102 km at 1.52 ¿m.
Conference Paper
Market research has yet to specify the services that the Post Office needs to provide to customers in the business and domestic sectors of the community by the end of the century, and the rapid advances of technology make forecasts uncertain. Nevertheless, there are indications of the range of services that could be offered. Telephony, text, facsim...
Conference Paper
The British Post Office has been studying ways by which broadband services such as vision with associated sound together with high fidelity audio, graphics, text and conventional telephony can be transmitted to customers by means of optical fibre. In terms of general application it is likely that the business sector would place emphasis on telephon...
Conference Paper
This paper outlines studies made by the British Post Office Research Centre for the introduction of optical fibre systems into the local distribution network. Two aspects of development are considered. The first concerns the use of simple but high performance, low bit rate digital systems for multi-channel telephony applications between local excha...

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