Application-level Programmable Internetwork Environment

Future requirements for a broadband multimedia network are likely to be very different from those today. Three key changes are identified — rapid introduction of new services, dynamic customisation of services by clients, and minimal management overhead. Application-layer active networking, perhaps the most pragmatic and immediately realisable active network proposal, is a potential solution to all three. In the 'Management of Multiservice Networks' project, BT and its academic partners are developing key middleware components required to support application-layer active networking.     

Fixed Access Network Technologies

Telecommunications operators around the world are facing flat or declining revenues in their traditional services and expanding commercial and political demand for ubiquitous broadband access. This creates two opposing pressures — to cut costs radically and to invest heavily in new technology. The traditional fixed access network is central to both of these issues and this paper describes the technology that is being developed to meet these challenges.     

Distributed objects and object databases

Due to the on-going shift from centralised to decentralised computing and a general trend towards the globalisation of commercial, economic and social activities, the information systems community has been faced with strong demands to develop distributed information systems (DISs) that span wide geographical areas. Three technologies have had significant impact on the new generation of DISs — distributed object technology, object database technology and Web technology. The paper examines two of these — DOT and ODBT. Each has advantages over the other, but more importantly they complement each other, and ways of using them together are explored.     

Interactive collaborative media environments

Virtual reality (VR) provides a revolutionary interface between man and machine. However, present display and interface peripherals limit the potential of virtual environments within many activities or scenarios. Mainstream immersive VR is centred on head mounted display (HMD) based solutions in which the user is isolated from their surrounding environment. The occlusion of real world interaction within such systems imposes unnatural social and physical constraints on the user. Media environments can be classified as one form of enhanced reality based around immersive physical spaces intensified for effective collaborative activities. Current research is directed at three forms of enhanced spaces — immersive projected displays, interactive video environments, and immersive desktop environments. While HMD and desktop VR facilitates many collaborative tasks, the synthesis of real and virtual realities within a life-size environment offers distinct advantages within other applications. This paper introduces the concepts behind media environments, reviews current research and presents applications being explored at BT Laboratories.     

AntiGroupWare and Second Messenger

Decision-making in groups has great potential due to the possibilities for pooling ideas and sharing knowledge, but also great drawbacks due to the social pressures inherent in these situations that can limit free exchange of these ideas and knowledge. This paper presents two technology-based approaches to improving group decision-making, Second Messenger and AntiGroupWare. Second Messenger — a system that encourages groups to change their interaction styles during meetings — is designed to improve meetings, while AntiGroupWare — an on-line polling system that allows companies to gather information through flexible, iterative polling of its employees — is designed to avoid them altogether.     

Advanced Multi-Objective Evolutionary Algorithms Applied to Two Problems in Telecommunications

Most research in optimisation is aimed at single objective problems, where the aim is to find a solution which maximises or minimises a single quality measure. However, as in nature, many problems in telecommunications are fundamentally multi-objective, particularly where the issues involved are related to quality of service, or cost/reliability trade-offs. There has been considerable research in multi-objective optimisation, but, until recently, the most prominently known multi-objective optimisation algorithms have tended to be rather slow, and there has been no universally accepted way to properly compare the performance of different methods. Here, we describe two evolutionary computation-based multi-objective optimisation methods which have recently been shown both to be considerably faster than the classical set of such methods, and to outperform existing methods on a wide range of test problems. We focus on two application areas in telecommunications — the adaptive distributed database management problem, and the offline-routeing problem. The speed and quality of these new methods suggest that their adoption in live applications of these and other telecommunications-related problems is feasible.     

One-multiplier adaptive lattice algorithm for recursive filters

The formulation of one-multiplier lattice structures of the Gray-Markel type forinfinite impulse response filters is reviewed. Several special cases of this formulation — including the well-known Gray-Markel normalized lattice—are presented as scaled polynomial versions of the two-multiplier lattice. A new adaptive algorithm is presented for updating the parameters of one-multiplier lattice structured recursive filters. The LMS-based algorithm requires fewer computations than earlier reported algorithms [1]–[4].The research reported here was conducted with funds administered by the Naval Postgraduate School research council.     

Personal Virtual Humans — Inhabiting the TalkZone and beyond

One of the fundamental goals of graphics has always been to visually create a three-dimensional person that is indistinguishable from a real person. This target is only slightly short of being reached, as was demonstrated when Columbia Pictures released Final Fantasy in 2001, an animated science fiction film with high-definition emotive characters. Through what has been a cultural and technological convergence, we are now starting to see software tools and techniques that can generate life-like characters while not sacrificing the human judgement and artistic skills that are needed in character animation. Computer games, films, and the Internet are now starting to use virtual humans, which as our conclusion will show will become more realistic. However, a new challenge has been set — people now do not want to just play a computer game with a visually realistic character, or see a television programme with a vivid computer generated character — they want to see themselves in that computer game or film. The future is towards individuals having their own virtual clones, which they can utilise in computer-generated worlds an applications. This paper will discuss the advantages of having a personal computer-generated character, and also describe several systems that BTexact Technologies have successfully developed and deployed to generate them, as well as some of the applications for which they can be used. The paper will finish by glimpsing into the future of what we can expect to see in the next few years, with the advent of this new exciting technology.     

Loss and Noise Characteristics of Microwave Direct Modulated Optical Links

Loss and noise figure of optical links transmitting microwave signals —e.g. for remote antennas in wireless communications — are dealt with.Conditions are rather general and include arbitrary matching conditions, shotnoise, and laser relative intensity noise. Specific and somewhat surprisingcharacteristics are derived. Among others, it is shown, that — likepassive, purely microwave systems — noise figure is not proportional toelectrical loss and it can be even lower than loss itself. Optical powershould be as low as possible — this limit is mainly determined by therequired dynamic range of the system. Loss and noise figure were measured inan experimental setup. Results of the measurements proved the theoreticalfindings rather well. Preliminary results on the transmission of 32TCM signalsover the link are briefly presented.     

Terminal Developments and Their Media Capabilities

Building a 3G network is like building a PC — just because you buy the fastest elements, it does not mean that you get the most efficient PC. It is important to integrate and optimise all the elements correctly in order to achieve the best performance. The 3G network is the same — each element of the solution is important. This paper focuses on one aspect of the complete 3G solution, i.e. the handsets/mobile devices that give the customer a gateway into the network services. Key elements of the mobile device that provide the best user experience are identified and briefly discussed and an insight is provided into the direction of the future technology.     

Everything Over IP — an Overview of the Strategic Change in Voice and Data Networks

This paper investigates the changes that are required in networking technology for 'everything over IP' to become a reality. Initially the changes that are taking place in the telecommunications industry are reviewed. This review ranges from a discussion about the companies installing massive global IP networks to the emergence of novel routeing technologies, e.g. multi-protocol label switching (MPLS) and terabit router technologies. The role of existing telecommunications operators is then discussed, along with the reasons why they are developing interworking and intelligence layers based on distributed computing principles to support all their networks — mobile, fixed, broadband and IP.     

Dielectric integrity of thin thermal oxides on silicon

The role of silicon dioxide layers in microelectronics and the importance of their integrity are undisputable. From passivating coatings and masking layers for diffusion to ultra-thin tunneling films — all the silicon technology could not exist without silicon dioxide. This review deals with some aspects of the integrity of thin silicon dioxide films for VLSI applications. The problems of dielectric strength and wear-out are considered from the point of view of their mechanisms, models, oxide processing dependence, testing, and measuring. A brief presentation of statistical approaches commonly applied to reliability topics is also included.     

Interconnect Geometry Optimization Using Modular Artificial Neural Networks

This paper describes a methodology for crosstalk prediction and minimization in interconnect wiring using artificial neural networks. Neural networks are used as parameterized models to achieve two important mappings. The first—forward map—maps the geometric and material parameters of interconnects (for example width, length, separation, conductivity, dielectric constant k) to equivalent electrical parameters (for example, R,L,C,G). Such a relationship would normally require quasi-TEM solutions of EM problems. The second—reverse map—is the reverse of the first mapping equivalent electrical parameters to interconnect geometric and material parameters. The crosstalk minimization approach proposed involves topological decomposition of interconnect into standard cells—portions of interconnect referred to as wirecells—and the derivation of the above two mappings for each wirecell. Crosstalk is iteratively minimized in the domain of SPICE circuit parameters and the resulting optimized SPICE equivalent circuit mapped back into the wirecell geometric domain using the reverse neural net mapping. For computational efficiency and high accuracy, the technique initially establishes a library of re-usable neural wirecell models using a field solver coupled with a circuit simulator and a neural network multi-paradigm prototyping system. The approach offers two important advantages. First, the simultaneous effect of multiple non-correlated geometric and material wirecell characteristics on crosstalk can be accurately computed and crosstalk minimized by iterative modification of interconnect geometry and material characteristics. Second, the approach produces—as a by-product—system level contours of equicoupling called isocouples to guide design activities such as placement and route. Crosstalk prediction and minimization results are presented for a high performance operational transconductance amplifier in which reduction in crosstalk by variation of interconnect layout geometry resulted in a 41% increase in gain.     

Desktop conversations — the future of multimedia conferencing

Both the recent explosion of interest in the Internet and the ongoing development of video-on-demand services have focused attention on the retrieval and delivery aspects of telecommunications networks. Yet the telephony network is fundamentally based on a much more basic human need — two-way communication. In fact, people normally communicate using conversation — interactive speech plus additional information in the form of non-verbal cues like body language.The underlying technologies and standards to enable the easy exchange of information in a conversational way are now converging — which brings together the fields of conferencing, multimedia, and telephony into a unified whole. This could well be the catalyst to turning data communications into the dominant conversational medium of the future.This paper looks at the ways that the desktop may soon rival the telephone as the natural route for carrying out a media-rich conversation with a remotely located person, and focuses on one example of a desktop conferencing application — Passepartout.     

Electronic Commerce Back-office Integration

This paper discusses some of the lessons learned from integrating two customers' back-office systems with a pilot BT-managed business-to-business electronic catalogue service. An overview of the two pilot implementations describes the experience and offers some important lessons learned.Three types of lesson learned are presented in this paper — firstly based on the design and implementation of both pilot catalogue systems, secondly about the importance of proper site security for Internet applications, and lastly about relationship building and information gathering — in the hope that others will be able to use this information in helping to avoid some of the mistakes and pitfalls encountered in this work. As George Santayana once said: 'Those who cannot remember the past are condemned to repeat it.'     

Internal and External Dimensions of Computer Self-Efficacy: An Empirical Examination

Researchers have found computer self-efficacy (CSE) to be important to technology adoption. Past research has treated CSE as a unitary concept. This paper proposes that CSE has two dimensions—internal and external. The idea that CSE has internal and external dimensions is based on attribution theory, which identifies the human tendency to attribute events to causes that are either internal or external to the self. The internal CSE dimension focuses on how individuals perceive their capacity to use computers independently (i.e., without help). The external CSE dimension focuses on how individuals perceive their ability to use computers with human assistance and other forms of external support. Using items drawn from the Compeau and Higgins’ CSE instrument, this paper examines each dimension's relationship to computer anxiety and perceived ease-of-use of information technology. The paper also reports on six studies that examine this proposal, and contributes to the literature by identifying two distinct CSE dimensions, developing theory-driven explanations for their relationships to constructs within the CSE's nomological network, and empirically establishing that they have distinct effects. Implications for research and practice are presented.      

Systems with two dual failure modes — A survey

A survey of the research done on reliability of systems exhibiting two dual modes of failure, which are often called open and short, is given. Particular attention is paid to books and papers published after the 1977 review by Dhillon [32]. The present survey discusses the different terminology and approaches that appear in the literature and covers results concerning mainly the following topics: the optimal structure of the system, the optimal allocation of units, Markov and semi-Markov models of systems with repairable units and investigation of the structures of particular importance — series-parallel, k-out-of-n:G and logic circuits.     

Modeling a Mobile Cellular Network Using a Discrete-Event Simulator

In this paper we introduce a discrete-event-based simulation technology suitable to model cellular mobile radio systems with respect to their dynamic behavior. The latter results in the need for simulation tools which support mutable system configurations. The problems encountered when modeling mutable system configurations using conventional discrete-event simulators are discussed. In order to show a possible solution to this problem we introduce configuration events and configuration objects into the theory of discrete-event simulations. We demonstrate how configuration objects can be implemented in a discrete-event simulator using a dynamic map-function, hereby extending a definition of higher order functions. We apply the configuration objects in a Multiple Layer Model for modeling an entire mobile cellular radio network in a discrete-event simulator as an application for the extended theory. In this model we use the configuration objects to change the network's configuration during runtime. We show that this solution—combined with an object-oriented software design and, possibly, a visual programming language—is a powerful tool for the simulation of the dynamic aspects of mobile cellular radio networks. The software technology presented will be applied by the German cellular network operator Mannesmann Mobilfunk to model dynamic features applicable to the radio resource management of mobile radio networks and to access their performance by simulation.