Progress in optical communications has historically succeeded in providing ever greater levels of communications capacity
at continually reducing costs. Innovations have led to growing applications for photonics in datacommunication standards,
such as the Ethernet standards.
As data bit rates have increased, demands on the physical layer have become exacting. This has been primarily found in
respect of the limits on the available bandwidth of the transmission media, the laser sources used to generate the optical
signals, the receiver performance levels and the performance of low cost electronics.
Following a review of the current work of the Centre for Photonics Communications, which is now partly based in the William
Gates Building, this seminar will address photonic, electronic and coding strategies now being employed to enhance further
link performance. For example, low cost multimode fibre links using both wavelength division and subcarrier multiplexing
techniques providing 200 Gb/s data rates, and new low cost high speed (10 Gb/s and greater) components will be discussed.
A special reference will be given to the UK PHOTON project which has been active in this area, and also to the impact that
new link technologies are likely to have on new routing and switching systems.
The talk will focus on potential future trends for higher bit rate systems likely to be required in future standards
implementations, and new areas of application for photonics in fixed and wireless computer networks.
New wireless and mobile technologies enable city-scale mixed reality experiences such as historical reenactments,
dramas and games in which participants on the streets interact with characters and objects in a parallel virtual
world. EQUIP is a new software platform (being developed within the EQUATOR IRC) which is designed and engineered
to support the development and deployment of applications such as these, which combine distributed input and output
devices with networked services to create a coordinated experience. A key element of EQUIP is its shared data service,
which combines ideas from tuplespaces, general event systems and collaborative virtual environments. EQUIP has been
used to support a number of projects and experiences, including: unearthing virtual history, city-wide mixed reality gaming,
and virtual co-visiting. This talk describes some of these experiences, the ways in which EQUIP has facilitated them,
and outlines ongoing work. EQUIP is freely available in source form, and currently supports native development and
deployment in both C++ and Java.
A brief review of e-Science demonstrates the central role of data. In today's projects, scientists expend
significant effort integrating data from geographically distributed heterogeneous sources. Our goal is to build
a plug & play collection of components that will greatly facilitate data integration. These components use the
open grid services architecture.
Interesting questions arise about how to automate and optimise data integration. Can we expect to make these
processes trustworthy and will scientists adopt this approach?
Buying a complex product like a financial portfolio, a new kitchen or a round the world trip can be a real
headache. Both customer and agent must engage in complex planning and decision-making, using a variety of information
sources and technologies. Findings from an ethnographic study of face to face consultations showed them to be disjointed,
one-sided and not well supported by information technology. As an alternative approach, we developed a novel arrangement
of multiple displays intended to promote shoulder-to shoulder collaboration using a variety of interlinked representations
and visualizations. The resulting interactional workspace was used by a travel company as part of a large international
trade show attended by the general public. The many consultations that took place between agents and customers were quite
different, proving to be more equitable, open, fluid and congenial. In my talk, I discuss the reasons behind this transformation
and suggest how other kinds of work settings could, likewise, be improved by introducing new forms of interactional workspaces.
The theory of computation, including modern cryptography, was laid down almost seventy
years ago, was implemented within a decade, became commercial within another decade, and
dominated the world's economy half a century later. Quantum information technology is a
fundamentally new way of harnessing nature. It is too early to say how important a way this will
eventually be, but we can reasonably speculate about its impact both on computation and data security.
I will review the basic concepts of quantum information science and describe experimental techniques which
aim to give data processing devices new functionality.
This talk will describe a policy driven role based access control system developed under the
EC PERMIS project. The user's roles, and the policy are stored in X.509 Attribute Certificates.
The policy, written in XML, describes who is trusted to allocate roles to users, and what permissions
each role has. The DTD has been published at XML.org. Access control decisions are made by an Access
Control Decision Function consisting of just three Java methods and a constructor. The decision is made
according to the requested mode of access, the user's trusted roles and the policy. We also have a tool,
the Privilege Allocator, that makes ACs and stores them in an LDAP directory.
Part IB and II (G) Group Project Presentations