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Corporate optical backbone network


The overall objective of the project is to establish the architectural and technological concepts for the next generation of high-performance corporate networks. These should take advantage of new and evolving photonic technologies and existing switching/multiplexing/routing techniques, in particular ATM, SDH and IP. Corporate Networks are networks formed by the interconnection of Customer Premises Networks (CPNs) either via a public wide area network (WAN) or via leased lines from a private network provider. They may cover a wide geographical area, including pan-European and intercontinental dimensions.

In the campus backbone, the objective is to use multi-channel photonic technologies, realised with space-division multiplexing (SDM) and wavelength-division multiplexing (WDM) techniques. This approach will ensure a optimal usage of fibre capacity and enhanced network flexibility, while creating new opportunities for control and management. These high-speed CPNs will then be interconnected to, and across, the public network.

A key advantage of these multi-channel techniques is that they will allow a 'Clear Channel' connectivity, which is essentially a bitrate, protocol and largely distance independent transmission technique, and which allows any proprietary or standard data formats e.g. ATM, SDH, IP, Fibre Channel Standard (FCS), etc. to be carried.

Component development is aimed at achieving significant reductions in projected hardware and maintenance costs, since cost is of paramount importance for the adoption of photonic technologies in the CPN environment.

The system and component concepts developed in the project will be verified in a field trial.
Since the start of the project an economical network architecture has been developed, including the corresponding node structures, their components, and the control and management system. First versions of the key technological components have been fabricated, e.g., planar WDM multiplexers, SDM laser arrays and optical switches. Based on these components, the nodes for the initial demonstrator network are in the process of being integrated. The work so far provides the project partners with a basic understanding of the critical issues such as ring power budgets, component performance and cost. This knowledge will guide the optimisation of the system and components for the final demonstrator and
provides valuable input for the final techno-economic studies.
Ultimately, the results of the project will be a solid understanding of the technical and economical positioning of photonic technologies in corporate networks, including an understanding of the synergies and trade-offs between SDM and WDM, and of the issues related to interconnection with public networks.
Expected Impact
The introduction of photonic technologies in corporate networks will provide indispensable performance improvements for the future. The components work will give the partners an ability to provide the low-cost components necessary.

Main contributions to the programme objectives:
Main deliverables
WDM metropolitan optical ring network demonstrator, implementing OADM and OXC developed by the project.
Contribution to the programme
Development of advanced telecom technology in the context of the communications needs of major corporations.
Technical Approach
The project is undertaken through four technical work packages:
WP1 develops and specifies the overall system design including hardware, control and management. Comparisons with alternative solutions and the issues of cost and private/public network interface are studied.
WP2 develops and integrates the 12-channel opto-electronic subsystems for the demonstrator, i.e. the opto-electronic parts for the WDM, SDM and the common WDM/SDM nodes.
WP3 develops the key components for the demonstrator, specifically SDM laser arrays, WDM lasers, photodetector arrays, switch arrays, custom ICs (in particular bit-rate programmable 3R chips), planar waveguide WDM (de)multiplexers and add/drop filters.
WP4 integrates and tests the demonstrator using the subsystems developed in WP2, the control and management developed in WP1 and commercial subsystems for user access. WP4 will implement the field trial and its evaluation through applications trials.
Summary of Trial
The field trial consists of the creation of two CPNs, one at GEC Hirst and the other at BT Laboratories interconnected via a futuristic PNO core network, the London East Anglian Network (LEANet).

Each CPN will consist of 2 rings: a WDM add/drop ring for the network nodes separated more than about 2km and an SDM add/drop ring for nodes closer together. Both ring types are interconnected via a common add/drop cross-connect node.

Access to the COBNET photonic transport network is via electronic access technologies such as ATM/SDH, IP, FCS or any other proprietary protocol.

Applications suitable for a business environment will be identified Eg. using broadband multimedia, video-on-demand and conferencing, and be incorporated in the demonstrator in order to load the network with realistic traffic.
Key Issues
Key issues for the suitability of photonic SDM and WDM techniques for future corporate networks are cost, and the interoperability with future public networks. Key issues for the field trial are the availability of a compatible photonic public network and the availability of suitable applications.

Funding Scheme

CSC - Cost-sharing contracts


IBM France
Le Plan Du Bois
06610 La Gaude

Participants (12)

British Telecommunications plc
United Kingdom
Compagnie IBM France SA
Raemistrasse 101
Ecole Polytechnique Fédérale de Lausanne
GEC-Marconi Materials Technology
United Kingdom
GPT Limited
United Kingdom
IBM Corporation Research Division
Piazziale Zavattari 12
20149 Milano
Nortel Technology
United Kingdom
Wittelsbacher Platz 2
Siemens Atea
August Schmidt Strasse 4