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Broadband Local Network Technology

Objective

The objective of the project is to develop a low cost local loop and switch technology which is capable of supporting a range of narrow-band and broadband services in a flexible and efficient manner.
The objective of the project is to develop a low cost local loop and switch technology which is capable of supporting a range of narrowband and broadband services in a flexible and efficient manner. The project is system led and vertically integrated so that the key dependent technologies can be considered in an overall system context. The experimental activities are actively supported by a theoretical workpackage which determines not only the requiremnets of broadband local network technology (BLNT), but also looks at the wider broadband system aspects.
BLNT consists of 2 major demonstrators, an experimental switch model and a customer access connection (CAC). The major functions of a full speed, International Telephone and Telegraph Consultative Committee (CCITT) compatible switch have been designed and built and tested as a model. The tests carried out have been able to verify the overall functioning of the switch system and show that the major concepts on which the switch is based are valid. The results of this work have provided invaluable experience and feedback and will form the basis for future development leading to the introduction of broadband systems.
The project has also produced a series of CAC prototypes based on optoelectronic integrated circuits (OEIC) and very large scale integration (VLSI) developed by the project. The ultimate target is for a 2 chip optoelectronic integrated circuit for the transmitter, receiver and wavelength duplexer, which will significantly reduce the price of the customer access. Significant system and technology experience has been gained in this area and components have developed to suit a number of different scenarios.
The switch and the customer access parts of the projects have defined a common interface, such that the 2 halves of the project can be readily integrated.
Technical Approach

The project is system led and vertically integrated so that the key dependent technologies can be considered in an overall system context. This provides the basis for ensuring a realistic proving environment for the components being developed within the project. The components are, where possible, being developed to fit into a number of various system and access architectures. The experimental activities are actively supported by a theoretical workpackage which determines not only the requirements of BLNT, but also looks at the wider broadband system aspects.

BLNT consists of two major demonstrators: an experimental switch model and a customer access connection. The experimental switch model has been completed and tested and the customer access will reach a similar stage early in 1992.

The major functions of a full speed, CCITT compatible switch have been designed and built and tested as a model. The tests carried out initially were limited by the availability of suitable traffic generating equipment. However, these have been able to verify the overall functioning of the switch system and show that the major concepts on which the switch is based are valid. The results of this work have provided invaluable experience and feedback and will form the basis for future development leading to the introduction of broadband systems.

The project has also produced a series of CAC prototypes based on opto-electronic integrated circuits (OEIC) and VLSI developed by the project. The ultimate target is for a two chip opto-electronic integrated circuit for the transmitter, receiver and wavelength duplexer, which will significantly reduce the price of the customer access. The model for the customer access is planned to be complete by early '92. This will comprise two sub- demonstrators, ie a multiplexing sub-demonstrator based on the CCITT Synchronous Digital Hierarchy for which all the components have been designed and produced within the project and the optical link sub-demonstrator which comprises opto-electronic modules for the NT and LT ends of the customer link. As with the experimental model significant system and technology experience has been gained in this area and components have developed to suit a number of different scenarios.

The switch and the customer access parts of the projects have defined a common interface, such that the two halves of the project can be readily integrated. This work which is outside the scope of BLNT is planned to be a part of the BUNI Demonstrator project and both demonstrators will therefore be made available for this purpose.

Key Issues

- Definition of local distribution requirements.
- Broadband system requirements.
- Compliance with relevant CCITT standards.
- Hardware design and performance.
- ATM switch architectures.
- VLSI requirements.
- Component integration (OEIC).
- Switch and CAC models.
- Evaluation procedures.

Achievements

- Requirements specification produced for switch and CAC.
- Design of switch and CAC completed.
- OEIC techniques and technology demonstrated and incorporated.
- VLSI technology chosen, designed, produced and tested.
- Realisation of CAC and switch demonstrators almost complete.
- Definition of ATM performance parameters.
- Phased test and evaluation.

Expected Impact

- Establishment of a fully flexible, low-cost local network architecture.
- Definition, development and demonstration of a switch architecture for interactive services using ATM.
- Establishment of a cost effective customer access connection based on OEIC's.
- Production of a set of components suitable for use in a variety of architectures.
- Contributions to ETSI and CCITT concerning ATM performance parameters.
- Establishment of a set of recommendations which will be used to aid in the specification of a broadband system.

Coordinator

Roke Manor Research Ltd
Address
Roke Manorold Salisbury Lane
SO51 0ZN Romsey
United Kingdom

Participants (2)

SIEMENS AG
Germany
Società Italiana Telecomunicazioni SpA
Italy