Distribution of DBS Signals by Fibre Optic

  • Status
    Ongoing
  • Status date
    2009-07-13
Objectives

To design a system to distribute DBS signals from the Universal LNB mounted on a standard satellite dish to multiple standard receivers in an MDU via a single fibre optic cable.

Challenges

Optical Output LNB
The project resulted in a new type of LNB being designed. This LNB is the first to provide a direct Optical output rather than a traditional coax cable. This LNB required extensive design into new Optical Laser devices to provide the reliablity required for a consumer device at a practical price point. The LNB also required the design of a new band stacking system with wide band 5.4GHz IF and driver circuits to drive and support the new Laser.

Optical Cable and Connectors
The new design required extensive research into optical connectors and cables for use in a consumer environment. The design is able to use standard FCPC optical connectors that have been adapted for fitting to cable without the use of special cleaving tools or skilled operators. The cable has also been adapted to have a low cost armour cover in order to avoid damage during installation by low skilled fitters and consumers.

Optical Convertor for DBS receiver
The main design activity in the project was the design of the IF convertor. This unit takes the Optical Output from the LNB and converts this format into the standard Universal DBS bands as used in Europe. This enables the system to be fully compatible with all existing legacy receivers on the market and the estimated 100M receivers installed in Europe. This design required the development of a complex multiple Oscillator and Mixer frequency conversion system along with a matrix switch. This design required a major effort in order to control the band to band isolation and Spurious signal levels in order to meet the standard ASTRA DBS specifications, as well as guarantee compatibility with receivers and other IF routing hardware such as switches.


click for larger image

Benefits

This new product has opened up a new market for Global Invacom. It has resulted in a new family of DBS products that are set to change previous perceptions about DBS signal distribution. It enables large numbers of receivers to be supported without the complexities of IF coax cable loss and the resultant amplifiers and switch matrix that used in previous systems.

Features
  1. An Optical Output Universal Band LNB.
  2. A Single Optical Fibre Network carrying the Universal IF Band.
  3. Optical Power Splitters to link to multiple IF convertors.
  4. A convertor unit to change the Optical signals back into standard Universal IF bands at the satellite receiver.
  5. Designed for high volume manufacture.
Plan

The project is divided into 14 Work Packages. These are:

WP1 System Integration & Test
WP2 Laser Development and Provision
WP3 Evaluation of multimode and singlemode fibre for home connection
WP4 Optical LNB Transmitter design & Development
WP5 LNB Electrical Design
WP6 Optical Cable and Connector selection
WP7 Splitter Box Design
WP8 Wall plate optical receiver design
WP9 Wall plate receiver Electrical design
WP10 Industrialisation for Demonstration
WP12 Environmental Test
WP13 Mechanical Design
WP14 Administration & Control

Current status

WP1 System Integration & Test
Activities Completed

WP2 Laser Development and Provision
Activities Completed

WP3 Evaluation of multimode and singlemode fibre for home connection
Activities Completed

WP4 Optical LNB Transmitter design & Development
Activities Completed

WP5 LNB Electrical Design
Activities Completed

WP6 Optical Cable and Connector selection
Activities Completed

WP7 Splitter Box Design
Activities Completed

WP8 Wall plate optical receiver design
Activities Completed

WP9 Wall plate receiver Electrical design
Activities Completed

WP10 Industrialisation for Demonstration
Activities Completed

WP12 Environmental Test
Activities Completed

WP13 Mechanical Design
Activities Completed

WP14 Administration & Control
Activities Completed