To this end, beginning in 1999 a series of projects were initiated to investigate the potential of Ka Band via satellite. Alenia Spazio began work on Euroskyway, while Alcatel Space started development of Domino, an offshoot of this activity was later to become the 'AmerHis: Switchboard in Space', and lastly EADS Astrium began the WEST Early Bird or WeB.
EADS Astrium has recently completed WeB and the synergy implemented at equipment level between mobile narrowband and fixed broadband has been highly beneficial for all partners. The completion of WeB marks a major commercial achievement and helps to reassert European industry's place as one of the leaders for processed mobile satellites.
At a European level, WeB has significantly contributed to the development of the DVB-RCS standard thanks not only to the involvement of EMS, Newtec and Nera but also to a comprehensive understanding of the various mechanisms and their validation on end-to-end test beds.
Market Context
WeB will have a positive impact on EADS Astrium's core business of satellite manufacturing by providing its customers with an end-to-end satellite network solution. ESA funding made it possible for EADS Astrium to develop a portfolio of products and satellite network infrastructures as well as to support the business developments of its customers.
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This strategic positioning imposed an industrial product policy where the products would be designed to target costs and schedules, with the highest modularity possible and with maximum synergies between the different products of the portfolio. It also required the building of industrial relationships with ground segment manufacturers in order to propose validated end-to-end solutions. |
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WeB is based on multi-beam satellite concept and is designed to offer multimedia services on Ka-band. The overall objectives of the programme were to design and develop a GEO satellite system, to manufacture some of the equipments in breadboard and EQM quality (genetic building blocks), and to test the whole system for both space and ground segments within a specifically developed system test bed.
A multi national industrial team was formed, led by EADS Astrium SAS. The team was made up of 19 companies including four SMEs and one research institute with 11 contributing countries: Austria, Belgium, Canada, France, Germany, United Kingdom, Italy, Norway, Spain, Sweden and Switzerland.
Web System Design
The WeB system has the ability to provide access and mesh broadband services using small end-user terminals. It is designed to provide high capacity and flexibility with the objective of achieving very low service costs.
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The WeB baseline architecture and sizing is based on a typical European coverage, provided through 40 high gain beams, each of 0.6º beamwidth in Ka-band (image left). |
One of the main drivers when designing the WeB system was the adaptability to various mission requirements. This took the form of a building block approach at system and equipment levels. Depending on the mission requirements, key features of WeB are that forward, return and mesh links can be considered independently or in a combined way.
Forward links can be both transparent or regenerated and return links can be bent-pipe or transparent. Mesh is always regenerated and can be in MPEG or ATM DVB-RCS profile, while channel bandwidth and overall capacity can be tailored to actual requirement.
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Digital On-Board Processor
The EADS Astrium approach for broadband on-board processors consists of a modular architecture based on generic building blocks (ASICs, MCMs modules).
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In considering large scale processor requirements it is clear that an advanced electronic component packaging approach is necessary in order the satisfy key requirements. |
| These were approached in terms of minimisation of mass, size and power while at the same time maintaining efficient thermal control, high reliability, modularity and manufacturability. |
Web Gateways and Terminals
The WeB Gateway is part of the Network Access Provider (NAP) facilities in the WEST overall architecture. For access services, the Gateway is the access point of the WeB terminals to the terrestrial networks via the satellite. The Gateway provides traffic transport functions and control functions (resource provisioning, traffic flow control), in addition to management functions. For mesh services, the Gateway facilitates the connections between WeB Terminals via the satellite. For these services the Gateway only provides control and management functions.
Resource Management
Satellite resource has to be used in the most efficient way in order to maximise overall capacity while keeping the quality of service promised to the end users. WeB architecture has been designed to offer a flexible solution which can be operated efficiently in various business environments. The WeB reference model of role involves a three-tier structure with one Network Operator, several Network Access Providers and several Service Providers.
Major Achievements
The WeB programme was a unique opportunity to put together relevant skills from various countries and companies in order to prepare future introduction of broadband satellite systems.
Thanks to this ESA initiative, European industry is now much better prepared to answer challenges related to bridging the Digital Divide and while easing the entrance of operators into the Digital TV market.
