The SkyLAN concept consists in splitting functions usually performed by a single large telecommunication satellite among a number of co-located and interlinked smaller satellites. In other words, SkyLAN is a cluster of relatively small satellites that perform an integrated function through a coordinated exchange of information via Inter-Satellite links (ISL).
The main objective of this study is to assess the viability of the SkyLAN cluster concept through both technical and financial analysis.
The major technical choices in clustering are the functional splitting and the SkyLAN configuration. The functional splitting is the way all functions are distributed between the satellites. SkyLAN configuration refers to the communication network topology between the satellite.
SkyLAN would potentially bring many advantages to satellite operators. Hereafter we present the main expected advantages of the SkyLAN concept:
Three systems have been chosen: Mobile, Fixed and Broadcast systems.
The mobile system is based on the Satellite Digital Multimedia Broadcast or S-DMB. This system provides the optimization of 3G DMB service over Europe.
The Fixed system is based on Domino system. This system provides broadband multimedia services over Europe: Internet Access, Virtual Private Network, Content delivery, Backbone Connectivity.
The Broadcast system is based on a Ku-band Multi-beam system. This system provides video broadcast services to linguistic regions in Europe.
The project is divided into two phases each of them is divided into 4 technical tasks:
Phase 1 will analyze and assess the SkyLAN concept with regards to three missions: fixed, mobile and broadcast satellite services. Preferred missions will be identified and preliminary SkyLAN configurations for these selected missions will be defined and analyzed. A technical and financial trade off with traditional satellite systems will conclude this phase.
Phase 2 will address in more details four aspects of the SkyLAN concept : the impacts on the payload architecture due to the function distribution, the evaluation of the Inter Satellite Link system (RF or optical), the analysis of the Station Keeping requirements and various programmatic domains.
The SkyLAN concept proves to be particularly attractive for FSS multispot beam broadband access. A cluster of 4 medium size satellites, each providing 16 beams, allows for the deployment of 64 spot beams over "extended" Europe for a total capacity of 14.4 GHz. Each satellite of the cluster works on a dedicated frequency and provides non-adjacent beam coverage. The satellites of the cluster are interconnected by optical ISL and are arranged in a double ring, for maximum routing flexibility and redundancy.