Network Coding for Satellite Communication

- In satellite communication, resources are very expensive. Systems that require less resources for the same amount of traffic are gaining interest.- Network coding is a technique that allows to perform coding operations at each node of the network and promises higher efficiency compared to the traditional systems that rely on routing. Aim of the Project:- The NEXT Project aims to develop network coding algorithms for satellite communication systems.- The developed algorithms and protocols are implemented on satellite hardware. The gains of network coding are presented with an on-earth demonstration.- This experiment is a candidate project for the Heinrich Hertz Satellite Mission (to be launched in 2017). System Model- Two users want to exchange their messages by using a satellite. Both of them are within the same beam of the satellite such that each transmission of the satellite can be heard by both users.- An example for such a scenario is video conferencing via satellite or bidirectional data exchange between two geographically separated areas.- Instead of just forwarding the packets, the satellite combines its received packets by using an XOR operation (S = A ⊕ B) and broadcasts this packet to both users.- The users receive S and perform an XOR operation with their own packet to extract the other user’s packet: B = S ⊕ A, A = S ⊕ B- With this method, the number of transmitted information bits from the satellite is reduced by 50%.- By using different algorithms, this can be converted in gains in terms of transmit duration, power or bandwidth