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Optimising Communication Satellites Payload Conguration with Exact Approaches

The satellite communications market is competitive and rapidly evolving. The payload, which is in charge of applying frequency conversion and amplification to the signals received from Earth before their retransmission, is made of various components. These include reconfigurable switches which permit to reroute the signals based on the market demand or because of some hardware failure. In order to meet the modern requirements, the size and the complexity of current communication payloads are increasing significantly. Consequently, the optimal payload configuration, which was previously done manually by the engineers with the use of computerised schematics, is now becoming a difficult and time consuming task. Efficient optimisation techniques are therefore required to find the optimal set(s) of switch positions to optimise some operational objective(s). In order to tackle this challenging problem for the satellite industry, this work proposes two Integer Linear Programming (ILP) models. The first one is single-objective and focuses on the minimisation of the length of the longest channel path, while the second one is bi-objective and additionally aims at minimising the number of switch changes in the payload switch matrix. Experiments are conducted on a large set of instances of realistic payload sizes using the CPLEX solver and two well-known exact multi-objective algorithms. Numerical results demonstrate the efficiency and limitations of the ILP approach on this real-world problem.