Future GNSS combined receivers will have to be compliant with requirements that are defined by means of performances specified in terms of integrity, continuity, availability and accuracy for Civil Aviation community. The architecture of those receivers is currently defined from investigations about the advantages and risks linked to the multiple constellation use of GNSS signals. The different means identified by EURopean Organization for Civil Aviation Equipment WG 62 to provide aircraft position and integrity during an aircraft all phases of flight are Galileo (E1, E5), GPS (L1, L5), GIC, SBAS(L1, L5) and RAIM algorithms.