Method of synchronizing base stations of a terrestrial cellular communication network

A method of synchronizing base stations of a terrestrial cellular telecommunication network, the network including at least first and second asynchronous base stations, which method includes the following steps:

• a step of said first and second base stations sending to a telecommunication satellite a first message, respectively a second message, including a first frame synchronization word, respectively a second frame synchronization word,
• a step of retransmission by the satellite to a processing device on the ground of said first and second messages, the satellite and the processing device being synchronous with a reference time system, the following steps being executed within the processing device:
• a step of searching for the first frame synchronization word sent in the message by the first base station,
• a step of searching for the second frame synchronization word sent in the message by the second base station,
• a step of apparent time stamping T16a-Reception of the first synchronization word and of apparent time stamping T16b-Reception of the second synchronization word,
• a step of calculating the distance between the first base station and the satellite, the processing device knowing the position of the first base station and the position of the satellite,
• a step of calculating the distance between the second base station and the satellite, the processing device knowing the position of the second base station and the position of the satellite,
• a step of calculation, by deduction from the distance calculated between the first base station and the satellite, of the routing time T16a-Routing to the satellite of the first synchronization word and of calculation by deduction from the distance calculated between the second base station and the satellite, of the routing time T16b-Routing of the second synchronization word,
• a step of calculation of the real TOW of the first synchronization word and of the real TOW of the second synchronization word, respectively in accordance with the formula T16a=T16a-Reception−T16a-Routing and the formula T16b-Reception−T16b-Routing,
• a step of transmission of information taking account of said real TOW to a synchronization device of the cellular telecommunication network.