Synchronization signal base stations.

Synchronization signal used to synchronize base stations in a telecommunication system, wherein it said signal comprises a first extended frequency (ext (A)) followed by a second extended sequence (ext (B)), consisting of said first extended sequence in a truncated portion of a sequence obtained by repetition of a first sequence (a) and consisting of said second extended sequence in a ppor obtained truncated portion of a sequence (B) repetition of a second sequence, said first and second sequences a complementary sequences of so that, if said signal is correlated with a replica of said first sequence and a replica of said second sequence, the sum of the correlation results generates a Dirac peak ailado in a time window.