Providing time sychronization to a GPS locator

A method for calibrating a network time of a communications network that has at least one cell and that transmits a control channel signal including a plurality of known bit sequences according to the network time from at least one base transceiver station into the at least one cell of the communications network, to provide an absolute time reference for a local clock in a mobile unit located in one of the at least one cell, comprising the steps of:

• a) providing:
• i) a source, of a standard time, that transmits at least one synchronization signal;
• and
• ii) a transceiver operative to communicate with the communications network and with the mobile unit;
• b) synchronizing the local clock with said standard time;
• c) synchronizing the network time of the communications network with the local clock;
• d) calculating a time offset, according to the local clock, of the network time of the communications network from said standard time;
• and
• e) calculating an absolute time reference as a sum of said time offset and said standard time.