Mobile telecommunications systems

1. A method for synchronizing between base stations in a telecommunications system which includes a plurality of cells, each of which cells has one of said of base stations and at least one mobile station situated therein, the method comprising:

a) providing at least one channel comprising time slots, for usage in the plurality of cells;

b) each base station transmitting a synchronization signal, in a given one of the at least one channel, to remaining base stations within transmission range of each respective base station;

c) for each base station, calculating respective time differences between corresponding time slots transmitted by the respective base station and received from the respective other base stations within transmission range of the base station; and

d) adjusting timing of the synchronization signals of the respective base station according to calculated time differences;

wherein the given one of the at least one channel, by which the synchronization signal is transmitted from each of the plurality of base stations to said remaining base stations, is a random access channel transmitted at a frequency within a band of frequencies that is provided for communications between mobile stations and base stations.

2. The method according to claim 1 , comprising:

e) for each of the plurality of base stations, reporting the time differences calculated in step c) to a radio network controller;

f) calculating a synchronizing adjustment corresponding to each base station from the reported time differences;

g) informing each base station individually of the corresponding synchronizing adjustment calculated in step f); and

h) synchronizing each base station according to the corresponding synchronizing adjustment.

3. The method according to claim 1 , further comprising:

i) each respective base station acting autonomously on the time differences calculated in step c) by adjusting its synchronization to minimize the time differences.

4. The method according to claim 1 , wherein the random access channel comprises a time slot per TDMA frame.

5. The method according to claim 4 , wherein the random access channel is allocated to uplink transmissions in order to initiate communications.

6. The method according to claim 5 , wherein communications are initiated by requesting a resource unit for uplink usage.

7. The method according to claim 4 , further comprising:

j) allocating utilization of each random access channel time slot for base station synchronization according to a schedule.

8. The method according to claim 4 , further comprising:

k) using a second channel of said at least one channel to silence uplink communications in the random access channel time slots to allow the transmission of synchronization transmissions from each respective base station to other base stations.

9. The method according to claim 8 , wherein the second channel is a broadcast control channel.

10. The method according to claim 1 , wherein the random access channel time slot used is always contained in a fixed numbered frame within a plurality of multi-frames in order to synchronize the plurality of base stations over multi-frames.

11. A method of locating a mobile station within a telecommunications cell forming part of a telecommunications system which includes a base station and at least one mobile station, the method comprising:

determining the location of at least three base stations;

scheduling synchronization measurements for each of the base stations utilizing a random access channel by each of the base stations transmitting a synchronization signal to the remaining base stations within its transmission range, via said random access channel

transmitting a signal from the mobile station;

receiving the transmitted signal at each of the three base stations;

comparing the received signals with timing signals in each of the base stations; and

using the comparison at each base station to determine the location of the mobile station.