Radio communication system mobile station which can communicate directly with another mobile station
AssigneeSagem Communications SAS
InventorMarc Dorion
Life of this patent
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Abstract
A mobile station of a mobile radiocommunication system for receiving synchronization channels transmitted on at least one carrier so as to be able to synchronize with a base station and transmit data in a traffic channel defined with respect to the synchronization channels. The mobile station may transmit synchronization channels on a carrier normally transmitted by a base station. The mobile station may transmit a traffic channel on the carrier. The synchronization and traffic channels are transmitted to at least one other mobile station so the first mobile station can synchronize with the other mobile station and read the traffic channel.
Claims12
A mobile station of a mobile radio communication system of a type comprising means for receiving a beacon channel comprising at least one frequency correction channel (FCCH), one synchronization channel (SCH), and at least one broadcast control channel (BCCH) transmitted on at least one carrier so as to be able to synchronise with a base station and transmit data in a traffic channel defined with respect to a synchronization channels including the least one FCCH and one SCH, said mobile station comprising:
- means for transmitting a beacon channel comprising at least one FCCH and one SCH on a carrier normally exclusively transmitted by a base station;
- means for transmitting a traffic channel (TCH) on said carrier, wherein said beacon channel transmitted from said means for transmitting said beacon channel and traffic channel are transmitted to at least one other mobile station so that the latter can synchronise with said mobile station and read said traffic channel;
- means for, when said mobile station is the first to transmit on a carrier, said mobile station then being known as a master mobile station,
- transmitting the master mobile station's own beacon channel including at least one FCCH, one SCH, and at least one BCCH in a predefined manner to at least one slave mobile station;
- means for, when said mobile station is the master mobile station, allocating resource for enabling a requesting mobile station to transmit said requesting mobile station's own beacon channel to at least one other mobile station;
- and
- means for, when it is not the first to transmit on a carrier, said mobile station then being known as a slave mobile station, synchronising firstly with the beacon channel of the master mobile station of said carrier before transmitting the slave mobile station's own beacon channel including at least one FCCH, one SCH without including at least one BCCH to other slave mobile station not receiving the master mobile station's own beacon channel.
A method for setting up a call in direct mode which is implemented by a master mobile station, said call being made to at least one other slave mobile station, comprising:
- (a) selecting a carrier from a predefined set of carriers;
- (b) transmitting a beacon channel comprising at least one frequency correction channel (FCCH), one synchronization channel (SCH), and at least one broadcast control channel (BCCH) on said selected carrier by said master mobile station if said carrier is not being used for another call;
- (c) transmitting a request to the master mobile station for said carrier by a slave mobile station if said carrier is already being used for another call, transmitting a request to the master mobile station for said carrier from said slave mobile station, said master mobile station in response to the request allocating channels for beacon channel and traffic channel (TCH) to said slave mobile station;
- and
- (d) transmitting, by said slave mobile station, the slave station's own beacon channel including at least one FCCH, one SCH without including at least one BCCH to other slave mobile station on said carrier allocated by said master mobile station.
Dependencies are inferred from the claim text.