Abstract: A communication procedure suitable for a cordless telephone system involves time division duplex radio communication between a handset 11 and a base station using alternating bursts of transmission over a single radio channel. Once a radio link has been set up, initial transmissions carry a synchronization logical channel S and a signalling logical channel D multiplexed together, but the link may switch to bursts carrying a communications logical channel B for the speech data and the signalling logical channel D. Burst synchronization is achieved by the asynchronous detection of words in a synchronization channel S. These words have bit patterns reducing the probability of incorrect asynchronous detection of them. If one part ceases to receive handset signals from the other, it transmits a special signal, informing the other part. This enables both parts to detect the failure of a link at substantially the same time, so that their actions to re-establish the link are synchronized.
Type:
Grant
Filed:
November 26, 1990
Date of Patent:
July 13, 1993
Assignees:
British Telecommunications Public Limited Company, Ferranti Creditphone Limited, GEC Plessey Telecommunications Limited, Mercury Communications Limited, Orbitel Mobile Communications Limited, Shaye Communications Limited, Phonepoint Limited, STC PLC
Inventors:
Richard Albrow, Nigel E. Barnes, Graham E. Beesley, Chris Cant, Malcolm Crisp, Michael T. Dudek, Rupert Goodings, David C. Odhams, Peter N. Proctor, Ian Rodgers
Abstract: A communication procedure suitable for a cordless telephone system involves time division duplex radio communication between a handset 11 and a base station 3 using alternating bursts of transmission over a single radio channel. Once a radio link has been set up, initial transmissions carry a synchronization logical channel S and a signalling logical channel D multiple together, bu the link may switch to bursts carrying a communications logical channel B for the speech data and the signalling logical channel D. Bursts synchronization is achieved by the asynchronous detection of words in a synchronization channel S. These words have bit patterns reducing the probability of incorrect asynchronous detection thereof. If one part ceases to receive handset signals from the other, it transmits a special signal to inform the other part. This enables both parts to detect the failure of a link at substantially the same time, so that their actions to reestablish the link are synchronized.
Type:
Grant
Filed:
November 26, 1990
Date of Patent:
May 4, 1993
Assignees:
British Telecommunications Public Limited Company, Ferranti Creditphone Limited, GEC Plessey Telecommunications Limited, Mercury Communications Limited, Orbitel Mobile Communications Limited, Shaye Communications Limited, Phonepoint Limited, STC PLC
Inventors:
Michael T. Dudek, Rupert Goodings, Emlyn Jones, David C. Odhams, Peter N. Proctor