Orbitel Mobile Communications Limited

British Telecommunications Public Limited Company

Gec Plessey Telecommunications Limited

Stc, Inc

Shaye Communications Limited

Mercury Communications Limited

Phonepoint Limited

Ferranti Creditphone Limited

Northern Telecom Limited

Kenwood Corporation

Gpt Limited

At&t Wireless Communications Products Limited

Peter N Proctor

David C Odhams

Rupert Goodings

Michael T Dudek

Nigel Everard Barnes

Malcolm Crisp

Ian Rodgers

Graham E Beesley

Andrew Bud

Emlyn Jones

Brian A Bidwell

Andrew S Pearce

Chris Cant

Richard Albrow

John M Baker

Peter I Love

A telecommunication system includes a number of radio base stations connected to a telephone network, the base stations forming a link to the network for a number of cordless telephones. Each base station determines in which of a number of predetermined signal strength bands the signal strength of a signal produced by a cordless telephone and received by the base station lies. If the received signal strength lies in a lower band, the base station stores an indication of the signal, and scans through the communication channels available between the base station and the cordless telephones to determine whether a new incoming signal lies in the highest signal band, or whether by increasing the rank of the band of a stored signal, the highest signal band is reached.

Radio telephone system with signal strength assessment

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 synchronisation 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 synchronisation is achieved by the asynchronous detection of words in a synchronisation 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 synchronised.

Time division duplex telecommunication system

Technique for time-division duplex cordless telecommunication

Telecommunications system

The method comprises transmitting an initiating signal in the form of a bit pattern as a continuous burst from one radio unit to the other. The pattern incorporates a preamble pattern and a security code having a plurality of bit sequences. Each sequence is transmitted a number of times. The received security code is compared with stored codes in the other unit, and if a matching pair is identified a response signal is transmitted from the other unit to said one unit. The response signal incorporates the preamble pattern for establishing synchronization between the radio units.

Method of establishing a radio link in one of a plurality of channels

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Basingstoke, United Kingdom

Peter N Proctor