Motorola Corporation

British Telecommunications Public Limited Company

Gpt Limited

Gec Plessey Telecommunications Limited

Orbitel Mobile Communications Limited

Northern Telecom Limited

Stc, Inc

Kenwood Corporation

Shaye Communications Limited

At&t Wireless Communications Products Limited

Mercury Communications Limited

Phonepoint Limited

Ferranti Creditphone Limited

Nigel Everard Barnes

Peter N Proctor

Michael T Dudek

Rupert Goodings

David C Odhams

Malcolm Crisp

Ian Rodgers

Stephen Andrew Howell

Graham E Beesley

Andrew Bud

Brian A Bidwell

Philip J Knight

Chris Cant

Colin Corbett

Richard Albrow

Gerald Anthony Warwick

A cellular telephone () in a vehicle includes a data carrier system comprising a first semi-permanent Subscriber Identity Module (SIM) () selectively couplable to the cellular telephone () and a second SIM () selectively couplable to the cellular telephone () in preference to the first SIM (), the first SIM () being arranged to be decoupled from the cellular telephone () when the second SIM () is coupled to the cellular telephone (). During a predetermined period of time, the cellular telephone () is arranged to be ensured of a supply of power and the second SIM () is arranged to be decoupled from the cellular telephone (), thereby causing the first SIM () to be coupled to the cellular telephone () for the execution of a task requiring the first SIM ().

Data carrier system

A communications system having a base station and a handset, capable of communicating over a base set of communication channels. Selecting one of the base channels for establishing communication. The handset sending a message, informing the base station, if it is capable of communicating over any extended set of communication channels, beyond the base set of channels, and if so, where the extended set of channels are located. The base station sends a message to the handset, informing the handset whether the base station has extended channel capability. If the base station has extended channel capability, the handset tunes its front end filters to match the indicated spectrum from the base station.

Communications system and communications unit for communicating over a

A method of on-air registration of a cordless telephone handset with a base station, includes the steps of: arming the handset so that it can indicate that it wants to register with a base station; arming the network to enable it to accept the registration request from the handset; activating the handset to start transmitting link request words; causing the base station and the associated network to determine that the link set-up is to be used for registration purposes, causing the base station to use the handset's identity to decide if that handset has a pending registration request, and transferring into the handset the registration details over the established link.

Cordless telephone registration method

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

A telecommunications sytem comprises a plurality of distributed base stations each operatively coupled to a public switched telecommunications network and being adapted to cooperate with one or more of a plurality of portable cordless telephone units by way of a plurality of cordless digital communication channels operating on a time division duplex basis. The base unit is arranged upon detection of an incoming public switched network call, to poll all the portable cordless telephone units by transmitting on a repetitious basis the identity of the portable units to be connected to the incoming call on a selected channel and the base unit is arranged to intersperse each poll operation with a signalling message. Each portable unit is arranged to scan the cordless channels at a predetermined interval and the base unit is adapted to postpone the sending of a ringing message to any of the portable units until a predetermined period has elapsed since the commencement of the polling action, the predetermined period being substantially similar to but larger than the predetermined interval.

Simultaneous ringing control in the time division duplex

Growing community of inventors

Basingstoke, United Kingdom

Nigel Everard Barnes