Method of conducting an intercom communication between two cordless telephone handsets

• US 5,619,553 A
• Filed: 06/01/1994
• Issued: 04/08/1997
• Est. Priority Date: 06/02/1993
• Status: Expired due to Term

• Current Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Original Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Inventors: Beatty, Michael, Young, Philip A.
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): TROST IV, WILLIAM GEORGE
• Application Number:
  US08/252,260
• Time in Patent Office: 1,042 Days
• Field of Search: 379/61, 379/63, 379/156, 379/159, 379/58, 379/59, 455/33.1, 455/54.1, 455/56.1, 455/51.1, 395/200.5, 395/290, 395/299, 364/230.4, 364/242.92, 364/269, 364/931.44, 364/931.48, 364/942.4
• US Class Current: 455/463
• CPC Class Codes: H04M 1/72505 Radio link set-up procedures
• CPC Class Codes: H04M 1/72513 On hold, intercom or transfer communication modes

Abstract

A method of conducting an intercom communication between two cordless telephone handsets is disclosed wherein a handset requests that the base unit designate the handset with temporary master status upon initiation of an intercom communication. The responsibility of providing master system timing is transferred from the base unit to the handset for the duration of the intercom call. Upon conclusion of the intercom call the responsibility of providing master system timing is returned to the base unit.

Claims

1. A method of conducting an intercom communication between two cordless telephone handsets, in a system having:

a master radio transmitter/receiver designated as system master, the system master being responsible for maintaining system timing;

two or more radio transmitter/receivers designated as slaves which synchronize to the system master,

each of the radio transmitter/receivers being capable of transmitting and receiving signals between one another on two or more radio frequencies, the method comprising the steps of;

one of the two or more slave radio transmitter/receivers requesting from the master radio transmitter/receiver temporary system master status upon user initiation of an intercom communication at the one of the two or more slave radio transmitter/receivers;

transferring from the master radio transmitter/receiver to the one of the two or more slave radio transmitter/receivers the responsibility of providing master timing for the system;

conducting the intercom communication directly between the one of the two or more slave radio transmitter/receivers and at least another of the two or more slave radio transmitter/receivers, exclusive of the master radio transmitter/receiver with the one of the two or more slave radio transmitter/receivers providing master system timing; and

transferring from the one of the two or more slave radio transmitter/receivers to the master radio transmitter/receiver the responsibility of providing master timing for the system upon conclusion of the intercom communication between the one of the two or more slave radio transmitter/receivers and at least another of the two or more slave radio transmitter/receivers.

2. The method according to claim 1 wherein the step of requesting from the master radio transmitter/receiver temporary master status comprises the substeps of:

transmitting from the one of the two or more slave radio transmitter/receivers to the master radio transmitter/receiver a request to initiate the intercom communication with the at least another one of the two or more slave radio transmitter/receivers;

transmitting from the master radio transmitter/receiver to the one of the two or more slave radio transmitter/receivers a message granting the request to initiate the intercom communication; and

transmitting from the one of the two or more slave radio transmitter/receivers to the master radio transmitter/receiver a link request message.

3. The method according to claim 2 wherein the step of transferring from the master radio transmitter/receiver to the one of the two or more slave radio transmitter/receivers further comprises the substeps of:

transmitting from the master radio transmitter/receiver, in response to receiving said link request message on the master radio transmitter/receiver, a message granting to the one of the two or more slave radio transmitter/receivers the timing master status;

in response to receiving the timing master status message on the one of the two or more slave radio transmitter/receivers, transferring the one of the two or more slave radio transmitter/receivers into master mode and transmitting from the one of the two or more slave radio transmitter/receivers a message accepting the grant of the timing master status;

in response to receiving said message accepting the grant of timing master status on the master radio transmitter/receiver, transmitting from the master radio transmitter/receiver a message acknowledging the acceptance of the grant of the timing master status; and

in response to receiving said message acknowledging acceptance of the grant of the timing master status, making the one of the two or more slave radio transmitter/receivers temporary master responsible for maintaining system timing.

4. A method of transferring timing master status from a master radio transmitter/receiver to a slave radio transmitter/receiver in a system having:

the master radio transmitter/receiver which maintains system timing;

two or more slave radio transmitter/receivers which synchronize to the master radio transmitter/receiver,

each of the master and slave radio transmitter/receivers being capable of transmitting and receiving signals between one another on one of two or more radio frequencies,

the method comprising the steps of;

transmitting from a requesting one of the two or more slave radio transmitter/receivers to the master radio transmitter/receiver a request to initiate a communication with another slave radio transmitter/receiver;

transmitting from the master radio transmitter/receiver to the requesting slave radio transmitter/receiver a message granting the request to initiate the communication;

transmitting from the requesting slave radio transmitter/receiver to the master radio transmitter/receiver a link request message;

in response to receiving the link request message on the master radio transmitter/receiver transmitting from the master radio transmitter/receiver a message granting to the requesting slave radio transmitter/receiver the timing master status;

in response to receiving the timing master status grant message on the requesting slave radio transmitter/receiver, transferring the requesting slave radio transmitter/receiver into master mode and transmitting from the requesting slave radio transmitter/receiver a message accepting the grant of the timing master status;

in response to receiving said message accepting the grant of the timing master status on the master radio transmitter/receiver, transmitting from the master radio transmitter/receiver a message acknowledging the acceptance of the grant of the timing master status; and

in response to receiving said message acknowledging acceptance of the grant of the timing master status by the requesting slave radio transmitter/receiver, making the requesting slave radio transmitter/receiver temporary master responsible for maintaining system timing.

5. A method of returning timing master status to a master radio transmitter/receiver from a temporary master, slave radio transmitter/receiver in a system having:

the master radio transmitter/receiver which maintains system timing;

two or more slave radio transmitter/receivers which synchronize to the master radio transmitter/receiver,

each of the master and slave radio transmitter/receivers being capable of transmitting and receiving signals between one another on one or two or more radio frequencies, the method comprising the steps of;

concluding communication directly between the temporary master, slave radio transmitter/receiver and at least another of the two or more slave radio transmitter/receivers, exclusive of the master radio transmitter/receiver wherein the temporary/master, slave radio transmitter/receiver provided and maintained the system timing;

transmitting from the temporary master, slave radio transmitter/receiver to the master radio transmitter/receiver a message granting to the master radio transmitter/receiver timing master status and returning the temporary master, slave radio transmitter/receiver to slave status;

in response to receiving the message granting the timing master status message on the master radio transmitter/receiver, returning the master radio transmitter/receiver to master mode and transmitting from the master radio transmitter/receiver a message accepting the grant of the timing master status;

in response to receiving the message accepting the grant of the timing master status on the temporary master, slave radio transmitter/receiver, transmitting from the temporary master, slave radio transmitter/receiver a message acknowledging the acceptance of the grant of the timing master status; and

in response to receiving the message acknowledging acceptance of the grant of the timing master status on the master radio transmitter/receiver, transferring to the master radio transmitter/receiver the system timing.