Abstract: An encoding apparatus and an associated decoding apparatus for a television signal having embedded viewer access control data. A program category code is inserted into a television signal by the encoding apparatus, identifying at least one attribute of program content of an associated television program. An individual viewer may preclude receipt of television programming identified by a corresponding program category code as containing a program content attribute for which the individual viewer has chosen to preclude viewing. The decoding apparatus compares the program category code embedded within a television program with a user category code indicating at least one of the attributes of programming content for which the individual user has elected to preclude receipt of television programming. Viewing of the television signal is precluded when the television signal includes a program category code corresponding to the user category code.

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.

Abstract: A transmitting and receiving system having two or more radios, each capable of transmitting and receiving a transmission signal on two or more radio frequencies where a first radio transmits on a selected frequency at a predetermined time interval and a second radio recovers the transmitted signal. The second radio has a first intermediate frequency generator which generates an intermediate frequency signal which is substantially equal to an integer multiple of the channel spacing whereby an image response corresponding to the selected frequency is separated by twice the intermediate frequency signal from the selected frequency. Thus, locations for the two or more transmission frequencies can be selected so as not to be located on the image responses corresponding to any and all of the two or more transmission frequencies.

Abstract: A method of communicating between two or more radios each capable of transmitting and receiving signals between one another on two or more radio channels wherein the radios hop from channel to channel in a pseudo-random sequence. The method comprises establishing hop synchronization between the radios utilizing a first cycle and operating the radios in a communication mode utilizing a second cycle. The first cycle is shorter than the second cycle so as to facilitate rapid synchronization while preserving the benefits and security obtained through the use of longer cycle length during communication mode.

Abstract: An alternative power supply apparatus for use in association with systems having a base unit connected to an external power supply and an associated battery-powered portable unit. The alternative power supply apparatus includes two rechargeable batteries one of which serves to provide electrical power to the portable unit. There are two ports associated with the base unit, each port operably and detachably accepts one of the two rechargeable batteries. The apparatus further includes a voltage regulator which provides regulated voltage to circuitry in the base unit. Two current sources each associated with a respective one of the two ports provides an electrical current to the batteries when they are operably accepted by the ports. The second rechargeable battery, which is interchangeable with the first rechargeable battery, provides a source voltage to the voltage regulator upon failure of the external power supply.