Cordless telephone base unit arranged for operating with multiple portable units

A method of establishing communications between a base unit and one of a plurality of handset units, the method comprising the steps of:

• storing a common predetermined security code in both the base unit and each of the plurality of handset units used in establishing each communication link between said base unit and one of the plurality of handset units over a communication channel;
• generating a substitute security code uniquely different form said predetermined security code, in at least one of the plurality of handset units responsive to the establishing of a communication link with said base unit, said substitute security code being substituted for said predetermined security code and used in subsequent communications with said base unit over said communication channel;
• and
• providing said substitute security code from said at least one of the plurality of handset units to said base unit over an established communication link for use in said subsequent communications with said base unit during said established communication link, said base unit being unresponsive to communication attempts from other of the plurality of handset units unaccompanied by said substitute security code while communicating with said at least one handset unit that provided said substitute security code.

In a cordless telephone system employing a plurality of handset units for establishing communications with a base unit in the telephone system, a handset unit comprising:

• means in the handset unit for storing a predetermined security code used in establishing each communication link between said base unit and the handset unit over a communication channel said predetermined security code also being stored in said base unit;
• means in the handset unit responsive to the establishing of a communication link with said base unit for generating a substitute security code uniquely different from said predetermined security code, said substitute security code being substituted for said predetermined security code for use in subsequent communications with said base unit over said communication channel;
• and
• means for providing said substitute security code from the handset unit to said base unit over an established communication link for use in said subsequent communications with said base unit during said established communication link, said base unit being unresponsive to communication attempts from other of the plurality of handset units unaccompanied by said substitute security code while communicating with said handset unit that provided said substitute security code.

In a cordless telephone system employing a plurality of handset units and a base unit for establishing communications with the plurality of handset units, the base unit comprising:

• means for storing a predetermined security code used in establishing each communication link between said base unit and one of the plurality of handset units over a communication channel said predetermined security code also being stored in each one of the plurality of handset units;
• means responsive to the establishing of a communication link with one of the plurality of handset units for receiving a substitute security code uniquely different from said predetermined security code, said substitute security code being substituted for said predetermined security code received from said one of the plurality of handset units over said communication channel;
• and
• means for adopting said substitute security code received from said one of the plurality of handset units for use in subsequent communications with said one of the plurality of handset units during said established communication link, said base unit being unresponsive to communication attempts from other of the plurality of handset units unaccompanied by said substitute security code while communicating with said one of the plurality of handset units that provided said substituted security code.

A method of establishing communications between a base unit and one of a plurality of handset units, the method comprising the steps of:

• storing a predetermined security code in a handset unit used establishing each communication link between said base unit and the handset unit over a communication channel said predetermined security code also being stored in the base unit;
• generating in the handset unit a substitute security code uniquely different from said predetermined security code responsive to the establishing of a communication link with said base unit over the communication channel;
• and
• providing said substitute security code from the handset unit to said base unit, said substitute security code being substituted for said predetermined security code for use in subsequent communications with said base unit during said established communication link, said base unit being unresponsive to communication attempts from other of the plurality of handset units unaccompanied by said substitute security code while communicating with said handset unit that provided said substitute security code.