Cordless Telephone

A base unit included in a cordless telephone which also includes a handset cordlessly linked to the base unit functioning as a cradle for holding the handset for charging, the base unit comprising:

• a storage means for storing a security ID;
• a detection means for detecting a start of a charge which occurs when a handset is placed on the base unit;
• a first transmission means for transmitting the security ID stored in the storage means to the handset when the detection means detects the start of the charge;
• a generating means for generating a new security ID which is different from the security ID stored in the storage means;
• a second transmission means for transmitting the new security ID to the handset;
• a judging means for judging whether a response corresponds to either the security ID transmitted by the first transmission means or the new security ID transmitted by the second transmission means has been received from the handset;
• a link means for establishing a cordless link with the handset when the judging means judges that the response has been received from the handset;
• and
• an update means for updating the security ID stored in the storage means to the new security ID when the judging means judges that the response has been received and when the received response corresponds to the new security ID, wherein
• the generating means includes a timer which counts a predetermined time from the transmission of the security ID stored in the storage means, wherein
• the generating means generates the new security ID when a response from the handset is not received within the predetermined time.

A handset included in a cordless telephone which also includes a base unit which is cordlessly linked to the handset and functions as a cradle for holding the handset for charging, the handset comprising:

• a storage means for storing a security ID;
• a detection means for detecting a start of a charge which occurs when the handset is placed on a base unit;
• a first reception means for receiving a first security ID which is transmitted from the base unit after the detection means detects the start of the charge;
• a second reception means for receiving a second security ID transmitted from the base unit;
• a judging means for judging whether the first security ID matches the security ID stored in the storage means;
• an update means for updating the security ID stored in the storage means to the second security ID when the judging means judges that the first security ID does not match the security ID stored in the storage means;
• and
• a link means for requesting the base unit to establish a cordless link between the base unit and the handset in response to the first security ID when the judging means judges that the first security ID matches the security ID stored in the storage means, and in response to the second security ID when the judging means judges that the first security ID does not match the security ID stored in the storage means.

A cordless telephone including a base unit and a handset which are cordlessly linked to each other, the base unit functioning as a cradle for holding the handset for charging, the base unit comprising:

• a first storage means for storing a security ID;
• a first detection means for detecting a start of a charge which occurs when a handset is placed on the base unit;
• a first transmission means for transmitting the security ID stored in the storage means to the handset when the first detection means detects the start of the charge;
• a generating means for generating a new security ID which is different from the security ID stored in the first storage means;
• a second transmission means for transmitting the new security ID to the handset;
• a first judging means for judging whether a response corresponding to either the security ID transmitted by the first transmission means or the new security ID transmitted by the second transmission means has been received from the handset;
• a first link means for establishing a cordless link with the handset when the first judging means judges that the response has been received from the handset;
• and
• a first update means for updating the security ID stored in the first storage means to the new security ID when the first judging means judges that the response has been received and when the received response corresponds to the new security ID,
• the handset comprising:
• a second storage means for storing the security ID;
• a detection means for detecting the start of the charge;
• a first reception means for receiving a first security ID which is transmitted from the base unit after the detection means detects the start of the charge;
• a second reception means for receiving a second security ID transmitted from the base unit;
• a second judging means for judging whether the first security ID matches the security ID stored in the second storage means;
• a second update means for updating the security ID stored in the second storage means to the second security ID when the second judging means judges that the first security ID does not match the security ID stored in the second storage means;
• and
• a second link means for requesting the base unit to establish a cordless link between the base unit and the handset in response to the first security ID when the second judging means judges that the first security ID matches the security ID stored in the second storage means, and in response to the second security ID when the second judging means judges that the first security ID does not match the security ID stored in the second storage means.