06198942 is referenced by 126 patents and cites 6 patents.

In a system having a response hold function as a standard function such as CDMA system, a telephone apparatus transmits a response hold request to a control center when an End key is operated upon arrival of an incoming telephone call from another telephone apparatus. Receiving the response hold request, the control center notifies the other telephone apparatus originating the telephone call of a response hold state. In a system with no response hold function provided as a standard function such as TACS system, the telephone apparatus transmits a response hold request to the control center when the End key is operated upon arrival of an incoming telephone call from the other telephone apparatus. Receiving the response hold request, the control center establishes a telephone conversation state between the telephone apparatuses. Then, hold state sound is transmitted by the telephone apparatus to the other telephone apparatus. Thus, the portable telephone apparatus operating under the TACS system is enabled to execute the response hold function of the CDMA system.

Title
Telephone apparatus adaptable to different communication systems
Application Number
9/273255
Publication Number
6198942 (B1)
Application Date
March 22, 1999
Publication Date
March 6, 2001
Inventor
Hidehiko Akatsuka
Nagoya
US
Keisaku Hayashi
San Diego
CA, US
Agent
Pillsbury Winthrop
US
Assignee
Denso Corporation
US
IPC
H04B 1/38
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