Abstract: A method and apparatus for allowing a conventional caller identification adjunct device to support spontaneous call waiting identification service. During an ongoing call, CPE alerting signals indicating a second, incoming call are received by a converter device which mutes a line to the connected telephone and responds with the appropriate DTMF signal. Following the correct response, the telephone company sends information in an FSK format which describes the number and name of a second caller. Upon receiving the FSK information, the converter adds the appropriate protocol information to the FSK information so that it can be understood by the CID display device. The modified information is then transferred to the CID display device where it is displayed.
Abstract: A technique for converting specific dial tone signals received from a telephone exchange, such as those which indicate a Message Waiting, into formats that are readily recognized by telephones or adjunct devices is disclosed. A dial tone converter device is connected between the telephone exchange providing the dial tone signalling and a message indicator device (such as an integrated telephone or message display adjunct device) which does not recognize dial tone signals. Alternately, the dial tone converter device is connected in parallel with the message indicator device. Under normal conditions, the message indicator device is connected to the telephone exchange in a way that all types of signalling (including dialing, voice, and FSK) can pass to and from the exchange. At specific intervals when neither the telephone nor any extensions at the subscriber's number are in use, the dial tone converter engages the line such that the dial tone signal is provided by the telephone exchange.