| 摘要 |
A system for connecting a computer to both cellular and landline telephone systems is disclosed. A cellular modem has a single RJ-11 jack for interfacing either to a landline jack or to a signal processing cable connected to a cellular transceiver. The analog data transmission signals of the modem, which are compatible with landline "tip" and "ring" lines, are provided on the third and fourth pins of the RJ-11 connector. When the modem is to be used as a landline modem, the RJ-11 connector is connected directly to a standard landline telephone jack using an ordinary modular telephone wire. When used with a cellular transceiver, the modem generates transceiver operation commands according to a predefined generic command language which is not specific to a particular transceiver. The generic commands are transmitted in serial digital form on the fifth terminal of the RJ-11 connector. The signal processing cable acknowledges the commands received via a serial digital signal transmitted to the second terminal of the RJ-11 connector. The signal processing cable then transmits control signals to the transceiver, with the signals being appropriate to the type of cellular transceiver used, to produce the function requested by the modem's universal command.
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