| 摘要 |
A cordless modem system where a mobile station unit (MSU) is located in the computer and a base station unit (BSU) is connected to the telephone line. A radio frequency (RF) link is developed between the two units to allow a cordless connection. A series of commands are used between the two units to allow the MSU to request a channel, the BSU to grant a channel, the BSU to notify of a ring, and the MSU to request the BSU to go off hook. In addition, there is preferably a command sequence to allow authorization of a particular MSU or BSU. There are two full duplex channels in each MSU and BSU. This allows multiple BSUs and MSUs to be utilized in a small area. Communications between the two units are secure based on address values for each unit contained in the various commands. The communications software utilized in the computer is not even aware of the presence of the cordless connection. Two embodiments of the MSU are provided, one configured as an external data access arrangement (DAA) to be connected with laptop modems configured to utilize external DAAs, and in a second embodiment the MSU is incorporated with the modem hardware to provide a single, fully integrated unit. The BSU is a single preferably relatively small box which simply plugs into the telephone line.
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