| 摘要 |
The cellular telephone interface system has the capability to automatically choose between AMPS and CDMA cellular transmission protocols for data transmissions. The cellular telephone interface system includes a PC-modem card, such as a PCMCIA card, for interconnecting the cellular telephone to a data source, such as a laptop computer, portable facsimile machine, or the like. The cellular telephone is capable of transmission in accordance with either AMPS or CDMA transmission protocols. For AMPS, the PC-modem card converts data signals received from the data source into PCM signals for forwarding to the cellular telephone. The cellular telephone converts the PCM signals into AMPS formatted signals for transmission to a local cellular base station. For CDMA transmission, the PC-modem card converts the data signals received from the data source into RS-232E signals for transmission to the cellular telephone. The cellular telephone converts the RS-232E signals into CDMA formatted signals for transmission to the local base station. A variety of data formatting and data compressing protocols are also provided including TCP, IP, PPP and V42.bis. In one embodiment, hardware and software for implementing the protocols are provided primarily within the PC-modem card to thereby reduce the cost, size and power consumption of the cellular telephone itself. In another embodiment, hardware and software for implementing the TCP, IP and PPP protocols are provided within the cellular telephone. Method and apparatus embodiments of the invention are disclosed. |
