Abstract: A GPRS controller interface communicates commands, events and data between two communication devices using a GPRS transport layer (GTL). In one embodiment, communication devices may include a host and a baseband controller of a modem that communicate over a serial link. Command event and data packets may be framed and multiplexed for transmission over the link. The framing includes, among other things, adding a flag to identify command and event packets from data packets, and a sequence number to help ensure synchronization. A first logical channel may be utilized for command packets including AT modem commands. A second logical channel may be utilized for outbound data packets. A third logical channel may be utilized for event packets, and a fourth logical channel may be utilized for inbound data packets. GTL commands may initiate an initialization or resynchronization of the GCI layer and may be generated, for example, in response to sequence number errors of check-byte errors.

Abstract: A GPRS controller interface communicates commands, events and data between two communication devices using a GPRS transport layer (GTL). In one embodiment, communication devices may include a host and a baseband controller of a modem that communicate over a serial link. Command event and data packets may be framed and multiplexed for transmission over the link. The framing includes, among other things, adding a flag to identify command and event packets from data packets, and a sequence number to help ensure synchronization. A first logical channel may be utilized for command packets including AT modem commands. A second logical channel may be utilized for outbound data packets. A third logical channel may be utilized for event packets, and a fourth logical channel may be utilized for inbound data packets. GTL commands may initiate an initialization or resynchronization of the GCI layer and may be generated, for example, in response to sequence number errors of check-byte errors.

Abstract: A method of bootstrapping executable code to a microprocessor controller from a personal computer (PC) via a bidirectional interface, e.g., a standard PC parallel port comprised of an external 25-pin D-shell connector. By bootstrapping its code from the PC, the microprocessor controller, which controls an adapter, e.g., a modem adapter, coupled to the PC is able to retrieve the most current version of the code stored in the PC.

Abstract: A method of bootstrapping executable code to a microprocessor controller from a personal computer (PC) via a bidirectional interface, e.g., a standard PC parallel port comprised of an external 25-pin D-shell connector. By bootstrapping its code from the PC, the microprocessor controller, which controls an adapter, e.g., a modem adapter, coupled to the PC is able to retrieve the most current version of code stored in the PC.

Abstract: A modem adapter for use with a standard parallel port of a personal computer (PC) for interfacing to the public switched telephone network (PSTN). The modem adapter accepts digital data, eight bits at a time, from a standard PC parallel port and modulates this digital data into an analog format, compatible with the PSTN. Conversely, the modem adapter accepts analog data from the PSTN and converts it into digital data and transfers this data to the parallel port, at least four bits at a time. The modem adapter of the present invention thus neither requires any additional circuit cards in the PC's card slots nor dedication of any of the existing serial ports. Redirector software intercepts software I/O instructions directed toward a serial I/O port and redirects and reformats these instructions to the modem adapter through the parallel port. This redirection permits existing modem control software to be used without modification with the modem adapter of the present invention.