Abstract: A method and apparatus for establishing a connection between a server and a remote device over a communication network. Data transmission is attempted at a first carrier frequency and bit rate. If transmission is unsuccessful, the bit rate is lowered. If transmission remains unsuccessful, the carrier frequency is changed to a second carrier frequency. As data transmission continues, the bit rate may be interactively increased or decreased in order to maximize data transfer throughput.

Abstract: A coupler enabling communication of information between a communication device, such as a PIM device, and an acoustic device, such as a telephone, using acoustic tones. The coupler includes a speaker for transmitting information in the form of acoustic tones to the acoustic device and a speaker for receiving acoustic tones from the acoustic device. The coupler may also include an adjustment mechanism which facilitates coupling between the microphone and an earpiece of the acoustic device and between the speaker and a mouthpiece of the acoustic device. The microphone and speaker positions may be adjustable to adapt to a variety of telephone handset styles, such as cellular telephones or cordless telephones.

Abstract: The present invention uses an acoustic modem embedded in a remote device enhanced with automatic repeat request and forward error correction routines to provide reliable transfer of electronic messages from the messaging server to the remote device. This may provide significantly better error correction than standard PC modems. Also the present invention, may provide a fast, reliable connection sequence by use of a preamble frame. According to an embodiment of the present invention, a method of communicating messages between a messaging server and a remote device is provided. The method includes a variety of steps such as establishing a connection between the messaging server and the remote communication device by transmitting a preamble frame, exchanging data frames between the remote device and the messaging server, detecting and correcting errors in received frames, and re-transmitting received frames, if errors are uncorrectable.