Abstract: A system and method for communicating electronic messages between a remote device and a messaging server over telephone lines using acoustic coupling. Information is communicated between the remote device and the messaging server using acoustical tones corresponding to the information. The messaging server provides store-and-forward capability for messages received from external sources and which are then forwarded to the remote device. The remote device generates acoustical tones corresponding to information to be transmitted to the messaging server. The acoustical tones are transmitted to the messaging server over a telephone network which is acoustically coupled to the remote device. The messaging server performs processing based on information received from the remote device. The messaging server generates acoustical tones corresponding to information, including messages, to be transmitted to the remote device.

Abstract: DSP error detection and filtering of a modem signal using a simple, robust, and low cost technique. The DSP technique utilizes a equalizer/filter to adjust the amplitude and phase delay of the transmitted data signal. The modem on the DSP chip may include a demodulator, parser/interpreter module, start and stop bit module, and modulator. The demodulator may include a switch, equalizer/filter, processing module, bit converter, adder, and averaging module. The averaging module computes an average value for the error signal during the frame training sequence. The error signal is the output of the bit converter minus the output of the demodulator. After each bit of the error signal is fed into the averaging module, the averaging module computes a new average. The averaging module performs an adaptive process. The average value of the error signal is compared to a threshold value.

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.

Abstract: A multi-function electronic messaging system for transmitting messages over a first communications link having a remote unit for generating forward error corrected signals representing various types of electronic messages, for generating acoustical tones corresponding to the error corrected signals is provided. The acoustical tones are coupled to the send-only first communications link and transferred to a computer. The computer sends an acknowledgement signal back to the user of the remote unit over the first communications link and decodes and error checks the signals. The computer also reformats the various messages and resends them out over various communication links depending on the ultimate destination of the message. The computer may also send messages to the remote unit over a receive-only second communications link. A multi-level method of error detecting and correcting data is also disclosed.

Abstract: A system for communicating data between a computer and a unit remote from the computer is provided, comprising receiving input information from a user in the remote unit and for producing data signals corresponding to the input information, producing error corrected message signals from the data signals, generating acoustical tones corresponding to the error corrected message signals, communicating said acoustical tones over a first communications link, said first communications link being bi-directional so that the remote unit communicates data with the computer, and receiving acoustic tones over said first communications link from the computer, the acoustical tones being adjusted for the conditions of the first communication link prior to transmission to the remote unit. The remote unit may also receive data from the computer over a second communications link, which is independent of the first communications link so that the remote unit receives data from two different communications links.

Abstract: A coupler is provided which may be incorporated into a handheld communications device to permit the handheld device to be acoustically coupled to a variety of telephone handsets. The device may include a spring-biased, adjustable microphone arm onto which a microphone is mounted in order to acoustically couple the microphone to the telephone handset. The microphone arm may be adjustable to adapt to a variety of telephone handset styles, such as cellular telephones or cordless telephones, in order to permit the acoustical coupling to be achieved with a large number of different telephone handsets.