Abstract: A user input device, e.g., a wireless keyboard, for providing user inputs to a receiver unit via a communications medium intermittently transmits diagnostic messages in the communications medium such that a diagnostic message is transmitted after a predetermined interval following transmission of a preceding diagnostic message has expired. A receiver unit is responsive to the communications medium and configured to receive the transmitted diagnostic message and process the received diagnostic message to determine a status of the user input device. Preferably, the user input device is configured to transmit a diagnostic message following at least one of passage of a predetermined fixed time interval after a diagnostic message was previously transmitted from the user input device and acceptance of a predetermined number of user inputs at the user input device after a diagnostic message was previously transmitted from the user input device.

Abstract: A data and message retrieval communications system utilizes a base station such as a PC or cellular phone to transmit received messages and stored data in accordance with an operator customized data configuration and transmission scheme. The system includes a remote receive-only communication unit that receives and processes the signal from the base station in accordance with an operator customized data configuration and retrieval scheme. The remote unit preferably includes a receiver having an antenna, a processor that processes the transmission signal received by the receiver, a memory storing the personal data and data corresponding to the transmission signal, and a display interface unit enabling an operator to interface with the processor programmed to access and control the receiver, the memory and the display interface in accordance with the operator customized data configuration and retrieval scheme. In one arrangement, the remote communication unit is embodied in a wristwatch for maximum portability.

Abstract: A method for transmitting key characters representative of keys on a keyboard is provided. A probability of use for one or more of the key characters may be determined by counting the number of occurrences of the key characters for a predetermined time period or for a literary work. Alternatively, the number of occurrences of one or more of the key characters may be calculated in real time and the probability of use adjusted accordingly for the key characters. Based on their calculated probability of use, the key characters are mapped into transmission formats. A system and a keyboard are also disclosed which map key characters into transmission formats based on probability of use of the key characters. Additional methods are disclosed for using error detection data in the transmission formats. Exemplary error detection may include adding parity bits or configuring the data in the transmission formats to indicate errors.

Abstract: A protocol processor functionality and a data pump functionality are included in a modem which is configurable in a number of modes of operation to effectuate both analog and digital data communications. When configured for analog data communications either over a telephone line of the wireline telephone network or using an analog capable mobile station of the cellular telephone network, data signals are routed through both the protocol processor functionality and the data pump functionality. The protocol processor is also connected to the mobile station to transmit and receive call supervision signals. When configured for digital data communications using a digital capable mobile station of the cellular telephone network, the data signals by-pass the data pump functionality and are transmitted by the protocol processor functionality along with the call supervision signals.