Abstract: A communication device (100) includes three levels and at least one feature and at least one protocol for communicating with other communication devices. The three levels are high level or user ergonomics (302), common level or feature/protocol (310), and low level or hardware platform (318). The feature/protocol level (310) is adapted for controlling the at least one feature and the at least one protocol. The user ergonomics (302) includes a first interface (304) coupled to the feature/protocol level (310) for allowing the user ergonomics level (302) to change without affecting the feature/protocol level (310). The, hardware platform (318) includes a second interface coupled to the feature/protocol level (310) for allowing the hardware platform (318) to change without affecting the feature/protocol level (310) or the user ergonomics level (302).

Abstract: A voltage monitoring method and apparatus starts with the operation of a normal microcomputer program flow, in a microcomputer (40). An input voltage source (90) is converted to a current digital output word (581) representative of the instantaneous amplitudes of the input voltage source (90). A threshold condition (562) is set ahead of time. When the current digital output word (581) satisfies the threshold condition (582), an interrupt signal (36) is generated. Finally, the normal microcomputer program flow is interrupted in response to the interrupt signal (36).

Abstract: In a radio transceiver having a microcomputer (11) that controls various hardware-dependent components (220) and functions (240) that form a plurality of radio control processes, a method and apparatus for executing the radio control processes includes providing the microcomputer (11) with a plurality of virtual sources (272). The virtual sources (272) are for collecting and distributing data (440) generated by the hardware-dependent components (220) and functions (240) in the radio transceiver. A plurality of hardware-independent tasks (292, 392) for executing the radio control processes are also provided by the microcomputer. A distribution controlling interface standard (228) for controlling which hardware-independent task (292, 392) will receive from which virtual source (272) is further provided by the microcomputer (11).

Abstract: In radio processing control (11), a plurality of architectural layers (270, 290, 390) separate at least one of a plurality of tasks (272) from another task (292). For communicating among the tasks within (274, 276, 278) or across (229, 239) the layers, a buffer (300) for each of the tasks is provided by a communication resource (602). A messaging protocol for passing information from the tasks is defined to be a predefined information packet having a header (700) preceding any optional data. A flag portion (701) of the header designates the information as intralayer or interlayer. If the information is interlayer (229, 239), an identifier portion (703, 704) of the header identifies the source (272) of the information and an operation portion (702) identifies an operation code.

Abstract: A clock recovery system for radio communication inserts a synchronization signal (102) at a frequency of 1/2 the baud rate, at the spectral null of an MSK data signal (108), which is also at 1/2 the baud rate, for later retrieval. Hence, in a transmitter-encoder (100), an MSK generator (106) generates an MSK digitally modulated data signal (108e) having a baud rate and a spectral null at 1/2 the baud rate. A synchronization clock generator (104) generates a synchronization signal (102e) having a frequency at 1/2 the baud rate. This frequency at 1/2 the baud rate corresponds to the spectral null of the MSK digitally modulated data signal (108e). A transmitter transmits the synchronization signal (102e), at the spectral null of the data signal (108e), together (112) with the MSK digitally modulated data signal (108e).

Abstract: A method and an apparatus for controlling a speaker mute time is provided to transmit an information message from a first communication device to a second communication device. In response to receiving the information message, the second communication device controls the duration of its speaker mute time.

Abstract: The initial transmission (108) from one subscriber to another subscriber is transmitted at full power. The receiving unit measures the received signal strength and returns a code (118) representing this value in a reply message (114), which is also transmitted at full power. The signal strength of the reply message is determined and may be sent to the replying subscriber unit in a subsequent transmission (122), which may now be accomplished at a reduced power level. Thereafter, both subscribers may modify their respective transmitter power levels during subsequent transmission to minimize battery consumption and maximize the operational life of the subscriber unit.

Abstract: This tone decoder utilizes three correlators for detecting the presence of a desired tone signal. A main correlator correlates to the desired tone frequency, while two side correlators are used to correlate to frequencies above and below the desired tone frequency. Tone detection is indicated by correlation of the main correlation and absence of correlation by the side correlators. Improved bandwidth and/or correlation time is achieved as compared to utilizing a single correlator.