Abstract: A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting a voice channel number from 319, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 319 and 0. The receiving device determines a receive frequency by 851.0125 MHz+[(319?a voice channel number)*25,000 Hz], if the voice channel number is between 319 and 0. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Abstract: A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting 440 from a voice channel number, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 440 and 559. The receiving device determines a receive frequency by 851.0250 MHz+[(a voice channel number?440)*25,000 Hz], if the voice channel number is between 440 and 559. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Abstract: Each communication unit (112A through 112F) and talkgroup in a communication system (100) is assigned a priority at each site (106, 108, and 110) in the system. As communication units (112A through 112F) request resources, contention among requesters at a site is resolved by the priority of requesters at the site. System-wide resources are allocated equitably based on the geographical location of the communication unit using site-based priority.

Abstract: A mobile repeater (300) is improved to include a database (303) that allows the mobile repeater to store registrations received from subscriber units. Additionally, the mobile repeater may include a voice on control switching element (309) for use with an extended control channel. Further still, the mobile repeater may include encryption elements (305-308) for the maintenance of encrypted control channels. In this manner, the mobile repeater may provide an improved quality of services to subscriber units.

Abstract: A key variable correction scheme allows errored encryption key material in mobile and portables radios to be quickly identified and corrected. The errored encryption material can be corrected automatically by a key management controller, once detected. Consequently, a mismatch problem can be diagnosed and resolved in a manner which is automatic, therefore quick and efficient, and in a way which overcomes the difficulty which users have in identifying by themselves a mismatch condition since the result is often only silence out of their respective radio speaker. Once the mismatch is corrected by the reassignment of correct keys, the user is free to join the radio call already in progress.

Abstract: A driver circuit provides a plurality of drive energies having a plurality of thermal distributions associated therewith. These thermal distributions interact with print media to form binary images having active and inactive areas. A driver control circuit is responsive to source image information to apply selected drive energies to selected heating elements. These drive energies produce interacting thermal distributions for selectively positioning boundaries between active and inactive areas.

Abstract: A thermal printer includes a thermal print head having a plurality of heating elements for printing dots. A source of drive pulses operates respective heating elements. Each drive pulse is modulated to provide first and second periods of the drive pulse to selectively energize the respective heating element, the first and second periods defining a selected energy level. A memory stores the modulated drive pulses and supplies respective modulated drive pulses to the respective heating elements. A measuring circuit measures a heating factor of each heating element and provides a correction factor for each heating element based on the respective measured heating factor. The correction factors are combined to the respective drive pulses to alter the first and second periods, thereby reducing variations in dots due to differences in the heating factors of the heating elements.

Abstract: A data communication protocol permits efficient and cost-effective transmission of control and ancillary messages among the components of a communication system infrastructure (200). Messages are organized into Infrastructure Control Words (300) with accompanying Format Identifiers (304), and interleaved with voice and data segments (707) to form message streams (700) that are transmitted from one infrastructure component, such as a base station (201), to another infrastructure component, such as a Digital Interface Unit (202).

Abstract: A model figure connected to a remote pistol grip handle has one or more activity motions for the figure controlled from the handle. Unlike other model figures which have activity motions, there is a pivot arrangement between the handle and the figure that allows the operator to easily move the figure on a surface. The model figure has a middle torso portion with a pin extending therethrough, a model limb for the figure is mounted to pivot on the pin, a rotating pulley is mounted on the pin to pivot the limb, and the remote pistol grip handle is connected to the figure through a wand. There is a linkage system from a trigger mechanism on the handle to the rotating pulley so that movement of the trigger mechanism pivots the limb on the pin.

Abstract: A non-gray scale anti-aliasing method for smoothing one or more edges of an image to be printed by a binary imaging printer. The image is generated by rasterizing an ideal outline of the image using a processor means for processing a plurality of raster lines to form a pixel representation of the image to be communicated to the binary imaging printer. An ideal fill area representing the area inside the ideal outline for the pixel currently being processed is determined for each pixel in the raster line and then compared to at least a first and second comparison value. Based upon the comparison, a determination is made as to whether the pixel currently being processed will be turned on or turned off. In one embodiment, the comparison is made by the use of a lookup table having a set of predetermined comparison values that contain estimated fill values used by an accumulator to determine whether to selectively modify the pixel.

Abstract: A line rasterization technique for a non-gray scale anti-aliasing method smoothes the edges of a single pixel width line image to be printed by a binary imaging printer. The line image is generated by rasterizing an ideal line image as a plurality of raster lines to form a pixel representation of the line image to be communicated to the binary imaging printer. For each vertical transition point created by the ideal line image crossing two adjacent raster lines, the present invention smooths the line image by selectively modifying the on and off states of one or more pixels in an adjacent raster line on either side of the vertical transition point. The pixel representation of the line image is then communicated to the printer such that the printer may print the smoothed line image.

Abstract: A non-gray scale anti-aliasing method for smoothing the horizontal components of the edges of an image to be printed by a laser printer having unequal pixel resolutions in the horizontal and vertical dimensions is accomplished by selectively modifying the on and off states of pixels on either side of each vertical transition point along the horizontal components of raster lines representing the edges of the pixel representation of the image. A processor is provided with an ideal outline of the image and rasterizes the ideal outline of the image to determine which pixels to turn on and which pixels to turn off in a frame buffer that stores a pixel representation of the iamge to be printed by the laser printer. The modified pixel representation in the frame buffer is then communicated to the laser printer such that the laser printer may print the smoothed image.

Abstract: A tuning machine is provided with an adjustable bearing surface for eliminating mesh backlash and end play which gradually develope between the worm and worm gear over years of service. The worm is held against the worm gear by a pair of saddle bearings formed on a sliding retainer. When the bearing wear develops an unacceptable backlash or end play develops, the retainer is loosened and repositioned closer to the worm. In the new position the worm is returned to its original intimate engagement with the worm gear. Simultaneously, the worm, is axially centered due to opposed bevel surfaces on the worm and saddle bearings. The new worm to worm gear mesh is free of backlash and endplay.