Abstract: A monitoring computer monitors the communications occurring within at least one communication system for at least one unique communication unit identification code (unit ID code) associated with a communication unit. Upon detecting the at least one unit ID code, the monitoring computer compares the type of communication made by the communication unit with known software parameters (including the allowable types of communications) for the communication unit. When the type of communication made by the communication unit does not substantially match the known software parameters for the communication unit, the communication unit is identified as using an unauthorized and/or duplicated software application.

Abstract: An addressing apparatus and method may be obtained in a data conveyance network by providing modular circuits with an addressing circuit and incorporating a coupling sense circuit. When a modular circuit is connected into the data conveyance modular network, the coupling sense circuit allows for a assignment token to be passed to the modular circuit such that the modular circuit can determine addresses of time slots which are to be allocated to it. The assignment token is only passed amongst the modular circuits at initial turn on of the data conveyance modular network or when a reset condition occurs which is triggered by a data conveyance controller.

Abstract: In a communication system, the following describes a method for the communication system to more efficiently process control information when the control channel is temporarily used as a voice channel. When a communication unit has control information to transmit to the communication resource allocator, it determines whether the monitored voice channel is busy. When the monitored voice channel is not busy, the communication unit transmits the control information to the communication resource allocator on the monitored voice channel. Regardless of whether the monitored voice channel is busy or not, the communication resource allocator transmits recommended channel parameters on the monitored channel wherein the recommended channel parameters comprises at least one recommended channel. When the monitored voice channel is busy, the communication unit decodes the recommended channel parameters to ascertain the at least one recommended channel.

Abstract: In a communication system having a communication resource allocator, a plurality of communication units, a plurality of communication resources, and at least one console, the communication resource allocator is improved to comprise system reconfiguration databases, selection information, execution information, and predetermined event receiving information. The improvement allows the communication system to be automatically reconfigured in response to a predetermined event. The predetermined event is typically initiated by one of the plurality of communication units.

Abstract: A communication unit may operate in either a trunking communication system and a cellular communication system when the coverage areas of each system overlap. Typically, the communication unit is affiliated with the trunking communication system and operates normally therein. When a call is received or being placed via the cellular communication system, the communication unit transfers its affiliation to the cellular communication system and operates therein. The communication unit is prompted by the trunking communication system to transfer its affiliation for incoming calls and does so automatically for outgoing calls. Once the communication ends, the communication unit transfers its affiliation back to the trunking communication system within a predetermined period of time.

Abstract: Protocol convertors associated with a mobile facsimile device and a fixed-end facsimile device are used to terminate the control data and image data protocols unique to each device. The protocol convertors interface with a digital RF communication system using a radio link protocol to ensure the error-free transmission of facsimile data.

Abstract: Sequential data transmission by a plurality of communication units may be achieved in a communication system by using an accurate external clock and transmitting at predetermined time intervals or time slots. By using a GPS clock signal as the external clock, a communication system may determine a cycle time and duration of time slots such that each communication unit is allocated a time slot for data transmission. This approach eliminates the need for polling of communication units and substantially reduces data congestion on control channels of the communication system.

Abstract: Within a fixed infrastructure of a communication system, message portions of code words that are found to be uncorrectable (erasures) are transmitted with a predetermined number of bits in place of the parity portion associated with those code words. These predetermined number of bits indicate the existence of the erasures, which can be reproduced for continued transmission to the final destination. By having the number of predetermined bits being less than the number of parity bits, the bandwidth requirement for wireline communication paths is reduced.

Abstract: A heat sinking apparatus that dissipates heat generated by a surface mountable power device, which can be auto picked and placed, comprises a first planar surface, at least one gull wing mounting tab, and at least one connective leg. The at least one connective leg thermally couples the first planar surface to the gull wing tab and all three structures are comprised of a thermally conductive material. When the heat sinking apparatus is coupled to a substrate, heat generated by the surface mountable power device is thermally transferred through a thermal plane of the substrate to the heat sinking apparatus.

Abstract: An encryption code and at least one key are provided to a secure transmission device, via an external keying device, and stored in a first volatile memory. An encrypted representation of the at least one key, based on the encryption code and the at least one key, is generated and stored in a non-volatile memory. Upon power down of the secure transmission device, the encryption code is stored in a second volatile memory and the at least one key and encryption code stored in the first volatile memory are erased.

Abstract: In a communication system that provides access to telephone resources of different types, a resource allocator of the communication system may more efficiently allocate the telephone resources in the following manner. Once a communication unit of a first communication group transmits a request for allocation of a telephone resource, the resource allocator determines what communication group the requesting communication unit is affiliated with. Subsequently, the resource allocator determines whether the requesting communication unit has primary access to either a first or second set of telephone resources. When a telephone resource is available and the requesting communication unit has primary access to that telephone resource, the resource allocator allocates the telephone resource to the requesting communication unit based upon a preestablished allocation procedure.

Abstract: An electromagnetic shielding assembly comprises a substrate, an electrically conductive carbon composition shielding plate, and a metallic plate, wherein the electrically conductive carbon composition plate is physically and electrically coupled to the substrate and the metallic plate. By positioning the substrate such that a circuit that emits, or is sensitive to, electromagnetic energy is substantially enclosed within a cutout area of the electrically conductive carbon composition plate, the electromagnetic shielding assembly substantially contains the electromagnetic energy radiating from, or towards, the circuit.

Abstract: In a secure communication system, a secure point-to-point communication may be accomplished in the following manner. A first communications unit receives a request from an operator for a point-to-point communication identifying at least one destination communication unit. In response, the first communication unit generates a private call key variable by modifying an encryption key variable through the use of a predetermined function. Identity of the encryption key variable and information pertaining to the predetermined function is transmitted by the first communication unit to the destination communication unit. Upon receiving the identity of the encryption key variable and information pertaining to the predetermined function, the destination communication unit generates the private call key variable. When the private call key variable has been determined by the first communication unit and the destination communication unit, both communication units can engage in the secure point-to-point communication.

Abstract: A wireless binary coded optical data receiver receives the binary encoded data via a photodiode. The binary encoded data is then supplied to the primary winding of a transformer and thus coupled to the secondary winding of the transformer. The secondary winding is coupled to a transimpedance amplifier wherein the transimpedance amplifier buffers the received binary encoded data. The buffered binary encoded data is then amplitude limited by a limiting circuit.

Abstract: Within a communication system having a plurality of communication system sites, each communication system site has a one cell re-use pattern of a limited number of communication resources. Communication units within the communication system utilize a redundant transmission of information such that the geographic separation of communication system sites utilizing the same communication resources is reduced.

Abstract: A power amplifier assembly that dissipates a maximum of one thousand one hundred watts includes a power amplifier circuit and a chassis that has an overall volume of 0.02 cubic meters. The chassis includes a heat sink base that contains a mounting pattern for the power amplifier circuit. By thermally coupling the power amplifier circuit to the heat sink base via thermal coupling devices and the mounting pattern, the heat sink base dissipates a maximum of one thousand one hundred watts in a volume of 0.016 cubic meters.

Abstract: In a network of communication systems, a communication resource allocator of any of the communication systems may reclaim system resources from inactive communication systems. This may be accomplished by having the communication resource allocator transmit at least one polling message to the communication unit to determine whether the communication unit is in need of the at least one system resource. If the communication unit does not respond to the polling message, the communication resource allocator determines whether the communication unit is inactive. If the communication unit is inactive, the communication resource allocator reclaims the at least one system resource from the communication unit.

Abstract: Adaptive digital coding of received analog information based on signal strength can be accomplished in the following manner. Once a repeater receives analog information from a communication unit, the signal quality of the received analog information is determined. Next the signal quality of the received analog information is compared with a first signal quality value. If the signal quality of the received analog information is above the first signal quality value, the received analog information is digitally coded based on a first digital coding format. If the signal quality of the received analog information is below the first signal quality value, the received analog information is digitally coded based on a second digital coding format.

Abstract: An amplifier for amplifying RF signals comprises a transistor, a first impedance, an impedance transformer, and a tuned resonant circuit. The amplifier receives the RF signals via a signal terminal of the transistor, wherein the RF signals are amplified by the transistor, the tuned circuit, the first impedance, and the impedance transformer. The degree of amplification is based on the impedance ratio between the impedance transformer and the first impedance, wherein the first impedance may be an output impedance matching transformer.

Abstract: In a communication system network, an operator station, for a particular communication group, may select communication systems wherein a communication group service will be performed for the particular communication group. This is accomplished when the operator station selects, for the particular communication group, the group service to be performed and which communication systems the service is to be performed in. Once these parameters are selected, the operator station transmits them to the central controller which determines whether at least one communication unit of the particular communication group is registered in the selected communication systems. When at least one communication unit of the particular communication group is registered in the selected communication systems, the central controller allocates a communication resource in the selected communication system to the operator when a communication resource is available such that the selected communication group service can be performed.