Abstract: Authentication of system status OSWs in a trunked communication system is provided by first verifying (411) that a received system ID (313) matches a pre-programmed system ID. A system status OSW must then be matched twice before the information in the system status OSW is programmed into a communication unit (115), thus limiting the possibility of false decoding of system status OSWs.

Abstract: A CM (105) receives requests for data transfer from a series of UMs (101-103) and from an EM (104). The requests contain the UM (101-103) or EM (104) address and the size of the data packet to be transferred. The CM (105) processes the requests on a FIFO basis, stores the requests in a queue and assigns either a small data channel or a large data channel, depending on the packet size to be transferred, and also the corresponding number of required timeslots. The CM (105) picks the first request off the queue and sends a grant to the particular UM (101-103) or EM (104) which receive the grant and immediately access either the assigned small or large data channels in the required number of timeslots.

Abstract: A radiotelephone data transfer apparatus connects peripheral devices external to the radiotelephone and other user information inputting devices, such as a handset for a cellular mobile radiotelephone, to the radiotelephone's central processor and speech processor. The data bus apparatus generates frame formats in which the information is sent over the data bus. The frame formats are further subdivided into time slots, the time intervals in which individual messages are sent. The data transfer apparatus is configured so that messages sent to the cellular radiotelephone's speech processor are not flow controlled, while messages sent to the radiotelephone's central processor are flow controlled. Further, the radiotelephone's central processor controls operation of peripheral devices attached to the radiotelephone.

Abstract: A battery type detector for battery-using and battery-charging equipment is disclosed. Operational characteristics of the using and charging equipment is modified in accordance with the battery type detected.

Abstract: Apparatus and method for transferring segmented memory between memory units determines a need for memory transfer and searches a memory unit segment by segment until a valid data record is found. This valid data record is conveyed to another memory unit via the asynchronous mode. If a valid data records is not found within a predetermined amount of time, a message identifying the memory segment last searched is conveyed. If no remaining valid data records are found, a message with no information is conveyed. Priority is given to asynchronous messages.

Abstract: In frequency-hopping spread-spectrum systems, it is necessary to maintain frequency and bit synchronization (sync) between the transmitter and receiver in order to maintain quality data recovery at the receiver. A protocol is described which includes a synthesizer lock field (109) to allow frequency sync, a clock sync field (123) to achieve quick clock sync, and a data sync field (125) to provide data sync. Other fields are provided in the protocol to allow both voice (141) and data (127) transmissions, inband signalling (139), and error correction (143). A method and apparatus, driven by a microprocessor (303) and ASIC (301) combination, are described that generate and transmit this protocol.

Abstract: A directional coupler (103) for radio equipment couples a radio frequency signal from an input of a microstrip transmission line (309) to an output and provides a directionally coupled output via a stripline microstrip (311). Open circuit microstrip transmission line stubs (313 and 315) are tuned to a quarter wavelength of the third harmonic of the radio frequency to provide third harmonic rejection within the directional coupler.

Abstract: A wedge-shaped receptacle for mounting a noise cancelling microphone transducer (105) and a ringer alert transducer (107) within a housing (101) is disclosed. The receptacle (111) is molded from a flexible material providing efficient assembly of the transducers within two apertures in the receptacle (129 and 133). Gaskets (137 and 145), molded as part of the receptacle, provide an acoustic and weatherproof seal between the receptacle (111) and the housing (101) for each transducer. The two apertures (129 and 133), providing acoustic interface for the ringer alert transducer (107) and the microphone transducer (105), share the same opening (113) in the front face of the housing (101). The aperture (133) for the noise cancelling microphone (105) is also open to a second opening (115) in the bottom face of the housing (101) to cancel background noise. The receptacle includes channels (201 and 202) which allow back pressure release for the ringer alert transducer (107 ).

Abstract: A cellular radiotelephone system transfers a call from a source base-site (200) to one target base-site (205,210). A source base-site (200) in the first RF coverage area (100) measures the signal strength (RSSI.sub.S) of a mobile (225), provides a forecasted signal strength (RSSI.sub.F) representing a would-be power increase of the mobile (225) and sets up two time windows. The source base-site (200) sends the measured and forecasted signal strengths to candidate target base-sites (205,210) found by the mobile (225) which measure the mobile (225) signal strength (RSSI.sub.T) and compare it once to RSSI.sub.S plus a hysteresis value. If RSSI.sub.T is greater than RSSI.sub.S, the call is transferred to the best responding cell. If RSSI.sub.T is below RSSI.sub.S, RSSI.sub.T is compared to RSSI.sub.F. During this time, the mobile 225 will increase power at the end of the first time window. If RSSI.sub.T is ever greater than RSSI.sub.

Abstract: In an exemplary embodiment, a communication device, such as a radiotelephone (100), has within its housing (106) an apparatus for electrically coupling an electroacoustic transducer (201), such as an earpiece, to radiotelephone circuitry (403). The apparatus comprises resilient conductive means, for example conductive barrel springs (213-216), abutting both the conductive contacts on the earpiece (214, 243) and the corresponding conductive contacts on a printed circuit substrate (205, 208, and 206, 207). A bracket (211) manually attached to the printed circuit substrate (203) positions the conductive barrel springs (213-216) while they are compressed between the earpiece (201) and the printed circuit substrate (203) during the assembly of the radiotelephone (100). A plurality of barrel springs (213-216) are used to provide redundant electrical coupling and stability for the earpiece (201). The apparatus advantageously provides for improved manufacturability and convenient replaceability of the earpiece (201).

Abstract: A semiconductor chip carrier (SCC) comprising means for physical orientation and attachment to a substrate which is independent of means for coupling electrical signals to the substrate, thereby alleviating many of the constraints often placed on the substrate and/or electrical coupling system.

Abstract: A communication control console center, able to receive at least one phone call, has a ring tone mute button (103). To prevent indefinite or permanent muting of ring tones automatic disabling of the ring tone mute circuit is provided by a programmable timer (107). An automatic mute button (111) is presented to automatically disable ring tone muting at call termination.

Abstract: A method of message authentication in an encrypted communication system with over-the-channel rekeying features the ability of a communication unit (107) to authenticate (1709) a rekeying message (701) from a key management controller (101) using a message number (1517A) comparison, thereby preventing outside interference from unauthorized rekeying message transmissions.

Abstract: A hinge apparatus for a foldable telephone (100) includes a body portion (101) and a flip element (103). The flip element (103) is held in a closed (FIG. 3A) and a open (FIG. 3B) position relative to the body portion (101) by an enclosed follower (201) which follows recesses (301 and 303) in two hinge shafts (205 and 207) integral to the hinge portion (112) of the flip element (103). The apparatus is assembled along a common axis (233) from a single direction. The flip element (103) is held tight against a keypad (109) of the body portion (101) in its closed position (FIG. 3A). The flip element (103) is secured in its open position (FIG. 3B) with no excessive play.

Abstract: A differential quadrature PSK receiver (100) recovers serial data in a forward and reverse direction in time using a forward and reverse mode PLL (232) and decoder switch (108). The DQPSK receiver (100) is particularly useful for recovering a packet of serial data (Rx) having a time-varying signal level and a relatively long duration. Sync words in the packet (Rx) or adjacent packets (Ry) provide starting points from which the data is recovered. The direction in time of data recovery is dependent on the quality of the time-varying signal level in the packet (Rx).

Abstract: A portable radiotelephone with a keypad, alphanumeric character display, and hands free function is disclosed. A movable flip element of the housing covers a keypad and other control buttons when in a closed, on-hook, position and activates the illumination of the keypad, enables the display, and enables the hands free function when in an open, off-hook, position. The duration of keypad illumination and display activation are timed to reduce battery drain and the hands free function may be deactivated with a hookswitch flash.

Abstract: This key management system effectively solves the key distribution problems of distance, time, operator error, and security risk by transferring encryption keys with appropriate system information between a key management controller (101) and a remote keyloader (109). The keyloader (109) is then coupled to a communication device to transfer (327) the keys and receive (329) identification information from the communication device. The keyloader (109) then sends (323) the information to the key management controller (101) that controls the distribution of the encryption keys and collection of the communication device identifications.

Abstract: A receiver 200 automatically compensates for intermodulation of an input signal. The receiver 200 is preceded by a receiver front-end 105 which is coupled to antennas 100-102 receiving the signal. The gain of the antenna path/frequency is calibrated and stored for all combinations of antenna path/frequency. When a signal is received, the receiver 200 determines the correct stored gain factor representing the antenna receiving the signal and the frequency of the signal. The gain factor is compared against a predetermined threshold, and if the gain factor is greater than the threshold, an attenuator 400 placed at the front of the receiver 200 is inserted to optimize signal intermodulation. If the gain factor less than the threshold, the attenuator 400 is bypassed to optimize the sensitivity of the receiver 200.