Abstract: A network entity and method for eliminating ranging collisions for a group call in a communication network includes a step 300 of provisioning a pre-established rule for all members of a group, the rule including a common random number generator seed. A next step 302 includes initiating a group communication to subscriber units belonging to a group. A next step 304 includes generating a list of unique ranging codes for the members of the group using the common seed. A next step 306 includes each member of the group transmitting on its unique ranging code.

Abstract: A microdevice (20, 120, 220) having a hermetically sealed cavity (22, 122, 222) to house a microstructure (26, 126, 226). In one embodiment, the microdevice (20) comprises a substrate (30), a cap (50) and an isolation layer (70). The substrate (30) has a plurality of conductive traces (38) formed on at least a portion of its top side (32) and outer edge (36). The conductive traces (38) provide electrical conductivity to the microstructure (26). The isolation layer (70) is attached between an outer edge of a sidewall (54) of the cap (50) and the plurality of conductive traces (38). The cavity (22) is at least partially defined by a recess (56) in the cap (50). There is also a microdevice (120) comprising a substrate (130), a cap (150) and a plurality of via covers (170). The substrate (130) has conductive vias (196) that terminate at a contact point (146) within the sealed cavity (122). The via covers (170) are attached to the substrate (130) to provide a hermetic seal.

Abstract: A wrist-carried radiotelephone, operable without removing from a user's wrist, includes a housing including a display and a battery, and a wristband having a plurality of rigid and flexing portions. The flexing portions mechanically connect the rigid portions. The wristband is electrically and mechanically coupled to the housing. The radiotelephone circuitry is distributed within the rigid portions of the wristband and is interconnected through the flexing portions of the wristband. The circuitry is coupled to the display and the battery through the wristband.

Abstract: A method and apparatus reduces the peak current drawn from a DC-to-DC voltage converter (126) in a battery powered communication device such as a radiotelephone handset (104). The radiotelephone handset (104) enters high current operating conditions during transmit time slots (208, 210) and receive time slots (212, 214) defined by a TDMA protocol. During the receive time slots (212, 214) and the transmit time slots (208, 210), operating power is removed from a portion of the communication device, such as the display (120), to reduce the peak current drawn from the voltage converter (126). Excessive current drain from the battery (124) and rapid battery discharge are thereby eliminated.

Abstract: A notch filter (100) includes a parallel coupled delay line (104) and surface acoustic wave resonator (102) which provides a pole at a desired passband. The surface acoustic wave resonator (102) and the delay line (104) are configured to provide a zero at an undesired frequency or stopband. In this way, the notch filter (100) augments the stopband rejection of an associated cascaded surface acoustic wave ladder filter (105). The notch filter (100) also provides a pole at a desired frequency or passband such that losses due to the notch filter (100) at the desired passband are minimized, thereby improving overall insertion loss performance.

Abstract: An improved wrist-carried radiotelephone includes a first housing including a microphone, a display and a radio transceiver. A second housing includes a latch, a user interface, a speaker, and a removable battery. A flexible wristband has a first portion including an antenna extending downwardly and a latch clip at one end thereof operable to be received in the latch of the second housing. A second portion of the wristband includes electrical connections to connect the circuits of the first and second housing. The wristband includes support members to maintain the wrist-carrier radiotelephone in a predetermined configuration when the first portion of the wristband is unlatched from the second housing such that the speaker and microphone of the radiotelephone are at an optimum orientation in relation to a user's ear and mouth.

Abstract: Quartz crystal resonators 30 with a first angle of rotation having an X-axis 17 and Z′-axis 19 lying within a plane corresponding to an AT-cut and a second angle of rotation 34 within the plane of the AT-cut and lying within a range of about ±1° to about ±11.5° from the Z′-axis of the AT-cut. The resonators includes substantially opposing electrodes 36 disposed on major faces of the quartz crystal plate 32. The second angle of rotation 34 results in quartz crystal resonators 30 being produced with a more uniform distribution of temperature performances.

Abstract: A cellular cordless telephone (10) operates with both a cordless base station (180) and a cellular base station (190) and cellular control terminal (196). In one embodiment (FIG. 2), a cellular cordless telephone (100) includes a cellular transceiver (120), antenna (128), keyboard (140), a display (180), handset (160), and microcomputer (130) together with a cordless transceiver (110) and antenna (118), all of which may be in a single housing. In another embodiment (FIG. 3), a cellular cordless telephone (200) includes a cellular telephone (220) and a cordless telephone transceiver (210) which may be a plugable module. Whenever cellular cordless telephone (10) is within range of cordless base station (180), telephone calls may be made over the cordless radio channel or transferred from the cellular radio channels to the cordless radio channel.

Abstract: A portable communication device (102) includes a housing (105), a first display area (130), and a second display area (132). The first display area (130) is outwardly directed from a side (122) of the housing (105), and the second display area (132) is outwardly directed from a front (120) of the housing (105). The housing (105) may include a housing portion (114) movable to an open position and a closed position, where the second display area (132) is covered by the housing portion (114) when positioned in one of the first and the second positions.

Abstract: A radiotelephone (104) in a radiotelephone system (100) enters a low power sleep mode and times the duration of the sleep mode using a sleep clock generator (205) having a coarse resolution. The radiotelephone synchronizes timing of the radiotelephone to system timing using an oscillator (116) having a fine resolution. The radiotelephone then exits the low power sleep mode synchronized with system timing.

Abstract: A switch assembly (100) includes a first switch (102), a second switch (104) and a third switch (106). The switch assembly further includes a rocker actuator (108) having a first rocker arm (152) and a second rocker arm (154) and a selector actuator (110). The rocker actuator pivots about a post (158) to actuate the first switch or the second switch. The selector actuator is disposed between the first switch and the second switch to slidingly actuate the third switch. In one application, a radiotelephone (800, 904) includes a switch assembly (840). A controller (914) responds to actuations of the rocker actuator and the selector actuator to control storage of data in a memory (926) and display of data in the display (818, 918).

Abstract: A piezoelectric substrate (120) and a method for preparing same. The method includes steps of (i) providing a boule of piezoelectric material, (ii) orienting the boule to Euler angles chosen to provide a boundary condition matched to a partially-metallized surface and (iii) sawing the boule into at least a first slice (120) having first and second surfaces, at least one of the first and second surfaces comprising a planar surface. The method desirably but not essentially further includes steps of (iv) polishing at least one of the first and second surfaces to provide a substantially planar polished surface, (v) disposing a layer of metal on the at least one of the first and second surfaces and (vi) patterning the layer of metal to provide at least one interdigitated pattern (105, 110) comprising an acoustic wave transducer (105, 110), the acoustic wave transducer (105, 110) providing the boundary condition matched to a partially-metallized surface.

Abstract: A substantially sealed frequency source (10) including a crystal oscillator (14) and a programmable IC (22) thermally and electrically coupled on a substrate (12). The IC (22) is accessed through an interface (26) with programming signals (42) so as to provide an analog temperature control signal (34) and a crystal oscillator frequency adjustment signal (36). The substrate (12) maintains a substantially constant temperature at a turning point (82) on a frequency-temperature response curve (80) of the crystal (64). The IC (22) allows programming of the source (10) after sealing to compensate for shifts in the crystal frequency-temperature response (80) due to sealing. The IC (22) provides electrical correction of the substrate temperature setpoint and the crystal oscillator frequency without mechanically or thermally disturbing the internal components of the source (10).