Abstract: A method for re-establishing communication between a base station (102) that transmits on a forward channel, and a subscriber unit (108) that has temporarily lost the forward channel, uses the concept of a re-registration interval. The base station (102) transmits, to subscriber units (106, 108) in its area, a signal indicating the duration of a re-registration interval. A subscriber unit that has temporarily lost the forward channel determines whether the duration of such loss exceeds the re-registration interval. If the interval is exceeded, the subscriber unit sends a re-registration signal to the base station on a reverse channel. A selective call transceiver (400) is programmed to operate as a subscriber unit that uses the re-registration interval.

Abstract: A method of encouraging a user of a SCR (Selective Call receiver) (10) to read advertisements stored in the SCR (10). The user is provided with an initial level of access to a feature of the SCR that enhances the SCR's usefulness. When the user reads an advertisement, additional access to that feature is provided for a predetermined time period. Preferably, the feature is memory space, and each time the user reads an advertisement, the memory space available for storing messages is temporarily increased.

Abstract: An electrical connection is formed between conductors (46, 48) on a substrate (36), and pads (42, 44) that are coupled to an electrical component. The conductive pads (42, 44) are arranged in two rows of oversize pads. Two corresponding rows of undersize conductors (46, 48) are electrically connected to the pads by a conductive elastomer (40). A display assembly (26) advantageously employs the electrical connection.

Abstract: A transceiver (10) used in an RF messaging system transmits unscheduled messages on a channel selected by the transceiver (10). The transceiver(10) examines a number of factors prior to selecting a channel, including the power available from its battery (39), the power required to send the message, and which channel it had previously used to successfully transmit a message. Depending on the results of this examination, the transceiver (10) can reject the channel it has used successfully on previous occasions and select a different channel having a different data rate.

Abstract: In a communication system that transmits diversity messages (an original message followed by one or more copies thereof), a selective call receiver (10) which receives an original message and one or more copies will display only one of the received messages and discard the others without displaying them. This is accomplished by storing in a memory (30) the identification tag of the message that was displayed and deleted. The identical identification tags carried by later copies of the same message are compared to the stored identification tag. If a match is found, this indicates that an earlier version of the received message has already been displayed and deleted, whereupon the received copy is discarded.

Abstract: In a liquid crystal display (16) having rows and columns of pixels (22), one or more selected rows of pixels are turned off (put in a standby mode) in a manner that saves power. A row of pixels is turned off by applying to the row a cyclical two-level voltage (BP2) having a magnitude that, when combined with voltages (FP3) applied to columns, results in each pixel in the selected row receiving a combined voltage (BP2-FP3) having a reduced number of transitions (30), having a magnitude that is insufficient to turn on a pixel, and having an average value of substantially zero over a cycle. The method is incorporated in a liquid crystal display apparatus (32) having a mode control (54) for switching selected rows of pixels between an active mode and a standby mode.

Abstract: A strain relief device (10) for wires is formed of a nonconductive plate (12) having a central axis (18) and a plurality of through-holes (14) distributed around the central axis (18). Each through-hole has a diameter selected to permit a wire to pass through it without binding. The non-conductive plate (12) includes a plurality of shoulders (20), one shoulder associated with each through-hole (14) and located between its associated through-hole and the outer perimeter of the plate (12). A preferred method of using the strain relief device is also described.

Abstract: A low power, fast starting oscillator (10) of the Colpitts type includes an amplifier (12) that provides voltage gain and feeds a source follower circuit (14) that provides a desirable output impedance. A crystal (16) is coupled from an output of the source follower circuit (14) back to the amplifier's input (32). The voltage gain of the amplifier (12) and the output impedance of the source follower circuit (14) are independently selectable to provide an optimum transconductance for the oscillator (10) to start quickly. When oscillations reach a threshold value, the transconductance may be reduced to save power.

Abstract: A method, in a SCR (Selective Call Receiver) (10), for providing to a user of the SCR (10) a voice memo in explanation of a received message. The SCR stores distinctive data (63) and a user-generated voice memo (67) that relates to the distinctive data. The voice memo (67) and the distinctive data (63) are stored in the SCR in association with each other. When a subsequent transmitted message (73) containing matching distinctive data is received, the SCR can annunciate the stored voice memo (67) in explanation of the subsequent message. Another feature allows voice memos to be stored and annunciated to explain the reason for alarms that are generated at times selected by the user.

Abstract: A method of providing compensation for distortion imparted to an input signal, principally by an amplifier (18), compares a delayed version of the input signal (34) to the amplifier's output signal. The result of the comparison is an error signal that is fed back to minimize distortion. This feedback technique is applied to a transmitter (10) in combination with predistortion that is selected to compensate for at least some of the distortion provided by the transmitter's output amplifier (18). The remainder of the compensation is provided by the error signal which can be generated by a relatively low gain analog feedback loop.

Abstract: A method for an RF base station (105) to transmit an emergency message to a selective call receiver (104). The base station (105) receives incoming messages that are to be transmitted to selective call receivers, some of which incoming messages are emergency messages that include an emergency code, such as "911". The base station (105) creates a shortened emergency message by removing the emergency code from an incoming emergency message, and sends the shortened emergency message to a selective call receiver (104), along with an alert instruction for actuating a priority alert in the selective call receiver (104).

Abstract: A method in a communication system (100) having a high power transmitter (104) for transmitting messages to selective call receivers (102) located within a wide coverage area (114), and having at least one low power transmitter (108) for transmitting messages to selective call receivers (102) located within a smaller, overlapping coverage area (112). The transmitters (104,108) transmit on the same frequency but during different time intervals, except that mutually remote, low power transmitters can transmit simultaneously. A selective call receiver (102), adapted to operate in the communication system, and having a special arrangement of canned messages (412), can determine its location based, at least in part, on the time interval during which it received a message.

Abstract: A PLL circuit (401), including a VCO (420) having a trimming port (418) and a tuning port (416), a PLL controller (404), a variable voltage source (408), a voltage measuring circuit (426) and a multiplexer (412, 414, 428), performs automatic trimming of the VCO (420). The PLL circuit (401) accomplishes this by initiating a trimming mode that controls the multiplexer so that it couples the output of the PLL controller (404) to the trimming port (418), and the output of the variable voltage source (408) to the tuning port (416), thereby to phase lock the VCO (420) to the reference frequency signal (421). The PLL circuit (401) then measures, by way of the voltage measuring circuit (426), a voltage at the trimming port (418), switches the PLL circuit (401) to an operational mode, and then adjusts the variable voltage source (408) to be substantially equal to the voltage measured.

Abstract: A communication system, including base transmitters (113) and base receivers (115) for transmitting and receiving messages to and from selective call transceivers (116), is used for selecting an optimal base transmitter (113) for transmitting messages to a selective call transceiver (116) that cannot identify its location within the communication system. The communication system selects an optimal base transmitter (113) having a highest of a plurality of probabilities for successfully transmitting a selective call message to the selective call transceiver (116) as a function of overlap between transmission coverage areas of the plurality of base transmitters (113) and a reception coverage area of the at least one base receiver (115) that received a negative acknowledge message from the selective call transceiver (116).

Abstract: A receiver (100) is utilized for demodulating a multi-level frequency shift keyed (FSK) signal. The receiver (100) includes a mixer (102) for mixing the multi-level FSK signal to generate an in-phase signal and a quadrature signal, and a demodulator circuit (110) coupled to the mixer (102). The demodulator circuit (110) is adapted to count a sequence of state transitions of the in-phase signal and the quadrature signal and to determine a frequency deviation of the multi-level FSK signal based on the sequence of state transitions counted.

Abstract: A battery-powered selective call transceiver, operating in two-way communication with an RF communication system, can be put in a power saving state. A user control on the transceiver allows a user to select the duration of a power saving interval. The transceiver sends to the communication system a signal requesting that the transceiver enter a power saving state for the selected interval. Upon receipt of an acknowledgment signal from the system, the transceiver enters the power saving state.

Abstract: A method for re-establishing communication between a base station (102) that transmits on a forward channel, and a subscriber unit (108) that has temporarily lost the forward channel, uses the concept of a re-registration interval. The base station (102) transmits, to subscriber units (106, 108) in its area, a signal indicating the duration of a re-registration interval. A subscriber unit that has temporarily lost the forward channel determines whether the duration of such loss exceeds the re-registration interval. If the interval is exceeded, the subscriber unit sends a re-registration signal to the base station on a reverse channel. A selective call transceiver (400) is programmed to operate as a subscriber unit that uses the re-registration interval.

Abstract: A selective call receiver such as a pager (44) sorts and stores received messages (24-32) by categories and, optionally, by sub-categories as well. The category of a received message is determined by comparing a received message to identifying data (106) stored in the pager (44). Both the identifying data (106) and the categories can by changed by the user. When the category of a received message has been determined, a user alert is generated, the alert being indicative of the category of the message.