Abstract: A printed circuit (pc) board (105) having at least two layers, wherein proper assembly and alignment of the at least two layers may be visually verified, comprises a first layer (410) having a first printed circuit pattern (305) formed thereon, the first printed circuit pattern (305) including a first identifier (115) formed along at least one edge (405) of the first layer (410). The pc board (105) further comprises a second layer (420) having a second printed circuit pattern (305) formed thereon, the second printed circuit pattern (305) including a second identifier (120) formed along at least one edge (405) of the second layer (420), the second identifier (120) being visibly aligned with the first identifier (115) in a predetermined alignment to indicate that the first layer (410) and the second layer (420) are correctly laminated.

Abstract: A filter (13) for providing temperature compensation for the quality factor thereof comprises transconductance amplifiers (23 and 24) in a gyrator configuration coupled between an input node (21) and an output node (22). A parallel capacitor (25) is coupled between the input node (21) and a supply voltage, and a parallel resistor (26) is coupled between the input node (21) and the supply voltage. A series capacitor (27) is coupled to the output node (22), and a series resistor (28) is coupled between the second capacitor (27) and the supply voltage.

Abstract: A holster (100) for receiving a pager (220) having an protrusion (225) comprises a housing (105) having an interior surface (205) and an exterior surface (210), the interior surface (205) forming a cavity (215) for receiving the pager (220). A flexible arm (110) is affixed to the housing (105) and moves between a first position wherein the flexible arm (110) engages the pager protrusion (225) when the pager (220) is within the cavity (215) and a second position wherein the flexible arm (110) is deflected by the pager protrusion (225) as the pager (220) is inserted into or removed from the cavity (215). A belt clip (230) mounted to the housing (105) secures the holster (100) to an article. The belt clip (230) selectably contacts the flexible arm (110) and exerts a pressure thereto which increases the force needed to deflect the flexible arm (110) when the pager ( 220) is inserted into or removed from the cavity (215).

Abstract: A control station 12 initiates a system timing signal transmission which is re-transmitted from a satellite 14. In response to receiving the system timing signal, the control station 12 then generates a time correction factor which is distributed to a plurality of transmission stations 16, 18. The transmission stations 16, 18 in response to receiving the system timing signal transmission and the time correction factor distributed from the control station 12 generate a time adjustment factor which is used to correct the local transmission clocks 36, 36', thereby providing time synchronization of data transmissions generated from the transmission stations 16, 18.

Abstract: A selective call receiver (200) is capable of receiving messages and storing the messages for subsequent retrieval by a user. The selective call receiver (200) assigns a status designation (706) and a chronological order (704) to each stored message, and further prioritizes the messages in a sequential order being prioritized first by a priority of the status designation (706) assigned to the messages and then further prioritized therewithin according to the chronological order (704) assigned to the messages. The selective call receiver (200) then presents the messages to the user in the sequential order for the messages.

Abstract: A selective call receiver (10) for receiving a radio frequency message having message characters includes a memory (14) for storing information including predetermined message characters and processing circuitry (13) for determining an amount of available space within the memory (14) in response to reception of a message. When the available space within the memory (14) is insufficient for storage of the message characters included within the received message, one or more of the message characters included within the received message is deleted prior to storing the received message. Alternatively, one or more message characters included within a previously stored message may be deleted prior to storing the received message.

Abstract: A simulcast transmission system (10) and method provides for time synchronizing data transmissions from a plurality of transmission stations (16, 18). The transmission stations (16, 18) include transmission clocks (36) for controlling the time of transmission of synchronization timing signals and data. The synchronization timing signals indicate a local time of transmission which are transmitted in response to system timing signals received from the control station (12). The control station (12) comprises apparatus (20) for generating and distributing the system timing signals, apparatus (26) for receiving the synchronization timing signals from the transmission stations, and apparatus (20, 22, 28) for generating and distributing time adjustment factor signals to the transmission stations (16, 18) in response to receiving the synchronization timing signals. The transmission clocks (36) are adjusted in response to the time adjustment factor signals for controlling the time of transmission of the data signals.

Abstract: A signalling system provides for efficient reception of message by a plurality of Earth based selective call receivers such as pagers. The signals are transmitted from satellites in orbit above the Earth. Each satellite includes a multiple lobe antenna capable of transmitting messages to a selected portion of the surface of the Earth. Methods for conserving satellite transmission power in the communication of message information are described. Furthermore, a signalling protocol transmitted by the satellite provides for power conservation by Earth based selective call receivers. Additionally, a method enabling an area of the Earth to receive messages from multiple satellites is described.

Abstract: An improved selective call addressing scheme provides local mode paging capability in a wide area paging network. A selective call receiver used in this system will configure its operating parameters by selecting one of a plurality of operational personalities in response to the presence or absence of a specific received signal having a signal indicative of the area in which the pager is operating.

Abstract: In a battery powered selective call receiver receiving a synchronous signal, a battery saving method extends battery life by optimizing the amount of time the receiver circuit is activated when searching for the signal after previously acquiring synchronization. The battery saving method allows for turning the selective call receiver on without activating the receiver circuit. The receiver circuit is activated at a time later than the energization of the selective call receiver, where the time of activation of the receiver circuit is determined in response to the time passed since synchronization was last acquired and the system signal stability.

Abstract: A receiver (200) receives (203) a transmitted signal having a first predetermined signal for indicating a start of a new transmission to the receiver and having a second predetermined signal inserted at periodic sampling time intervals for synchronizing the receiver to the transmitted signal. The receiver (200) synchronizes to the transmitted signal by detecting the first predetermined signal (208) followed by the second predetermined signal (210), and establishing subsequent periodic sampling time intervals therefrom. The receiver (200) conserves power (228) during a second portion of a periodic sampling time interval following a detection of a first portion of the second predetermined signal (210) during a first portion of the periodic sampling time interval.

Abstract: This invention relates to a satellite signalling system. A ground station receives paging signals from an earth-bound terminal, and an up-link radio transmitter/antenna transmits paging signals and control signals to a satellite in earth orbit. An up-link receiver coupled to the satellite receives the paging and control signals. A down-link transmitter is coupled to an antenna whose beam may be directed in a predetermined sequence to a plurality of locations on earth as paging signals are transmitted to earth.

Abstract: A satellite based paging communication system comprises a plurality of terrestrial stations capable of communicating the paging information with at least one satellite. The satellite(s), in turn, are capable of communicating the paging information to at least one terrestrial receiver or terrestrial station. Also included is at least one control station for determining where and how to deliver the paging information to one or more of a plurality of terrestrial receivers (pagers), at least some of which are capable of receiving the paging information from one or more of the satellites and one or more of the terrestrial stations.

Abstract: A photodetector mounted on an electrical device serves as an ambient light sensor for low light illumination control and an optical receiver for receiving optically transmitted data.

Abstract: An electromechanical assembly for use in a portable communications device including an antenna loop and a coil spring coupled to the antenna loop for making electrical contact with one terminal of a battery and for supplying a bias for physically holding the battery substantially immobile, wherein the coil spring and the antenna loop are formed of a continuous piece of material.

Abstract: A switch includes a housing (36) which retains an elastomeric actuating member (38) having an actuating portion (46) and a contact portion (37). The contact portion (37) deforms in a first direction (52) in response to a force exerted on the actuating portion (46) in a second substantially different direction (e.g. orthogonal thereto)(48). The housing (36) comprises a rigid member in contact with a side of the elastomeric actuating member (38) opposite the actuating portion (46) on which the force is exerted.

Abstract: A selective call receiver, such as a pager, has a real-time clock and is capable of determining the response of the receiver to a message in accordance with a status associated with that message. The selective call receiver can also change the status at a selected time or if a characteristic of the message matches a predetermined characteristic. Additionally the selective call receiver may choose from a plurality of priorities a priority of a received message in order to determine if a message stored in the memory of the selective call receiver will be deleted by the received message. The selective call receiver is further capable of determining the type of data decoded by an address with respect to the time of day.

Abstract: A paging receiver has a predetermined minimum operating voltage. A method of operation thereof comprises the step of determining the predetermined minimum operating voltage of the paging receiver operating the paging receiver at a plurality of different operating voltages until the paging receiver operates unsatisfactorily, and selecting the operating voltage of the paging receiver at a level greater than the unsatisfactory operating voltage.

Abstract: A tone only pager including an EEPROM with telephone numbers stored therein at different predetermined addresses and a DTMF signal generator. If a received signal includes one of the predetermined addresses, a DTMF telephone number corresponding to the address is generated. If a received signal also includes a different telephone number, any telephone number stored at that predetermined address may be replaced with the different telephone number. The pager also determines if the telephone number is a long distance telephone number and activates an indicator in response thereto.