Abstract: A method is provided for background scanning in a selective call communication system (102) having a plurality of channels (110, 112, 114), wherein a selective call device (104) has designated thereto one of an odd and even frame compulsory decoding schedule. The selective call device (104) decodes system configuration information (SCI) on odd SCI frames during the odd compulsory decoding schedule, scans for even SCI frames of target channels while maintaining the odd compulsory decoding schedule, and releases or maintains the odd compulsory decoding schedule based on the system configuration information found on the target channels.

Abstract: A multichannel selective call receiver (10) includes-a receiver (11), a controller (16), a baud detector (17) and a memory (18). The controller is adapted to control the receiver in receiving information on a channel (14). The information on the channel includes mandatory frames having information fields. If the information fields in a mandatory frame on the channel do not indicate more information for the multichannel selective call receiver in the rest of the mandatory frame, the controller controls the receiver to receive information on other channels (15) during the rest of the mandatory frame. The information on the channel and the other channels is processed in accordance with channel priority as indicated in a channel list stored in the memory.

Abstract: Methods and apparatus for forming a metal shield on a printed circuit board (10) include a layer of dielectric material (23) one or more printed circuits (21) on the layer of dielectric material (23), a layer of metal (27) on the layer of dielectric material (23), a metal-clad trench or opening surrounding the printed circuit (44) and electrically connected to the layer of metal(27), a solder pad (24) on the layer of dielectric material (23), a microvia (25) through the solder pad (24) and the layer of dielectric material (23), and electrical components (11) soldered to the solder pads (24) and to the printed circuit (21).

Abstract: A quiz game in which a player must attempt to answer one or more questions in a selected category employs a method for selecting the category to enhance the fairness of the game over a wide range of players' ages. At least one attribute of the category is selected by chance and at least one other attribute of the category is selected based on an individual preference of the player, wherein the selected category is defined by all of the selected attributes. Basing the category selection at least in part on the individual preference of the player increases the player's chances of correctly answering the question(s). Such a category selection method may be beneficially employed in an audio quiz game (e.g., a music trivia game) that includes a source of categorized questions and answers, an audio playing device that can selectively access and play pre-stored audio clips, and one or more selectors for selecting the by-chance attribute(s) of the category.

Abstract: An electrostatic discharge protection device for a high-density printed circuit board consists of a layered structure starting at the bottom layer with a ground conductor. A dielectric layer covers the ground conductor to electrically isolate it from a circuit trace that is on top of the dielectric layer. A via is formed in the dielectric layer such that a portion of the ground conductor is exposed, and the via is strategically located such that the edge of the via is tangent to an edge portion of the circuit trace. The via forms a spark gap between the edge portion of the circuit trace and the underlying ground conductor, using air as the dielectric medium.

Abstract: A communication device (12) transmits a communication signal during repetitive time slots. The communication device (12) includes a duty-cycle adjustment signal generator (82) that generates an adjustment signal based on a proximity signal. A controller (54) in response to the proximity signal, adjusts a transmission duty cycle relating to the repetitive time slots for transmitting a communication signal during a time slot. The communication signal is then radiated via an antenna (70).

Abstract: A communication device (1) comprising a receiver (2) for receiving coded messages transmitted on one or more channels. There is a micro-processor (13), in communication with the receiver (2) and a frequency synthesizer (4) coupled to both the micro-processor (13) and the receiver (2) to thereby control reception of the channels. The communication device (1) also has a memory (14) storing a group of-channel frequencies, wherein the micro-processor (13) is adapted, in combination with the frequency synthesizer (4), to control the receiver (2) to scan at least some of the channels during baud detect periods of a protocol cycle associated with at least one of the channels. Further, the micro-processor (13) cyclically offsets a start of the baud detect periods after completion of a protocol cycle.

Abstract: A pager (20) for operating within the communication environment of a cyclical frame based synchronous selective call system. The pager (20) has a receiver (22) for receiving selective call signals, a controller (25), a memory (26) to store signal parameters, a demodulator (27) and a decoder (28). In operation, receiver (22) processes selected frames within a selective call signal transmitted on a channel. During such operation, controller (25) determines whether to control receiver (22) to continue monitoring the channel or to scan for or select another channel to monitor for other selective call signals. A count of missed selected frames of a selective call signal is compared with a threshold count. This threshold count is based upon one of the signal parameters indicative of the selected frames. Controller (25) also schedules non-selected frames for processing when this signal parameter is greater than a predetermined number.

Abstract: Caller-related information, such as a telephone number, in a voice mail message intended for a communication unit (102) is extracted from the voice mail message and converted into an alpha-numeric string by a converter device (112). The alpha-numeric string is conveyed by a messaging device (110) to the communication unit and stored in the communication unit. Using the stored caller-related information, a user of the communication unit is able to repeatedly initiate a call to the caller identified by the caller-related information without having to access a voice mail device or enter the caller-related information manually.

Abstract: A first communication device (107) transmits user data (102), divided into a plurality of data blocks, at a first modulation rate. The first communication device (107) then receives an acknowledgment (104) from the second communication device (101) indicating a quantity of the data blocks that were not received and compares this quantity to a threshold. When the quantity is less than the threshold, the data blocks that were not received are retransmitted (106) at a second, usually lower, modulation rate. Otherwise, they are retransmitted at the first modulation rate. A comparison between the quantity of data blocks to be retransmitted and a threshold is being introduced to known communication techniques by the present invention.

Abstract: An unsynchronized base site (104) transmits a time synchronization request to a communication unit (110). A time synchronization error, or a timing offset, for the unsynchronized base site (104) is then determined and transmitted back to the unsynchronized base site (104) to enable the unsynchronized base site to synchronize itself. The time synchronization error is determined for the unsynchronized base site (104) based on the time difference of arrival of the signals received by the communication unit (110) from the base site (104) and at least one synchronized base site (101), the location of the communication unit (110), the location of the base site (104), and the location of the at least one synchronized base site (101).

Abstract: A controller (120), in response to receiving a request for a group call (201) targeting a group (101), allocates at least one power adjustment channel to the group call (202) and sends identification of the at least one power adjustment channel to at least some of the subscriber units in the group (203). Using the at least one power adjustment channel, the controller also sends unique power adjustment information to each of the at least some subscriber units (204). Unique power adjustment channel access information is also sent to the subscriber units so that each subscriber unit can receive its own unique power adjustment information (503) and adjust its inbound transmission power (504) in response. In this manner, efficient reverse power control is provided for multiple subscriber units thereby facilitating group calls in CDMA systems.

Abstract: A communication device employs a method and apparatus for transmitting and receiving information packets using multiple layers of error detection. A sending communication device constructs an information packet to include user information divided into multiple data blocks, a primary error detection code for each data block, and at least a portion of a secondary protection code. The secondary protection code provides error protection for the entire information packet. The secondary protection code is selected such that it can be incrementally determined by a receiving device as data blocks are received and accepted by the receiving device, regardless of order of reception of the data blocks. Since the secondary protection code is incrementally determined, processor utilization is better regulated and delays associated with sending acknowledgments are minimized.

Abstract: A wireless communication system (100) that includes a plurality of base sites (101-103) employs a method and apparatus for determining a location of a communication unit (107) in the system. Upon transmission of an information signal (109) by the communication unit, each of the base sites receives the transmitted information signal. A serving base site (e.g., 103) determines a stream of information symbols from the information signal, derives timing information based on the information signal and the stream of information symbols, and conveys the stream of information symbols preferably to at least two non-serving base sites (101-102). The non-serving base sites determine respective timing information based on the information signal received from the communication unit and the stream of information symbols received from the serving base site.

Abstract: A radio communication system (100) employs a method for setting an output power of a base site (e.g., 107) in the system. The radio communication system includes at least two base sites (101-107) and a communication path (109, 131-137) coupling the base sites together. A first base site (e.g., 107) transmits a signal (147) via a radio communication resource. A second base site (e.g., 101) receives the signal and determines a signal quality metric of the received signal. Upon determining the signal quality metric, the second base site generates and conveys a message to the first base site via the communication path, wherein the message instructs the first base site to adjust an output power of the first base site. The first base site then adjusts its output power responsive to the message.

Abstract: A dispatch controller (103) located logically external to an existing telephone network (101) is coupled to the existing telephone network. When an originating communication device (e.g., 111) desires to initiate a dispatch call, the originating device transmits a call request to the existing telephone network, wherein the call request includes an identification (ID) of the originating device and a target address associated with the dispatch controller. The existing telephone network provides the call request to the dispatch controller. Upon receiving the call request, the dispatch controller retrieves dispatch-related information from a database (105) coupled to the dispatch controller based on the originating device's ID. Based on the retrieved dispatch-related information, the dispatch controller identifies a group of target communication devices (e.g., 107-110) for the dispatch call.

Abstract: A packet data communication system (100) employs a method and apparatus for tracking data packets in the packet data communication system. A sending communication device (e.g., 101) transmits a data packet (130) to a receiving communication device (e.g., 105), wherein the data packet includes a respective packet sequence number (131). Responsive to the transmission, the sending device increases a transmit tracking number (V(S)) that is used to indicate the packet sequence number of the data packet that is next in sequence to be transmitted. Upon receiving the data packet, the receiving device transmits an acknowledgment data packet (140) to the sending device, wherein the acknowledgment data packet includes a receive tracking number (139). The receive tracking number indicates the packet sequence number of the data packet that the receiving device expects to receive next.

Abstract: A radio frequency (RF) circuit (300) includes two parallel sections (310, 312) that are designed to function collectively through the use of a signal splitter/switching circuit (200) and a signal combiner (314). To optimize the performance of the RF circuit (300), a switching arrangement (214, 216, 218, 220, 222, 224, 226, 228, and 230) that is part of the signal splitter/switching circuit (200) is used to separate and isolate the two parallel sections (310, 312) for tuning purposes. After each parallel section (310, 312) has been individually tuned, the two parallel sections (310, 312) are recombined for joint operation.

Abstract: A communication device employs a method and apparatus for amplifying a radio frequency (RF) signal that eliminates the need for a signal splitter. An RF input signal (202) is coupled to a first RF amplifier stage (206) only. A signal coupler (222) couples an output of the first amplifier stage (206) to an input of a second amplifier stage (208). The input signal (242) for the second RF amplifier stage is an attenuated version of the output signal (240) from the first RF amplifier stage. The outputs of the first and second RF amplifier stages (206, 208) are combined by a signal combiner (234) to produce a combined output signal (246) for transmission.

Abstract: A communication unit (200) employs a method and apparatus for increasing an output impedance of a transmit amplifier during a receive mode of the communication unit. The communication unit includes a transmit amplifier, an antenna (209), and a signal receiver (211), and is operable in at least a transmit mode and a receive mode. During the transmit mode, the transmit amplifier, which includes an amplifying device (201), amplifies an input signal (221) and provides the amplified signal (233) to the antenna for transmission. During the receive mode, the antenna receives signals and provides the received signals to the signal receiver. To mitigate the transmit amplifier's effect on the received signals during the receive mode, the communication unit, during the receive mode, couples the transmit amplifier to the antenna and applies a bias (225) to the amplifying device to increase the output impedance (Z.sub.