Abstract: A method and apparatus for rejecting a request for call initialization a device capable of multi-mode communications. A user of the multi-mode wireless communication device enters one or more desired communication modes into the wireless communication device, where an indication of the selected mode(s) are stored in a memory. When a page message is received by the wireless communication device, it is examined to determine if a communication mode of an incoming call associated with the page message matches the indication of the selected communication mode(s) as stored in the memory. If a match is determined, the incoming call is accepted by the wireless communication device. If the communication mode of the incoming call does not match the indication of the selected communication mode(s), the call is rejected by the wireless communication device without interrupting the user or a call already in progress.

Abstract: A system and method for spatial multiplexing signals on the feeder links of a satellite communication system. A beamforming antenna forms a plurality of feeder beams from signals received from system gateways, each feeder beam illuminating one of the gateways and including a plurality of frequency division multiple access (FDMA) channels. A plurality demultiplexers separate each of the feeder beams into the FDMA channels, and signal combiners combine first and second ones of the channels, each comprising signals corresponding to user terminals illuminated by a specific user beam, to produce a user beam signal which is used by a beamforming user link antenna to form a specific user beam. In a further aspect, a user link beamforming antenna forms a plurality of user beams from signals received from user terminals, each including a plurality of FDMA channels, and a plurality of demultiplexers separate each of the user beams into the channels.

Abstract: A system and method for automatically calculating safety-related compliance data for vehicle operators. Vehicle operators enter an identification code and status information into a mobile communication terminal located on a vehicle. The identification code and status information is generally stored in a memory located within the mobile communication device. The identification code and status information can be transmitted to a central station where it can be processed to determine compliance with safety regulations. The resulting data may be transmitted back to the vehicle upon request. In another embodiment, a processor located within the mobile communication terminal processes the identification code and status information. The resultant data may then be transmitted to the central station or presented to the vehicle operator upon request.

Abstract: A method and apparatus for providing fair access to members of a group communication system in which the members experience differing signaling delays. Members of the communication system send a transmission request to an arbitration device when they wish to communicate with other members. The transmission requests are ultimately received by the arbitration device. A time window is opened by a processor located at the arbitration device at the time an initial transmission request is received. The time window is used to treat all transmission requests that are received within the time window as having been received at the same time. Any transmission requests that are received within the time window are included in determining which member should be granted an exclusive transmission privilege.

Abstract: An apparatus, method, and process for quickly and accurately determining the position of a user terminal in a satellite communications system. An initial coarse estimate of the radius of the Earth at a terminal position is made. The geometry of satellites being used and the user terminal is then determined. When only one satellite is used, the satellite-user terminal geometry includes the range and range rate of the satellite with respect to the user terminal. When two satellites are used, the satellite-user terminal geometry includes the range of each satellite with respect to the user terminal. An initial position estimate is determined based on the radius and the satellite-user terminal geometry. The coarse radius estimate can then be formed into a fine estimate and the initial position estimate further refined.

Abstract: A method and apparatus for controlling a signal transmission power. The method of the present invention includes the steps of demodulating a received signal to produce a demodulated signal and distorting the demodulated signal to produce a distorted demodulated signal. The demodulated signal can be distorted by, for example, adding noise. A signal quality measurement, such as signal-to-noise ratio, is then determined based on the distorted demodulated signal rather than the demodulated signal. An adjustment in the transmission power is then requested based on the signal quality measurement of the distorted demodulated signal.

Abstract: A method and apparatus for providing fair access in a group communication system. Permission to transmit is based on a variable-level priority scheme. The variable priority level of each member in the system is based upon the number of event occurrences that have occurred in the past. In a first embodiment, the number of event occurrences is defined as the number of times that a member has been denied permission to transmit. The more denials that a member accumulates, the higher an corresponding priority level becomes. In a second embodiment, the priority level is based on the amount of time which has elapsed from when a net member was last granted the transmission privilege. The greater the time differential between when a member has last been granted the transmission privilege and a present access request, the greater the variable priority level becomes.

Abstract: A dielectric-patch resonator antenna having a resonator formed from a dielectric material mounted on a ground plane with a conductive skirt, and a patch element disposed inbetween. The ground plane and patch are formed from conductive materials. First and second probes are electrically coupled to the resonator for providing first and second signals, respectively, to or receiving from the resonator. The first and second probes are spaced apart from each other. The first and second probes are formed of conductive strips that are electrically connected to the perimeter of the resonator and are substantially orthogonal with respect to the ground plane. A dual band antenna can be constructed by positioning and connecting two dielectric resonator antennas together. Each resonator in the dual band configuration resonates at a particular frequency, thereby providing dual band operation. The resonators can be positioned either side by side or vertically.

Abstract: A variable rate receiving system where a packet of variable rate data is reassembled on a traffic channel if the capacity of the traffic channel is greater than or equal to the data rate of the packet. When the rate of the packet of variable rate data exceeds the capacity of the traffic channel, the packet is received on a traffic channel and at least one overflow channel. Also described is a transmission system for transmitting the data on the traffic channel and at least one additional overflow channel.

Abstract: An apparatus, system, method, and computer program product for providing a flexible ringer for multiple deskset phones. A controller detects a flag message that precedes an incoming telephone call, and selects one or more frequencies based on a local expectation of a ringing telephone at the geographic location, or according to a user preference. A digital signal processor (DSP) generates a digital ringer signal based the selected frequencies. An audio code converts the digital ringer signal to an analog ringer signal and sends the analog ringer signal to multiple deskset phones using a receive cable. The analog ringer signal is amplified to drive a speaker that converts the analog ringer signal into an audible ringer sound at each deskset phone. The audible ringer sound can be customized for multiple geographic locations by modifying the selected frequencies used in the digital ringer signal.

Abstract: An apparatus and method for generating an accumulated phase measurement of a communications signal over a predetermined time interval. A frequency estimate of the signal is generated; the frequency estimate is then converted to a coarse phase measurement. A phase error is generated based on the frequency estimate; the phase error is then converted to a fine phase measurement. The coarse and fine phase measurements are summed to yield an accumulated phase measurement.

Abstract: In an orthogonal frequency division multiplexing (OFDM) system which uses an outer Reed-Solomon encoder and interleaver an inner convolutional encoder, after the inner convolutional encoding the data bits are interleaved, and then grouped into symbols, each symbol having “m” bits. After grouping, the symbols are mapped to a complex plane using quadrature amplitude modulation (QAM). Thus, bits, not symbols, are interleaved by the inner interleaver. A receiver performs a soft decision regarding the value of each bit in each complex QAM symbol received.

Abstract: A bent-segment helical antenna utilizes one or more radiators wrapped in a helical fashion. The radiators are comprised of a plurality of segments. A first segment extends from a feed network at a first end of a radiator portion of the antenna toward a second end of the radiator portion. A second segment is adjacent to and offset from the first segment. A third segment connects the first and second segments at the second end of the radiator portion.

Abstract: A control interface protocol governs communications in a satellite telephone system. The satellite telephone system comprises a radio antenna unit (RAU) and a plurality of desksets connected to the RAU. An interface bus connects the desksets to the RAU. The RAU and the desksets communicate with each other by packets. Each packet comprises a start of header (SOH) byte, an address number (ADDR) byte, a command (CMD) byte, an argument (ARG) and a block check character (BCC). The ADDR byte comprises a source and a destination address of the packet. All packets, except negative acknowledgment (NAK) packets from the desksets, are acknowledged by the RAU. The packets originating from the desksets are tagged with an address of the desksets. A packet to a specific deskset includes a destination address. A packet originating from the RAU to all desksets includes a first default address. A packet originating from the RAU to a deskset that does not have an address includes a second default address.

Abstract: A system and method for optimizing power control provides dynamic adjustment of a power-control threshold thereby allowing transmitter power to be reduced when signal quality is high. In a communication system having at least one mode for controlling the power of a transmitter in the communication system, the threshold level of the system is optimized by determining performance of the communication system based on a predetermined metric such as the system error rate, for example. Additionally, the power of the transmitter or transmitted signal in relation to the threshold of the communication system is determined. The threshold of the communication system is adjusted based on the performance of the communication system and the power of the transmitter in relation to the threshold.

Abstract: The present invention comprises a system and method for gain control of individual narrowband channels using a wideband power measurement. The present invention comprises a transmit power tracking loop which controls the power of the transmitted signal by controlling the gain applied to the signal. The function of the transmit power tracking loop is to measure power, accept commands for power adjustment, and adjust the power. Gain control is performed by producing an error signal using the comparison of measurements of a total of estimated powers of each narrowband signal and a measurement of the modulated wideband signal In addition, open loop control is performed by accepting open loop commands generated by an algorithm.

Abstract: A system and method for narrowing the range of frequency uncertainty of a Doppler shifted pilot signal in a satellite or other communications system with relative signal source and receiver motion. The satellite communications system includes a user terminal (for example, a mobile wireless telephone), a gateway (terrestrial base station), and at least one satellite with unknown position and unknown relative velocity. The method includes the steps of shifting the pilot signal over a plurality of frequency hypotheses, coherently accumulating samples of the pilot signal over a plurality of chips, measuring the energy of the accumulated pilot signal samples, accumulating the energy measurements over a plurality of chips to produce an energy accumulation value, and determining which of the plurality of frequency hypotheses results in the highest energy accumulation value.

Abstract: A handoff technique in which system users detect transitions in service between a current service area and an adjacent service area, and request a forward link channel in the new service area when a detected signal strength for the new service area exceeds predetermined threshold levels. The forward communications link in the current service area is maintained until the strength of the new service area signal reaches a certain level and appropriate channel quality is confirmed, as based on various known criteria. Typically, service area transitions are detected using the signal strength of pilot or paging signals associated with service areas, which are used to determine a relative signal strength of new service area signals. Pilot signal level adjustments used to counter roll-off effects are detected and compensated for in comparing signal levels.

Abstract: A system and method for detecting an unauthorized attempt to access components in a housing of a portable electronic device. The housing is secured in a closed state by a mechanical fastener that couples a first portion of the housing to a second portion of the housing. The mechanical fastener has a top end disposed within a recess in the housing. A ball bearing is first disposed within the recess above the top end of the fastener, after which at least a portion of the recess is filled with a curable resin. Later, a portion of the housing proximate the recess is visually inspected. In response to the visual inspection, a determination is made as to whether there has been an unauthorized attempt to access components in the housing.

Abstract: A method for reducing call dropping rates in a multi-beam communication system. The multi-beam communication system includes a user terminal, a gateway, and a plurality of beam sources, where each beam source projects a plurality of beams, and where a communication link between the user terminal and the gateway is established on one or more beams. The method according to the present invention relies on a messaging protocol between the gateway and the user terminal. Based on messages sent from the user terminal to the gateway, preferably on a preselected periodic basis, the gateway can determine the more desirable beam(s) for transmitting data or information to the user terminal. The messages sent from the user terminal to the gateway contain values representing beam strengths as measured at the user terminal. The gateway uses the user terminal measured beam strengths to select the beams that should be used for transmitting data or information to the user terminal.