Abstract: An extender card arrangement having ejector levers attached to the unitary card portion of an extender card to aid in the insertion and removal of the extender card into and from a backplane, and having ejector lever brackets attached to the extender card card guides to allow the ejector levers on a card under test to be used to aid in the insertion and removal of the card under test into and from the extender card.

Abstract: The device (100) includes a processor (132) coupled to a memory (134) containing a program adapted to control the processor (132) to manage communications between data communications systems.

Abstract: An enhancement to AIN fault handling that allows SSP triggers to access an alternative treatment application when fault handling is invoked. If an alternative treatment application is referenced in the BCM fault handling attribute, then the application is called when AIN fault handling is invoked. If the alternative treatment application is not successful in completing the service function, then one of the traditional fault handling options is applied, (i.e., routing to a specific directory number, voice announcement then terminate call, continue, or final treatment). The present invention allows a last attempt at completing the service function by the alternative treatment application after fault handling is called, but before default handling or final treatment is invoked.

Abstract: A communications quality measurement system for use with packet and other networks comprises a test signal transmitter, a test signal receiver, and a test signal analyzer. A test transmitter is used to produce a series of test signals selected or engineered for measuring one or more desired Quality of Service or other performance parameters of a network path to be tested. A first copy of the test signal is transmitted via a reference path of known characteristics and with minimal impairments. A second copy of the test signal is transmitted via the network path to be tested. A test receiver receives and records the signals which were carried via the reference and test paths. A test signal analyzer compares the signals received over the reference and test paths and analyzes differences to determine Quality of Service or other parameters, such as Bearer Delay, Cell or Packet Loss, Echo Delay, and Echo Amplitude, some of which are directed to the particular impairments that are characteristic of packet networks.

Abstract: A multi-packet-switch system having a standard primary switch interconnect to handle inter-switch packet traffic, separate buffer areas for each primary interconnect and the device ports, the ability to identify specific packet streams by an identifier in each packet, and the ability to specifically manage static routing of packets based on the packet stream identifier. Creating secondary switch interconnects between device ports, and routing identified packet streams to these secondary switch interconnects. The secondary switch interconnects can be dedicated to identified packet streams, thus eliminating primary interconnect buffer contention with other packet streams.

Abstract: A circuit and method for reducing local oscillator frequency transmission in a homodyne, or direct conversion, radio transceiver using I/Q modulation/demodulation minimizes local oscillator leakage to the antenna and its subsequent reception by the receiver by interfacing I/Q input signals to the modulator in a controlled manner so as to increase isolation during reception by presenting high impedance states to the I/Q modulator input terminals during reception thereby nulling the carrier during reception.

Abstract: A system that provides additional voice lines with data over a single two-wire subscriber loop. At the subscriber premise, one or more telephone instruments and data devices are connected to a digital modem into either a voice or a data interface. Analog voice signals are PCM sampled then packetized, and voice and data packets are transmitted to a CO modem over the subscriber loop. The CO modem depacketizes the voice packets into PCM format and transmits PCM voice information to a CO switch over a standard digital trunk interface. Data packets are routed to a data network. Voice packets are given transmission priority over data packets to ensures that voice is transported in the presence of data with low latency.

Abstract: Method and apparatus for updating a subscriber unit with an announcement group identification. A subscriber unit (210) requests affiliation (301) with a talk group (202) and an unknown announcement group identification is issued (315) in response to the request for affiliation. The present invention includes an embodiment where information that identifies which subscriber unit (210) received the unknown announcement group signal is stored (309). An updated announcement signal is subsequently sent to the subscriber unit (210) when a zone controller (114) receives an updated announcement group identification.

Abstract: A state machine that allows an audible alarm for a given fault condition to be extinguished while allowing subsequent audible alarms for different fault conditions.

Abstract: An isolator eliminator for a linear transmitter receives a plurality of digital samples of an information signal and a drive signal sampled from a feedback loop at periodic time intervals and, responsive to processing the digital samples, provides high accuracy phase and level correction signals to the feedback loop. The phase and level correction signals maintain stable, linear operation of the feedback loop and limit splatter. In a preferred embodiment, the isolator eliminator includes a digital signal processor such that multiple communication protocols may be accommodated by changing software code executed by the processor.

Abstract: The invention concerns a digital radio (2) for pseudo-duplex radio communication, and a method of transmission time mediation for pseudo-duplex radio communication. A digital radio (2) is in time division duplex communication with a second digital radio (4) over a single radio channel. Control of the radio channel may reside with either radio. However, authority for a radio to change the frame format in order to increase the proportion of time for which it transmits always resides entirely with the radio currently transmitting the least per frame. This arrangement allows rapid response to a need for a radio to move from listening to speaking mode, thereby reducing speech clipping. When the digital radio (2) and the second digital radio (4) are transmitting for equal proportions of the frame, authority to change the frame format passes to the radio that is transmitting at that instant.

Abstract: A line card circuit using a pair of comparators such that the output of the first comparator is coupled to an input of the second comparator through an RC circuit. The RC circuit is tuned such that short transients, such as false pulses and false off hook indications passed by the first comparator are not passed by the RC circuit to the second comparator. The input of the first comparator is coupled to the subscriber line and the output of the second comparator is coupled to the switch's hook status detection circuitry.

Abstract: A method of determining a quality metric for a message. The method comprises receiving (500) a message, constructing (502) a trellis array associated with the message, and determining (512) a quality metric for the message based on the trellis array. In one embodiment, the quality metric is derived from state information obtained from selected columns in the trellis array. The state information may include target states defining correct and/or incorrect transitions in the selected columns. The quality metric comprises in one embodiment a cumulative number of the occurrences of the target states in the selected columns.

Abstract: A PCB scrap edge removal tool comprising scrap removal jaws formed of two matching opposing pieces of metal having cut-outs in a castellated fashion. The jaws have a gap between them for receiving a PCB work piece to be finished. Metal dowels for PCB positioning span the gap. A PCB is positioned in the gap and rocked back and forth to break off the scrap edge pieces. The cut-outs in the scrap removal jaws correspond to portions of the PCB edge that are not to be removed. These portions move freely in the cut-outs as the PCB is rocked back and forth.

Abstract: A wireless communication system 200 comprises a connectionless packet network 201 coupled to a plurality of sites 203-208 that are in location areas 260, 261. The sites join respective location area multicast addresses to receive messages from other sites in their location area. Communication units desiring to participate in talkgroup calls need only to register affiliation with a first site of the location area. Upon the first site receiving an affiliation message, it joins a payload multicast group address to receive payload for the talkgroup. In alternative embodiments, the first site sends, via the location area multicast address, either control message(s) or tunneled payload associated with the talkgroup call to secondary site(s) of the location area.

Abstract: The invention discloses a radio network for radio communication in an enclosed environment such as a tunnel or an in-house environment including a first head end station (1) and cascaded bi-directional repeaters (4, 5, 10) connected via a radiation cable (3). In case of a break of the radiation cable, a second redundant head end station (2) is connected to the radiating cable via switch (30) and to the first head end station via a second connection (11) and the repeaters behind a disconnection point of the radiating cable (3) interchange their downlink and uplink transmission directions, such that the radio communication is possible in front and behind the disconnection point. Furthermore, the repeaters are adapted to detect a malfunction of themselves and to bypass themselves in reaction to the detection of a malfunction.

Abstract: A radio frequency communications system (100) includes wireless terminals (102) and base sites (104). The wireless terminals communicate with the base sites over a radio frequency channel (106). The base sites are interconnected to each other and other network elements via a packet network. A method and apparatus determine for a particular delay-sensitive application on the wireless terminal, for example, an audio or video transmission, the requirements for bandwidth for transmission over the radio frequency channel (500, 502). After the requirements on the radio frequency channel are determined, the necessary channel bandwidth, if available, is reserved or allocated to guarantee performance to the application (510). The reserved bandwidth is utilized by selectively granting access to the radio frequency channel on the basis of the bandwidth allocated to the device.

Abstract: A system and method that uses the flexible bandwidth of a data network in order to provide more flexible services to remote line units comprises a telephone switch configured to provide telephony service to a wireline terminal and an access network head end connected via circuit switch transmission facilities to the telephone switch and configured to manage bearer channels in a data network. The system also includes a data network carrying the bearer channels and a line unit separate from the telephone switch connected to the data network and to the wireline terminals configured to interface wireline terminals to one of the bearer channels. The access network head end reserves a predetermined bandwidth through the network and allocates a portion of the bandwidth to each of the line units. The amount of bandwidth allocated to each line unit is variable.

Abstract: A frame timing lock detector circuits and a methods of frame timing lock detection for a digital communications system. A known data sequence is extracted from a received radio signal and multiplied, in a multiplier, together with a reference signal that includes the symbols of the known data sequence raised to the power of a multiple of three. The phase of the multiplier output is measured and an average of an absolute value of this measured phase is compared with a threshold to detect correct frame timing lock.

Abstract: Systems and methods for implementing dispatch calls using IP multicasting protocols are disclosed. The methods include utilizing a payload multicast group address for distributing payload, and utilizing a control multicast group address for distributing control messages to members of the talkgroup in a single-zone (FIG. 1). A zone controller 116 dynamically identifies payload and control multicast group addresses and sends them to participating sites 102, 104. The participating sites 102, 104 issue Join commands to associated network devices 108, 110 to receive payload and control messages addressed to the respective payload and control multicast group addresses. There is further disclosed a system and method for implementing dispatch calls for members in multiple zones (FIG. 6). Zone controllers 630, 632 separately identify control multicast group addresses and send them to affiliating devices in their respective zones.