Abstract: A method of setting up a network connection of an image forming device connectable to a network via a first interface and a second interface, the method including setting up a network connection via the second interface, stopping operation of the first interface and initiating operation of the second interface after the setting up of the network connection via the second interface is completed, determining whether the second interface is connected to the network, and, stopping operation of the second interface and initiating operation of the first interface if determined that the second interface is connected to the network.

Abstract: A method is set forth for reducing the total acoustic echo cancellation convergence time for all look directions in a microphone array based full-duplex system. The method is based on capturing the loudspeaker signal due to the first far-end speech bursts when the conferencing system is first used, as well as the corresponding loudspeaker feedback signals in the individual microphones. The captured signals are then used for consecutive adaptation of the acoustic echo canceller on all echo paths corresponding to all look directions of the beamformer, thereby training the AEC. This training process can be executed concurrently with normal phone operation, for example, as a background process that utilizes available processing cycles.

Abstract: The invention relates to bus type connection systems, in particular those for wiring backplanes of electronic systems, when the bus comprises connectors distributed in an irregular manner. It consists in selecting segments (D1, D2) over which the intervals (d1, d2) between the connectors are substantially constant. The structure of all the segments except one is then modified to make the effective impedance of the modified segments coincide with that of the unmodified segment. It produces a bus that is fully matched from end to end and able to operate at a very high frequency with a slight reduction of its propagation constant.

Abstract: The present invention provides a low power method and apparatus for detecting a signaling tone. The apparatus comprises a resonator which can be configured to resonate at a specified frequency, a controller for configuring the resonator, and a comparator for comparing the output of the resonator as configured by the controller. The method comprises configuring the resonator to resonate at a first frequency to generate an output, configuring the resonator to resonate at a second frequency to generate an output, comparing the outputs, and indicating the presence of a signal if the output of the resonator configured to resonate at a first frequency exceeds the output of the resonator configured to resonate at a second frequency by a predefined amount.

Abstract: An improved reclocker circuit and router cell are provided that are particularly useful when configured into a router matrix comprising a plurality of interconnected router cells. The improved reclocker circuit includes an integral N-to-1 multiplexer (MUX), wherein N is at least three. The improved router cell includes the reclocker/MUX circuit, a switch, and a fan-out circuit. A plurality of ports are coupled to the router cell circuitry, including an input port, an output port, a plurality of expansion input ports, and a plurality of expansion output ports. The improved router cell couples either the input port or one the expansion input ports to its output port, and it also couples the input port to each of the expansion output ports. By using the improved router cells in the design of a router matrix, jitter induced by the reclocker circuits is minimized.

Abstract: The present invention relates to a control method for a call-forward procedure in telecommunications, in which method calls placed on a user's home address are forwarded to a new target address. According to the invention, the final activation step of the target address is required to be accomplished from the registered target address only. Further according to the invention, the control method of telecommunications location resolution completes the update of location data only if the authenticated user verified to be situated in the location that according to the user's desire is to be registered as the new user location in the location resolution service.

Abstract: In the connection of a number of telephone sets to a private branch exchange, control information is communicated between the telephone sets and the exchange set in such a way that a bidirected conversion unit is required. In order to provide a high degree of service at a reasonable cost the telephone sets are collected in groups which share a generally smaller number of conversion units. By way of suitable control devices and switch units in the forwarding of control information, a suitable non-occupied conversion unit can be selected.

Abstract: A method of improving the sensitivity and speech immunity of a receiver in conjunction with DTMF-reception is disclosed. The number of zero-crossings of the input signal are counted during one of a number of measuring intervals in real time at frequencies which occur in the low frequency group and the high frequency group of a DTMF-signal. At the end of each of the measuring intervals, the number of zero-crossings in a current measuring interval is compared for each frequency group, with a corresponding number of zero crossing in a number of nearest preceding measuring intervals, and the magnitude of any difference is established. The input signal is treated as a DTMF-signal when the difference is at most equal to a permitted limit value.

Abstract: An office interface unit (OIU) transfers data and signaling between a telephone local exchange and distribution lines. Information from the telephone local exchange is contained in repetitive frames containing signaling time slots which each contain two distinct nibbles of information. The OIU translates each local exchange signaling channel into first and second internal signaling channels, each internal signaling channel containing information representative of one signaling nibble therein. This simplifies DSO time slot interchange in the OIU. In addition, each internal signaling channel is provided with at least one additional significant signaling bit thereby providing additional signaling states so that the OIU equipment can account for multiple types of telephone local exchange equipment easily.

Abstract: In a telephone exchange apparatus which accommodates digital communication liens and employs a slave synchronization system in which a clock is extracted from a signal received from the network, an exchange switch is operated in synchronism with the extracted clock so as to prevent data omission caused by a difference between operating frequencies of a network and an exchange apparatus. If there is a phase difference between a pre-switching clock and a post-switching clock when the extracted clocks are switched upon changing communication lines, the postswitching clock is delayed by the phase difference between the two clocks so as to cause the phase of the post-switching clock to coincide with the phase of the pre-switching clock.

Abstract: A telephone network with distributed processing capabilities. A local controller is provided for monitoring status of a plurality of users. A primary controller performs circular polls of the local controllers to determine status changes. The system operates in a time division multiplexed fashion, and the primary controller assigns during which time slot each particular conversation will occur. A synchronizer for synchronizing between the primary and the secondary controller is also provided. In addition, the ring timing for the subscriber premise can be performed in the microprocessor at the subscriber premise.

Abstract: An electronic telephone apparatus comprising a trunk circuit, a sync signal generating circuit, an oscillator circuit, a selector, and a time-division switch. The trunk circuit is connected between a digital line and a highway, for transmitting signals therebetween and extracting sync clock pulses from the digital line. The sync signal generating circuit is connected to the trunk circuit, for generating a first reference clock signal of a predetermined frequency from the clock pulses extracted by the trunk circuit. The oscillator circuit generate a second reference clock signal similar to the first reference sync signal. The selector monitors the first reference clock signal, it selects the first reference clock signal when no abnormality is found in the first reference clock signal, and selects the second reference clock signal when abnormality is found in the first reference clock signal.

Abstract: A bus interface loading assembly used to equalize electrical loads of termination slots on a backplane assembly is disclosed. It is comprised of loading means adapted to be converted on said backplane at unused slots thereof. The loading means is also adpated to emulate a real load such that the characteristic impedance discontinuities of the backplane assembly are minimized.

Abstract: In communications control unit for sequentially scanning a plurality of line sets to which full-duplex lines are connected, for reading out line control word provided in correspondence to the line from a memory when a data transmission/reception request exists in the line set, and for executing the data transmitting and receiving operations with the relevant line set, one line control word including both of transmission control information and reception control information is read out in the time slot assigned to one full-duplex line, and the data transmitting and receiving operations are simultaneously executed.

Abstract: A telephone exchange, now often called a switch, includes a switching network of the space division type which switches PCM highways, and includes a number of sub-networks (SEG1, SEG2 . . . SEGN) each of which is a plural (e.g. three) stage array. When a call is to be set up it is set up via one of these sub-networks, and a reserve path chosen for it through a different sub-network. The identity of this reserve path is noted in memory for use if the path via which the connection is actually set up fails. If that happens the call switched to the reserve path. This facility can also be used for "block transfers" of all calls in a sub-network, e.g. when the latter is taken out of service for maintenance. In one embodiment in which three stages are used, part at least of the middle stage is common to all sub-networks. Such an apparently large amount of switching corss-points is not too "cost ineffective" since the switching sub-networks are made up of relatively cheap VLSI units. Since the physical paths are e.g.

Abstract: A system for expanding the number of signal ports accommodated by a base communication system having one or more switching circuits for interconnecting a plurality of local signal ports via a multiple line signal bus under control of a central controller. The expansion system is comprised of a plurality of expansion port circuits connected in parallel to the signal bus, for selectively interconnecting one or more respective remote signal ports to predetermined lines of the signal bus under control of the central controller. Each of the expansion port circuits preferably includes a selector/multiplexer circuit for selectively interconnecting the remote signal port with the predetermined line of the signal bus. According to a preferred embodiment of the invention, the communication system is a telephone system, such as a key telephone system or PABX, and the multiple line signal bus is comprised of a set of junctors.

Abstract: The invention relates to a distributed control-type electronic switching system which includes a first group of processors paired for act/standby redundancy, and a second group of master processors which are provided as single units. The first group of processors is connected to the speech-path switches and line and trunk circuits of a telephone switching system while the second processor group controls the various connections for the speech-path switches and the line and trunk circuits. Data communications between the first group of processors and the second group of processors is achieved on a distributed basis such that each processor of the first group designates a subset of the second group of processors as potential receivers, and conducts communications with the first non-busy processor of the subset.

Abstract: The invention provides a circuit and method for the time-sharing of a DTMF tone receiver. A DTMF receiver has its input terminal connected to a common output terminal of a pair of transmission gates, each gate having an input terminal connected to a respective source of DTMF signals. A control circuit provides switching signals to the transmission gates to cause their input terminals to be connected alternately to the input terminal of the receiver at a predetermined rate until the receiver detects a tone signal on at least one of the input terminals of the gates. The control circuit includes circuitry responsive to the initial tone detection for inhibiting the further generation of switching signals until the tone detection by the receiver has been completed.