Abstract: A method and a system for providing a skewed clock signal which is used for latching a data signal received from a memory into a read-data latch. A control signal latch and a control-signal buffer provide a control sign to the memory. A read-data buffer feeds a data signal from the memory to a read-data latch, which is provided with skewed read-clock signal. A read-clock delay circuit provides a clock signal to the read-data latch, and delays the read clock signal a period of time approximately equal to the signal propagation delay time of the read data buffer and the propagation delay time associated with transmitting a signal from the output terminal of said control signal latch circuit to the control-signal input terminal of the memory.

Abstract: A cordless telephone employed in a public telephone system provides mobility and service at reasonable cost to users of portable communications equipment. The system includes a plurality of base units which are accessible by a plurality of similarly configured cordless telephones. Each one of these base units is assigned and operates on one of multiple frequency channels and each one of the cordless telephones is capable of establishing a communications link with each one of these base units. Once a cordless telephone establishes communications with a base unit within its reception range, other cordless telephones within this reception range are precluded from establishing communications with this base unit or monitoring or otherwise interfering with communications between the cordless telephone and this base unit while the communications link is established therebetween.

Abstract: A spread-spectrum signal which conveys identifying information for an associated information signal is superimposed on the associated signal and transmitted therewith. Such identifying information distinguishes between voice and data information signals and between different types of data information signals. Such identification can be used for a variety of purposes within a communications network, such as facility and equipment selection, equipment disablement and bypass, setting communications parameters, e.g., speed, and inhibiting communications upon fault detection.

Abstract: A timing control arrangement that dynamically controls the distribution of timing information in a distributed digital communication system having standard nodes and prioritized master nodes. Reference timing signals to control the system are distributed from the highest priority master node currently operational. Should a higher priority master node than the current master node become operational, the higher priority master node automatically takes control of the timing for the system. Each node is connected by links to at least one other node, and each node receives timing signals and a timing priority number (TPN) from all of the connected node. The TPN defines the number of links over which the timing signals travel to the receiving node from the current master node. Each standard node selects timing signals and TPN from the link having the lowest TPN and transmits the selected TPN (after incrementing the selected TPN by one) and timing signals on all connected outgoing links.

Abstract: An arrangement for data conferencing either multiple computers (FIG. 1), or multiple terminals with a computer (FIG. 4), includes software (21;511) for communicating keystrokes from conference participants to an application program (22;550) that is the object of the conference, and for communicating display signals from the application program to the participants. In one embodiment (FIG. 1), a first program (23) executing on a first computer (PC 2) transmits first computer-generated keystrokes to a second computer (PC 1), and displays on the first computer images received from the second computer, while a second program (21) co-resident with the application program (22) on the second computer enters received first computer keystrokes into the second computer, and sends second computer-generated images for display to the first computer. In a second embodiment (FIG. 4), a program (511) executing on a UNIX.RTM.

Abstract: Apparatus for automatically polling message service systems to obtain messages for a user of the apparatus. The apparatus is a computer attached to the user's telephone connected to a communication switching system. The computer responds to messages from the communication switching system or to an internal real time clock timing out to poll a number of message service systems to obtain messages for the user. The computer automatically performs logon procedures, message access procedures and message deletion procedures with the various message service systems. If the message service system is audio only, the computer generates audio tones and interprets verbal instruction in order to implement the above procedures.

Abstract: In a network (10) of voice-mail message service systems (12-14), each system includes an arrangement (22) for automatically moving the serving of one or more subscribers from itself to another system. In response to administrator (29) input, the source system retrieves each moving subscriber's mailbox (200) contents, translates subscriber I.D.s appearing therein into universal names and extension numbers, and transfers the translated contents, including delivery lists (222) and messages (211), to the destination system. The destination system creates a new mailbox for each moved subscriber, translates the universal information into subscriber I.D.s, and populates the new mailbox with the transferred contents. The source system informs third systems of the move, so they can update their information. During audits, the source and destination systems search their databases to find any information affected by the move and update it; the source system also deletes the moved subscribers' old mailboxes.

Abstract: An automatic call coverage feature arrangement for unattended PBX stations including attendant consoles. When an incoming call is received at an unattended station, a control processor monitors the number of ring cycles at the called station. The control processor automatically diverts the incoming call to a prescribed coverage station or facility following a prescribed number of ring cycles. Concurrently, the control processor activates an indicator to indicate that the feature is active. Thereafter, the control processor automatically diverts all subsequently received incoming calls from the unattended PBX station to the coverage station or facility. This feature does not require manual activation by a subscriber or an attendant, but is automatically activated in response to a first unanswered incoming call. This allows remote activation of the feature by a subscriber or attendant since all that is required to activate this feature is a first unanswered incoming call to the called station.

Abstract: The subject communication system is an improved cellular mobile telecommunication system which provides business communication features to cellular mobile telecommunication customers.This is accomplished by using a business communication system as the switch element in the mobile telecommunication office. The master-slave relationship between the mobile telecommunication controller and the system processor that is found in the prior art is replaced by a peer-peer relationship. The mobile telecommunication control functions are handled by the mobile telecommunication controller while the call processing/connection control functions are handled by the system processor. Thus, the existing business communication call processing software can be used directly and any new business communication service provided by the business communication system is also available to the cellular mobile telecommunication customer.

Abstract: A flow control mechanism for a packet switching system that provides for the continuous dynamic control of station window size beginning with call setup and extending through the duration of the call. A station window size can be of a first magnitude at call setup time when system traffic may be low. The window size can be subsequently reduced to free up port buffer space as system traffic increases. This permits the serving of more calls during periods of heavy traffic.

Abstract: A second order gradient microphone arrangement is implemented with four commercially available, inexpensive first order gradient electret microphones which are arranged in the wall of a hollow cylinder at ninety degrees angular spacings and whose outputs are added to produce a toroidal directional characteristic. The distance between the tops of the microphones and the top of the cylinder equals the distance between the bottoms of the microphones and the bottom of the cylinder. The directional characteristic is relatively frequency independent. The arrangement is characterized by rotational symmetry around the cylinder axis and further by a cosine squared dependence in the planes containing the rotational axis. In the direction of the axis, the sensitivity at midfrequencies is typically twenty decibels lower than in the equatorial plane. The equalized frequency response in this plane is within .+-.3 dB from 0.3 to 3 kHz.

Abstract: The invention relates to a hand-held device for detecting whether or not an optical fiber is carrying a light signal. The device includes a spring loaded hook for grabbing an exposed optical fiber anywhere along its length, thereby introducing microbending, a photodetector for responding to the presence of light emitted in the proximity of the microbend, and a light emitting diode connected by way of an amplifier to the photodetector for indicating when a light signal has been detected. Upon release of the spring loaded hook, the fiber returns to its normal state. The device can be easily modified to indicate not only the presence of a light signal, but also the strength of the signal and the direction in which the signal is being transmitted.

Abstract: A security system arrangement utilizing a standard PBX for monitoring a plurality of concurrently administrable guard tours. A control processor of the PBX administers the security monitoring processing operation. This processing operation monitors the activities of tour guards as the guards progress through one or more tours. In particular, a programmable memory defines a plurality of tours. Each tour comprises a finite list of sequentially defined checkpoints where each checkpoint is a designated conventional station set of the PBX. A security controller activates the security system by "dialing" the appropriate feature code at a central control facility, such as an attendant console. The security controller than selects one or more the available tours by "dialing" a tour code. Following the selection and activation of a tour, a tour guard "dials" a check-in code at each checkpoint and progresses sequentially through the checkpoints contained in the list comprising the selected tour or tours.

Abstract: The present invention relates to a wireless PBX network wherein direct sequence spread spectrum multiple access is used for voice and data communications to support a plurality of local-local and local-external calls. The present wireless PBX arrangement comprises a plurality of local user transceivers using a first separate unique chip sequence patterns for information communication and a second common chip sequence pattern for call-set up; and a central PBX comprising (a) a plurality of PBX transceivers, each of which uses a separate first chip sequence pattern which is matched to a corresponding local user transceiver; (b) a switching means for interconnecting local users to each other or to an external network via the associated PBX transceivers; and (c) a call set-up receiver responsive solely to initial call set-up information sent by any user using the second common chip sequence pattern.

Abstract: There is disclosed a multiple electrical contact switch which has a comb block whose teeth are inserted into receptacles of a mounting block thereby wedging pairs of electrical spring contacts, which are also inserted into the receptacles, between the teeth and the receptacles without bending the spring contacts. The electrical contacts extend from the receptacles and are activated by an operating card, which engages the extended portions of the electrical contacts to open or close electrical conduction paths. When pressure on the spring contacts from the actuating card is released, the spring contacts then move the operating card to an original position wherein the sequence of open and closed contact springs is as if there were no contact with the operating card and the contact springs.

Abstract: A nonhierarchial switching system employing a modified unified algorithm for developing link sizes for paths that connect switches in the system and routing sequences for the switches in the system, and further employing means for updating the routing sequences to minimize potential blocking in the network. In one embodiment, the modified unified algorithm develops improved link size determinations by taking advantage of traffic sensitive dynamic routing on the alternate paths available in the nonhierarchial switching system for connecting any switch to any other switch in the system. Updating of the routing sequences is achieved in that embodiment by evaluating the least loaded path for each potential connection of two switches in the system and, when appropriate, by installing the least loaded path as the second choice path in the routing sequence for that potential connection.

Abstract: Optical functions such as Q-switching, mode locking, cavity dumping, and modulation are generated by a simple laser arrangement which includes a gain medium and an electrically controllable, optical waveguide device optically coupled to the gain medium. The gain medium and waveguide device are either interposed between two reflective surfaces or coupled by a waveguide in order to form a single composite cavity laser structure.

Abstract: A signal limiting amplifier includes interstage limiting devices to restrict the range of output voltage signals. The devices are base-emitter circuits of transistors, one of which operates in response to one polarity of signals and has its collector terminal unconnected, and the other of which operates in response to the other polarity of signals and has its collector circuit connected (when limiting) to operate an appropriate utilization circuit. In one embodiment, the limiting amplifier is applied as a common mode feedback amplifier in a telephone line feed circuit, and the limiter signal is used to limit large longitudinal signals on a customer line and to power down the line feed circuit in the event the limited signals persist beyond a certain interval.