Abstract: A connector is disclosed that includes spring contacts (200) for making a solderless connection to other electrical conductors (310). Each spring contact (200) has a loop contact portion (230) that is supported so that its end regions (232 and 234) are restrained in a direction generally normal to the site of engagement of its arcuate contact surface (236) with the other electrical conductor (310). As a result, the main region (235) of the loop contact portion (230) is essentially rotated rather than compressed when pressed into engagement with the other electrical conductor (310). The desired contact force necessary for a good solderless electric connection is thereby provided.

Abstract: A cable connection unit includes a mounting arrangement for holding a variety of modular interconnection units for interconnecting a variety of communication cables. Each interconnection unit has the same length and a width which is an integer multiple of the width of the narrowest interconnection unit. The mounting arrangement can be mounted to a plate surface or to an apparatus enclosure having cable entry and exit opening and a moveable front panel. The apparatus enclosure perimeter includes a mortise and tenon to enable mechanical interconnection to one or more additional housing enclosures.

Abstract: A communication system includes a plurality of station sets each connected over two pair communication facilities to a control module. An adapter unit switchably connects an external data or voice device via a station set to either facility in response to a control signal from the control module. A data mode is established by sending a data mode request signal from the station set to the control module. An off-hook signal from a connected data device is used to request a data call. The control module signals to which facility the adapter is to connect the data call and outputs a unique visual on the data call facility. The control module prevents other calls from bridging onto or interfering with the data call. The system also permits a voice call on a facility to be converted to a data call on the other facility. Furthermore, a user can make a voice call over one facility while a data call is in progress on the other facility.

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: Apparatus and a technique for echo cancellation is described in which the real and imaginary parts of an echo replica signal can evolve independently of each other. By removing the coupling heretofore found in cross coupled echo canceller structures, the echo replica obtained in conjunction with carrier-phase tracking circuitry can be a more exact duplicate of the real and imaginary components of a received echo containing signal. The echo canceller may include a plurality of subcancellers, each including at least four adaptive filters. Alternatively the filters within each subcanceller can be implemented by a suitably programmed digital signal processor.

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: Improved alternate routing in a packet switching system is provided by inserting alternate routing control information into each packet and by storing alternate routing information at each network node. The stored information at each node includes a list of the available paths extending from the node towards all other nodes together with a list of available algorithms that can be used to select one of the available routes. The alternate routing control information in each packet contains postage information specifying the maximum number of nodes through which the packet is to travel. The alternate routing control information also includes a destination node index code identifying the destination node. The destination node index is used as address information by each node receiving a packet to read out the stored information at the node identifying the available paths and the algorithm to be used in selecting one of these paths for use in transmitting the packet towards the destination node.

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 modular, hierarchical local area network is realizable by using existing twisted pair wiring, for example, in a building together with several elements known as network access units and hub units. A network access unit is connected to a device (microprocessor, display terminal, peripheral device, other local area network, information systems network or the like) in the local area network to give that device access to and from the network. The network access device is designed for simple daisy chaining with other devices to form a node when devices are colocated in the same section or room in the building. The hub unit is the network building block which permits extensive expansion of the local area network. It provides a connection point for access units or other hub units, performs collision detection operations, if necessary, and serves as a loop-back point for the network.

Abstract: A multi-stage time division switch interconnects a plurality of processors that individually communicate over one or more channels at various signalling rates. Any processor may initiate a call and request that a connection be set by the switch. The switch assigns one or more time slots to the call and gathers or distributes data over the interconnecting channels through the utilization of polling techniques, thereby creating a virtual circuit through the combination of a time division switch and a polled communication line.

Abstract: There is disclosed a clock circuit for a PBX system that uses phase locked loop technology to perform synchronization between two input signals. The system can switch between different reference sources without introducing error and without requiring the entire circuit to become realigned with the phase of the newly selected reference signal. This is accomplished with a phase build-out circuit that uses a phase locked loop divider to change the phase of the internal control signal to match the phase of the newly selected reference thereby eliminating timing changes on the system clock bus. The system can also be used to change between redundant clock circuits.

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: A tape, with holes therein adjacent an edge of the tape, an adhesive surface and a succession of discs on such surface, is moved step by step to advance each disc in turn to a work station having pins outward of that edge. At the station, wire is wound around the disc and the pins to form (a) a wire coil surrounding the disc and adhered to such surface, and (b) wire segments extending from such disc to such pins so that each segment spans one of such holes. The segments are pressed against the surface so that each is adhered thereto on opposite sides of the hole spanned by that segment. The segments are severed at such edge to detach them from the pins, and a piece of the tape bearing the coil and adhered severed segments is severed from the rest of the tape and removed from the station. The assemblage comprising such tape piece and the coil and segments thereon constitutes a useful article of manufacture.

Abstract: A data structure and program routines for use in a private branch exchange telephone system (PBX) for automatically routing calls via a private telephone network in response to a dialed public telephone network number and for restricting outgoing calls from the PBX to specific public network telephone stations. In a large corporate PBX switching network interconnected by both a public telephone network and a private telephone network, a telephone set connected to one PBX system establishes a switch connection through the private network by dialing the public telephone network's number for a destination telephone set connected to another PBX system. In response to the dialed number, the first PBX system automatically determines that the destination telephone set can be reached via the private telephone network and automatically converts the dialed public telephone network number to a private telephone network number designating the destination telephone set.