Abstract: An arrangement for providing Automatic Call Distribution (ACD) service from a mixture of local and remote agents. The remote agents are connected via a voice connection to the home switch of the ACD and voice data connection to a Home Agent Server (HAS). The HAS passes call event data to a Management Information System (MIS) of the ACD, which informs the ACD switch of call events that make a remote agent available or unavailable, and passes applications data to a host processor for serving the applications of the ACD. Call set-up time is reduced by establishing longer term connections between the ACD and the remote server and using these connections for a plurality of calls; such connections are established or disconnected when the traffic level suggests the desirability of having more or fewer remote servers. Advantageously, ACD service can be provided efficiently and economically from a remote server.

Abstract: A plurality of ATM networks may be interconnected to allow communication of voice-band signals between them by using one or more PSTNs and a novel interface that converts ATM formatted data packets to a format usable by digital multiplication equipment (DCME). Such an interface thus allows the DCME to advantageously function as a gateway between the ATM network and PSTN by providing for optimum bandwidth usage between the networks. In an illustrative example of the invention, a DCME available from AT&T as the Integrated Access and Cross Connect System ("IACS"), is provided with an ATM-to-DCME interface that converts ATM formatted packets to a regular channelized bitstream usable as an input by the IACS. The interface and the IACS are positioned on both ends of a PSTN to allow for connectivity between the PSTN and a plurality of ATM networks, as well as the required optimization of bandwidth usage.

Abstract: The present invention overcomes the prior art limitations by dividing a coverage area into very small regions or cells. The inventive system can be built as an adjunct to a wired telecommunication system such as a PBX. Advantageously, because of the relatively small size of each cell, transceivers in the inventive system can use very low transmission power, compared with a pico-cellular communications system, to communicate with a fixed transceiver. In addition, because of the relatively short distance between the mobile handset and the fixed transceiver, the communication paths between any two transceivers are reduced and, therefore, the multipath distortion which can affect the received signals is substantially reduced.A concomitant problem normally associated with relatively small cells is the need for a switching system which can accommodate the large amount of switching or handovers required to accommodate the various mobile units as they move from one cell to another.

Abstract: An inexpensive, yet robust color matcher is achieved by an apparatus which includes a compare device coupled to receive, as a first input, an input signal representing a combination of a luminance component Y and a chrominance component, and further coupled to receive as a second input, a threshold T, for comparing the input signal to the threshold T and outputting a color match signal if the input signal falls within a range defined by T and -T; and a threshold supply device coupled to the second input for supplying the threshold T, wherein the threshold T is a function of Y and at least two adjustable parameters.

Abstract: A test fixture is provided for testing electrical characteristics associated with a printed circuit board (PCB). Spaced-apart solenoids each have an extendible arm aligned along an axis defined by a connector assembly on the PCB to be tested. The arms are located to have sufficient travel to engage the side of the connector assembly. A mechanism is provided which detects which of the arms engage the connector assembly. Arm engagement data is stored in memory of a PC for type of connector assembly to be tested by the apparatus. A mechanism is provided for determining if a correct test program has been selected by a user for testing a particular connector assembly based on whether the arm engagement data matches the arms that engage the connector assembly.

Abstract: Smart card techniques are disclosed for integrating and administering records related to the ownership and/or operation of motor vehicles. A smart identification card stores and administers a plurality of motor vehicle records corresponding to a single motorist. These motor vehicle records include items selected from the group of motor vehicle registration information, drivers license information, vehicle code violations, automobile insurance information, parking garage entry times, parking garage account balance, highway toll account balance, motor club information, and environmental inspection information. Each smart identification card is equipped to interact with any of a plurality of computer databases through the utilization of a conventional communications link in conjunction with a smart card scanner. Each of the computer databases administers motor vehicle records.

Abstract: An upgrade arrangement wherein the switching functions of an in-service switch or cross-connect system are transferred or "re-homed" onto a new, larger capacity switch via the existing input and output ports of the original system. The re-homing can be performed without loss of service, even if the original system is operating at full-capacity. By exploiting the protection redundancy engineered into existing telecommunication switching systems, all of the signals being routed through the original switch are temporarily consolidated onto only one-half of the switching fabric normally required to accommodate such connectivity. This signal consolidation allows half of the original switch ports to be brought off-line (without a service disruption), and linked to the new, higher capacity switching fabric.

Abstract: Telephone calls are directed from a first telecommunications platform to a second telecommunications platform, together with an identifier which uniquely identifies the call and enables telecommunication switches to monitor and maintain control over the call. The unique identifier enables the call to be returned from the second platform to the first platform. Once returned to the first platform, the call can be directed to a third telecommunications platform (and, subsequently, back to the first platform), without requiring the caller to place another call or to re-verify the caller's identity. The call identifier is used either to automatically return the call to the first platform after the occurrence of a predetermined event, or upon detecting predetermined, caller-dialed keystrokes indicating that the caller wishes to return to the interexchange carrier platform.

Abstract: An ATM cell carrying a voice-band signal originating in an STM network is processed in accordance with a particular signal processing function in an ATM mode at an ATM data rate without incurring a delay penalty that arises.

Abstract: A method of coding a video signal at a fixed bit rate with use of a vector quantization codebook, wherein advantageous codebook updates are determined by comparing a coding error associated with a first provisional coding of a frame with a coding error associated with a second provisional coding of the frame. The first provisional coding uses a fixed available number of bits to code a frame with use of the unmodified codebook, whereas the second provisional coding uses a modified codebook to code the same frame. However, the second provisional coding codes both the frame and the codebook updates with the fixed available number of bits. The provisional coding having the smaller coding error is selected as the coding of the frame which will be adopted. In addition, the codebook may be replaced with the modified codebook when the second provisional coding is selected. In this manner, the coder will adapt the codebook to the characteristics of the scene.

Abstract: A method for a post-processors provides reliability information about every decoded data symbol at the output of an arbitrary decoder. This reliability information is generated by comparing the decoded sequence to a small list of alternative sequences which differ from the decoded sequence at least in the symbol for which the reliability is being evaluated. It is shown that this algorithm is a simplification of the optimal symbol-by-symbol detector (OSSD).

Abstract: The invention provides a method and apparatus for transmitting digital signal information to a receiver using a plurality of antennas. The invention involves applying a channel code to a digital signal producing one or more symbols. A plurality of symbol copies is made and each copy is weighted by a distinct time varying function. Each antenna transmits a signal based on one of the weighted symbol copies. Any channel code may be used with the invention, such as a convolutional channel code or block channel code. Weighting provided to symbol copies may involve application of an amplitude gain, phase shift, or both. The present invention may be used in combination with either or both conventional interleavers and constellation mappers.

Abstract: Pseudo-exhaustive self-testing of an electronic circuit (10), containing groups of combinational elements (14.sub.1,14.sub.2, 14.sub.3 . . . 14.sub.n), is accomplished by first partitioning the groups of combinational elements into sub-cones having no more than w inputs each by designating appropriate nodes ("test points") in each cone as the output of a sub-cone. A set of test vectors {a.sub.1, a.sub.2 . . . a.sub.w, b.sub.1, b.sub.2 . . . b.sub.w } is then generated (via an internal generator 74) such that when the vectors are applied to the sub-cones (14.sub.1.sbsb.a, 14.sub.1.sbsb.b . . . . 14.sub.i.sbsb.j), each sub-cone will be exhaustively tested. Each of the inputs of the sub-cones is assigned to receive a vector such that the vectors received at the inputs are linearly independent. The subset of vectors is applied through each of a plurality of pseudo-exhaustive self-test (PEST) flip-flop circuits (88) and through the test points to test the circuit.

Abstract: The present invention relates to methods and apparatus for wavelength division multiplexing (WDM) using arrays of optical filtering elements to create a desired wavelength passband in an optical filter. In one aspect of the invention, an optical demultiplexer is formed using an input waveguide, such as a planar waveguide or an optical fiber, coupled to plural output waveguides. Each output waveguide includes a wavelength selective configuration of optical filtering elements formed within a contiguous portion of the waveguide forming an optical channel-selective filter having spectral regions having an optical transmission passband and spectral regions of low transmissivity. Exemplary optical filtering elements are Bragg gratings formed into an optical filter which transmits a characteristic wavelength band.

Abstract: In order to extend the geographical coverage of a line unit utilized in a telecommunications system, a host line apparatus is utilized in place of a conventional line group apparatus in a line unit. The host unit communicates information directed to the line group apparatus which it replaces via a transmission media to a remote line group unit which is geographically separated from the line unit. The remote line group supports a plurality of individual subscriber lines and provides service to the subscribers without requiring many of the elements normally required in a normal common shelf utilized in a conventional line unit.

Abstract: ATM test cells are generated and inserted into an ATM combined data stream in such a manner that a desired average insertion rate is maintained. The desired average insertion rate is obtained by enabling generation of and insertion of test cells into each idle cell of the ATM combined data stream so long as the actual number of test cell being inserted does not exceed a number that should have been inserted.

Abstract: An optical device includes a semiconductor optical amplifier and a lens for receiving optical energy from the optical amplifier. The lens and the optical amplifier are monolithically integrated on a common substrate. The optical amplifier may be of the type having a tapered active region. Rather than an optical amplifier, a semiconductor laser may be integrated with the lens. The lens may be formed by changing the refractive index of the waveguide core which is formed in the semiconductor material. This refractive index change may be produced by changing the thickness of a portion of the waveguide core layer.

Abstract: A file system which has component file systems including a primary file system which is react/write and a number of dump file systems which are read only. Each dump file system is created from the primary file system by means of a dump operation and conserves the state of the primary file system at the time the dump operation was performed. Component file systems share read only storage elements with older component file systems. The file system is implemented on a system including a file server, a magnetic disk mass storage device, and an optical write once-read many (WORM) disk. The magnetic disk mass storage device contains the read/write storage elements of the primary file system and encached read only storage elements from the WORM disk. Space is reserved on the unwritten portion of the WORM disk for the read-write storage elements of the primary file system.

Abstract: This application discloses, to the best of our knowledge, the first unipolar laser. An exemplary embodiment of the laser was implemented in the GaInAs/AlInAs system and emits radiation of about 4.2 .mu.m wavelength. Embodiments in other material systems are possible, and the lasers can be readily designed to emit at a predetermined wavelength in a wide spectral region. We have designated the laser the "quantum cascade" (QC) laser. The QC laser comprises a multilayer semiconductor structure that comprises a multiplicity of essentially identical undoper "active" regions, a given active region being separated from an adjoining one by a doped "energy relaxation" region. In a currently preferred embodiment each active region comprises three coupled quantum wells designed to facilitate attainment of population inversion. In the currently preferred embodiment the energy relaxation regions are digitally graded gap regions. However, other energy relaxation regions are possible.

Abstract: In accordance with an embodiment of the invention, a data converter is disclosed that provides a sampling rate conversion. The converter receives a clock signal, a divided-down clock signal, and first digital signal samples at a first rate. The converter converts the first digital signal samples to second digital signal samples at a second rate. The ratio of the first rate to the second rate is defined as a fist conversion rate factor. A first programmable counter receives the clock signal and divides down the clock signal to produce a divided-down clock signal. The first programmable counter is programmable to selectively determine the first conversion rate factor.In an alternate embodiment, another stage of sampling rate conversion is provided by a second data converter. The second converter receives the divided-down clock signal, a further divided-down clock signal, and the second digital signal samples. The second data converter converts the second digital signal samples to the third rate.