Abstract: An exemplary embodiment of an acousto-optic planar waveguide modulator includes a planar waveguide structure with an input section connected to a multimode section connected to an output section. The input and output sections have structures for propagating an optical signal in a first transmission mode. The multimode section has a structure in which an optical signal can propagate in the first transmission mode and a second transmission mode. A surface acoustic wave source is used to direct a surface acoustic wave at the multimode waveguide section to cause a periodic change in the refractive index for coupling optical signal energy between the even and odd transmission modes. As a consequence, power of an optical signal propagating in the even transmission mode is transferred to the odd transmission mode. This power transfer causes an attenuation of the optical signal propagating in the even transmission mode from the multimode section to the output section.

Abstract: A menu level indicator facilitates ease of use of a telephone terminal by a user by providing easily understandable information about selectable menu options available in an interactive display on the telephone terminal. The menu level indicator provides a visual indication for permitting the user to directly determine the number of menu options available while at one of multiple selectable menu levels in the menu. The menu level indicator also provides a visual indication for the user as to the relative position of a displayed, selectable menu option with respect to other selectable menu options commonly located at one of the multiple selectable menu levels. As a user maneuvers through the menu levels, such user is able to quickly develop a mental model of the feature menus and easily navigate through these menu selections.

Abstract: Determining by a telecommunication switching systems in response to the initialization of a new BRI interface if a communication terminal connected to the new BRI interface is presently active on another BRI interface within the telecommunication switching system. If the answer is yes, then the telecommunication switching systems automatically transfers all active calls to the new BRI interface from the other BRI interface preventing the loss of the active calls.

Abstract: A recognition criterion or set of recognition criteria are updated automatically, over time, in accordance with the speech input of the user(s). Each input utterance is compared to one or more models of speech to determine a similarity metric for each such comparison. A model of speech which most closely matches the utterance is determined based on the one or more similarity metrics. The similarity metric corresponding to the most closely matching model of speech is analyzed to determine whether the similarity metric satisfies the selected set of recognition criteria. The recognition criteria are automatically altered during use or "on-the-fly", so that more appropriate criteria (and associated thresholds) may be used to either increase the probability of recognition or decrease the incidence of false positive results. Illustratively, if a voice sample results in a near miss of a template, a more liberal criterion is thereafter employed to increase the probability of recognition for subsequent input.

Abstract: Disclosed is a system and method which screens all telephone call originations on an access system for calls to emergency services during times of telephone system congestion and bases a decision as to how to handle the call on such determination. According to this invention, all access system call originations (including dialed digits) are delivered to the switching system. If the access facilities are in an overload condition due to high volume or equipment failure, the switching system makes a predetermination as to whether the digits dialed indicate a call for emergency services (a 911 call) or a regular telephone call. Calls for emergency services are immediately routed. Regular telephone calls are advantageously routed to an announcement which announces traffic congestion and disconnects the call, thus providing access facilities for additional emergency calls.

Abstract: The encoding/transmission of information in an OFDM system is enhanced by using complementary codes and different patterns of amplitude modulation representing respective data words. The complementary codes, more particularly, are converted into phase vectors and modulated by the selected pattern. The result is then used to modulate respective carrier signals. The modulated result is then transmitted to a receiver which decodes the received signals to recover the encoded information.

Abstract: Testing of digital-to-analog converters is accelerated by applying one or more different approaches. One approach relies on a switched capacitor, which lowers the overall capacitance of the converter during testing, thereby reducing the settling time for each code value. Another approach makes the duration of each testing step a function of the particular code value, rather than using the worst-case settling time for each testing step. Yet another approach uses a sequence of non-consecutive code values to determine whether each switch in the converter is functional. Using non-consecutive code values permits the use of partial settling times during converter testing. Each of the approaches can be used to accelerate the testing of D/A converters, whether they have linear or folded resistor strings.

Abstract: There is disclosed a method of positioning an optical subassembly for testing includes positioning an optical subassembly within a capture zone on a support surface of a test fixture. At least two probes engage surfaces of respective ones of precisely located fiducials in a surface of the optical subassembly. A third probe contacts a surface of the optical subassembly, which in a preferred embodiment may be another fiducial in the surface of the optical subassembly. Upon engagement of the probes with surfaces of respective fiducials and movement of the probes further into respective fiducials, the optical subassembly is translated into more precise alignment with optics of the test fixture.

Abstract: In accordance with the invention, a conductive lead line extending between a source and a capacitance load has a width w(x) which is a function of the distance x. For many practical applications such as leads for multichip modules, w(x) can be taken as the exponential function of the distance from the load given by the equation below. For many applications w(x) can be adequately approximated by the first three terms of a power series representation: ##EQU1## where W.sub.0 is the width of the lead line at x=0, C.sub.0 is the load capacitance and C.sub.0 is the area capacitance. For VLSI applications w(x) is a friction which can be designated.noteq.E(W.sub.0, C.sub.0, C.sub.p, C.sub.S, x) where C.sub.p is the perimeter capacitance. E(W.sub.0, C.sub.0, C.sub.p, C.sub.S, x) is derived herein.

Abstract: A temperature compensating optical waveguide device including an optical fiber in which a grating formed of grating elements embedded within the fiber core reflects fiber-transmitted light within a range about a central wavelength that varies with temperature and with an axial strain applied to the grating. A top surface of a compensating member is affixed to a portion of the fiber that includes the grating and a tension adjusting member is connected to the compensating member. The tension adjusting member and the compensating member are formed of materials selected so that as the temperature of the device decreases, the tension adjusting member contracts more than the compensating member so as to control the deformation of the compensating member and thereby impose an axial strain on the grating.

Abstract: A videoconferencing network of audiovisual communication terminals is interconnected by a telephone network. Each terminal is activated only when the balance in a user account has been read and the account has been made available for debiting. The terminal includes a monitor system for playing out and receiving voice and picture information, an interface system for conditioning signals passing between the monitor system and the telephone network, and a database which contains the locations and telephone numbers of other terminals of the videoconferencing network. The terminal further includes a display of information from the database, a pointing device by means of which a user can make a selection from the display by indicating the relevant position in the display, and a device for automatically dialing up the selected remote terminal.

Abstract: A bidirectional optoelectronic transceiver assembly comprises a pair of interconnectable modules. One module houses a laser diode and a lens; the other a photodiode, a beam splitter and a fiber pigtail.

Abstract: A facility is provided for more efficiently controlling transmitted power in a forward link of CDMA telecommunications system. This is done by offsetting a power reference level that adjusts the level of the transmitted power using an power offset selected as a function of a transmission rate specified for the transmission of a coded frame. The coded frame is then transmitted at a power level selected as function of the adjusted power reference level, rather than the unadjusted level. Such efficiently is particularly noticeable when there is transition from one frame transmission rate to another such rate and vice-versa.

Abstract: A backplane testing method is provided in which test vectors are applied to individual circuit boards in a system while remaining circuit boards in the system are disabled. The signals on all receivers in the system are observed during testing. The circuit boards are connected to a test bus in a multi-drop arrangement, so that individual circuit boards can be addressed using slave interfaces. A walking enable technique is used to systematically toggle all of the drivers on the circuit boards. An intraboard testing technique is used for applying test vectors including an all 0's vector, an all 1's vector, and a series of test vectors generated from a binary counting sequence. Backplane faults are identified by comparing the observed receiver signals to the signals expected in response to the applied test vectors.

Abstract: The customer premise equipment of the invention consists of an OC-1, OC-3C or OC-12C receiver and an OC-1, OC-3C or OC-12C transmitter that interface with an ATM segmentation/reassembly circuit. In the downstream direction the segmentation/reassembly circuit receives the signals from the receiver and separates the signals into ATM cells. In the upstream direction the segmentation/reassembly circuit reassembles the ATM cells from the customer premise into a broadband signal and delivers the signal to the transmitter. The segmentation/reassembly circuit interfaces with a passive bus to deliver to and receive cells from a video decoder, POTS line card and a personal computer interface such that the customer can receive voice, data and video on a fiber to the home access architecture. A video system provides an ensemble of video channels at the customer premise.

Abstract: A method and apparatus for implementation of a code division multiple access encoding scheme in a fiber-optic network. One preferred embodiment of the present invention provides an encoder and decoder for each terminal in the communications network, for example SONET OC-3, and allows each terminal to transmit their signals into the fiber-optic network at random. Because no time slot management is used, signals from all terminals interfere with one another. A coding technique is used by each decoder to sort its own signal out of this interference. The encoded data from each terminal is modulated with a technique known as MFSK (multiple frequency shift keying). The modulated signal is further used to intensity-modulate a semiconductor laser diode which may or may not be a single wavelength laser. At the receiver, the combined interference signal is first detected by a optical intensity detector and then sent to a frequency tone detectors which demodulate the MFSK signal.

Abstract: A utility meter or other fixed device is assigned a permanent dialed number that is unrelated to the telephone number of the customer premise where the device is located. Instead, the dialed number is permanently assigned to a line termination location in the switch such that when the dialed number is dialed a connection is made to the line terminated at that physical location in the network switching system irrespective of the customer's telephone number. As a result, the number dialed by the calling party is unrelated to the customer's telephone number such that changes in a customer's telephone number do not affect the telemetry system. Moreover, the telemetry number could be selected from a specified range of numbers or could include a predetermined command digit such as *8 prior to the number string.

Abstract: An ergonomic personal telecommunication device that is of optimum size for user operation and manipulation allowing the user to operate the device as a telephony device or an electronic messaging device with one finger by using virtual function keys and buttons appearing at a function display.

Abstract: Disclosed is an optical package which is economical to manufacture. An optical component, such as a PIN photodiode, is bonded to a substrate such as silicon with no metallization on its side surfaces. The resulting assembly is solder bonded to the bottom surface of the package so that a side surface of the substrate is adjacent to the bottom surface with essentially no solder therebetween.