Abstract: Frames of data are encrypted by combining each of the frames with a mask that varies from frame to frame. The mask is obtained by using a frame counter as the seed for a pseudo random number generator, generating n pseudo random numbers, where n is the number of bytes to be encrypted in each frame, and concatenating the most significant bytes of each of the n pseudo random numbers to form the mask. The encrypted frames are transmitted, received and decrypted by combining them with the mask, which is independently generated at the receiver. The frame counter is aperiodically reset to a new initial value that is a substantially random number with respect to a previous initial value.

Abstract: A loss-less optical cross-connect advantageously employs a plurality of optical rare earth-doped fiber optical amplifiers as gain-switched optical connections, for example, gain-switched optical distributors and gain-switched optical selectors. Each of the optical rare earth-doped fiber optical amplifiers acts as an ON/OFF switch. Also, both the gain-switched optical distributors and selectors employed in the optical cross-connect arrangement of this invention are a natural fit into today's optically amplified optical communication systems. In one embodiment, this is realized by employing a pump select circuit in conjunction with a plurality of pumps and the plurality of corresponding rare earth-doped fiber optical amplifiers. The particular pump and corresponding optical amplifier are selected by use of a control circuit arrangement to determine which output port or ports is (are) connected to the input port.

Abstract: A system for providing low cost data connections directly to a long distance switch in order to connect a plurality of ISDN-based data connections to a data network such as the Internet. A line card of this invention connects directly to a time slot interchange unit of a digital switch and receives ISDN data and control information, extracts the control information and sets up channels through to the data network, and provides ATM segmentation reassembly and header routing information in both directions. This system also provides policing and traffic shaping control for each ISDN connection and traffic control so that a particular ISDN connection does not overload the resources of the line card. The line card of this invention also provides ATM physical layer processing SONET encapsulation, and SONET optical interfaces to a router on the Internet. In this manner, numerous ISDN connections may be made inexpensively by using fewer ISDN modems and channel banks, and lessen the load on local switching systems.

Abstract: The specification describes a double poly Mechanical Anti-Reflection Switch (MARS) device in which shorting between the lower poly metallization and the silicon substrate is prevented by providing an insulating layer on the surface of the silicon substrate.

Abstract: A high speed logic module is formed to include a differential input formed as a pair of inductive transmission lines and a differential output also formed as a pair of inductive transmission lines. A pair of logic devices are included in the module, with the gate terminals of the devices coupled to separate ones of the input inductive transmission lines. The output terminals of the logic devices are coupled to separate ones of the pair of output inductive transmission lines. The effects of the intrinsic gate-to-drain capacitance C.sub.gd inherent in each logic device is compensated for by including a pair of cross-coupled neutralizing capacitors between the drain and gate terminals of the logic devices. Various logic circuits, such as oscillators, latches, delay lines, etc. can be formed using the differential, neutralized structure of the invention.

Abstract: An outdoor assembly exposed to rain water has an enclosure and a cover. A first mounting means for the cover installs the cover to form a barrier to rain water for the enclosure rendering it drip proof or water proof. A second mounting means for the cover on the enclosure installs the cover to form a rain shield for the enclosure. The first mounting means allows opening or rotation of the cover about a vertical axis thus allowing access to the enclosure. The second mounting means releasingly engages the cover with respect to the enclosure generally at a right angle to the vertical direction, thus providing a rain shield for the enclosure.

Abstract: A multipoint-to-point wireless System using directional antennas in an indoor environment. Optical pulses in an asynchronous transfer mode network may be converted into radio pulses, which are transmitted by a radio transmitter to a radio receiver, and then may be reconverted into optical pulses. Transmitter antennas having predetermined beamwidths are used and positioned within the indoor environment for transmitting data signals at a selected carrier frequency. A receiver antenna with a predetermined bandwidth is positioned within the indoor environment for receiving data signals transmitted at the selected carrier frequency. Amplitude Shift Keying (ASK) is used so that the output between transmitted data packets is zero, thereby allowing other users to utilize the system during the gap between the packets.

Abstract: A method for accurately and objectively evaluating stress migration effects on long term reliability of integrated circuits. A sample containing a conductive runner is fabricated according to a given fabrication process. The fabricated sample undergoes a heating step at a first temperature for a first time period to induce material interactions at an accelerated rate, followed by cooling the sample to a second temperature and maintaining the second temperature for a time of sufficient duration such that relaxation occurs. Then the sample undergoes a heating process at a third temperature for a time sufficient to nucleate a predetermined number of voids, followed by heating the sample runner at a fourth temperature, less than than the third temperature, to propagate the voids such that a maximum void size is determined. Void distribution is preferably monitored by optical and scanning electron microscopy.

Abstract: Apparatus for steerable nulling of a radiation pattern of a main lobe and at least one side lobe with at least one null point produced by an antenna array of n elements relative to wideband radio frequency signals having a carrier wave modulated with pulse signals, while receiving the radio frequency signals from, or transmitting to, a desired station and at least one interfering station. An interference rejection processor (IRP) that has n inputs, each connected to a respective element of the antenna array, is connected between the receiver or transmitter and the antenna array. The IRP steers the effect of the antenna radiation pattern such that the at least one null point substantially corresponds to the reception of the radio frequency signal from, or transmission to, the interfering station. The antenna array has an aperture bandwidth, E, such that the IRP is implemented using only phase delay of the radio frequency signals to steer the radiation pattern.

Abstract: For use with a power converter having a switching circuit coupled to a primary winding of a transformer and a rectifier coupled to a secondary winding of the transformer, the switching circuit exhibiting switching losses and the rectifier inducing reverse recovery currents in the converter, a snubber circuit and a method of reducing the switching losses and reverse recovery currents.

Abstract: A circuit for stabilizing the gain-bandwidth product of analog circuits containing bipolar devices which determine the gm is disclosed. The stabilization circuit is formed to generate a reference current that is proportional to a reference capacitance C.sub.S and the thermal voltage V.sub.T. The reference current is ultimately mirrored (as the bias current) into the bipolar devices which determine the gm within the analog circuit. Since the transconductance gm of a bipolar device can be expressed as collector current, I.sub.C, divided by V.sub.T, the thermal voltage factor of the bias current itself will "cancel" the thermal voltage factor present in the transconductance. The effects related to the remaining variable, the capacitance, will be eliminated as long as the reference capacitance is formed to "track" the analog circuit capacitance by using similar types of capacitance to implement both capacitors and forming both the stabilization circuit and the analog circuit on the same silicon chip.

Abstract: In modem, modularly structured mobile radio systems, a call between a base station and a mobile subscriber station is to be handed over to a different base station the moment the mobile subscriber station leaves the coverage area of a base station. For this purpose, a switching system providing the route between a fixed network and the base stations is to carry out appropriate switching operations. In order to realise shortest possible dead times caused by interruptions during call handovers from one radio cell to another radio cell, a first and a further base station each comprise switching equipment for inserting a signal (S.sub.k) coming from a switching center into a signal (S.sub.g) going to the switching center.

Abstract: An information processing system adapted for use in conjunction with a telephone communication system. The information processing system includes a caller identification signal receiver, a timed switching device, and a call forwarding device. When no incoming call is being received, the timed switching device is in a first, open state, such that a circuit between the telephone line and the call forwarding device is interrupted. Upon receipt of an incoming call on the telephone line, the timed switching device and the caller identification signal receiver are activated. The timed switching device enters a second, closed state after a finite amount of time has elapsed such as, for example, several seconds, thereby allowing sufficient time for the caller identification signal to arrive on the incoming telephone line.

Abstract: A system for service control and operations for a telecommunications network. In particular, an architecture and method for a service control and operations element system. The system communicates with a plurality of interconnected telecommunications network elements via a switching and signaling subsystem. The system provides and controls the functions of the telecommunications network, including a method of measuring delay between the time a customer dials a phone number of a called party and the time the customer hears a ringback tone indicating that the called party was alerted to the call, a method of synchronizing clocks located at individual network elements with a centralized time source, and a method of time-of-day clock surveillance.

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 method for reducing frequency-related power losses in a telecommunication line interface circuit comprises operating a switching converter circuit at an optimum frequency. Determination of the optimum frequency is based upon a subscriber loop length. Particularly, the subscriber loop voltage is detected at a battery feed circuit of the line interface circuit, and used to access an optimum frequency stored in an initialized database. The optimum frequency information is received in the switching converter circuit, and determines its operating frequency.

Abstract: Apparatus and methods for communicating using protocols. The apparatus and methods employ protocol descriptions written in a device-independent protocol description language. A protocol is executed by employing a protocol description language interpreter to interpret the protocol description. Communication using any protocol for which there is a protocol description may be done by means of a general protocol. The general protocol includes a first general protocol message which includes a protocol description for a specific protocol. The protocol apparatus which receives the first protocol message employs a protocol description language interpreter to interpret the included protocol description and thereby to execute the specific protocol.

Abstract: An apparatus for lifting, carrying, and positioning probemats or fixtures. The apparatus comprises movable opposing side arms having a mechanism for receipt of a fixture handle, as well as a stationary support member. An arrangement is provided to connect the side arms to the support member by the use of a first track positioned on the front of the support member and a second track positioned on the rear of the support member. First and second rollers for rolling engagement with the tracks are connected to each side arm to support the weight of the side arm and to permit each side arm to slidably move along the tracks. The fixture handler also includes jaws comprising a channel and stops at the ends of the channel to permit the handler to be used with a plurality of different fixtures handles. Finally, an insert is provided for use with the jaws to further enhance the ability of the fixture handler to support a myriad of fixture types.

Abstract: A method and apparatus for visually rendering a three dimensional structure as an image on a two dimensional display without specialized hardware. The invention renders each object of the structure one at a time on the display in descending order according to a measured distance, i.e., rear to front of the structure, of the object from a predetermined view point. As each object is rendered, depth relationships between the objects are conveyed to users. To reduce the number of computations required for rendering the objects, the present method and apparatus use a reference point to determine the measured distance from the predetermined view point to each object.

Abstract: A user interface for resolving contention for a data channel is coupled to a broadband network having a plurality of user interfaces and a distribution hub. The user interface comprises a contention circuit for generating a contention signal in substantial absence of a common frequency with other user interfaces. The contention signal is a contention request for allocation of a data channel on the broadband network. A sensor for sensing other contention signals on the broadband network determines a status of the contention request. In a further enhancement, the contention signal is related to the unique id number. This relationship in a further enhancement is based on a multiple of a step frequency relative to a base frequency, wherein the multiple is related to the unique id number. In a yet further enhancement, a contending user having a highest unique id number is given access to the data channel.