Abstract: A method and system for detecting a presence of a preceding vehicle moving in a front detection area of a controlled vehicle. In the method and system thereof, a plurality of laser or other kinds of beams are transmitted to any object present in the front detection area and the plurality of reflected beams are received so that the respective distances to the reflecting objects are measured on the basis of the propagation delay times between the transmission and reception of the beams.

Abstract: A film folding control apparatus of a wrapping machine is a type in which a length of film fed by a film feeding mechanism is extended at a predetermined section of the wrapping machine. An article to be wrapped is raised into taut engagement with the extended film from therebelow. The edges of the film are folded under the bottom of the article, thereby wrapping the article in the film, by a film folding mechanism comprising left, right and front folding plates. The control apparatus comprises a data setting device for setting film length data, film tension data and tray type data in dependence upon a number of an article to be wrapped. A preset memory stores this data in correspondence with the number of the article to be wrapped. A control unit is responsive to an input of the number of the article to be wrapped.

Abstract: A method and apparatus is provided for measuring the timing jitter of a tributary data stream that has been multiplexed into a higher-rate multiplex stream using pulse stuffing techniques. The required jitter measurement is carried out by monitoring the relevant stuffing control bits of the multiplex stream. In one embodiment, the apparatus comprises a first microprocessor for determining the tributary stuffing ratio from the stuffing control bits, and a second microprocessor operative to determine a current jitter signal value by using both the stuff information contained in the stuffing control bits, and the stuffing ratio determined by the first microprocessor. The second microprocessor carried out its task by updating a preceding jitter signal value by incrementing this value each time a stuff occurs while decreasing the jitter signal value at a rate dependent on the stuffing ratio. Preferred algorithms are disclosed for determining both the stuffing ratio and current jitter signal value.

Abstract: Clamping a piezoelectric transducer onto the arm produces a signal whose integration with respect to time corresponds directly to the energy produced by the arm's movement. By clamping four (4) such transducers onto the body, one on each arm and one on each leg, the total integration of the four (4) signals gives a measure of the total energy spent in motion by the body. The desired body energy spent can be displayed quantitatively by first converting the integrated signal into a pulse train, then counting the pulses, and then driving a display with the counter's value.

Abstract: This invention provides a system for recording operation data of a machine, wherein a program for converting signals stored through a sensor or measuring means into operation data in conformity with the increase or alteration of the sensor or measuring means due to the operation status of the machine or to the type of the component of the machine is preliminarily stored in one or separate card-type external memory or other transportable external memory. The terminal of the system is designed to allow an connection of various kinds of the sensor or measuring means. Accordingly, it is possible to conduct processing and recording of various kinds of operation data by exchanging the external memory stored with a prescribed operation data-processing program, or by changing the writing of the program. It is also possible to record operation data in the external memory stored with the operation data-processing program after the program is read out to simplify the operation of an operator.

Abstract: A navigation system for a vehicle generates a guide display in the form of a diagrammatic roadmap during travel on surfaces roads and in the form of a textual road-name display exclusively during travel on freeways. In addition, the navigation system has a manual reset switch which triggers the change of the display image back to the diagrammatic roadmap after freeway travel and replacement of a deduced vehicle position with the known position of a road feature at which a driver is prompted to push the reset switch.

Abstract: A method and apparatus are described for directing operators to a plurality of locations to gather data in a portable data collection apparatus. The method provides for data compression for efficient utilization of solid state memory in the apparatus and allows for the data describing the multiple accounts to be in variable numbers of fields and field lengths. The apparatus keyboard provides for sequential and random accessing of the accounts for data entry and display, and for listings of the different types of areas to be visited. Additionally, it provides for searching missed accounts and for locating a desired account in the record. Capabilities are provided for storing new accounts and identifying their location in the record. Specifically, the application for utility meter reading is disclosed, in which, data read from a plurality of utility meters is stored in the apparatus by the meter reader, and later transmitted to a data processor for billing purposes.

Abstract: A numerical control apparatus having a feedrate difference reduction capability suitable for use with a multi-axis machine tool. Feedrate differences for respective control axes are calculated from a machining program, and decelerations for the respective control axes are calculated from preestablished allowable feedrate difference settings and the calculated feedrate differences. The control axes are controlled to be displaced within the allowable feedrate difference settings based on the calculated decelerations.

Abstract: There is disclosed a control method for returning a robot control operation to an accurate zero point before the start of the operation. The method is suitable when applied even to a turning operation of 360 degrees or more. For this control, the arm of the robot is turned counterclockwise at a low speed until a zero position detecting switch is turned on, and these turns are then reversed and stopped when a zero position detecting pulse is generated. The counted value (A) of the deviation between the instant when the zero position detecting switch in this case is turned on and the instant when the zero position detecting pulse is generated is registered. The counted value (B) measured likewise each time during the subsequent zero point adjustments is compared with the aforementioned counted value (A) of the deviation first registered so that the zero point of the control operation of the robot can be detected.

Abstract: Apparatus and method are disclosed for teaching a cycle of operation to a computer operated robot arm. A keyboard is provided comprising first keystroke means which are operative in two different teaching modes. In a first teaching mode, the keystroke means cause storage of individual instructions defining an operation to be performed by the robot arm at a point in space. In the second teaching mode the first keystroke means are operative for creating a macro comprising a sequence of such instructions for later use. There is a pendant which controls the movement of the end of the robot arm and has second keystroke means for causing a previously stored macro to be assembled into an operating control program for the robot arm. The second keystroke means also may be used for causing assembly of individual instructions into the operating control program.

Abstract: A broadband communications network includes a plurality of stations interconnected through selected forward and reverse channels by a network translator. Each station continuously monitors the forward channel for detecting the presence or absence of a forward channel carrier. A given station is allowed to transmit a data packet as modulation of the reverse channel carrier only after the expiration of a predetermined time interval during which no carrier is detected on the forward channel. By establishing the predetermined time interval for each respective station in inverse relation to the distance of the station from the network translator, a synchronized transmission time base as well as equalized station access is achieved for improving network performance.

Abstract: A process for graphically representing a simulated workpiece as processed by a numerically-controlled machine tool. Stored data defining the workpiece and the tool as well as program data defining relative movement therebetween are used to generate polygons which represent the workpiece and the tool and the path of movement of the tool. These polygons are hierarchically ordered and liked. Corresponding to the hierarchic order of the polygons, intersection point calculations in the linkage are made only for the workpiece polygons which overlap the tool polygon. The image of the processed workpiece is generated successively through the continuous superposition of the changing workpiece polygons with the processing polygons corresponding to the tool and its path. Workpiece edges which drop out are erased, and invisible workpiece edges are nto represented.

Abstract: A pattern pitch adjustment is applied to dot matrix pattern data as it is output from a CPU to a printer. The data is transferred from a DMA to the printer bit by bit, and the number of synchronizing signals output from the printer for each bit is counted to decide picture element timing. During a given period of time after transferring each data pattern, a waiting signal is applied to the DMA so that space picture element data is fed to the printer.

Abstract: In a computerized automotive vehicle diagnostic system, a test probe cable is attached to individual components and consists of a multiple conductor cable which is attached ultimately to the component and to a computer in a technician terminal. Where the probe cable enters the technician terminal the conductors contained within it are fed into a programmable crosspoint switch which is controlled by a microcontroller. Test functions are provided by three programmable resources: (1) A program controlled multimeter, (2) A program controlled DC voltage source and ground sink; and (3) the microcontroller itself which receives and interprets commands from the computer and controls the various probe elements based upon the test commands received.

Abstract: An apparatus for recognizing relative extrema in a dispersive digital data word sequence which includes relatively few, simple component elements specifically including a comparator which generates a positive or zero logic signal depending on the sign of the word comparison between two successive words, a counter operating within a limited numerical range for counting the comparator output signals upward or downward, and a threshold detector responding when a given counter status is exceeded or fallen short of for maximum or minimum indication, and which due to its structurally and operatively simple design ensures real-time processing of scattering data word sequences with a high word frequency, e.g., 500 MHz.

Abstract: The digital interpolator herein selectively provides linear interpolation between successive digital data words in a stream of such data words. The data words each contain a control bit together with first and second multi-bit fields with the control bit having a first or second level respectively designating whether or not interpolation is to take place through that data word. The first bit field contains differential data, representing the value between successive data words, only when the control bit is at a first level. The second bit field contains the interpolation interval to be effective when the control bit is at the second level. When no interpolation through the assigned data point is desired, the control bit is at the first level and the circuitry responds to provide an output signal having a digital value corresponding with a first data word to which there is added the differential data from the first bit field to obtain the next output signal.

Abstract: A processing method and apparatus for providing high speed computations including an exchange network for discriminating a first processing node which can execute a predetermined arithmetic operation. The processing node being capable of executing the arithmetic operation and determining a second processing node to which the output of the executed node is to be applied. The invention may include a plurality of first and second processing nodes in parallel to enable high speed computations.

Abstract: Circuitry for calculating the square root of a binary number iterates the equation E(K+1)=E(K)+(S-E(K).sup.2) where E(K+1) is the current estimate of the square root of the sample S and E(K) is the previous estimate. The value E(K).sup.2 is estimated in order to reduce the complexity of the hardware. An application is described for real time processing of digital audio signals in serial-bit format.

Abstract: An apparatus for controlling access to a program stored in a read-only memory is described. In one embodiment, the memory includes a random number generator and an encryptor for encrypting random numbers from the generator. A second encryptor which provides identical encryption to the first encryptor is included within the system and is coupled to receive random numbers from the generator. A comparator compares the results from the first and second encryptors and if they are identical, enables the memory. The encryptors are programmable with a 64-bit key and 32-bit random numbers are used. By making the encryption process relatively slow (e.g., one second) many decades are required to break the key.

Abstract: A random access memory is used to realize a sequence of delay lines (40, 46, 48, 50). The delay lines are linked so that a common end point of two delay lines can be addressed in a read/modify/write operation. Furthermore, the address step between two successive data elements of the delay line is increased, so that the new address must be calculated modulo the length of the consecutive zone reserved for the delay lines. It has been found that in many cases the incrementation step between the various read addresses has a value which can be expressed in a number of bits which is smaller than the number of bits necessary to express the length of the consecutive memory zone itself.

Abstract: A display subsystem having a graphics capability includes a bit map memory for storing bits, each bit representing a displayed pixel. A read only memory stores words, each word representative of a pixel of a selected pattern which is used to fill out an area of the display thereby clearly identifying adjacent areas of the display to the operator. The selected patterns are displayed in a REPLACE, an OR or an EXCLUSIVE OR mode of operation.

Abstract: An electrographic printing apparatus comprises a photoconductive member surrounded by a charging unit, an optical print head, a developing unit, a transfer unit, a cleaning unit, and an erasing unit arranged in sequence about the photoconductive member. Paper travels along a planar path across the top of the photoconductive member and the developed image is transferred to the underside of the paper. In a preferred embodiment, the photoconductive member comprises a vertically mounted photoconductive belt. By providing a separate and independent cleaning unit, the electrographic printing apparatus is capable of producing one sheet of copy material per revolution of the belt.

Abstract: An optical memory system for storage and retrieval of digital data using a source of writing light in the visible light range and a separate source of near infrared, polarized reading light. The writing light is amplitude modulated by a signal containing the digital data to be stored. Horizontal and vertical deflectors deflect the beams to scan horizontally and vertically in response to control signals. The scanning beams are focused to a focal point to impinge upon a stationary medium manufactured of a dry film having submicron electrically photosensitive particles embedded in a thermoplastic layer mounted on a substantially transparent electrically conductive substrate. The particles are insensitive to light at the reading light wavelength. The particles are initially uncharged and the film is sensitive to light after receiving an initial surface charge.

Abstract: A dual-port memory circuit comprises a random port having a memory cell array randomly accessable and a serial port serially readable or writable from/to the memory cell array. In the memory circuit, two modes are provided to the serial port, and when a first mode is designated, the data are consecutively read or written a plurality of bits at a time, and when a second mode is designated, the data are consecutively read or written one bit at a time. High speed read/write operation is attained by designating the mode to allow parallel input/output. For an application which does not require high speed operation, the number of components to be externally added to the memory circuit can be reduced.

Abstract: A semiconductor memory device includes a redundancy circuit having upper address bit input terminals receiving upper address bit, lower address bit input terminals receiving lower address bits, a regular memory cell array having a plurality of word lines and bit lines, and a plurality of memory cells are arranged at each intersection of the word and bit lines. A redundancy memory cell array is provided having a plurality of word and bit lines, and a plurality of memory cells are arranged at each intersection of the word and bit lines. The capacity of the redundancy memory cell array being smaller than the regular memory cell array. A first selection circuit selects a word or bit line in the regular memory cell array in accordance with the upper and lower address bits. A second selection circuit select a word or bit line in the redundancy memory cell array in accordance with the lower address bits.

Abstract: A bipolar-transistor type semiconductor memory device having a redundancy configuration includes a memory cell array, a redundancy memory cell array, and an address buffer circuit having a predetermined number of emitter-coupled logic gates which receive input address signals and have an output terminal. Each of the logic gates compares a voltage level of the corresponding input address signal with a voltage level of a reference signal. A group of first decoder lines connected to the predetermined output terminals. A comparator circuit detects whether or not each of the input address signals coincides with each of address signals corresponding to a defective circuit portion and puts a selection signal in accordance with the detection of a coincidence signal. A switching circuit compares a voltage level of the selection signal with a voltage level of a reference signal. A second decoder line is connected to a predetermined output terminal provided in the switching circuit.

Abstract: A dummy word line driving circuit for a MOS dynamic RAM comprises a dummy word line controller connected to each end of a pair of dummy word lines. A sub-decode signal which is opposite to the one inputted to a dummy word driver and a dummy set signal for writing a bit line information into a not-selected dummy cell are inputted to the dummy word line controller. Means for applying a dummy equalizing signal is connected to two full-sized dummy cells, for equalizing the two before the dummy word line is driven. The two full-sized dummy cells are equalized by the signal, resulting in a charge amount, which is to be a reference value, of a half of a full-sized memory cell.

Abstract: A dual-port semiconductor memory device having one serial memory cell of a serial access memory provided for a predetermined number of bit line pairs. A transfer gate circuit is provided between the serial memory cell and the predetermined number of bit line pairs so that only one bit line pair is selectively coupled to one serial memory at one time. Access to the dual-port semiconductor memory device is made in n/m stages when there are n bit line pairs and m serial memory cells in the serial access memory.

Abstract: An elementary decoder circuit for a monolithically integrated static random access memory is constructed by means of gallium arsenide field effect transistors and formed by a NOR-gate whose n inputs receive the n coded addressing signals a.sub.1, a.sub.2, . . . , a.sub.n of the memory, or their complements, and whose output supplied a signal which is applied to the upper transistor of a push-pull stage as well as a complementary signal, obttained via an inverter transistor, which is applied to the lower transistor of the push-pull stage.

Abstract: In accordance with principles of the present invention methods and apparatus are provided for evaluating the quality of the cement bond in cased boreholes. Acoustic energy is used to excite the borehole-casing-annulus-formation system and the quality of the cement bond is determined by examining the ratios of the signals received by two longitudinally spaced apart receivers supported on a sonde. The acoustic energy is generated by two transmitters symmetrically disposed above and below the receivers along the sonde. The spacings between the receivers themselves and between the receivers and the transmitters are selected so as to enhance the correlation between the ratios of the received signals and the quality of the cement bond log. An additional receiver, supported on the sonde at a small distance from one of the transmitters, is employed to determine the quality of the cement bond in hard formations.

Abstract: A method and apparatus for filtering seismic data are provided. More particularly, the method and apparatus of the present invention attenuate surface wave generated noise in seismic-trace signals. Seismic data comprising multicomponent seismic-trace signals acquired with single station, multicomponent geophone arrays are comb filtered to produce a plurality of comb filtered signals for each component of the multicomponent seismic-trace signal. The comb filtered signals are sorted into orthogonal sets and a measure of rectilinearity for each orthogonal set is obtained. Surface wave generated noise can then be attenuated in each orthogonal set with its respective measure of rectilinearity.

Abstract: The depth of water ahead of a vessel is detected by sonar means carried aboard a drone stationed by radio control ahead of the vessel. Detected depth information is transmitted from the drone to the vessel where it is displayed for use by the vessel pilot in navigating shallow waters.

Abstract: A plurality of submerged control station junction boxes each include a microprocessor having data storage and transmission capability, airgun firing and related electronic circuits to control a predetermined airgun or airgun groups. These junction boxes are towed at spaced positions along an airgun array. An electrical cable and sections of high pressure air supply line are detachably coupled to each junction box. The predetermined airguns to be controlled by a junction box are detachably coupled thereto. Thus, the number of airguns in the towed array can be changed by coupling or uncoupling junction boxes and the associated airguns controlled by them. The junction boxes are automatically cooled on shipboard by increasing low pressure air until a relief valve opens for establishing a continuous cooling flow of low pressure through a protective hose sheath and the junction boxes.

Abstract: An analog clock comprises an oscillator circuit for producing a signal having a predetermined frequency, a circuit for frequency-dividing the output signal of the oscillator circuit so as to produce a clock pulse signal and adjustment pulse signals having a period different from that of the clock pulse signal, a manipulation part for producing an adjustment instruction signal responsive to a time adjustment made in the manipulation part, a circuit for producing a driving pulse signal from one of the clock pulse signal and the adjustment pulse signals depending on the adjustment instruction signal and for supplying the driving pulse signal to a coil for forward rotation or to a coil for reverse rotation, and a stepping motor having a rotor which is rotated in the forward (or reverse) direction by a predetermined angle responsive to an excitation of the coil for forward (or reverse) rotation by one pulse of the driving pulse signal. Hands of the analog clock are rotated by the rotation of the rotor.

Abstract: The clock device has a hollow housing bearing readily viewable adjacent first, second and illuminatable display panels, the first panel bearing the hour indicator and an inverted V indicating zero, four dots indicating ones and two horizontal bars each indicating five, the second panel being the tens of minutes indicator and bearing four dots and one horizontal bar, while the fifth panel is the minutes indicator and bears an inverted V, four dots and one horizontal bar. A power supply such as electrical house current or a battery is disposed in the housing, connected to a clock timing mechanism and a signal generator which is, in turn, connected to symbol-illuminating incandescent bulbs, liquid crystal display components and/or light emitting diodes in the panels.

Abstract: A composite wrist watch comprises a case body, a case body mounting structure for accommodating the case body therein and a strap removably coupled to the case body mounting structure. The case body mounting structure comprises a plurality of segments each being disposed radially from the outer circumferential portion of the case body and having means provided thereon for releasable engagement with adjacent segments. The segments are arranged in radial alignment with at least a part of the surfaces defining a portion of the exterior configuration of the wrist watch. The strap consists of a plurality of links each having coupling means provided thereon adapted to removably couple to one another or to a strap receiving segment of said case body mounting structure by means of snap-fit action.

Abstract: A metal watch case and metal bracelet assembly in which the tail ends of the bracelet components are attachable to the complementary ends of the case in a manner simulating a "soldered look," yet these components may readily be detached to replace the bracelet. The case has a frame-like form defined by a pair of opposing side legs and a pair of opposing end legs, each end leg having a slot indented therein at its rear. The rear of the case is depressed along its inner periphery to form a socket for accommodating the watch movement so that its dial is exposed at the front of the case. Attached to the tail of each bracelet component is a connector having a hook projecting therefrom that is received in the slot of the related end leg. Snap fitting into the socket behind the movement is a cover plate having a marginal flange that overlies the slots of the end legs of the case to entrap the hooks of the bracelet components, whereby to detach these components from the case one has only to unsnap the cover plate.

Abstract: In a method of detecting track crossings on an optical disc, a light source irradiates a light beam onto an optical disc having guide tracks in the form of a recess and the light beam is reflected and diffracted into a zero order light beam and positive and negative primary light beams. The light beams are defocused so as to produce interference patterns between the zero light beam and the positive and negative primary light beams. The interference patterns are detected by a four split light detector disposed between two parts of a two split detector. The outputs of the detectors are fed to an adder and to a subtractor for producing a sum signal and a difference signal respectively. The sum signal and difference signal are fed to a phase detector. Defocusing of the light beams is effected by a focusing coil to which is fed the amplified output of an adder of a reference signal controlled by a control circuit.

Abstract: A rotation control apparatus for a CLV system disc sets an initial value based on an address signal reproduced from the CLV system disc and carries out a rotation control by use of the initial value, so that it is possible to carry out the rotation control even with respect to a CLV system disc on which an information signal is only recorded up to an intermediate position within a program region of the disc. An information signal is newly recordable in conformance with the CLV system from a position in a vicinity of the intermediate position where the previous recording had been discontinued.

Abstract: A rotation control apparatus controls a rotation frequency of a disc which is to be rotated at a constant linear velocity. The rotation control apparatus comprises a circuit for obtaining a first signal having a first frequency proportional to a rotation frequency of the disc, a circuit for comparing the first signal with a second signal having a second frequency which successively increases, and a control device for obtaining a present rotation frequency of the disc from the second signal which is obtained at a time when the first and second frequencies become equal to each other. The control device supplies to a motor which rotates the disc a driving signal which is obtained from the present rotation frequency in a recording mode, so that the disc rotates at the constant linear velocity.

Abstract: In the present invention, there is provided an abnormality detector circuit for comparing a scanning width signal with an upper limit setting signal and a lower limit setting signal and detecting that a scanning width indicated by the scanning width control signal becomes larger than an upper limit scanning width indicated by the upper limit setting signal or becomes smaller than a lower limit scanning width indicated by the lower limit setting signal, whereby when a signal level of an electrical input signal indicative of an information to be recorded exceeds a proper range, this can be positively discriminated by an operator.

Abstract: A pair of photoconductive elements are provided on an inner surface of a light transmitting outer skin of a doll. When the amount of light impinging on either one of the pair of photoconductive elements differs from the other as a result of interruption of the light impinging on the one of the photoconductive elements, a sound generating device is actuated to generate a sound.

Abstract: A method for recording and reproducing information on or from an optical recording medium, which comprises:recording information by illuminating light to the optical recording medium which is equipped as a recording film with a thin film comprising dispersed fine grains of a material capable of showing a metal-insulator transition to cause the metal-insulator transition owing to the heating effect of the light; and reproducing the information by utilizing changes in optical characteristics owing to a plasma resonance absorption by the fine grains dispersed in the thin film. The method of this invention permits high-density recording with high sensitivity and upon reproduction, enables reproduction of record with a high signal/noise ratio. The recording medium obtained by this method is an erasable optical recording medium, which permits its reutilization for recording and reproduction after erasure of the previously-stored record.

Abstract: Multi-party conferencing apparatus for use in a pulse code modulated, time division multiplexed telephone communication system including a data bus on which operating times are divided into equal frames of time and each channel of a plurality of channels has a transmit time slot and a receive time slot in each time frame. Voice signals on conferencing channels are sampled in each time frame and compared in the conferencing apparatus with the highest amplitude sample being rturned to all conferencing channels except the channel on which it originated and a second highest amplitude sample being returned to the channel originating the highest sample.

Abstract: A method for generating additive combinations of PCM voice samples separates the samples into magnitude portions and sign portions. The magnitude portion of each PCM voice sample is converted from compressed PCM form to linear form. The magnitudes of the two voice samples, in linear form, along with their respective signs are added together to form a resultant linear value. If there is any overflow as a result of the addition, the resultant value is truncated so as not to exceed a maximum allowable value. The resultant value is then converted from linear form to compressed PCM form along with the proper sign. These steps are iterated for each possible value of the input PCM voice samples. These resultant values are stored in a storage medium for rapid on-line use by a switching system. Off-line generation of combined PCM samples saves system real time as compared to generating these combinations on-line in real time.

Abstract: The present invention relates to an apparatus and method for the simultaneous transmission of analog speech and modulated data, such apparatus and method being optimized for use over impaired and bandwidth restricted analog channels, or digital representations of such channels. In each instance of use, an evaluation is made of the available channel bandwidth, with a frequency division multiplex scheme allocating a voice sub-band, with data transmission allocated to sub-bands above, below, or around, this selected voice sub-band. The speech and data sub-band allocations are made by the multiplexor in response to user input of either a requested speech quality, a requested data rate, or a value indicating the relative user weighting of speech quality and data rate.

Abstract: A communication system is provided for the interconnection of telephones and other instruments capable of communicating via the voice spectrum, the system providing a single transmission line such as a coaxial cable by which full duplex communication is provided between any pair of telephones. Each instrument is coupled to the transmission line by a control unit which includes computer operated transceiver equipment for paging other ones of the control units to initiate a telephonic communication. Each control unit is provided with an identification number and circuitry for recognizing the identification number contained within a paging signal so as to initiate a response. In a separate spectral portion of the transmission line, there are provided sets of analog communication channels each of which has upper and lower spectral portions to provide two-way communication in opposite directions between a pair of telephones engaged in communication.

Abstract: A distributed, digital voice/data communications and switching system for connecting stations which may provide voice-only transmission, data only or voice and data. The system comprises one or more physical nodes, each serving (in an exemplary case) up to about 30 ports (i.e., station interfaces); nodes may be geographically distributed on the user's premises or one or more nodes may be collected together at a common location. The nodes are interconnected via a hierarchical network configuration formed of at least two, generally three, and perhaps even four interlocking networks. The first network is a slotted ring (the "regional" ring) employing coaxial cable to connect the nodes; it carries all control messages transmitted among the nodes, as well as the users' data traffic, using a frame which circulates continuously at about 20 Mbps. The second network is a "star" arrangement carrying PCM-encoded digitized voice traffic; at the hub of the star, in one of the nodes, is a digital voice switch.

Abstract: In a receiver for a C-or D-MAC Packet television signal the bits of a pocket from the first subframe (DATA `A`) are multiplexed with the bits of a correspondingly positioned packet in the second subframe (DATA `B`) and applied to a data line of a packet bus so that the bits from the two packets alternate (DATA).

Abstract: This method is a scheme for suppressing excessive amounts of logic zeros transmitted via T-carrier line facilities between switching systems or channel banks. This scheme provides proper zero bit suppression for alternating mark inversion signalling (AMI). A proper AMI signal contains no more than 15 consecutive logic zero bit positions. This scheme provides for encoding and decoding a 4 frame octet group of an extended superframe. Logic ones are introduced into octets which would otherwise violate the AMI signalling rules. These logic ones are then removed by the receiving system and replaced with the indicated all zero octets before being given to down stream processing. Intermediate storage octets are utilized to contain addresses of an all zero octet. This scheme provides for minimal buffering at the encoding system, which facilitates error detection and correction by the decoding system.