Abstract: In a mobile radio communication system, a mobile station has a field level decision section which outputs a decision signal when the electric field level of a received signal exceeds a threshold level. A controller sequentially sets a plurality of different threshold levels. In response to the decision signal from the decision section, synchronization to the received control signal begins. When the mobile station receives down-going control signals from a plurality of base stations, it selects the one having the highest field level, and then sets up synchronization to the signal selected.

Abstract: Receiver and transmission system for orthogonal frequency-division multiplexing signals comprising a frequency synchronization circuit (116) which has a local oscillator (214) whose frequency is controlled by a correction signal .epsilon.. The latter is generated by a frequency detector (213) which operates in the time domain, by utilizing the redundant information contained in such signals. The performance of the invention is particularly of interest for transmissions on multipath channels which occur in mobile radio, digital television, and so on.

Abstract: High speed network nodes can establish new connections by preempting existing ones when insufficient bandwidth is available in the network. Numerous preemption priorities are arranged in a limited number of groups and a median priority level is defined within each group. This median, stored in the topology database of each node of the network, permits better bandwidth utilization per group while consuming very little memory space and generating very low traffic overhead.

Abstract: A programmable data link module (32) for use in a time division multiplexing control system (30) having a plurality of modules interconnected by a bus (40) for passing control signals between data link modules on a serial multiplex basis. Each module includes an integrated circuit (80) having signal conditioning circuits (180, 186 and 188) including a programmable hysteresis circuit (126), a power on reset delay circuit (190), a safety input inhibit circuit (220), a clock loss detect circuit (240), a safety output protection circuit (262), a data verifier (260), a polarity selector for a third output terminal (350), an input synchronizer (182 and 184), a combined mode/sync output terminal (110), a multiplex clock output terminal (108), a programming circuit (232) for accepting programming over the clock bus (44) and data bus (46), input/output word extender circuits (104, 106), a high voltage protection circuit (420) including a transistor (600) and a data bus integrity checker (630).

Abstract: There is provided an encoding and decoding apparatus which can provide a high quality of reproduction of sound. There are provided an encoding section and a decoding section. A block length determining section of the encoding section time-sharingly divides an input signal into blocks having a block length corresponding to the degree of change of the input signal. A frequency band dividing section divides the signal of each block into a plurality of frequency bands. A bit allocating section obtains a masking threshold value-to-noise ratio of each frequency band from the magnitude of the power of each frequency band reflecting a psychoacoustic characteristic, and determines the number of quantization bits to be allocated to each frequency band based on the magnitude of the masking threshold value-to-noise ratio. A quantizing section generates a code string by quantizing the signal while allocating a specified amount of bits to each frequency band based on information from the bit allocating section.

Abstract: The system and method provide for efficiently resolving collisions in an environment where a transmitting device cannot hear collisions without a headend control station/control device, i.e., master, repeating transmission of all upstream frames in the downstream direction. This invention also prevents additional collisions from occurring between a device that is retransmitting and a device that is transmitting a packet for the first time. Further, the present invention allows continued utilization of a channel by other devices while contending devices are processing collision resolution procedures.

Abstract: An arrangement for interconnecting groups of users into collision domains in a Local Area Network such as an Ethernet comprises a plurality of repeater groups, with each repeater group being connected to a group of user stations. The arrangement also comprises an electronically reconfigurable switch matrix. The switch matrix comprises a plurality of segment lines (or other transmission media) each of which is used to form one collision domain or Ethernet segment. Switch elements under the control of a microcontroller selectively connect particular repeater groups (and the associated user groups) to particular segment lines to form Ethernet segments, each Ethernet segment being a single collision domain. Internetworking devices such as bridges and routers may also be connected to the switch matrix to interconnect particular collision domains.

Abstract: A new technique for the determination of the masking effect of an audio signal is employed to provide transparent compression of an audio signal at greatly reduced bit rates. The new technique employs the results of recent research into the psycho-physics of noise masking in the human auditory system. This research suggests that noise masking is a function of the uncertainty in loudness as perceived by the brain. Measures of loudness uncertainty are employed to determine the degree to which audio signals are "tone-like" (or "noise-like"). The degree of tone-likeness, referred to as "tonality," is used to determine masking thresholds for use in the compression of audio signals. Tonality, computed in accordance with the present invention, is used in conventional and new arrangements to achieve compression of audio signals.

Abstract: In order to transmit or to store digitalized, multi-channel audio signals which are digitally represented by a plurality of spectral subband signals, at an encoder, subband signals of different audio channels but having the same frequency position are combined across channels according to a dynamic control signal. This control signal is derived from several audio channels by an audio signal analysis based on a psycho-acoustic binaural model. At a decoder, the subband signals of several audio channels but having the same frequency position are dissociated across channels according to a control value derived from the dynamic control signal, transmitted or stored therewith.

Abstract: A ones bit density monitor is disclosed which is comprised of a 31-bit shift register, a counter, and a clock circuit having logic to preclude the number representing a number of pulses within the shift register from changing whenever a pulse is simultaneously input and output from the 31-bit shift register. To accomplish this, the counter increments every time a pulse is input to the 31-bit shift register and is decremented every time a pulse is output from the 31-bit shift register. Once the count reaches the number four, the ones density monitor circuit, and more specifically the counter, outputs a signal reflecting that a carrier is back on line.

Abstract: Reservation controllers and reservation systems for reservation of access to multimedia multipoint telecommunications servers (MCUs) are provided. The reservation controller establishes a reservation domain having a reservation request channel on which reservation applications may be taken. An ongoing reservation conference is associated with the reservation domain. The reservation domain is preferably established within the ITU-T T.120 standard series requirements, with multipoint connection under T.122/T.125, and interface to profiles such as ISDN, TCP/IP, X.25, ATM, Ethernet, etc., under T.123. A user makes reservations for MCU resources by knowing the address of the reservation domain, attaching himself to the reservation domain, joining the reservation conference via establishing one or more transport connections, and sending the reservation request onto the reservation request channel.

Abstract: A transparent bridge between a pair of local area networks is comprised of a database for storing destination addresses for frames of data, a pair of frame transfer agents each connected to the database for transferring frames of data in respectively opposite directions from one LAN to the other depending on whether addresses stored in the database correspond to destination addresses of the frames of data.

Abstract: A vector quantizing apparatus includes a first search section for obtaining an approximate vector X1 which is approximated to a desired vector R, a residual vector calculator for calculating a residual vector Rv from the desired vector R and the approximate vector X1, a weighting section for obtaining weighted vectors X2 to XN of code vectors x2 to xN, and a second search section for calculating an estimation value which is the magnitude of a projection vector of the residual vector Rv with respect to the vector space formed by the approximate vector X1 and the weighted vectors X2 to XN, and searching a code vector which maximizes this estimation value.

Abstract: A high-efficiency encoding method and apparatus assuring a higher data compression ratio than with known encoding method and apparatus. The multi-channel signals including bandwidth-limited signals of at least one channel are encoded by the same encoding technique by an encoding unit. The bandwidth-limited signals of at least one channel, resulting from encoding by the encoding unit, are re-encoded by a re-encoding unit for eliminating the redundant information produced by the bandwidth limitation.

Abstract: A bandwidth allocation system allows packets or cells within traffic flows from different sources contending for access to a shared processing fabric to get access to that fabric in an order that is determined primarily on individual guaranteed bandwidth requirements associated with each traffic flow, and secondarily on overall system criteria, such as a time of arrival, or due date of packets or cells within traffic flows.

Abstract: A personal communications system is described which includes components of software and hardware operating in conjunction with a personal computer. The user interface control software operates on a personal computer, preferably within the Microsoft Windows.RTM. environment. The software control system communicates with hardware components linked to the software through the personal computer serial communications port. The hardware components include telephone communication equipment, digital signal processors, and hardware to enable voice, fax and data communication with a remote site connected through a standard telephone line. The functions of the hardware components are controlled by control software operating within the hardware component and from the software components operating within the personal computer.

Abstract: CDMA mobile communication method and system for realizing an autonomous distributed control of radio channel allocation, a synchronization control for a smooth establishment/switching, and a VOX control for a capacity increase are provided. At either one station of each base station and the mobile station, one of a plurality of prescribed short spread codes is selected, and a data sequence to be transmitted is spread by using the selected short spread code and a prescribed long spread code and then transmitted, while at another one station, the data sequence before spreading is reproduced and received by despreading the data sequence from that either one station by using the selected short spread code and the prescribed long spread code.

Abstract: The invention relates to the use of CDMA techniques. Data signals to be transmitted from a plurality of wireless devices are spread across a common bandwidth. The data signals are received by a base station as a composite spread signal. The base station partially despreads the composite spread signal with unique codes to extract data signals from individual wireless devices. The data rate and quality of service requirements for each wireless device are used to calculate a power factor and a control signal is sent to control the power from a particular wireless device. In addition, a probability of transmission value is calculated based on an equivalent current load value and an equivalent population value. The probability of transmission value determines whether a particular wireless device is allowed access to an uplink frequency channel.

Abstract: A scalable communications network employing shared logical nodes and a related method are provided. The network includes one or more sources for providing program streams. The program streams may comprise a number of frequency-division multiplexed program streams generated by media servers in an interactive network. Each such source is coupled to a corresponding logical node, which receives a corresponding set of program streams. One or more subscribers are allocated to a logical node according to an expected peak subscriber usage constraint. This constraint is met by allocating subscribers to a node so that an expected maximum number of simultaneously active subscribers within the node substantially avoids exceeding the number of program streams provided by the source corresponding to the node. Each logical node includes at least one physical node. Each physical node includes at least one subscriber.

Abstract: A satellite channel interface (SCI) is constituted by an analog section having a multiplexer unit and a down converter unit, and a digital section constituted by a modulator-demodulator unit. The satellite channel interface has a single printed circuit board on which all of the above units are formed. A rectangular member surrounds the analog section, and a shield cover shields an opening portion of the rectangular member. The single printed circuit board is a multi-layered board constituted by at least three conductive layers, of which the bottom two layers are grounding electrodes. The SCI does not require the terminals and cables which are otherwise necessary, can be made compact, and can be manufactured with the reduced number of processing steps.