Abstract: The present invention relates to a high speed, multihop, Local Area Network (LAN) comprising a communications medium for supporting a plurality of channels therealong and a plurality of Network Interface Units (NIUs) disposed along the medium in a predetermined sequence. Each channel of the communications medium comprises one or more point-to-point communication links, and each NIU is arranged to transmit to, or receive from, at least two other NIUs using point-to-point links from a separate subset of the multiple channels. Several of the NIUs are also arranged to transmit to, or receive from, additional NIUs on the network using (i) point-to-point links from a separate subset of the channels and, (ii) a non-linear connection pattern. Each channel can be used to establish point-to-point links between several pairs of NIUs in nonoverlapping sections of the sequence of NIUs.

Abstract: The present invention relates to an N-input, N-output "Knockout" packet switch (11) which uses decentralized control and distributed routing for routing high-speed, time-multiplexed, variable-length packets of information from the N inputs to the N outputs. More particularly, within the switch, the N input signals are separately synchronized such that the start of each arbitrarily arriving variable-length packet is synchronized to the start of a next mini time period of a sequence of mini time periods common to all inputs. The synchronized N input signals then propagate along separate broadcast buses (14) to each of N bus interface units (15) which include N packet filters (20), a concentrator (21) and a shared buffer (22) capable of processing variable-length packets.

Abstract: The present invention relates to a fast packet assignment technique, and a TDMA or FDMA multi-port switching arrangement for implementing such technique. In the present technique, the total traffic in a two-dimensional traffic matrix (T) from and to each of N remote service areas, regardless of destination or origination, is totaled to form separate input (R) and output (S) traffic vectors, respectively. Non-conflicting assignments are then made from these vectors for each packet or channel available during a predetermined time period while also providing the capability of substantially reducing multi-path or antenna sidelobe interference. An M.times.M switch (16) is designed to implement such technique which directs C input packets from M inputs (20.sub.1-M) into separate memory locations (Z.sub.ij). During the time period of the next C input packets, the M.times.M switch directs the presently stored packets to the proper ones of M outputs (27.sub.

Abstract: The present invention relates to a technique for automatically cataloging and storing pictorial and/or written sections of information in the form of, for example 35-mm slides, X-rays, store catalog pages, etc. in a database for subsequent retrieval by end users of the database. In accordance with the present technique, a bar-code label, including a unique bar-code, is assigned and affixed to each piece or section of information to be separately stored in the database. Each section of information is sequentially fed into a recording arrangement where (a) the bar-code versus a brief description of the information section is recorded in a computer memory, (b) an image of the pictorial and/or written information section is transformed into a video signal and recorded on a separate location of a video tape or disk, and (c) the location of the video signal on the video tape or disk for each section of information is recorded in the computer memory with the associated bar-code and brief description.

Abstract: The present invention relates to a Time Compression Multiplexing (TCM) technique for transmitting three consecutive television picture signals from a television picture source during the time period normally used to send one television picture signal. More particularly, three consecutive lines or fields from a TV signal source are compressed into an ordinary line or field period, respectively, by sending one line or field as is, but time compressed, in one portion of a line or field period and sending two other lines or fields as differential signals, also time compressed, to occupy two separate and different portions of the same line or field period as is used by the first one line or field. With such technique it is possible to send three consecutive line or field signals from each of three separate colocated or non-colocated TV sources on a Time Division Multiple Access (TDMA) basis.

Abstract: The bandwidth required for a regularly occurring signal, such as a television signal, as received from a signal source can be substantially reduced by not transmitting each and every one of the horizontal scan lines. Rather, firstly, one or more selected lines may be transmitted and, secondly, instead of transmitting the remaining, unselected lines, a signal representing a predetermined arithmetic difference among predetermined ones of the scan lines may be transmitted. The bandwidth may be further reduced by a time expansion of the time interval of the selected line signal and by a time compression of the time interval of the differential signal. The bandwidth required for each regularly occurring signal as received from each of a plurality of N signal sources may be more efficiently used by time compression multiplexing the respective time expanded and time compressed signals.

Abstract: The present invention relates to a technique for the synchronization of multiplexed television signals within each burst signals received at a remote station or satellite in a TDMA communication system from non-colocated ground stations. The technique employs a dynamic master/slave ground station arrangement where a first station signing on assumes the role of the master ground station. Other stations subsequently signing on synchronize their transmissions to the master station signal burst or the signal burst of the last station to sign on by using apparatus which monitors the received burst from the remote station, measures its own signal delay to the distant station and then phase-locks its local subcarrier clock to the master or last station's transmission burst. Dynamic transfer to the second station signing on occurs when the current master station terminates transmission for any reason.

Abstract: The present invention relates to a time compandor (40) including a cascaded pair of chirp transformers (41,42) of chirp rates .beta. and .sigma., respectively, capable of companding a continuous time signal x(t) to form a companded and delayed output signal x(a[t-.tau.]). Each chirp transformer includes a pi-network arrangement of linear dispersive filters (44,45,46,47,48,49), wherein the first chirp transformer (41) performs a Fourier transform on a continuous time input signal x(t) to produce X(.beta.t) and the second chirp transformer (42) performs an inverse Fourier transform on the product of the output of the first chirp transformer and a signal associated with the desired time delay .tau., to form the desired companded output signal x(.sigma./.beta.[t-.tau.]), where .sigma./.beta.=.alpha. is the desired companding rate, and .tau. is the desired time delay.

Abstract: Bandwidth is a precious resource in a communication system. High frequency signals, for example, video signals, typically require a relatively large bandwidth. One means for reducing bandwidth is by way of time compression multiplexing wherein signals may be stored a short period of time, compressed in time and then transmitted over a communication path. The subject signal processor may time compress and time synchronize an input signal with a time multiplexed signal. In a first arrangement, responsive to a time delay difference between the signals (215), a first frequency signal (220) is used to modulate (230) the input signal (210). The modulated signal is extended through a dispersive filter (260) for introducing a delay to the input signal, the delay for synchronizing same with the time multiplexed signal. The synchronized output of the dispersive filter may be extracted by an envelope detector (270) for extension to an output terminal (280).