Abstract: An alert transceiver in commuter vehicles in a line-of-site warning area receive line of sight (LOS) alert signals from another vehicle, such as an emergency vehicle. Upon detecting the LOS alert signal, the alert transceiver can relay the alert signals to other alert transceivers in commuter vehicles within a warning zone that are outside of LOS zone, thereby creating mobile tracking network (MTN). The alert signals can include any relevant information, such as information regarding a hazard that includes the type of hazard (emergency vehicle, fire, ambulance, etc.), the time stamped location, direction of travel, speed and planned route for the emergency vehicle; and/or the coordinates of warning zone as determined by alert transceivers.

Abstract: An alert transceiver in commuter vehicles in a line-of-site warning area receive line of sight (LOS) alert signals from another vehicle, such as an emergency vehicle. Upon detecting the LOS alert signal, the alert transceiver can relay the alert signals to other alert transceivers in commuter vehicles within a warning zone that are outside of LOS zone, thereby creating mobile tracking network (MTN). The alert signals can include any relevant information, such as information regarding a hazard that includes the type of hazard (emergency vehicle, fire, ambulance, etc.), the time stamped location, direction of travel, speed and planned route for the emergency vehicle; and/or the coordinates of warning zone as determined by alert transceivers.

Abstract: A baseband signal is spectrally efficiently transmitted on a broadband transmission medium by inserting gaps in packets of digital data transmitted in a modulated first radio frequency carrier. The transmitted packets of data are received by demodulating the modulated first radio frequency carrier, and the gap is monitored for the presence of digital data thus indicating a collision of simultaneously transmitted packets of digital data. A seed of arbitrary digital bits are used in scrambling each packet of digital data and is transmitted with the packet of data for use in descrambling the data. In retransmitting the packet of data the seed is included. The originally transmitting node receives the retransmitted packet and compares the retransmitted seed with the originally transmitted seed for detecting an error in retransmission.

Abstract: Apparatus for combining broadband RF signals and baseband signals in a baseband distribution cable includes a bridge for coupling the distribution cable to an RF broadband trunk and to a baseband repeater. The trunk is connected through bidirectional amplifier, an impedance transformer, and a signal splitter for applying the amplified and impedance transformed broadband signal to a plurality of baseband segments. The RF signal from the splitter is passed through a 35 MHz high pass filter to the baseband segment. Baseband signals from a repeater are passed through a 25 MHz low pass filter to the baseband segment. The two filters prevent interference between the baseband and broadband signals.

Abstract: A method and an apparatus for demodulating M-ary PSK signals of the type wherein the modulation is limited to phase transitions between adjacent phase states. The method is operative in a demodulator which comprises a phase splitter dividing a source signal into two paths with a preselected phase relationship among phases, one of the phases being delayed by nominally one bit period, a mixer or multiplier receiving as one input a representation of the delayed-phase component and as a second input a representation of the other phase component. A signal is filtered by a lowpass filter and provided to at least one corresponding two-level comparator, each of which produces a digital output. Digital logic circuitry responds to the digital outputs of each of the comparators to map the digital outputs into a single digital bit stream of ones and zeros.

Abstract: A lock detector (12) used in conjunction with a bit synchronizer (14) for determining when a random binary input signal (2) is in lock with a clock (7) generated by the bit synchronizer (14). A window comparator (3, 5; or 23, 25, 27) determines whether the amplitude of the input signal (2) is within or without an amplitude window, and generates a signal (33) as a result of said determination. This signal (33) is sampled at periodic sampling points (X, Y). The set of X sampling points and set of Y sampling points are interleaved and usually separated by half a bit period. The X samples and Y samples are averaged and compared. Means (19) are provided for declaring a lock condition when the X average exceeds the Y average by a preselected threshold (V.sub.REF), which occurs when the X points are positioned near mid-points of data bits (35) and the Y points are positioned near data transitions (39). The circuit (12) will not lock on false sidebands and can operate at very low signal-to-noise ratios.

Abstract: A dynamic electronic switch (10) having n inputs (2) and m outputs (4), where n and m are any positive integers. The electromagnetic signal on any given input (2) may be switched onto any number of outputs (4), but any given output (4) may have no more than one input signal switched thereonto at any given time. Switching nodes (8), comprising at least one switching diode (11, 13, 15) and a directional edge coupler (17) embedded between two parallel ground planes (9, 1) in a planar mother board (5), perform switching at each intersection of an input (2) and an output (4). Each output (4) is mounted on a planar dielectric summer board (6) positioned orthogonal to the mother board (5).