First Pacific Networks

David E Hansen

Robert P McNamara

Michael J Serrone

Chinh Q Phan

James C Long

Long K Tran

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.

Spectrally efficient broadband transmission system

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. A tap in the distribution cable for accessing the broadband and baseband signals includes first and second low pass filters and a directional coupler serially connected between two cable terminals with a high pass filter connected in parallel with a first and second low pass filters whereby broadband signals can pass around the low pass filters. A third low pass filter connects an MAU port to the first and second low pass filters whereby baseband signals can be transmitted in either direction on the distribution cable without injecting noise in the broadband signal.

Growing community of inventors

Sunnyvale, CA, United States of America

David E Hansen