Wide area fiber and tv cable fast packet cell network

• US 5,870,395 A
• Filed: 06/18/1997
• Issued: 02/09/1999
• Est. Priority Date: 01/04/1993
• Status: Expired due to Fees

• Current Assignee: Arris International, Inc. (CommScope Holding Company, Inc.)
• Original Assignee: Com 21 Incorporated
• Inventors: Baran, Paul
• Primary Examiner(s): NGUYEN, CHAU T
• Application Number:
  US08/877,906
• Time in Patent Office: 601 Days
• Field of Search: 370/395, 370/480, 370/485-490, 455/3.1, 455/5.1, 455/6.1, 455/6.2, 348/6, 348/10, 348/11, 348/12
• US Class Current: 370/395.1
• CPC Class Codes: H04L 2012/5605 Fibre
• CPC Class Codes: H04L 2012/5606 Metallic
• CPC Class Codes: H04L 2012/561 Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
• CPC Class Codes: H04L 2012/5631 Resource management and allocation
• CPC Class Codes: H04N 7/173 with two-way working, e.g. subscriber sending a programme selection signal
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: Y10S 370/906 Fiber data distribution interface, FDDI

Abstract

53 byte length ATM compliant cells are transmitted over a digital optical fiber path to interconnect with a coaxial feeder cable TV system to support two-way digital services at a plurality of sites connected to the TV cable system. At the point of interconnection between the fiber optic path and the cable TV feeder subsystem, digital signals are converted to a UHF rf carrier frequency above the cutoff pass-band of the analog signal feeder amplifier carrying TV broadcast signals. This rf carrier conveys a high data rate digitally modulated signal limited to sections of feeder cable between the cable TV broadcast channel amplifiers. In-house access to this UHF carrier signal is via the normal TV cable tap and drop cable to a SIU, located near the subscriber'"'"'s TV set. The feeder cable and the passive taps used in cable TV practice have a higher cutoff frequency than the feeder amplifiers themselves. This allows passage of an UHF signal over the feeder cable. Low pass filters at the feeder amplifiers prevent this UHF signal from being shorted out by the in-cable amplifiers. Each SIU so connected sends and receives the UHF carrier signal, which conveys the ATM type cells. Each cell'"'"'s payload contains the local address of the source and destination of that cell. Each SIU decodes each cell'"'"'s address and accepts only those cells that are for itself. The SIUs speak to and receive signals from an FTU located at the TV cable headend or at a fiber connection node. The common channel conveying the ATM cells alternatively sends and receives cells in a ping-pong fashion.

Claims

1. A shared communication transmission distribution system for the bi-directional transmission of cell packets over a cable TV broadcast distribution system as a shared communications channel, said system comprising:

a first bi-directional transmission path; and

a second bi-directional transmission path;

wherein said first bi-directional transmission path includes;

a first feeder cable having an up-stream end and a downstream end having a defined length therebetween divided into an up-stream section and a downstream section;

a first feeder amplifier serially connected between said up-stream and downstream sections of said first feeder cable to convey broadcast TV signals downstream on said first feeder cable, wherein said feeder amplifier has a downstream terminal;

a first bandpass filter having a first terminal coupled to said downstream terminal of said first feeder amplifier and a second terminal connected to said downstream section of said first feeder cable, said first bandpass filter having a lower cut-off frequency and an upper cut-off frequency with frequencies of the commercial TV band being between said lower and upper cut-off frequencies;

a first tap along the length of said downstream section of said first feeder cable downstream of said first bandpass filter, with said first tap having an upper cut-off frequency that is above the upper cut-off frequency of said first bandpass filter;

a first drop cable having an up-stream end connected to said first tap, and having a downstream end;

a first slave transceiver connected to the downstream end of said first drop cable to receive downstream signals from said first drop cable and to deliver up-stream signals to said first drop cable;

a first low pass filter having a downstream terminal and an up-stream terminal, said downstream terminal being connected to said second terminal of said first bandpass filter and said up-stream terminal being coupled to said up-stream section of said first feeder cable up-stream of said first feeder amplifier, said first low pass filter having an upper cut-off frequency that is below the lower cut-off frequency of said first bandpass filter;

a third section of said first feeder cable, said third section being serially coupled to said downstream section and extending further downstream;

a second feeder amplifier serially connected between said downstream and third sections of said first feeder cable to convey broadcast TV signals downstream on said first feeder cable, wherein said second feeder amplifier has an up-stream terminal and a downstream terminal;

a second bandpass filter having a first terminal coupled to said downstream terminal of said second feeder amplifier and a second terminal connected to said third section of said first feeder cable, said second bandpass filter having a lower cut-off frequency and an upper cut-off frequency that are substantially the same as said lower and upper cut-off frequencies of said first bandpass filter;

a second tap along the length of said third section of said first feeder cable downstream of said second bandpass filter, with said second tap having an upper cut-off frequency that is substantially the same as said first tap;

a second drop cable having an up-stream end connected to said second tap, and having a downstream end;

a second slave transceiver connected to the downstream end of said second drop cable to receive downstream signals from said second drop cable and to deliver up-stream signals to said second drop cable;

a second low pass filter having a downstream terminal and an up-stream terminal, said downstream terminal being connected to said second terminal of said second bandpass filter and said up-stream terminal being coupled to said downstream section of said first feeder cable up-stream of said second feeder amplifier, said second low pass filter having an upper cut-off frequency that is substantially the same as the upper cut-off frequency of said first low pass filter; and

a two stage filter connected between said up-stream terminal of said second feeder amplifier and said downstream section of said first feeder cable, said two stage filter having;

a third bandpass filter having a first terminal connected to said up-stream terminal of said second feeder amplifier and a second terminal, said third bandpass filter having a lower cut-off frequency and an upper cut-off frequency that are substantially the same as said lower and upper cut-off frequencies of said first bandpass filter;

a third low pass filter having a first terminal coupled to said up-stream terminal of said second feeder amplifier and a second terminal, said third low pass filter having an upper cut-off frequency that is substantially the same as the upper cut-off frequency of said first low pass filter; and

a fourth low pass filter having a first terminal connected to said downstream section of said first feeder cable, and a second terminal connected to said second terminal of each of said third bandpass filter and said third low pass filter, said fourth low pass filter having an upper cut-off frequency that is substantially the same as the upper cut-off frequency of said first bandpass filter; and

wherein said second bi-directional transmission path includes;

a second feeder cable having a first section with said first section having a first end and a second end;

a first high pass filter having an up-stream terminal coupled to said second end of said first section of said second feeder cable and a downstream terminal connected to said downstream terminal of said first bandpass filter wherein said first high pass filter has a lower cut-off frequency that is above the upper cut-off frequency of said first bandpass filter;

a second section of said second feeder cable serially coupled to said second end of said first section of said second feeder cable, said second section having a first end and a second end; and

a second high pass filter having an up-stream terminal coupled to said second end of said second feeder cable and a downstream terminal connected to said downstream terminal of said second bandpass filter wherein said second high pass filter has a lower cut-off frequency that substantially the same as said lower cut-off frequency of said first high pass filter; and

an FTU/headend processor coupled to first end of said first section of said second feeder cable to send packet cells to and from said first slave transceiver; and

wherein said first slave transceiver, responsive only to packet cells addressed to itself, upon receipt of instructions from said FTU/headend processor transmits packet cells to said FTU/headend processor, and wherein the transmission of said packet cells is restricted to frequencies above the upper frequency of said commercial TV band; and

wherein said FTU/headend processor also sends packet cells to and from said second slave transceiver, wherein said second slave transceiver, responsive only to packet cells addressed to itself, upon receipt of instructions from said FTU/headend processor transmits packet cells to said FTU/headend processor, and wherein the transmission of said packet cells is restricted to frequencies above the upper frequency of said commercial TV band.