Point-to-multipoint broadband services drop with multiple time slot return channel for customer premises equipment served by fiber optic telecommunication system employing STS-based transmission format containing asynchronous transfer mode cells

• US 5,754,941 A
• Filed: 02/06/1995
• Issued: 05/19/1998
• Est. Priority Date: 02/06/1995
• Status: Expired due to Fees

• Current Assignee: Broadband Technologies, Inc.
• Original Assignee: Broadband Technologies, Inc.
• Inventors: Sharpe, Randall B., Long, Thomas Joel
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Flynn, Nathan J.
• Application Number:
  US08/383,984
• Time in Patent Office: 1,198 Days
• Field of Search: 348/6, 348/7, 348/8, 348/9, 348/10, 348/12, 348/13, 455/3.1, 455/4.1, 455/4.2, 455/5.1
• US Class Current: 725/119
• CPC Class Codes: H04J 14/086 Medium access H04J3/16 takes precedence
• CPC Class Codes: H04J 3/1617 carrying packets or ATM cells
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

A broadband fiber optic communication system conveys telecommunication messages over a fiber optic link between a master site and one or more remote sites. The remote sites are coupled over an unshielded twisted pair-configured, communication link to an optical network unit, which is ported to the fiber optic link. In order to convey broadband information signals that have been downlinked, from the master site to the optical network unit, to the remote sites, and to provide for return messages from the remote sites, a point-to-multi-point communication scheme is provided. Pursuant to this scheme, an upstream transceiver in the optical interface unit transmits STS-1 frames, which contain broadband information signals, such as asynchronous transfer mode (ATM) data cells, intended for one or more remote sites, and a return time slot-representative control code associated with each destination remote site, over the communication link to the remote sites. At a respective remote site, a downstream transceiver uses the return time slot-representative control code to control its time of transmission over an uplink slotted bus return channel. The remote site also transmits communication signals that encapsulate asynchronous transfer mode data cells. The data in these cells is extracted by the optical network unit and forwarded over the fiber optic link to the master site.

Claims

1. For use with a broadband communication system for conveying telecommunication messages over a broadband communication path from a master site to one or more remote sites, and from said one or more remote sites to said master site, said one or more remote sites being coupled over a communication link to a broadband communication path interface device which is ported to said broadband communication path, a method of conveying broadband information signals, that have been downlinked from said master site to said broadband communication path interface device, from said broadband communication path interface device to said one or more remote sites, and for conveying message signals from said one or more remote sites to said broadband communication path interface device, so that said message signals may be transmitted to said master site, said method comprising the steps of:

(a) at said broadband communication path interface device, assembling a first message for transmission to one or more remote sites, said first message having a data portion that contains broadband information signals destined for said one or more remote sites and an overhead portion that contains a return channel transmission opportunity control code representative of an uplink return channel transmission opportunity for a remote site to transmit a message on said uplink return channel, and transmitting said first message from said broadband communication path interface device over a multi-drop communication link to said one or more remote sites; and

(b) at a destination remote site, detecting said return channel transmission opportunity control code contained in said overhead portion of said first message received thereby, assembling a second message intended for transmission to said broadband communication path interface device, and transmitting said second message during a portion of a time division slotted return channel of said multi-drop communication link to said broadband communication path interface device in accordance with the detected return channel transmission opportunity control code of said first message.

2. A method according to claim 1, wherein said first message is comprised of synchronous optical network based communication signals.

3. A method according to claim 1, wherein step (a) comprises incorporating said broadband information signals as first fixed size data cells together with said return channel transmission opportunity control code into said first message and transmitting said first message from said broadband communication path interface device over said multi-drop communication link to said one or more remote sites.

4. A method according to claim 3, wherein said first fixed size data cells comprise asynchronous transfer mode data cells.

5. A method according to claim 4, wherein said first communication signals comprise synchronous optical network based communication signals.

6. A method according to claim 3, wherein step (b) includes assembling second fixed sized data cells into said second message.

7. A method according to claim 6, wherein said second fixed size data cells comprise asynchronous transfer mode data cells.

8. A method according to claim 1, wherein said one or more remote sites corresponds to a single remote site at which customer premises broadband communication receiver equipment is installed.

9. A method according to claim 1, wherein said one or more remote sites corresponds to a plurality of remote sites at which respective customer premises broadband communication receiver equipments are installed.

10. A method according to claim 1, wherein step (a) includes inserting respectively different return slot-representative return channel transmission opportunity control codes associated with respectively different remote sites into a common overhead portion of successive first messages, and wherein step (b) comprises, at respectively different ones of said remote sites, detecting said respectively different return channel transmission opportunity control codes contained in said common overhead portion of said first messages received thereby, and transmitting second messages during respectively different portions of said time division slotted return channel of said multi-drop communication link in accordance with said detected return channel transmission opportunity control codes.

11. A method according to claim 1, wherein step (a) comprises transmitting said first message in a first frequency band below that assigned for broadcast cable television signals, and step (b) comprises transmitting said second message in a second frequency band below that assigned for broadcast cable television signals and spaced apart from said first frequency band.

12. A method according to claim 11, wherein said destination remote site further includes a coaxial cable port, to which cable television signals from a cable television service provider may be supplied, and a telephony signalling port, to which customer premises telephone equipment at said destination remote site may be connected, and wherein step (b) further includes coupling a diplexer filter with said coaxial cable port and said multi-drop communication link, said diplexer filter being operative to couple said first message received over said multi-drop communication link and cable television signals at said coaxial cable port to a broadband output port, and to couple telephony signals received over said multi-drop communication link to said telephony signalling port.

13. A method according to claim 11, wherein step (a) comprises transmitting said first message as first carrierless amplitude modulation phase modulation signals, and step (b) comprises transmitting said second message as second carrierless amplitude modulation phase modulation signals.

14. A method according to claim 1, wherein said multi-drop communication link comprises an unshielded twisted pair.

15. For use with a broadband communication system for conveying telecommunication messages over a broadband communication path from a master site to one or more remote sites, and from said one or more remote sites to said master site, said remote sites being coupled over a multi-drop communication link to a broadband communication path interface device which is ported to said broadband communication path, an arrangement for conveying broadband information signals, that have been downlinked from said master site to said broadband communication path interface device, from said broadband communication path interface device to said one or more remote sites, and for conveying return message signals from said one or more remote sites to said broadband communication path interface device, so that said return message signals may be transmitted to said master site, comprising:

an upstream transceiver, provided in said broadband communication path interface device and being operative to generate a first message having a data portion that contains broadband information signals destined for said one or more remote sites and an overhead portion that contains a return channel transmission opportunity control code representative of an uplink return channel transmission opportunity for a remote site to transmit a message on said uplink return channel, said upstream transceiver transmitting said first message from said broadband communication path interface device over a multi-drop communication link to said one or more remote sites; and

a downstream transceiver, provided at a respective destination remote site, and being operative to detect a respective return channel transmission opportunity control code contained in said overhead portion of said first message received thereby, said downstream transceiver assembling a second message and transmitting said second message from said respective destination remote site during a portion of a time division slotted return channel of said multi-drop communication link to said upstream transceiver in said broadband communication path interface device in accordance with the detected return channel transmission opportunity control code of said first message.

16. An arrangement according to claim 15, wherein said first message is comprised of synchronous optical network based communication signals.

17. An arrangement according to claim 15, wherein said upstream transceiver is operative to insert said broadband information signals as first fixed size data cells together with said return channel transmission opportunity control code into said first message and to transmit said first message from said broadband communication path interface device over said multi-drop communication link to said one or more remote sites.

18. An arrangement according to claim 17, wherein said first fixed size data cells comprise asynchronous transfer mode data cells.

19. An arrangement according to claim 18, wherein said first message is comprised of synchronous optical network based communication signals.

20. An arrangement according to claim 19, wherein said downstream transceiver is operative to assemble second fixed sized data cells into said second message.

21. An arrangement according to claim 20, wherein said second fixed size data cells comprise asynchronous transfer mode data cells.

22. An arrangement according to claim 15, wherein said one or more remote sites corresponds to a single remote site.

23. An arrangement according to claim 15, wherein said one or more remote sites comprises a plurality of remote sites.

24. An arrangement according to claim 15, wherein said upstream transceiver is operative to insert respectively different return slot-representative control codes associated with respectively different remote sites into a common overhead portion of successive first messages, and wherein plural downstream transceivers are provided at respectively different remote sites, and are operative to detect said respectively different return channel transmission opportunity control codes contained in said common overhead portion of said first messages received thereby, and transmit second messages during respectively different portions of said time division slotted return channel of said multi-drop communication link in accordance with said detected return channel transmission opportunity control codes.

25. An arrangement according to claim 15, wherein said upstream transceiver is operative to transmit said first message in a first frequency band below that assigned for broadcast cable television signals, and wherein said downstream transceiver is operative to transmit said second message in a second frequency band below that assigned for broadcast cable television signals and spaced apart from said first frequency band.

26. An arrangement according to claim 25, wherein said destination remote site further includes a coaxial cable port, to which cable television signals from a cable television service provider may be supplied, and a telephony signalling port, to which customer premises telephone equipment at said destination remote site may be connected, and further including, at said destination remote site, a diplexer filter coupled with said coaxial cable port and said multi-drop communication link, said diplexer filter being operative to couple said first message received over said multi-drop communication link and cable television signals at said coaxial cable port to a broadband output port for application to said downstream transceiver, and to couple telephony signals received over said multi-drop communication link to said telephony signalling port.

27. An arrangement according to claim 26, wherein said upstream transceiver is operative to transmit said first message as first carrierless amplitude modulation phase modulation signals, and wherein said downstream transceiver is operative to transmit said second message as second carrierless amplitude modulation phase modulation signals.

28. An arrangement according to claim 15, wherein said multi-drop communication link comprises an unshielded twisted pair.

29. An arrangement according to claim 15, wherein said upstream transceiver is operative to receive said second message transmitted by said downstream transceiver, and to forward said second message over said broadband communication path to said master site.

30. An arrangement according to claim 15, wherein said upstream transceiver is operative to receive said second message transmitted by said downstream transceiver, and to forward first selected message signals contained therein over said broadband communication path to said master site, and to extract second selected message signals contained therein for use by said broadband communication path interface device.