Search Images Maps Play YouTube News Gmail Drive More »
Advanced Patent Search | Web History | Sign in

Patents

A real time device polling method for multiplexed transmission of on/off constant bit rate data, such as voice data from a telephone call, over a cable data network is disclosed. The network serves as a shared bus for both the downstream and upstream traffic. The upstream channel is modeled as a stream of mini-slots. A cable modem termination system at the head end supports a number of cable modems attached to the cable network and connected to customer premises equipment. Allocation maps are transmitted on the downstream channel to the cable modems to define transmission opportunities on the upstream channel. The cable modem termination system polls the cable modems in an efficient way such that the overhead associated with the polling is minimized, and the availability of data transmission slots is synchronized with the data packet generation by the codec for the cable modem, which minimizes delay.

InventorsThomas E. Moore, Andrew W. Sundelin, Jeff Weaver
Original AssigneeCable Television Laboratories, Inc.
Primary Examiner: Ricky Ngo
Secondary Examiner: Yvonne Q. Ha
Attorney: James R. Young
Current U.S. Classification725/111; 370/449; 370/451; 370/458
International Classification: H04N/7173

View patent at USPTO
Search USPTO Assignment Database

Citations

Cited PatentFiling dateIssue dateOriginal AssigneeTitle
US5577043Sep 21, 1994Nov 19, 1996Motorola, Inc.Method and apparatus for controlling information transmission on a multipoint link
US5745837Mar 14, 1996Apr 28, 1998Terayon CorporationApparatus and method for digital data transmission over a CATV system using an ATM transport protocol and SCDMA
US5805586May 2, 1995Sep 8, 1998Motorola Inc.Method, device and data communication system for multilink polling
US5818828Oct 4, 1996Oct 6, 1998Metricom, Inc.Hybrid multiple access protocol for wireless frequency hopping microcells with adaptive backhaul and heartbeat
US6212196Nov 26, 1997Apr 3, 2001NEC CorporationMultiple access communication system and method for multiple access communication
US6308328Apr 10, 1997Oct 23, 2001Scientific-Atlanta, Inc.Usage statistics collection for a cable data delivery system
US6453472Jun 2, 1999Sep 17, 2002Cisco Technology, Inc.Method and apparatus for performing periodic ranging for cable modems

Referenced by

Citing PatentFiling dateIssue dateOriginal AssigneeTitle
US6742186Jun 2, 1999May 25, 2004Cisco Technology, Inc.Method and apparatus for enhancing periodic ranging for cable modems
US6765925Sep 28, 2000Jul 20, 2004Nortel Networks LimitedApparatus and method of maintaining state in a data transmission system
US6980542Sep 29, 2003Dec 27, 2005Avaya Technology Corp.Poll scheduling for periodic uplink and downlink traffic
US7154877Aug 10, 2001Dec 26, 2006Broadcom CorporationSystem and method for best effort scheduling
US7242694Mar 11, 2002Jul 10, 2007Juniper Networks, Inc.Use of group poll scheduling for broadband communication systems
US7333513Jul 18, 2002Feb 19, 2008Broadcom CorporationMethod, system, and computer program product for synchronizing voice traffic with minimum latency
US7561593Sep 6, 2001Jul 14, 2009Cisco Technology, Inc.Frame relay accelerated local management interface status-inquiry messages
US7693182Mar 21, 2007Apr 6, 2010Broadcom CorporationMethod for synchronizing voice traffic with minimum latency in a wireless communications network
US7782832Jun 1, 2007Aug 24, 2010Juniper Networks, Inc.Use of group poll scheduling for broadband communication systems
US7787435Sep 22, 2005Aug 31, 2010Samsung Electronics Co., Ltd.Method and system for polling mobile stations in a wireless network
US7848234Feb 19, 2007Dec 7, 2010Allocating access across shared communication medium to user classes
US7856497Mar 7, 2001Dec 21, 2010Method for determining an appropriate algorithm to apply for forecasting network access usage
US7920594Feb 19, 2009Apr 5, 2011Apparatus and methods for incorporating bandwidth forecasting and dynamic bandwidth allocation into a broadband communication system
US7925750Oct 19, 2007Apr 12, 2011Allocations of access across a communications medium
US7957417Feb 14, 2006Jun 7, 2011Methods of allocating access across a shared communications medium
US7970011Feb 19, 2009Jun 28, 2011Apparatus and methods for incorporating bandwidth forecasting and dynamic bandwidth allocation into a broadband communication system
US7983272Sep 18, 2007Jul 19, 2011Apparatus and methods for incorporating bandwidth forecasting and dynamic bandwidth allocation into a broadband communication system
US8042139Mar 4, 2008Oct 18, 2011The DIRECTV Group, Inc.Method for configuring broadcast components of a broadcast system including a compression control system
US8054856Apr 1, 2010Nov 8, 2011Broadcom CorporationMethod for synchronizing voice traffic with minimum latency in a communications network
US8116337Jul 27, 2007Feb 14, 2012Bandwidth requests transmitted according to priority in a centrally managed network
US8144669Dec 22, 2006Mar 27, 2012Broadcom CorporationSystem and method for best effort scheduling

Claims

1. In a telecommunications system supporting polled communications, a polling method comprising the steps of:

(a) transmitting a polling signal at a first periodic rate;
(b) receiving a response, from a first polled device, to said polling signal transmitted in step (a);
(c) increasing said transmitting said polling signal to said first polled device from which a response was received in step (b), from said first periodic rate to a second periodic rate, wherein said second periodic rate causes polling to occur more frequently than said first periodic rate;
(d) receiving a second response from said first polled device;
(e) decreasing said transmitting said polling signal to said first polled device to a third periodic rate, wherein said third periodic rate causes polling to occur less frequently than said second period rate.

2. The telecommunications system of claim 1 wherein said third periodic rate is equal to said first periodic rate.

3. The telecommunications system of claim 1 further comprising the steps of:

(f) when no response is received from said first polled device to a transmitted polling signal before a subsequent poll signal is transmitted, increasing said transmitting said polling signal to said first polled device, from said third periodic rate to a fourth periodic rate, wherein said fourth periodic rate causes polling to occur more frequently than said third periodic rate;
(g) receiving a response from said first polled device to a polling signal sent in step (f);
(h) decreasing said transmitting said polling signal to said first polled device to a fifth periodic rate, wherein said fifth periodic rate causes polling to occur less frequently than said fourth period rate.

4. The telecommunications system of claim 3 wherein said first, third and fifth periodic rates are the same.

5. The telecommunications system of claim 3 wherein said second and fourth period rates are the same.

6. A real time device polling method for multiplexed transmission over a cable network, said method comprising the steps of:

(a) generating, by at least one cable modem at a periodic rate, a plurality of data packets from data received from a customer premises equipment connected to said at least one cable modem;
(b) polling at a first polling rate, by a cable modem termination system at a head end of said cable network, said at least one cable modem connected to said cable network, wherein said polling further comprises sending a plurality of allocation maps at an allocation map frequency;
(c) when said at least one cable modem receives one of said plurality of allocation maps from said polling, after generating a first of said plurality of data packets, requesting by said at least one cable modem a first transmit opportunity in a request slot within said one of said plurality of allocation maps;
(d) when said cable modem termination system receives said request for said first transmit opportunity in said request slot in said one of said plurality of allocation maps,
(d1) granting said first transmit opportunity for said at least one cable modem in a first grant allocation map from said plurality of allocation maps from said polling, and
(d2) polling said at least one cable modem at a second polling rate, wherein said second polling rate is more frequent than said first polling rate;
(e) when said at least one cable modem receives said first grant allocation map, transmitting said first of said plurality of data packets,
(f) when said at least one cable modem receives another one of said plurality of allocation maps from said polling, after generating a second of said plurality of data packets, requesting by said at least one cable modem a second transmit opportunity in a request slot within said another one of said plurality of allocation maps;
(g) when said cable modem termination system receives said request for said second transmit opportunity in said request slot in said another one of said plurality of allocation maps,
(g1) granting said second transmit opportunity for said at least one cable modem in a second grant allocation map, and
(g2) polling said at least one cable modem at a third polling rate, wherein said third polling rate is less frequent than said second polling rate; and
(h) when said at least one cable modem receives said second grant allocation map, transmitting said second of said plurality of data packets.

7. A real time device polling method for multiplexed transmission over a cable network according to claim 6 further comprising the step of:

(i) repeating steps (f), (g), and (h) for said plurality of allocation maps and said plurality of data packets for a plurality of requests from said at least one cable modem for a plurality of transmit opportunities in a plurality of request slots within said plurality of allocation maps while polling said at least one cable modem at said third polling rate.

8. A real time device polling method for multiplexed transmission over a cable network according to claim 7 further comprising the steps of:

(j) when said cable modem termination system fails to receive a next request from said polling of said at least one cable modem for a next transmit opportunity in a next request slot in a next allocation map, polling said at least one cable modem at a fourth polling rate, wherein said fourth polling rate is more frequent than said third polling rate; and
(k) when said cable modem termination system fails to receive another next request immediately after step (j) from said polling of said at least one cable modem for a next transmit opportunity in a next request slot in a next allocation map, polling said at least one cable modem at a fifth polling rate, wherein said fifth polling rate is less frequent than said fourth polling rate.

9. A real time device polling method for multiplexed transmission over a cable network according to claim 8 wherein step (k) is replaced by the following new step (k):

(k) when said cable modem termination system receives-another next request immediately after step (j) from said polling of said at least one cable modem for a next transmit opportunity in a next request slot in a next allocation map,
(k1) granting said next transmit opportunity for said at least one cable modem in a next grant allocation map, and
(k2) polling said at least one cable modem at a fifth polling rate, wherein said fifth polling rate is less frequent than said fourth polling rate.

10. A real time device polling method for multiplexed transmission over a cable network according to claim 8 wherein said first polling rate, said third polling rate, and said fifth polling rate are the same.

11. A real time device polling method for multiplexed transmission over a cable network according to claim 8 wherein said second polling rate and said fourth polling rate are the same.

12. A real time device polling method for multiplexed transmission over a cable network according to claim 6 wherein said allocation map frequency is a sub-multiple of said first polling rate.

13. A real time device polling method for multiplexed transmission over a cable network according to claim 6 wherein said periodic rate for said generation of said plurality of data packets has an integer relationship with said first polling rate.

14. A real time device polling method for multiplexed transmission over a cable network according to claim 13 wherein said periodic rate for said generation of said plurality of data packets is the same as said first polling rate.

15. A real time device polling method for multiplexed transmission over a cable network according to claim 6 wherein a first group of cable modems are polled by said cable modem termination system at said first polling rate starting at a first time, and a second group of cable modems are polled by said cable modem termination system at said first polling rate starting at a second time.

16. A real time device polling method for multiplexed transmission over a cable network according to claim 6 wherein said customer premises equipment is a telephone.

17. A real time device polling method for multiplexed transmission over a cable network according to claim 6 wherein said customer premises equipment is a personal computer.

18. A cable network for transmitting constant bit rate data comprising:

a plurality of cable modems connected to said cable network, wherein each of said plurality of cable modems generates a plurality of data packets at a periodic rate for transmission upstream over said cable network;
a plurality of customer premises equipment, wherein each of said plurality of customer premises equipment is connected to one of said plurality of cable modems through a customer interface, wherein each of said plurality of customer premises equipment generates said constant bit rate data, wherein said constant bit rate data is transferred over said customer interface to each of said plurality of cable modems; and
a cable modem termination system connected to a head end of said cable network, wherein said cable modem termination system polls said plurality of cable modems at a first polling rate, and further wherein when said polling indicates to said cable modem termination system that one of said plurality of cable modems has requested a first transmit opportunity to transmit at least one data packet, allocating bandwidth by said cable modem termination system for said first transmit opportunity for said one of said plurality of cable modems, and polling by said cable modem termination system said one of said plurality of cable modems at a second polling rate, wherein said second polling rate is more frequent than said first polling rate, and further wherein when said polling at said second polling rate indicates to said cable modem termination system that said one of said plurality of cable modems has requested a second transmit opportunity to transmit at least one other data packet, allocating bandwidth by said cable modem termination system for said second transmit opportunity for said one of said plurality of cable modems, and polling by said cable modem termination system said one of said plurality of cable modems at a third polling rate, wherein said third polling rate is less frequent than said second polling rate.

19. A cable network for transmitting constant bit rate data according to claim 18 wherein when said cable modem termination system fails to receive a next request for a next transmit opportunity to transmit a next data packet from said polling of said one of said plurality of cable modems, polling by said cable modem termination system said one of said plurality of cable modems at a fourth polling rate, wherein said fourth polling rate is more frequent than said third polling rate, and further wherein when said cable modem termination system fails to receive another next request for another next transmit opportunity to transmit another next data packet immediately after said failure to receive said next request for said next transmit opportunity from said polling of said one of said plurality of cable modems, polling by said cable modem termination system said at least one cable modem at a fifth polling rate, wherein said fifth polling rate is less frequent than said fourth polling rate.

20. A cable network for transmitting constant bit rate data according to claim 19 wherein said first polling-rate, said third polling rate, and said fifth polling rate are the same.

21. A cable network for transmitting constant bit rate data according to claim 19 wherein said second polling rate and said fourth polling rate are the same.

22. A cable network for transmitting constant bit rate data according to claim 18 wherein when said cable modem termination system fails to receive a next request for a next transmit opportunity to transmit a next data packet from said polling of said one of said plurality of cable modems, polling by said cable modem termination system said one of said plurality of cable modems at a fourth polling rate, wherein said fourth polling rate is more frequent than said third polling rate, and further wherein when said cable modem termination system receives another next request for another next transmit opportunity to transmit another next data packet immediately after said failure to receive said next request for said next transmit opportunity from said polling of said one of said plurality of cable modems, allocating bandwidth by said cable modem termination system for said another next transmit opportunity for said one of said plurality of cable modems, and polling by said cable modem termination system said at least one cable modem at a fifth polling rate, wherein said fifth polling rate is less frequent than said fourth polling rate.

23. A cable network for transmitting constant bit rate data according to claim 18 further comprising:

a network-side interface connected to said cable modem termination system; and
a wide-area network connected to said network-side interface, wherein said network-side interface allows said cable modem termination system to receive external signals from said area network, and further wherein said network-side interface allows said cable modem termination system to transmit signals to said wide-area network.

24. A cable network for transmitting constant bit rate data according to claim 18 wherein said polling further comprises transmitting by said cable modem termination system a plurality of allocation maps at an allocation map frequency.

25. A cable network for transmitting constant bit rate data according to claim 24 wherein said allocation map frequency is a sub-multiple of said first polling rate.

26. A cable network for transmitting constant bit rate data according to claim 18 wherein said periodic rate for said generation of said plurality of data packets has a substantially integer relationship with said first polling rate.

27. A cable network for transmitting constant bit rate data according to claim 26 wherein said periodic rate for said generation of said plurality of data packets is the same as said first polling rate.

28. A cable network for transmitting constant bit rate data according to claim 18 wherein said customer premises equipment is a telephone.

29. A cable network for transmitting constant bit rate data according to claim 18 wherein said customer premises equipment is a personal computer.