Downstream time domain based adaptive modulation for DOCSIS based applications

• US 7,508,785 B2
• Filed: 12/12/2002
• Issued: 03/24/2009
• Est. Priority Date: 11/06/2002
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Lin, Dorothy, Kwentus, Alan, Jaffe, Steven, Dale, Mark, Hebsgaard, Anders, Wang, Joyce, Hartman, David, Gin, Alan, Brescia, Rocco, Chien, Jen-chieh (Jack), Cameron, Kelly, Krafft, Stephen
• Primary Examiner(s): Moore; Ian N
• Application Number:
  US10/319,929
• Publication Number:
  US 20040085976A1
• Time in Patent Office: 2,294 Days
• Field of Search: 370/316, 370/327, 370/326, 370/322, 370/325, 370/233, 370/474, 370/480, 370/401, 370/429, 455/59, 455/3.01, 455/3.02, 455/452.2, 455/12.1, 455/69, 455427-428, 455/3.06, 455 131- 134, 380/212, 725/114, 725/138, 725/111, 725/129
• US Class Current: 370/322
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• CPC Class Codes: H04N 2007/17381 the upstream transmission being initiated by the user terminal
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/6143 involving transmission via a satellite
• CPC Class Codes: H04N 21/6193 involving transmission via a satellite arrangements for data linking, networking or transporting, or for controlling an end to end session in a satellite broadcast system H04B7/18526
• CPC Class Codes: H04N 21/6377 directed to server one-way streaming services wherein the source is controlled by the destination H04L65/613

Abstract

In a DOCSIS based satellite gateway data is transmitted over a single downstream channel, at different throughput rates. Data destined for each subscriber/receiver is assigned a throughput rate depending upon the downstream signal quality of that subscriber/receiver. To accomplish this, the downstream DOCSIS MAC data is parsed to extract DOCSIS packets. The DOCSIS packets are then loaded into packet queues based on an identifier within such packets such as the MAC destination address or SID. Each of the queues represents a bandwidth efficiency or throughput rate that can be currently tolerated by specific subscribers based on the current signal quality being experienced at the subscriber location. A PHY-MAP describing the downstream data structure to be transmitted and inserted into the downstream data. Data is extracted from the packet queues in queue blocks as defined by the PHY-MAP. The queue blocks are modulated with transmission parameters appropriate for each queue block and transmitted to the DOCSIS based satellite modems. The satellite modems extract the PHY-MAP from the downstream data and use the information contained in it to demodulate and decode the queue for which they have sufficient downstream signal quality. Satellite modems measure and transmit downstream signal quality to the satellite gateway to be used to assigned traffic to the appropriate queues.

Claims

1. A method of adaptively controlling a throughput rate of data traffic destined for a plurality of receivers, the data traffic combined into a single data stream and transmitted over a single downstream channel, the method comprising:

assigning data traffic for each of the plurality of receivers to the throughput rate based on downstream signal quality information for each of the plurality of receivers;

associating each of a plurality of packet queues with one of a plurality of throughput rates, establishing a profile for each of the plurality of packet queues, the profile including a modulation type and an error correction encoding rate that support the associated throughput rate;

parsing the single data stream into the plurality of packet queues based on said data traffic assigning;

modulating and encoding the parsed data stream in each of the plurality of packet queues in accordance with the established profile for the respective packet queue;

transmitting, by a transceiver, the modulated and encoded parsed data stream from each of the packet queues over the downstream channel; and

transmitting Physical Layer MAPs (PHY-MAPs) to each of the plurality of receivers over the single downstream channel, wherein the PHY-MAPs store a description of a downstream data structure that includes all information necessary for the plurality of receivers to demodulate and decode the modulated and encoded data traffic, wherein said transmitting of the PHY-MAPs includes assigning the PHY-MAP to a lowest throughput rate of the plurality of throughput rates.

2. The method of claim 1 wherein the downstream signal quality information is a signal-to-noise-ratio for the receiver.

3. The method of claim 1 wherein the downstream signal quality information is a packet error rate for the receiver.

4. The method of claim 1 further comprises:

receiving the downstream signal quality information from each of the plurality of receivers over an upstream signal channel.

5. The method of claim 1 wherein said assigning data traffic further comprises:

placing a packet queue identifier in each traffic packet of the data stream.

6. The method of claim 1 wherein said assigning data traffic further comprises:

assigning the data traffic destined for one of the plurality of receivers to any one or more throughput rates that are supported by the downstream signal quality information of the receiver.

7. An apparatus for adaptively controlling a throughput rate of data traffic destined for a plurality of receivers, the data traffic combined into a single data stream and transmitted over a single downstream channel, the apparatus comprising:

means for assigning data traffic for each of the plurality of receivers to the throughput rate based on downstream signal quality information for each of the plurality of receivers;

means for associating each of a plurality of packet queues with one of a plurality of throughput rates, means for establishing a profile for each of the plurality of packet queues, the profile including a modulation order and an error correction encoding rate that support the associated throughput rate;

means for parsing the single data stream into the plurality of packet queues based on said data traffic assigning;

means for modulating and encoding the parsed data stream in each of the plurality of packet queues in accordance with the profile for the respective packet queue;

means for transmitting the modulated and encoded data traffic from each of the packet queues over the downstream channel; and

means for transmitting a Physical layer MAP (PHY-MAP) to each of the receivers over the downstream channel, wherein the PHY-MAP stores the profile, and wherein said means for transmitting the PHY-MAP further includes means for assigning the PHY-MAP to a lowest throughput rate.

8. The apparatus of claim 7 wherein the downstream signal quality information is a signal-to-noise ratio for the receiver.

9. The apparatus of claim 7 wherein the downstream signal quality information is a packet error rate for the receiver.

10. The apparatus of claim 7 further comprises:

means for receiving the downstream signal quality information from each of the plurality of receivers over an upstream signal channel.

11. The apparatus of claim 7 wherein said means for assigning data traffic further comprises:

means for placing a packet queue identifier in each traffic packet of the data stream.

12. The apparatus of claim 7 wherein said means for assigning data traffic further comprises:

means for assigning the data traffic destined for one of the plurality of receivers to any one or more throughput rates that are supported by the downstream signal quality information of the receiver.

13. The apparatus of claim 7 wherein the profile for each packet queue further comprises:

start times for bursts from each queue.

14. The apparatus of claim 13 further comprising:

means for dynamically allocating time for transmission from each queue to optimize overall system throughput.

15. A method of adaptively controlling a throughput rate of data traffic destined for a plurality of receivers, the data traffic combined into a single data stream and transmitted over a single downstream channel, the method comprising:

generating the single data stream in accordance with a Data Over Cable Service Interface Specification (DOCSIS) MAC layer, and assigning DOCSIS MAC management messages and DOCSIS time stamp messages to a lowest throughput rate;

assigning data traffic for each of the plurality of receivers to the throughput rate based on downstream signal quality information for each of the plurality of receivers;

associating each of a plurality of packet queues with one of a plurality of throughput rates, establishing a profile for each of the packet queues, the profile including a modulation type and an error correction encoding rate that support the associated throughput rate;

parsing the single data stream into the plurality of packet queues based on said data traffic assigning;

modulating and encoding the parsed data stream in each of the plurality of packet queues in accordance with the profile for the respective packet queue; and

transmitting, by a transceiver, the modulated and encoded parsed data stream from each of the packet queues over the downstream channel.

16. The method of claim 15 further comprising:

extracting packet data from the packet queues; and

framing the extracted packets in accordance with the profile stored in a Physical layer MAP (PHY-MAP) for each queue from which the data is extracted and framed.

17. The method of claim 16 wherein said modulating and encoding further comprises:

generating modulation and encoding control signals for each burst from a queue in accordance with the profile associated with the queue from which the framed data was extracted.

18. The method of claim 17 further comprising:

updating the PHY-MAP periodically to reflect changing downstream signal quality information.

19. A method of adaptively controlling a throughput rate of data traffic destined for a plurality of receivers, the data traffic combined into a single data stream and transmitted over a single downstream channel, the method comprising:

assigning data traffic for each of the plurality of receivers to the throughput rate based on downstream signal quality information for each of the plurality of receivers;

associating each of a plurality of packet queues with one of a plurality of throughput rates, establishing a profile for each of the plurality of packet queues, wherein the profile for each packet queue of the plurality of packet queues includes information selected from the group consisting of modulation type, Forward Error Correction (FEC) type, FEC rate, FEC block size, queue block size, and a number of Moving Picture Experts Group (MPEG) frames per queue block that support the associated throughput rate;

parsing the single data stream into the plurality of packet queues based on said data traffic assigning;

dynamically allocating time for transmission from each packet queue to optimize overall system throughput by altering a number of blocks and a number of MPEG frames per block;

modulating and encoding the parsed data stream in each of the plurality of packet queues in accordance with the profile for the respective packet queue; and

transmitting, by a transceiver, the modulated and encoded parsed data stream from each of the packet queues over the downstream channel.

20. An apparatus for adaptively controlling a throughput rate of data traffic destined for a plurality of receivers, the data traffic combined into a single data stream and transmitted over a single downstream channel, the apparatus comprising:

means for generating the data stream in accordance with a Data Over Cable Service Interface Specification (DOCSIS) MAC layer, and means for assigning DOCSIS MAC management messages and DOCSIS time stamp messages to a lowest throughput rate;

means for assigning data traffic for each of the plurality of receivers to the throughput rate based on downstream signal quality information for each of the plurality of receivers;

means for associating each of a plurality of packet queues with one of a plurality of throughput rates, means for establishing a profile for each of the packet queues, the profile including a modulation order and an error correction encoding rate that support the associated throughput rate;

means for parsing the single data stream into the plurality of packet queues based on said data traffic assigning;

means for modulating and encoding the parsed data stream in each of the plurality of packet queues in accordance with the profile for the respective packet queue; and

means for transmitting the modulated and encoded data traffic from each of the packet queues over the downstream channel.

21. An apparatus for adaptively controlling a throughput rate of data traffic destined for a plurality of receivers, the data traffic combined into a single data stream and transmitted over a single downstream channel, the apparatus comprising:

means for assigning data traffic for each of the plurality of receivers to the throughput rate based on downstream signal quality information for each of the plurality of receivers;

means for associating each of a plurality of packet queues with one of a plurality of throughput rates, means for establishing a profile for each of the plurality of packet queues, the profile including a modulation order and an error correction encoding rate that support the associated throughput rate;

means for parsing the single data stream into the plurality of packet queues based on said data traffic assigning;

means for extracting packet data from the plurality of packet queues;

means for framing the extracted packets in accordance with the profile stored in the Physical layer MAP (PHY-MAP) for each queue of the plurality of queues from which the data is extracted and framed;

means for updating the PHY-MAP periodically to reflect changing downstream signal quality information;

means for modulating and encoding the parsed data stream in each of the plurality of packet queues in accordance with the profile for the respective packet queue, wherein the modulating and encoding means further include means for generating modulation and encoding control signals for each frame in accordance with the profile associated with the queue from which the framed data was extracted; and

means for transmitting the modulated and encoded parsed data stream from each of the plurality of packet queues over the downstream channel.