Data transmission over multiple upstream channels within a cable modem system

• US 7,017,176 B1
• Filed: 06/10/1999
• Issued: 03/21/2006
• Est. Priority Date: 06/10/1999
• Status: Expired due to Term

• Current Assignee: Cisco Systems, Inc.
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: King, Patrick S., Lee, Glenn E.
• Primary Examiner(s): Srivastava, Vivek
• Application Number:
  US09/330,225
• Time in Patent Office: 2,476 Days
• Field of Search: 725/111, 725/121, 725/122, 725/126, 725/125, 370/536, 375/260
• US Class Current: 725/111
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission

Abstract

A system and method are disclosed for transmitting upstream data from a cable modem within a cable television plant. One aspect of the invention pertains to a method that includes transmitting a first portion of the upstream data on a first upstream channel from the cable modem and transmitting a second portion of the upstream data on a second upstream channel from the cable modem. The second upstream channel differs from the first upstream channel. In another aspect, the invention pertains to a cable modem that includes a processor configured to initiate transmission on multiple upstream channels. The cable modem further includes an upstream transmitting component operating in conjunction with the processor and configurable by the processor to transmit data over multiple upstream channels. In one embodiment, the upstream transmitting component includes a first transmitter that is capable of being configured by the processor to transmit data at both a first upstream channel and a second transmitter that is capable of being configured by the processor to transmit at a second upstream channel that differs from the first upstream channel.

Claims

1. A method for transmitting upstream data from a cable modem within a cable plant, the method comprising:

selecting a first upstream channel for transmission of a first portion of the upstream data and selecting a second upstream channel for transmission of a second portion of the upstream data, wherein the selection of the first and second upstream channels is based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria;

transmitting the first portion of the upstream data on the first upstream channel from a first PHY block of the cable modem; and

transmitting the second portion of the upstream data on the second upstream channel from a second PHY block of the cable modem, the second upstream channel differing from the first upstream channel in their respective frequency ranges, wherein the first PHY block differs from the second PHY block.

2. A method as recited in claim 1, further comprising:

obtaining the first upstream channel from information in the downstream channel input to the cable modem; and

obtaining the second upstream cannel from the information in the downstream channel input to the cable modem.

3. A method as recited in claim 2, wherein the information comprises one or more upstream channel descriptors (UCDs) and obtaining the first upstream channel comprises collecting the one or more UCDs from the downstream channel, and selecting a first one of the collected UCD(s), wherein the first upstream channel is based on the first selected UCD.

4. A methods as recited in claim 3, wherein the second upstream channel is obtained by selecting a second one of the collected UCD(s), wherein the second upstream channel is based on the second selected UCD.

5. A method as recited in claim 4, wherein selecting the first and second UCD'"'"'s is based on a random algorithm.

6. A method as recited in claim 4, further comprising verifying whether the second upstream channel is still valid.

7. A method as recited in claim 1, wherein transmitting data over the first upstream channel is alternated with transmitting data over the second upstream channel.

8. A method as recited in claim 1, wherein a first type of data are transmitted over the first ups channel, and a second type of data are transmitted over the second upstream channel.

9. A method as recited in claim 1, wherein data are transmitted over the first upstream channel when it is less congested than the second upstream channel, and data are transmitted over the second upstream channel when it is less congested than the first upstream channel.

10. A method as recited in claim 1, wherein data are primarily transmitted over the first upstream channel, and data are transmitted over the second upstream channel to facilitate load balancing.

11. A cable modem comprising:

a processor configured to initiate selective transmission on multiple upstream channels, wherein the selective transmission on multiple upstream channels is based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria; and

an upstream transmitting component operating in conjunction with the processor and configurable by the processor to transmit data over multiple upstream channels through different PHY blocks, wherein the multiple upstream channels are assigned within a downstream channel received into the cable modem and wherein the first upstream channel has a different frequency range than the second upstream channel.

12. A cable modem as recited in claim 11, wherein the upstream transmitting component includes a first transmitter that is capable of being configured by the processor to transmit data at a first upstream channel and a second transmitter that is capable of being configured by the processor to transmit at a second upstream channel that differs from the first upstream channel if the second upstream channel is available.

13. A cable modem as recited in claim 12, further comprising;

a first media access controller (MAC) coupled with the first transmitter and the processor, the first MAC arranged to receive data from the processor for outputting to the first transmitter so that the first transmitter outputs the data over the first upstream channel; and

a second MAC coupled with the second transmitter and the processor, the second MAC arranged to receive data from the processor for outputting to the second transmitter so that the second transmitter outputs the data over the second upstream channel.

14. A cable modem as recited in claim 12, filter comprising a combiner receiving data transmitted over the first and second upstream channels from the first and second transmitter, the combiner multiplexing the first and second upstream channels so that the received data are output on a single line.

15. A cable modem as recited in claim 13, wherein the first MAC is integrated within a first integrated MAC and PHY device, and the second MAC is integrated within a second integrated MAC and PHY device.

16. A cable modem as recited in claim 13, wherein the first MAC is coupled with a first packet memory, and the second MAC is coupled with a second packet memory, the first and second MAC being arranged to transmit data that is written to its corresponding packet memory.

17. A cable modem as recited in claim 16, wherein the first and second packet memory are located within a DRAM device.

18. A cable modem as recited in claim 12, further comprising:

a MAC coupled with the first transmitter block, the second transmitter, and the processor, the MAC being arranged to receive data from the processor for outputting to the first transmitter and/or the second transmitter so that the first transmitter and/or second transmitter outputs the data over the first upstream channel and/or second upstream channel.

19. A head end for receiving upstream data from a cable modem, comprising a splitter that receives an upstream signal from the cable modem, the upstream signal including a first portion of the upstream data on a first upstream channel and a second portion of the upstream data on a second upstream channel that differs from the first upstream channel and wherein the first upstream channel has a different frequency range than the second upstream channel, the splitter being arranged to separate the first portion of the upstream data transmitted over the first upstream channel from the second portion of the upstream data transmitted over the second upstream channel for further processing of the separated data, wherein the head end is further operable to assign the first upstream channel and the second upstream channel to the cable modem, wherein the first and second upstream channels have been selected for transmission of their respective data from different PHY blocks based on a load balancing criteria or a data type criteria.

20. A method of transmitting upstream data from a cable modem over multiple upstream channels within a cable plant, the method comprising:

receiving a downstream signal within a downstream channel into the cable modem;

configuring the cable modem to transmit over a first upstream channel specified in the downstream signal;

configuring the cable modem to transmit over a second upstream channel which has a different frequency range than the second upstream channel if the second channel is specified in the downstream signal; and

selectively transmitting different data portions over the first and second channels through two different PHY blocks based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria.

21. A method as recited in claim 20, further comprising:

determining whether the cable modem is authorized to transmit over multiple upstream channels prior to configuring the cable modem to transmit over the second upstream channel; and

confirming the cable modem with the second upstream channel only when the cable modem is authorized to transmit over multiple upstream channels.

22. A method as recited in claim 21, further comprising:

transmitting over a single channel if the cable modem is set up only to transmit over the first upstream channel; and

transmitting over both the first and second upstream channels if the cable modem is set up to transmit over both the first and second upstream channels.

23. A method as recited in claim 22, wherein transmitting over both the first and second upstream channels includes alternatively selecting the first and second upstream channels for transmission of one or more packets of data.

24. A method as recited in claim 22, wherein transmitting over both the first and second upstream channels includes selecting either the first or second upstream channels for transmission of a particular type of data.

25. A method as recited in claim 22, wherein transmitting over both the first and second ups channels includes selecting either the first or second upstream channels for transmission of data based on which upstream channel is least congested.

26. A method as recited in claim 22, wherein transmitting over both the first and second upstream channels includes selecting the first upstream channel for primary data transmission and selecting the second upstream channel for load balancing.

27. A method as recited in claim 20, further comprising powering up the cable modern, wherein the setting up of the cable modem with the first upstream channel is initiated by the powering up.

28. A method as recited in claim 20, wherein the setting up the cable modem with the second upstream channel is initiated when the cable modem has previously been set up for transmitting over only a single upstream channel.

29. A method as recited in claim 20, wherein the setting up of the cable modem with the second upstream channel is initiated when the cable modem has previously been set up for transmitting over only a single upstream channel.

30. A method as recited in claim 20, further comprising:

prior to setting up the cable modem to transmit over the second upstream channel requesting initial ranging using the first upstream channel;

if a transmission power level of the cable modem is not greater than a maximum transmission power level, adjusting the transmission power level of the cable modem when the head end fails to respond to the initial ranging request using the first upstream channel; and

if the transmission power level is greater than the maximum transmission power level, setting up the cable modem with a next first upstream channel; and

performing periodic ranging between the head end and the cable modem using the first upstream channel when the head end responds to the initial ranging request using the first upstream channel.

31. A method as recited in claim 30, wherein the transmission power level is adjusted in increments from a minimum value to a maximum power level.

32. A method as recited in claim 30, wherein a value of the first upstream channel is altered by the periodic ranging and the cable modem is set up to transmit over the second upstream channel that differs from the altered first upstream channel value.

33. A method as recited in claim 30, further comprising:

after setting up the cable modem to transmit over the second upstream channel, requesting initial ranging using the second upstream channel;

if a transmission power level of the cable modem is not greater than the maximum transmission power level, adjust the transmission power level of the cable modem when the head end fails to respond to the initial ranging request using the second upstream channel;

if the transmission power level is greater than the maximum transmission power level, setting up the cable modem with a next second upstream channel if available; and

performing periodic ranging between me head end and the cable modem using the second upstream channel when the head end responds to the initial ranging request using the second upstream channel.

34. A method as recited in claim 33, wherein a value of the first upstream channel is altered by the periodic ranging and the cable modem is set up to transmit over the second upstream channel that differs from the altered first upstream channel value.

35. A cable modem comprising:

a first media access controller associated with a first memory portion into which data is written for mission upstream from the cable modem;

a second media access controller associated with a second memory portion into which data is written for transmission upstream from the cable modem;

a first PHY block coupled with the first media access controller, a second PHY block coupled with the second media access controller; and

a processor configured to receive a downstream signal within a downstream channel into the cable modem, configure the first PHY block to transmit data over a first upstream channel obtained from the downstream signal, configure the second PHY block to transmit data over a second upstream channel having a different frequency than the first upstream channel and obtained from the downstream signal if the second upstream channel is available, select the first upstream channel for transmission of a first data portion by writing to the first memory portion of the first media access controller so that the first data portion is transmitted through the first PHY block and select the second upstream channel for transmission of a second data portion by writing to the second memory portion of the second media access controller so that the second data portion is transmitted through the second PHY block, wherein selection of the first and second channels is based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria.

36. A computer readable medium containing programming instruction for transmitting data from a cable modem within a cable plant, the computer readable medium comprising;

computer readable code for selecting a first upstream channel for transmission of a first portion of the upstream data and selecting a second upstream channel for transmission of a second portion of the upstream data, wherein the selection of the first and second upstream channels is based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria;

computer readable code for transmitting the first portion of the upstream data on the first upstream channel from a first PHY block of the cable modem; and

computer readable code for transmitting the second portion of the upstream data on the second upstream channel from the cable modem, the second upstream channel differing from a second PHY block of the first upstream channel in their respective frequency ranges, wherein the first PHY block differs from the second PHY block.

38. A computer readable medium as recited in claim 36, further comprising:

computer readable code for obtaining the first upstream channel from information in the downstream channel input to the cable modem; and

computer readable code for obtaining the second upstream channel from the information in the downstream channel input to the cable modem.

39. A computer readable medium as recited in claim 38, wherein the information comprises one or more upstream channel descriptors (UCDs) and obtaining the first upstream channel comprises collecting the one or more UCDs from the downstream channel, and selecting a first one of the collected UCD(s), wherein the first upstream channel is based on the first selected UCD.

40. A computer readable medium as recited in claim 39, wherein the second upstream channel is obtained by selecting a second one of the collected UCD(s), wherein the second upstream channel is based on the second selected UCD.

41. A computer readable medium as recited in claim 40, wherein selecting the first and second UCD'"'"'s is based on a random algorithm.

42. A computer readable medium as recited in claim 40, further comprising verifying whether the second upstream channel is still valid.

43. A computer readable medium as recited in claim 39, wherein transmitting over the first upstream channel is alternated with transmitting data over the second upstream channel.

44. A computer readable medium as recited in claim 39, wherein a first type of data are transmitted over the first upstream channel, and a second type of data are transmitted over the second upstream channel.

45. A computer readable medium as recited in claim 39, wherein data are transmitted over the first upstream channel when it is less congested than the second upstream channel, and data are transmitted over the second upstream channel when it is less congested than the first upstream channel.

46. A computer readable medium as recited in claim 39, wherein data are primarily transmitted over the first upstream channel, and data are transmitted over the second upstream channel to facilitate load balancing.

37. A computer readable medium containing programming instructions for transmitting upstream data from a cable modem over multiple upstream channels within a cable plant, the computer readable medium comprising;

computer ale code for receiving a downs signal within a downstream channel into the cable modem, wherein the downstream signal specifies an assignment of a first upstream channel and a second upstream channel;

computer readable code for configuring the cable modem to transmit over a first upstream channel if the first upstream channel is represented by information within a downstream channel;

computer readable code for configuring the cable modem to transmit over a second upstream channel if the second upstream channel is represented by information within the downstream channel and if the second upstream channel differs from the first upstream channel and wherein the first upstream channel has a different frequency range than the second upstream channel; and

computer readable code for selectively transmitting different data portions over the first and second channels through two different PHY blocks based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria.

47. A computer readable medium as recited in claim 37, further comprising:

computer code for determining whether the cable modem is authorized to transmit over multiple upstream channels prior to configuring the cable modem to transmit over the second upstream cannel; and

computer code for configuring the cable modem with the second upstream channel only when the cable modem is authorized to transmit over multiple upstream channels.

48. A computer readable medium as recited in claim 47, further comprising:

computer code for transmitting over a single channel if the cable modem is set up only to transmit over the first upstream channel; and

computer code for transmitting over both the first and second upstream channels if the cable modem is set up to transmit over both the first and second upstream channels.

49. A computer readable medium as recited in claim 48, wherein transmitting over both the first and second upstream channels includes alternatively selecting the first and second upstream channels for transmission of one or more packets of data.

50. A computer readable medium as recited in claim 48, wherein transmitting over both the first and second upstream channels includes selecting either the first or second upstream a channels for transmission of a particular type of data.

51. A computer readable medium as recited in claim 48, wherein transmitting over both the first and second upstream channels includes selecting either the first or second upstream channels for transmission of data based on which upstream channel is least congested.

52. A computer readable medium as recited in claim 48, wherein transmitting over both the first and second upstream channels includes selecting the first upstream channel for primary data transmission and selecting the second upstream channel for load balancing.

53. A computer readable medium as recited in claim 37, further comprising computer code for powering up the cable modem, wherein the setting up of the cable modem with the first upstream channel is initiated by the powering up.

54. A computer readable medium as recited in claim 37, wherein the setting up the cable modem with the second upstream channel is initiated when the cable modem has previously been set up for transmitting over only a single upstream channel.

55. A computer readable medium as recited in claim 37, wherein the setting up of the cable modem with the second upstream channel is initiated when the cable modem has previously been set up for transmitting over only a single upstream channel.

56. A computer readable medium as recited in claim 37, further comprising

computer code for, prior to setting up the cable modem to transmit over the second upstream channel, requesting initial ranging using the first upstream channel;

computer code for adjusting the transmission power level of the cable modem when the head end fails to respond to the initial ranging request using the first upstream cannel if a transmission power level of the cable modem is not greater than a maximum transmission power level; and

computer code for setting up the cable modem with a next first upstream channel if the transmission power level is greater than the maximum transmission power level; and

computer code for performing periodic ranging between the head end and the cable modem using the first upstream channel when the head end responds to the initial ranging requesting the first upstream channel.

57. A computer readable medium as recited in claim 56, wherein the transmission power level is adjusted in increments from a minimum value to a maximum power level.

58. A computer readable medium as recited in claim 56, wherein a value of the first upstream channel is altered by the periodic ranging and the cable modem is set up to transmit over the second upstream channel that differs from the altered first upstream channel value.

59. A computer readable medium as recited in claim 56, further comprising:

computer code for requesting initial ranging using the second upstream channel after setting up the cable modem to transmit over the second upstream channel;

computer code for adjusting the transmission power level of the cable modern when the head end fails to respond to the initial ranging requesting the second upstream channel if a transmission power level of the cable modem is not greater than the maximum transmission power level;

computer code for setting up the cable modem with a next second upstream channel if available if the transmission power level is greater than the maximum transmission power level; and

computer code for performing periodic ranging between the head end and the cable modem using the second upstream channel when the head end responds to the initial ranging request using the second upstream channel.

60. A computer readable medium as recited in claim 59, wherein a value of the first upstream channel is altered by the periodic ranging and the cable modem is set up to transit over the second upstream channel that differs from the altered first upstream channel value.

61. An apparatus for transmitting upstream data from a cable modem within a cable plant, the apparatus comprising:

means for selecting a first upstream channel for transmission of a first portion of the upstream data and selecting a second upstream channel for transmission of a second portion of the upstream data, wherein the selection of the first and second upstream channels is based on a criteria selected from a group consisting of a load balancing criteria and a data type criteria;

means for transmitting the first portion of the upstream data on the first upstream channel from a first PHY block of the cable modem; and

means for transmitting the second portion of the upstream data on the second upstream channel from a second PHY block of the cable modem, the second upstream channel differing from the first upstream channel in their respective frequency ranges, wherein the first PHY block differs from the second PHY block.

62. An apparatus for receiving upstream data from a cable modem, comprising:

means for receiving an upstream signal from the cable modem, the upstream signal including a first portion of the upstream data on a first upstream channel and a second portion of the upstream data on a second upstream channel that differs from the first upstream channel and wherein the first upstream channel has a different frequency range than the second upstream channel, wherein the first portion of the upstream data transmitted over the first upstream channel is separated from the second portion of the upstream data transmitted over the second upstream channel for further processing of the separated data; and

means for assigning the first upstream channel and the second upstream channel to the cable modem, where the first and second upstream channels have been selected for transmission of their respective data from different PHY blocks based on load balancing or data type criteria.