Program for controlling DMT based modem using sub-channel selection to achieve scaleable data rate based on available signal processing resources

• US 6,073,179 A
• Filed: 06/30/1997
• Issued: 06/06/2000
• Est. Priority Date: 06/30/1997
• Status: Expired due to Term

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Integrated Telecom Express, Inc.
• Inventors: Gross, John Nicholas, Chen, Steve, Liu, Ming-Kang, Liu, Young Way
• Primary Examiner(s): Asta, Frank J.
• Assistant Examiner(s): VU, THONG H
• Application Number:
  US08/884,959
• Time in Patent Office: 1,072 Days
• Field of Search: 370/281, 370/32, 370/522, 395/800, 379/97, 379/28, 379/399, 386/95, 709/225, 709/231, 709/232, 709/233, 709/234, 709/229, 375/233, 375/377
• US Class Current: 709/229
• CPC Class Codes: G06F 15/163 Interprocessor communication
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04L 5/1446 of transmission speed
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

An applications program is provided for permitting a user of a host processing system to dynamically control a modem having forward compatible and expandable functionality. In a preferred embodiment, the applications program is designed to run on a personal computer running the Windows® shell, and the modem is compatible with ADSL promulgated standards. As part of such program, initialization and detection routines determine the capabilities of an ADSL modem, including whether the same has been upgraded to have enhanced data throughput. A calibration routine measures the computing power available to the host processor, and based on this information and other relevant parameters determines nominal setup parameters for the modem. These parameters are stored in a Device Parameter Table so that they can be accessed by various application programs that may make use of such modem. A user of such program can at that time or thereafter alter the characteristics of the ADSL modem (including a target data rate) subject to availability of sufficiently powerful analog front end sampling circuitry and processing power.

Claims

1. An applications program which includes program routines executable by a host processing device for permitting a user to control a high speed communications device that can be coupled to a remote transceiver capable of transmitting at a data rate Z, said applications program comprising:

a detection routine for detecting the communications device and a host processor within said host processing device;

a calibration routine for determining recommended performance characteristics of such communications device, including a maximum data rate X achievable by such device and for storing information relating to such communications device performance characteristics including such data rate X, and for determining recommended performance characteristics of such host processor, including a proposed maximum data rate Y achievable by such processor under conditions in which such host processing device is loaded with an operating system and other user application programs and for storing information relating to such processor performance characteristics including such data rate Y; and

wherein the information pertaining to data rates X and Y can be used to cause said remote transceiver to use a data rate no greater than the lesser of X and Y when such transceiver is coupled through a data link in a channel to said communications device.

2. The program of claim 1, wherein the detection routine can further detect whether the communications device or the host processor has been modified.

3. The program of claim 1, wherein if either the communications device or the host processor has been modified, the calibration routine re-determines the recommended performance characteristics of such device or processor respectively.

4. The program of claim 3, wherein the calibration routine measures computing power available in said host processing device for executing the signal processing routine.

5. The program of claim 4, further including a user acceptance routine for presenting the recommended performance characteristics including the maximum data rate Y for review by a user of such program, and wherein after reviewing such characteristics, the user can accept or reject such recommended performance characteristics.

6. The program of claim 5, further including a user configuration routine for permitting a user of the host processing device to configure performance characteristics of the processor, including a new proposed maximum data rate Y'"'"'.

7. The program of claim 6, further including a verification routine for confirming the feasibility of such proposed maximum data rate Y'"'"'.

8. The program of claim 7, wherein if the new proposed maximum data rate Y'"'"' is not feasible, the verification routine generates a set of recommended performance characteristics, including another new proposed maximum data rate Y" for review by such user.

9. The program of claim 1 wherein the recommended performance characteristics are stored in a table that can be accessed by other programs that can be run on said host processing device.

10. The program of claim 1, wherein the data link as an ADSL compatible link, and the high speed communications system is an ADSL software modem.

11. An applications program configured to run on a host processing device for controlling a high speed ADSL modem, which ADSL modem can communicate through a channel with a remote transceiver capable of communicating at a data rate Z by intentionally limiting a downstream data transmission to use only a selected set of N sub-channels from a set of M available sub-channels, the program including:

a calibration routine for determining recommended performance characteristics of said modem, including a proposed maximum data rate Y to be used by said modem, where Y<

=Z/2, and which data rate is based in part on data carrying capacities of the selected N sub-channels, in part on channel transmission conditions and in part on the computing power available in said host processing device;

a configuration routine for configuring said ADSL modem to use said data rate Y, and data transmission protocols compatible with T1.413 requirements for downstream and upstream data transmissions;

wherein said ADSL modem operates as a fully compatible T1.413 ADSL transceiver using an intentionally reduced data rate.

12. The program of claim 11, wherein the calibration routine determines a proposed maximum achievable data rate X by said host processing device, and also determines a nominal maximum achievable data rate Y achievable by said modem, and the lesser of X and Y is thereafter used for data transmissions with the upstream transceiver.

13. The program of claim 11, wherein the recommended performance characteristics of said modem are modifiable by a user of said host processing device.

14. An applications program configured to run on a host processing device for controlling a high speed ADSL modem, which ADSL modem can communicate through a channel with a remote transciever by intentionally limiting a downstream data transmission to use only a selected set of N sub-channels from an available set of M sub-channels, the program including:

a calibration routine, which routine selects which k of the set of N sub-channels can be used for data transmission, based on channel transmission conditions, performance characteristics of said sub-channels and the processing power available in said host processing device for extracting data from said selected set of N sub-channels;

a configuration routine for configuring said ADSL modem to use said k sub-channels, and data transmission protocols compatible with T1.413 requirements for downstream and upstream data transmissions;

wherein said ADSL modem operates as a fully compatible T1.413 ADSL transceiver using an intentionally reduced data rate.

15. The program of claim 14, wherein the calibration routine can determine a maximum number of sub-channels N'"'"' that can be processed by said processing device so that if N'"'"'<

N, k is set to be equal N'"'"', and only '"'"' sub-channels are transmitted by the upstream transceiver, and otherwise k is set to be equal to N, and N sub-channels are transmitted by the upstream transceiver.

16. The program of claim 14 further including a modem device parameter storage table for storing information relating to results of the calibration routine, and wherein table can be accessed by other programs that can be run on said host processing device.

17. The program of claim 14, wherein a maximum data rate Y can be achieved by said modem using said N sub-channels, and further including a user configuration routine for permitting a user of the host processing device to designate a data rate Y'"'"', where Y'"'"' can range from 0 to Y, and where Y'"'"' is related to the number of sub-channels k for which data extracting is to be performed, such that Y'"'"' is approximately equal to Y when k=N.

18. The program of claim 17, further including a verification routine for confirming the feasibility of the data rate setting Y'"'"' designated by the user.

19. The program of claim 18, wherein if the new proposed maximum data rate Y'"'"' is not feasible, the verification routine generates a set of recommended performance characteristics, including another new proposed maximum data rate Y" for review by such user.

20. The program of claim 14, wherein a maximum data rate Y can be achieved by said modem using said N sub-channels, and further including a user configuration routine for permitting a user of the host processing device to review the performance characteristics of such N sub-channels, and to designate which k sub-channels, k<

=N, are to be used for data extraction, so that a new data rate Y'"'"', where Y'"'"'<

=Y, is achieved.

21. The program of claim 20, further including a verification routine for confirming the feasibility of the sub-channel selection designated by the user.

22. The program of claim 21, wherein if the new proposed sub-channel selection is not feasible, the verification routine generates a set of recommended sub-channels for review by such user.

23. The program of claim 14, wherein the ratio of N to M is 0.5 or less.

24. The program of claim 14, further including a detection routine for determining whether said ADSL modem has been upgraded to include additional signal processing capability to handle an additional set of sub-channels P, where N+P<

M.

25. The program of claim 24, wherein the detection routine also determines whether said host processing device has been upgraded so that additional signal processing capability is available for handling more of the N+P sub-channels.

26. The program of claim 25, wherein if the communications device or the host processor has been modified, the calibration routine re-determines which k of the set of N+P sub-channels are to be used for extracting data.

27. The program of claim 14, wherein an upstream data transmission can be configured by the user to use a second set of sub-channels L, and where L<

M.

28. The system of claim 14, wherein the upstream transceiver uses discrete multi-tone (DMT) modulation for generating the M modulated sub-channels, and the channel supports asymmetric digital subscriber loop (ADSL) transmission protocols.

29. A method of configuring a data receive rate for a host processing device coupled to an ADSL modem, for communicating through a channel with a remote transciever by intentionally limiting a downstream data transmission to use only a selected set of N sub-channels from a set of M available sub-channels, the method including the steps of:

(a) determining a potential maximum data rate Y achievable by said modem based on channel transmission conditions and performance characteristics of said N sub-channels;

(b) determining a potential maximum data rate X achievable by the host processing device, which data rate is based on the computing power available in said host processing device for extracting data from said N-sub-channels under conditions in which such host processing device is loaded with an operating system and other user application programs;

(c) configuring said data receive data at the lower of rates X and Y.

30. The method of claim 29, wherein during step (b), a determination is made of the number of sub-channels k from the selected set of N sub-channels which can be processed by said host processing device.

31. The method of claim 30, further including a step (d):

designating a new data receive rate Y'"'"', where Y'"'"' can range from 0 to Y, and where Y'"'"' is related to the number of sub-channels k for which data extracting is to be performed, such that Y'"'"' is approximately equal to Y when k=N.

32. The method of claim 31, further including a step (e):

confirming the feasibility of the new designated data rate setting Y'"'"'.

33. The method of claim 32, further including a step (f):

generating a recommended data rate setting Y" if the new designated data rate setting Y'"'"' is not feasible.

34. The method of claim 29, further including a step (a)'"'"' prior to step (a):

determining whether said ADSL modem has been upgraded to include additional signal processing capability to handle an additional set of sub-channels P, where N+P<

M.

35. The method of claim 34, further including a step (b)'"'"' prior to step (b):

whether said host processing device has been upgraded so that additional signal processing capability is available for handling more of the N+P sub-channels.

36. The method of claim 35, wherein if the communications device or the host processor has been upgraded, a new determination is made to determine which k of the set of N+P sub-channels are to be used for extracting data.

37. An applications program which includes routines executable by a host processing device for permitting a user to control a high speed communications device that can be coupled to a remote transceiver capable of transmitting a data signal at frame rate T, at a data rate Y, said applications program comprising:

a detection routine for determining properties of said communications device and a host processor within said host processing device; and

a calibration routine for determining a data rate X achievable by said communications device, said data rate being based on said frame rate T, and an evaluation of signal processing capabilities of the host processor when a specified portion of such host processor'"'"'s computing resources are made available for processing the data signal, said specified portion being configurable by the user; and

wherein the program can be used to cause said upstream transceiver to use a data rate no greater than X when said transceiver is coupled through a data link in a channel to said communications device.

38. The program of claim 37, wherein the detection routine can further detect whether the communications device or the host processor has been modified.

39. The program of claim 37, wherein the calibration routine measures computing power available in said host processing device for executing a signal processing routine.

40. The program of claim 37, further including a user acceptance routine for presenting data rate X for review by a user of such program, and wherein after reviewing such characteristics, the user can accept or reject such data rate.

41. The program of claim 40, further including a user configuration routine for permitting a user of the host processing device to configure performance characteristics of the processor, including a new proposed maximum data rate X'"'"'.

42. The program of claim 41, further including a verification routine for confirming the feasibility of such proposed maximum data rate X'"'"'.

43. The program of claim 42, wherein if the new proposed maximum data rate X'"'"' is not feasible, the verification routine generates a set of recommended performance characteristics, including another new proposed maximum data rate X" for review by such user.

44. The program of claim 37, wherein the data link as an ADSL compatible link, and the high speed communications system is an ADSL software modem.

45. A method for permitting a user to control a high speed communications device that can be coupled to a remote transceiver capable of transmitting a data signal at a frame rate T and a data rate Y, said method comprising the steps of:

determining properties of said communications device and an associated signal processor; and

determining a data rate X achievable by said communications device based on channel transmission conditions, said frame rate T, and an evaluation of signal processing capabilities of the associated signal processor under conditions in which a varying portion of such signal processor'"'"'s computing resources are available for processing the data signal;

wherein said remote transceiver can be constrained to use a data rate no greater than X when such transceiver is coupled through a data link in a channel to said communications device.

46. The method of claim 45, further including a step of detecting whether the communications device or the signal processor has been modified.

47. The method of claim 45, further including a step of presenting data rate X for review by said user, and wherein after reviewing such characteristics, the user can accept or reject such data rate.

48. The method of claim 47, further including a step of permitting a to configure performance characteristics of the communications device, including a new proposed maximum data rate X'"'"'.

49. The method of claim 48, further including a step of confirming the feasibility of such proposed maximum data rate X'"'"'.

50. The method of claim 49, wherein if the new proposed maximum data rate X'"'"' is not feasible, the verification routine generates a set of recommended performance characteristics, including another new proposed maximum data rate X" for review by such user.

51. The method of claim 45, wherein the data link as an ADSL compatible link, and the communications device is an ADSL software modem.

52. An applications program for controlling a high speed ADSL modem, which ADSL modem can communicate through a channel with a remote transceiver using a variable number N of DMT modulated sub-channels, where N<

=M/2 and M is a maximum number of sub-channels supportable in such channel, the program including;

a configuration routine which is adapted for;

(i) permitting a user of such program to identify a target data rate R to be used by the ADSL modem, where R'"'"'/10<

=R<

=R'"'"', where R'"'"' represents a data rate that would otherwise be achievable by a full rate T1.413 ADSL compatible transceiver using the channel to communicate with the remote transceiver;

(ii) permitting a user of such program to select which of the M sub-channels should be included in the variable number N of DMT modulated sub-channels to achieve said target data rate R; and

(iii) constraining the remote transceiver to use only said variable number N of DMT modulated sub-channels and said target data rate R during a data transmission, even if such channel can support a higher data rate and/or all of the M sub-channels during said transmission.

53. The program of claim 52, wherein a configurable amount of computer resources can be made available to the ADSL modem for achieving said target data rate.

54. The program of claim 53, further wherein said target data rate is determined by evaluating a number of DMT frames processed in a given period of time by said configurable amount of computing resources.

55. The program of claim 52, further wherein a host processor executing the program is also used for executing a signal processing routine for demodulating said N subchannels.

58. The program of claim 53, further wherein said calibration routine evaluates a number of DMT frames processed in a given period of time by said computing resources.

56. An applications program for configuring a high speed modem, which modem can communicate through a channel with a remote transceiver using a variable number N of modulated sub-channels, where M is a maximum number of sub-channels supportable in such channel, the program including:

(a) a calibration routine for determining which and how many of the N modulated sub-channels can be supported by the modem, wherein said calibration routine calculates such modem'"'"'s ability to process modulated data within a specified time period; and

(b) a configuration routine for permitting a user of such program to modify such selection of sub-channels by said calibration routine, and/or an amount of computing resources available to such modem for processing modulated data; and

(c) a verification routine for analyzing whether any modifications made by such user are supportable by the modem and/or said computing resources; and

wherein said modem operates using a scaled data rate, said scaled data rate being a function of the number N of modulated sub-channels.

57. The program of claim 56, wherein said amount of computer resources can be made available to the ADSL modem as a fractional percentage of said computer resources.

59. The program of claim 56, further wherein a host processor executing the program is also used for executing a signal processing routine for demodulating said N modulated subchannels.

60. An applications program for configuring a high speed ADSL modem, which ADSL modem can communicate through a channel with a remote transceiver supporting a full data rate achievable by an ANSI T1.413 compatible modem in such channel, the program including:

(a) a calibration routine for determining a modem data rate supported by the ADSL modem, wherein said calibration routine calculates such ADSL modem'"'"'s ability to process DMT modulated data within a specified time period; and

(b) a configuration routine for permitting a user of such program to modify such modem data rate determined by said calibration routine, and/or an amount of computing resources available to such ADSL modem for processing DMT modulated data; and

(c) a verification routine for analyzing whether any modifications made by such user are still supportable by the ADSL modem and/or said computing resources; and

wherein said modem data rate can be configured to vary from a full data rate achievable by the ANSI T1.413 compatible ADSL transceiver connected in such data channel to a fractional portion of such full data rate.

61. The program of claim 60, wherein said amount of computer resources can be made available to the ADSL modem as a fractional percentage of said computer resources.

62. The program of claim 60, further wherein said calibration routine evaluates a number of DMT frames processed in a given period of time by said computing resources.

63. The program of claim 60, further wherein a host processor executing the program is also used for executing a signal processing routine for demodulating said N modulated subchannels.

66. The method of claim 63, further wherein during step (b) a number of DMT frames processed in a given period of time by said computing resources is determined.

67. The method of claim 63, further wherein during step (b) an evaluation is made of a host signal processing routine used for demodulating said N modulated subchannels.

64. A method of controlling a high speed ADSL modem, which ADSL modem can communicate through a channel with a remote transceiver using a variable number N of DMT modulated sub-channels, where N<

=M, and M represents a maximum number of independent modulated sub-channels supportable in such channel using a T1.413 data transmission protocol, the method comprising the steps of;

(a) specifying a target data rate R to be used by the ADSL modem during a data transmission, where R is less than or equal to a data rate that would otherwise be achievable by a full rate T1.413 ADSL compatible transceiver using the channel to communicate with the remote transceiver;

(b) determining a maximum value for the variable number N of DMT modulated sub-channels that can be supported by the ADSL modem by analyzing available computing resources for processing said variable number N of DMT modulated subchannels;

(c) selecting which ones of the M sub-channels should be included in the variable number N of DMT modulated sub-channels to achieve said target data rate R; and

(d) configuring the ADSL modem to use said target data rate R and the variable number N of DMT modulated sub-channels; and

(e) constraining the remote transceiver to use only said variable number N of DMT modulated sub-channels and said target data rate R during a data transmission, even if such channel can support a higher data rate and/or all of the M sub-channels during said transmission.

65. The method of claim 64, wherein said computer resources can be made available as a fractional percentage of total computer resources.

68. A method of controlling a high speed modem, which modem can communicate through a channel with a remote transceiver using a variable number of subchannels N, where N<

=M, and M represents a maximum number of independent modulated sub-channels supportable in such channel, the method comprising the steps of;

(a) determining a maximum modem data rate and a maximum value for the variable number of subchannels N supported by the modem by calculating such modem'"'"'s ability to demodulate data within a specified time period when such modem is allocated a predetermined amount of signal processing resources; and

(b) configuring the modem to utilize said maximum modem data rate and said maximum value for the variable number of subchannels N;

(c) when a different maximum modem data rate is desired, determining whether a different amount of signal processing resources can be allocated to such modem for supporting said different maximum modem data rate.

wherein the modem is operated with a variable maximum modem data rate that is based on signal processing resources that have been allocated to such modem, such that when channel conditions are acceptable and signal processing resources are available, the modem can process up to the maximum number of M of modulated subchannels in the channel.

69. The method of claim 68, wherein said predetermined amount of signal processing resources can be automatically determined by such modem or specified as a portion of total computer resources.

70. The method of claim 68, further wherein during step (a) a number of DMT frames processed in a given period of time by said computing resources is determined.

71. The method of claim 68, further wherein during step (c) an evaluation is made of a host signal processing routine used for demodulating said N modulated subchannels.