DSL pre-synchronization auto baud

• US 6,546,046 B1
• Filed: 07/31/2000
• Issued: 04/08/2003
• Est. Priority Date: 11/17/1999
• Status: Expired due to Term

• Current Assignee: MACOM Technology Solutions Holdings, Inc.
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Rushing, Mickey C., Sweitzer, Ralph F., Rasmussen, Dean E.
• Primary Examiner(s): CORRIELUS, JEAN B
• Application Number:
  US09/629,565
• Time in Patent Office: 981 Days
• Field of Search: 375/222, 375/219, 375/224, 375/259, 375/225, 370/468, 341/61
• US Class Current: 375/225
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 5/1446 of transmission speed

Abstract

A DSL communication system including a DSL transmission unit at a central office (DTU-C) and a DSL transmission unit at a remote location (DTU-R) in communication over a communication link. DTU-C and DTU-R are capable of transmitting and receiving packets of data prior to synchronization or training. DTU-C transmits a discovery message to DTU-R and awaits receiving a discovery response message from DTU-R. After receiving the discovery response message, DTU-C transmits a probe message to DTU-R followed by a probe signal. DTU-R measures the line quality while receiving the probe signal. After receiving the probe signal, DTU-R transmits a probe signal to DTU-C, using which signal DTU-C measures the line quality. After transmitting the probe signal, DTU-R transmits a probe response message, including line quality measurements performed by DTU-R. DTU-C and DTU-R may negotiate a startup data rate by transmitting data rate messages based on the line quality measurements and/or based on other information that may be exchanged between DTU-C and DTU-R.

Claims

1. A pre-synchronization method of determining a data rate in a communication system including a first DSL device and a second DSL device, for use to synchronize said DSL devices at said data rate, said method comprising the steps of:

transmitting a discovery message by said first DSL device to said second DSL device;

receiving a discovery response message from said second DSL device in response to said transmitting said discovery message;

transmitting a probe message to said second DSL device in response to said receiving said discovery response message;

transmitting a first probe signal to said second DSL device following said transmitting said probe message;

receiving a second probe signal from said second DSL device in response to said transmitting said first probe signal;

receiving a probe response message from said second DSL device in response to said transmitting said first probe signal; and

negotiating said data rate based on said probe response message;

wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time.

2. The method of claim 1, wherein said negotiating step includes the steps of:

transmitting a first rate message to said second DSL device after said receiving said probe response message; and

receiving a second rate message in response to said transmitting said first rate message, said second rate message including said data rate.

3. The method of claim 1, wherein said negotiating step includes the steps of:

transmitting a first rate message to said second DSL device after said receiving said probe response message;

receiving a second rate message in response to said transmitting said first rate message;

determining said data rate based on said second rate message; and

transmitting a third rate message in response to receiving said second rate message, said third rate message including said data rate.

4. The method of claim 1, wherein said second DSL device performs a measurement of a line quality based on said first probe signal.

5. The method of claim 4, wherein said measurement of said line quality includes measuring an attenuation.

6. The method of claim 4, wherein said measurement of said line quality includes measuring a noise margin.

7. The method of claim 1 further comprising the step of measuring a line quality during the step of receiving said second probe signal.

8. The method of claim 7, wherein said step of measuring said line quality includes measuring an attenuation.

9. The method of claim 7, wherein said step of measuring said line quality includes measuring a noise margin.

10. The method of claim 1, wherein said first probe signal includes a third probe signal at a first data rate followed a fourth probe signal at a second data rate.

11. The method of claim 10, wherein said second DSL device performs a first line quality measurement based on said third probe signal and a second line quality measurement based on said fourth probe signal.

12. The method of claim 11, wherein said probe message response includes said measurements.

13. The method of claim 1, wherein said step of receiving said probe message response occurs after said step of receiving said second probe signal.

14. The method of claim 1, wherein said discovery message includes a device type of said first DSL device.

15. The method of claim 1, wherein said discovery message includes a payload type.

16. The method of claim 1, wherein said energy on-time for a first predetermined period of time indicates a “

1”

data bit and said energy off-time for a second predetermined period of time indicates a “

0”

data bit.

17. The method of claim 16, wherein said energy on-time includes scrambled two level ones.

18. The method of claim 1, wherein said energy on-time for approximately 50 ms indicates a “

1”

data bit and said energy off-time for approximately 50 ms indicates a “

0”

data bit.

19. A pre-synchronization method of determining a data rate by in a communication system including a first DSL device and a second DSL device, for use to synchronize said DSL devices at said data rate, said method comprising the steps of:

transmitting a probe message to said second DSL device;

transmitting a first probe signal to said second DSL device following said transmitting said probe message, wherein said first probe signal is at a first data rate;

transmitting a second probe signal after said transmitting said first probe signal, wherein said second probe signal is at a second data rate;

receiving a probe response message from said second DSL device in response to said transmitting said first probe signal and said transmitting said second probe signal; and

determining said data rate based on said probe response message;

wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time.

20. A communication system comprising:

a first device;

a second device; and

a communication line;

wherein, prior to synchronization between said first device and said second device, said first device transmits a discovery message to said second device over said communication line and said second device transmits a discovery response message to said first device over said communication line in response to said discovery message, said first device transmits a probe message followed by a first probe signal to said second device in response to receiving said discovery message, wherein said first device receives a probe response message from said second device in response to said first probe signal and said first device determines a data rate based on said probe response message for synchronizing said first device with said second device.

21. The communication system of claim 20, wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time.

22. The communication system of claim 21, wherein said energy on-time includes scrambled two level ones.

23. The communication system of claim 22, wherein said second device transmits a second probe signal to said first device prior to transmitting said probe response message to said first device over said communication line.

24. The communication system of claim 23 wherein said second device measures a first line quality during transmission of said first probe signal.

25. The communication system of claim 24, wherein said first device measures a second line quality during transmission of said second probe signal.

26. The communication system of claim 25, wherein said first device and said second device negotiate said data rate based on said first line quality.

27. The communication system of claim 25, wherein said first device and said second device negotiate said data rate based on said second line quality.

28. The communication system of claim 25, wherein said first device determines said data rates by transmitting a first rate message based on said probe response message and receiving a first rate response message based on said first rate message from said second device.

29. The communication system of claim 28, wherein said first device transmits a second rate message based on said first rate response message.

30. A communication device comprising:

a transmitter; and

a receiver;

wherein, prior to synchronization with a remote device, said transmitter transmits a first discovery message over a communication line and said receiver receives a second discovery message in response to said first discovery message, said transmitter transmits a probe message followed by a first probe signal over said communication line in response to receiving said second discovery message, wherein said receiver receives a probe response message in response to said first probe signal and a data rate is determined based on said probe response message for synchronizing over said communication line.

31. The communication device of claim 30, wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time.

32. The communication device of claim 31, wherein said receiver further receives a second probe signal prior to receiving said probe response message.

33. The communication device of claim 32 further comprising a line quality module, wherein said line quality module measures a line quality based on said probe signal.

34. The communication device of claim 33, wherein said transmitter further transmits a rate message including said data rate based on said line quality.

35. The communication device of claim 34 further comprising a training module for synchronizing at said data rate.

36. A pre-synchronization method of determining a data rate in a communication system including a first DSL device and a second DSL device, for use to synchronize said DSL devices at said data rate, said method comprising the steps of:

receiving a discovery message by said first DSL device from said second DSL device;

transmitting a discovery response message to said second DSL device in response to said receiving said discovery message;

receiving a probe message from said second DSL device in response to said transmitting said discovery response message;

receiving a first probe signal from said second DSL device following said receiving said probe message;

transmitting a second probe signal to said second DSL device in response to said receiving said first probe signal;

transmitting a probe message response to said second DSL device in response to said receiving said first probe signal; and

negotiating said data rate based on said probe response message;

wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time.

37. The method of claim 36, wherein said negotiating step includes the steps of:

receiving a first rate message from said second DSL device after said transmitting said probe response message; and

transmitting a second rate message to said second DSL device, said second rate message including said data rate.

38. The method of claim 36, wherein said negotiating step includes the steps of:

receiving a first rate message from said second DSL device after said transmitting said probe response message;

transmitting a second rate message to said second DSL device;

receiving a third rate message from said second DSL device, said third rate message including said data rate.

39. The method of claim 36 further comprising the step of measuring a line quality during the step of receiving said first probe signal, wherein said line quality is used to determine said data rate.

40. The method of claim 36, wherein said step of transmitting said probe message response occurs after said step of transmitting said second probe signal.

41. The method of claim 36, wherein said discovery message includes a device type of said second DSL device.

42. The method of claim 36, wherein said discovery message includes a payload type.

43. A method of communication with a remote device, said method comprising the steps of:

transmitting a discovery message to said remote device;

receiving a discovery response message from said remote device in response to said transmitting said discovery message; and

configuring said remote device, in response to said receiving said discovery response message, by transmitting one or more command messages;

wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time, and wherein said energy on-time includes scrambled two level ones.

44. The method of claim 43, wherein said energy on-time for approximately 50 ms indicates a “

1”

data bit and said energy off-time for approximately 50 ms indicates a “

0”

data bit.

45. The method of claim 43, wherein said one or more command messages set a default data rate for said remote device.

46. The method of claim 43, wherein said configuring step includes transmitting layer 2 information.

47. A pre-synchronization method for use between a central DSL device and a remote DSL device over a telephone communication line, said communication method comprising the steps of:

transmitting a discovery message by said central DSL device to said remote DSL device;

receiving a discovery response message from said remote DSL device by said central DSL device in response to said discovery message;

transmitting a probe message by said central DSL device to said remote DSL device in response to said discovery response message;

transmitting a first probe signal by said central DSL device to said remote DSL device in response to said discovery response message;

receiving a second probe signal from said remote DSL device by said central DSL device in response to said first probe signal;

receiving a probe response message from said remote DSL device by said central DSL device in response to said first probe signal; and

negotiating said data rate with said remote DSL device based on said probe response message;

wherein each said message includes an opcode segment, a data field segment and a checksum segment, and wherein each said segment includes a plurality of data bits represented by an energy on-time or off-time.

48. The method of claim 47, wherein said discovery message includes a device type of said central DSL device.

49. The method of claim 47, wherein said discovery message includes a payload type.

50. The method of claim 47 further comprising the step of transmitting a third probe signal by said central DSL device to said remote DSL device after said step of transmitting said first probe signal, wherein said first probe signal is at a first data rate and said third probe signal is at a second data rate.