SYSTEMS AND METHODS FOR FACSIMILE ECHO CANCELLATION

• US 20110013544A1
• Filed: 09/24/2010
• Published: 01/20/2011
• Est. Priority Date: 05/09/2005
• Status: Active Grant

• Current Assignee: j2 Cloud Services, LLC (Consensus Cloud Solutions, Inc.)
• Original Assignee: J2 Global, Inc.
• Inventors: Smith, Robert, Erringer, Alan
• Granted Patent: US 8,325,635 B2
• Time in Patent Office: Days
• US Class Current: 370/286
• CPC Class Codes: H04M 11/066 Telephone sets adapted for data transmision
• CPC Class Codes: H04M 2201/52 Telephonic communication in combination with fax communication
• CPC Class Codes: H04M 3/002 Applications of echo suppressors or cancellers in telephonic connections in two-way loud-speaking telephone systems H04M9/08, echo suppressors or cancellers per se H04B3/20

Abstract

The present invention is related to methods and systems for reducing or canceling echoes during fax communications. In an embodiment, during a fax call, a first fax signal from a first fax device intended for a second fax device is detected. Based at least in part on detecting the first fax signal from the first fax device or on the termination of the first fax signal, an echo audio packet is muted, wherein the echo audio packet is at least partly the result of the first fax signal being transmitted over a network, the network including at least a data network.

Claims

1-43. -43. (canceled)

44. A non-transitory machine-readable storage medium containing stored instructions that program a machine to monitor a network for a fax signal that is transmitted from a first fax device and is directed to a second fax device, wherein the network includes a data packet network and a circuit switched telephone network, to detect the fax signal from the first fax device, and to mute an audio packet in the network, that is directed to the first fax device, based in part on detecting the fax signal from the first fax device.

45. The non-transitory machine-readable storage medium of claim 44, wherein the data packet network is the Internet.

46. The non-transitory machine-readable storage medium of claim 44, wherein the fax signal is a confirmation to receive signal, which indicates that the first fax device is ready to receive a fax page from the second fax device using an incoming call to the first fax device.

47. The non-transitory machine-readable storage medium of claim 44, wherein the instructions are such that the muting comprises intercepting the audio packet and substituting the audio packet with an audio packet containing silent audio.

48. The non-transitory machine-readable storage medium of claim 44, wherein the audio packet is muted only in response to waiting a predetermined time interval following detection of the fax signal.

49. The non-transitory machine-readable storage medium of claim 48, wherein the predetermined time interval is at least 80 ms after termination of the fax signal.

50. The non-transitory machine-readable storage medium of claim 44, wherein the audio packet is muted only during a window period beginning at least 80 ms after termination of the fax signal, and ending 120 ms after termination of the fax signal.

51. The non-transitory machine-readable storage medium of claim 44, containing additional instructions that program the machine to measure network latency.

52. The non-transitory machine-readable storage medium of claim 51, wherein the audio packet is muted during a window period selected based at least in part on a plurality of network latency measurements.

53. The non-transitory machine-readable storage medium of claim 51, wherein the audio packet is muted during a window period selected based at least in part on network latency for at least a portion of the network between the first fax device and the second fax device.

54. A non-transitory machine-readable storage medium containing stored instructions that program a machine to monitor a network for a fax signal that is transmitted from a first fax device and is directed to a second fax device, wherein the network includes a data packet network and a circuit switched telephone network, to detect the termination of the fax signal from the first fax device, and to mute an audio packet in the network, that is directed to the first fax device, based in part on detecting the termination of the fax signal from the first fax device.

55. The non-transitory machine-readable storage medium of claim 54, wherein the data network is the Internet.

56. The non-transitory machine-readable storage medium of claim 54, wherein the fax signal is a confirmation to receive signal, which indicates that the first fax device is ready to receive a fax page from the second fax device using an incoming call to the first fax device.

57. The non-transitory machine-readable storage medium of claim 54, wherein the audio packet is muted only in response to waiting a predetermined time interval following detection of the termination of the fax signal.

58. The non-transitory machine-readable storage medium of claim 57, wherein the predetermined time interval is at least 80 ms after termination of the fax signal.

59. The non-transitory machine-readable storage medium of claim 54, wherein the audio packet is muted only during a window period beginning at least 80 ms after termination of the fax signal, and ending 120 ms after termination of the fax signal.

60. The non-transitory machine-readable storage medium of claim 54, containing additional instructions that program the machine to measure network latency.

61. The non-transitory machine-readable storage medium of claim 60, wherein the audio packet is muted during a window period selected based at least in part on a plurality of network latency measurements.

62. The non-transitory machine-readable storage medium of claim 60, wherein the audio packet is muted during a window period selected based at least in part on network latency for at least a portion of the network between the first fax device and the second fax device.

63. A non-transitory machine-readable storage medium containing stored instructions that program a machine to monitor a network for a fax signal that is transmitted from a first fax device and is directed to a second fax device, wherein the network includes a data packet network and a circuit switched telephone network, to detect the fax signal from the first fax device, and to prevent an audio packet in the network, that is directed to the first fax device, from reaching the first fax device only in response to waiting a predetermined time interval following detection of the fax signal.

64. The non-transitory machine-readable storage medium of claim 63, wherein the data packet network is the Internet.

65. The non-transitory machine-readable storage medium of claim 63, wherein the fax signal is a confirmation to receive signal, which indicates that the first fax device is ready to receive a fax page from the second fax device using an incoming call to the first fax device.

66. The non-transitory machine-readable storage medium of claim 63, wherein the predetermined time interval is at least 80 ms after termination of the fax signal.

67. The non-transitory machine-readable storage medium of claim 63, wherein the audio packet is prevented from reaching the first fax device during a time window beginning at least 80 ms after termination of the fax signal, and ending 120 ms after termination of the fax signal.