Power line communication system

• US 20030184433A1
• Filed: 02/12/2003
• Published: 10/02/2003
• Est. Priority Date: 08/14/2000
• Status: Active Grant

• Current Assignee: Main Net Communications Limited
• Original Assignee: Main Net Communications Limited
• Inventors: Zalitzky, Yeshayahu, Keret, Jacob, Efrati, Ofir
• Granted Patent: US 6,995,657 B2
• Time in Patent Office: Days
• US Class Current: 340/310.06
• CPC Class Codes: H04B 2203/5408 using protocols
• CPC Class Codes: H04B 2203/5437 Wired telephone
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 2203/545 Audio/video application, e.g. interphone
• CPC Class Codes: H04B 2203/5466 using three phases conductors
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04L 12/2801 Broadband local area networks

Abstract

A method for communication over a network of power lines (34), including establishing a communication link within a selected frequency band over the network between a first transceiver (32B) coupled to the network and a second transceiver (32C) coupled to the network. The method further includes transmitting a first signal over the link from the first transceiver to the second transceiver at a transmission power level that is sufficiently strong that the signal can be decoded by the second transceiver, but is attenuated sufficiently when it reaches a third transceiver (32E) coupled to the network so that the third transceiver can receive a second signal over the network in the selected frequency band substantially without interference by the first signal.

Claims

1. A method for communication over a network of power lines, comprising:

establishing a communication link within a selected frequency band over the network of power lines between a first transceiver coupled to the network and a second transceiver coupled to the network; and

transmitting a first signal over the link from the first transceiver to the second transceiver at a transmission power level that is sufficiently strong that the signal can be decoded by the second transceiver, but is attenuated sufficiently when it reaches a third transceiver coupled to the network so that the third transceiver can receive a second signal over the network in the selected frequency band substantially without interference by the first signal.

2. A method according to claim 1, wherein the first transceiver comprises level-setting circuitry, and wherein transmitting the first signal comprises controlling the circuitry so as to set the transmission power level responsive to an attenuation of the first signal on the network.

3. A method according to claim 1, wherein transmitting the first signal comprises transmitting the first signal as at least partly a base-band signal.

4. A method according to claim 1, wherein transmitting the first signal comprises transmitting the first signal as at least partly a modulated signal.

5. A method according to claim 1, wherein transmitting the first signal comprises transmitting the first signal as one or more data frames.

6. A method according to claim 1, wherein transmitting the first signal comprises setting He transmission power level to be below a predetermined level so as to prevent radio-frequency interference from the network.

7. A method according to claim 1, and comprising:

terminating the communication link;

establishing a re-transmission communication link between the second transceiver and the third transceiver; and

transmitting the first signal from the second transceiver to the third transceiver.

8. A method according to claim 7, wherein establishing the re-transmission communication link comprises transmitting a request-to-send signal from the second transceiver to the first and third transceivers, and preventing the first transceiver from receiving the first signal responsive to the first transceiver receiving the request-to-send signal.

9. A method according to claim 7, and comprising coupling further transceivers to the network of power lines, wherein establishing the re-transmission communication link comprises transmitting a request-to-send signal from the second transceiver to the first and third transceivers, and preventing all but the third transceiver from receiving the first signal responsive to the first and third transceivers receiving the request-to-send signal.

10. A method according to claim 1, and comprising:

establishing a third-transceiver-communication link between the first transceiver and the third transceiver; and

transmitting the first signal from the first transceiver to the third transceiver at a third-transceiver-power level greater than the transmission power level to the second transceiver.

11. A method according to claim 1, wherein at least one of the first, second, and third transceivers comprises controlling circuitry which is adapted to control the communication link and transmission and reception of at least one of the first signal and the second signal.

12. A method according to claim 11, wherein the controlling circuitry comprises a central processing unit and a memory having a routing table, and wherein transmitting the first signal comprises transmitting the first signal responsive to one or more parameters comprised in the routing table.

13. A method according to claim 12, wherein the one or more parameters are chosen from a group comprising a destination transceiver, a routing to the destination transceiver, a minimum signal level, a maximum data rate for signal transmission, and an alternative routing to the destination transceiver.

14. A method according to claim 1, wherein the first and second transceivers comprise respective data-conversion circuitries, and wherein transmitting the first signal comprises:

converting data incoming to the first transceiver to the first signal in the first transceiver data-conversion circuitry; and

recovering the incoming data from the first signal in the second transceiver data circuitry.

15. A method according to claim 1, wherein a first distance measured along the power lines from the first to the second transceiver is less than a second distance measured along the power lines from the first to the third transceiver.

16. A method according to claim 15, wherein the first distance comprises a first directed distance and wherein the second distance comprises a second directed distance.

17. A method according to claim 1, wherein transmitting the first signal comprises transmitting the first signal over a given period and receiving the second signal during the given period.

18. A method according to claim 1, wherein at least one of the transceivers is coupled to external circuitry, so as to act as a personal computing system.

19. A method according to claim 1, wherein the network comprises an internal-power-line within a location of a subscriber to the network and an external-power-line external to the location, wherein at least some of the first, second, and third transceivers are coupled to the internal-power-line, and wherein at least some of the first, second, and third transceivers are coupled to the external-power-line.

20. A method according to claim 1, and comprising transmitting the first signal from the second transceiver to a fourth transceiver external to the network via a data communication system operative independent of the network.

21. A method according to claim 20, wherein the fourth transceiver is adapted to operate as a controller of the first, second, and third transceivers, and is comprised in a distributed network.

22. A method according to claim 1, wherein the network comprises power lines terminated by a step-down transformer delivering a mains voltage.

23. A method according to claim 1, wherein establishing the communication link comprises:

waiting a first pre-determined backoff time before sending a first request-to-send (RTS) signal, and

waiting a second pre-determined backoff time, responsive to an acknowledgement to the first RTS signal, before sending a second RTS signal.

24. A method according to claim 1, wherein establishing the communication link comprises:

sending an RTS signal from the first transceiver;

receiving the RTS signal at the second transceiver

acknowledging the RTS signal with a clear-to-send (CTS) signal sent from the second transceiver; and

receiving the CTS signal at the first transceiver.

25. A method according to claim 24, wherein acknowledging the RTS signal comprises:

receiving the CTS signal at the third transceiver; and

beginning a third-transceiver-guard-time responsive to receiving the CTS signal during which time the third transceiver does not transmit.

26. A method according to claim 25, and comprising ending the third-transceiver-guard-time responsive to correct reception of the first signal by the second transceiver.

27. A method according to claim 24, wherein sending the RTS signal comprises incorporating a value of a number of frames comprising the first signal in the RTS signal, and wherein transmitting the first signal comprises transmitting the number of frames.

28. A method according to claim 24, wherein a first directed distance measured along the power lines from the first to the second transceiver is less than a second directed distance measured along the power lines from a the first to the third transceiver, and wherein establishing the communication link comprises:

receiving the RTS signal at a fourth transceiver located at a third directed distance measured along the power lines substantially equal to a negative of the first directed distance; and

beginning a fourth-transceiver-guard-time responsive to receiving the RTS signal during which time the fourth transceiver does not transmit.

29. A method according to claim 28, wherein transmitting tie first signal comprises:

transmitting the first signal as a multicast frame to the second receiver; and

receiving the multicast frame at the fourth transceiver during the fourth-transceiver-guard-time.

30. A method according to claim 1, wherein the network of power lines operates at substantially one voltage.

31. A method according to claim 1, wherein the network of power lines comprises lines operating at a plurality of voltages, and wherein at least one of the first, second, and third transceivers is coupled to a first line operating at a first voltage, and wherein at least one other of the first, second, and third transceivers is coupled to a second line operating at a second voltage, different from the first voltage.

32. Communication apparatus, comprising:

a network of power lines; and

first, second and third transceivers, coupled to the network, the first transceiver being adapted to transmit a first signal over the network to the second transceiver within a selected frequency band at a transmission power level sufficiently strong that the first signal can be decoded by the second transceiver, but is attenuated sufficiently when it reaches the third transceiver so that the third transceiver can receive a second signal over the network in the selected frequency band substantially without interference by the first signal.

33. Apparatus according to claim 32, wherein the first transceiver comprises level-setting circuitry which is adapted to set the transmission power level responsive to an attenuation of the first signal on the network.

34. Apparatus according to claim 32, wherein the first signal comprises at least partly a base-band signal.

35. Apparatus according to claim 32, wherein the first signal comprises at least partly a modulated signal.

36. Apparatus according to claim 32, wherein the first signal comprises one or more data frames.

37. Apparatus according to claim 32, wherein the first transceiver is adapted to set the transmission power level to be below a pre-determined level so as to prevent radio-frequency interference from the network.

38. Apparatus according to claim 32, wherein the second transceiver is adapted to re-transmit the first signal to the third transceiver after receiving the first signal.

39. Apparatus according to claim 32, wherein the first transceiver is adapted to:

establish a third-transceiver-communication link between the first transceiver and the third transceiver; and

transmit the first signal from the first transceiver to the third transceiver at a third-transceiver-power level greater than the transmission power level.

40. Apparatus according to claim 32, wherein at least one of the first, second, and third transceivers comprises controlling circuitry which is adapted to control transmission and reception of at least one of the first signal and the second signal.

41. Apparatus according to claim 40, wherein the controlling circuitry comprises a central processing unit (CPU) and a memory having a routing table, wherein the CPU is adapted to adjust the transmission power level of the first signal responsive to one or more parameters comprised in the routing table.

42. Apparatus according to claim 41, wherein the one or more parameters are chosen from a group comprising a destination transceiver, a routing to the destination transceiver, a minimum signal level, a maximum data rate for signal transmission, and an alternative routing to the destination transceiver.

43. Apparatus according to claim 32, wherein the first transceiver comprises first data-conversion circuitry which is adapted to convert incoming data to the first transceiver to the first signal, and wherein the second transceiver comprises second data-conversion circuitry which is adapted to recover the incoming data from the first signal.

44. Apparatus according to claim 32, wherein a first distance measured along the power lines from the first to the second transceiver is less than a second distance measured along the power lines from the first to the third transceiver.

45. Apparatus according to claim 44, wherein the first distance comprises a first directed distance and wherein the second distance comprises a second directed distance.

46. Apparatus according to claim 32, wherein the first transceiver is adapted to transmit the first signal over a given period and wherein the third transceiver receives the second signal during the given period.

47. Apparatus according to claim 32, wherein at least one of the transceivers is coupled to external circuitry, so as to act as a personal computing system.

48. Apparatus according to claim 32, wherein the network comprises an internal-power-line within a location of a subscriber to the network and an external-power-line external to the location, wherein at least some of the first, second, and third transceivers are coupled to the internal-power-line, and wherein at least some of the first, second, and third transceivers are coupled to the external-power-line.

49. Apparatus according to claim 32, wherein the first transceiver is adapted to transmit the first signal to a fourth transceiver external to the network via a data communication system operative independent of the network.

50. Apparatus according to claim 49, wherein the fourth transceiver is adapted to operate as a controller of the first, second, and third transceivers, and is comprised in a distributed network.

51. Apparatus according to claim 32, wherein the network of power lines comprises power lines fed by a common step-down transformer delivering a mains voltage.

52. Apparatus according to claim 32, wherein the first transceiver is adapted to:

wait a first predetermined backoff time before sending a first request-to-send (RTS) signal, and

wait a second pre-determined backoff time, responsive to an acknowledgement to the first RTS signal, before sending a second RTS signal, so as to establish a communication link between the first transceiver and the second transceiver.

53. Apparatus according to claim 32, wherein the first transceiver is adapted to send an RTS signal and wherein the second transceiver is adapted to receive the RTS signal and acknowledge receipt by transmitting a clear-to-send (CTS) signal and the first transceiver is adapted to receive the CTS signal, so as to establish a communication link between the first transceiver and the second transceiver.

54. Apparatus according to claim 53, wherein the third transceiver is adapted to receive the CTS signal and to begin a third-transceiver-guard-time responsive to receiving the CTS signal during which time the third transceiver does not transmit.

55. Apparatus according to claim 54, wherein the third transceiver is adapted to end the third-transceiver-guard-time responsive to correct reception of the first signal by the second transceiver.

56. Apparatus according to claim 53, wherein sending the RTS signal comprises incorporating a value of a number of frames comprising the first signal in the RTS signal, and wherein transmitting the first signal comprises transmitting the number of frames.

57. Apparatus according to claim 53, wherein a first directed distance measured along the power lines from the first to the second transceiver is less than a second directed distance measured along the power lines from a the first to the third transceiver, and wherein establishing the communication link comprises:

receiving the RTS signal at a fourth transceiver located at a third directed distance measured along the power lines substantially equal to a negative of the first directed distance; and

beginning a fourth-transceiver-guard-time responsive to receiving the RTS signal during which time the fourth transceiver does not transmit.

58. Apparatus according to claim 57, wherein the first transceiver is adapted to transmit the first signal as a multicast frame to the second receiver, and wherein the fourth transceiver is adapted to receive the multicast frame during the fourth-transceiver-guard-time.

59. Apparatus according to claim 32, wherein the network of power lines operates at substantially one voltage.

60. Apparatus according to claim 32, wherein the network of power lines comprises lines operating at a plurality of voltages, and wherein at least one of the first, second, and third transceivers is coupled to a first line operating at a first voltage, and wherein at least one other of the first, second, and third transceivers is coupled to a second line operating at a second voltage, different from the first voltage.

61. A transceiver, for communication over a network of power lines, comprising:

a communication controller, adapted to establish a communication link over the network with a first receiver coupled to the network, and to generate a first signal for transmission over the link to the first receiver in a selected frequency band; and

level-setting circuitry, adapted to control a power level of the first signal so that the first signal is sufficiently strong to be decoded by the first receiver, but is attenuated sufficiently when it reaches a second receiver, also coupled to the network, so that the second receiver can receive a second signal over the network in the selected frequency band substantially without interference by the first signal.

62. A transceiver according to claim 61, wherein the first signal comprises at least partly a base-band signal.

63. A transceiver according to claim 61, wherein the first signal comprises at least partly a modulated signal.

64. A transceiver according to claim 61, wherein the first signal comprises one or more data frames.

65. A transceiver according to claim 61, wherein the level-setting circuitry is adapted to set the power level of the first signal to be below a pre-determined level so as to prevent radio-frequency interference from the network.

66. A transceiver according to claim 61, wherein the first receiver is adapted to transmit the first signal to the second receiver after receiving the first signal.

67. A transceiver according to claim 61, wherein the communication controller is adapted to establish a second-receiver-communication link between the transceiver and the second receiver, and to transmit the first signal from the transceiver to the second receiver at a second-receiver-power level greater than the power level of the first signal.

68. A transceiver according to claim 61, wherein the communication controller comprises a central processing unit and a memory having a routing table, and wherein the level-setting circuitry is adapted to control the power level of the first signal responsive to one or more parameters comprised in the routing table.

69. A transceiver according to claim 68, wherein the one or more parameters are chosen from a group comprising a destination transceiver, a routing to the destination transceiver, a minimum signal level, a maximum data rate for signal transmission, and an alternative routing to the destination transceiver.

70. A transceiver according to claim 61, wherein the communication controller is adapted to convert incoming data to the first signal, and wherein the first receiver comprises data-conversion circuitry which is adapted to recover the incoming data from the first signal.

71. A transceiver according to claim 61, wherein a first distance measured along the power lines from the transceiver to the first receiver is less than a second distance measured along the power lines from the transceiver to the second receiver.

72. A transceiver according to claim 71, wherein the first distance comprises a first directed distance and wherein the second distance comprises a second directed distance.

73. A transceiver according to claim 61, wherein the communication controller is adapted to transmit the first signal over a given period and wherein the second receiver receives the second signal during the given period.

74. A transceiver according to claim 61, and comprising external circuitry causing the transceiver to act as a personal computing system.

75. A transceiver according to claim 61, wherein the network comprises an internal-power-line within a location of a subscriber to the network and an external-power-line external to the location, wherein the transceiver is coupled to the internal-power-line, and wherein at least one of the first and second receivers are coupled to the external-power-line.

76. A transceiver according to claim 61, wherein the communication controller is adapted to transmit the first signal to a third receiver external to the network via a data communication system operative independent of the network.

77. A transceiver according to claim 76, wherein the third receiver is adapted to operate as a controller of the transceiver, and is comprised in a distributed network.

78. A transceiver according to claim 61, wherein the network of power lines comprises power lines fed by a common step-down transformer delivering a mains voltage.

79. A transceiver according to claim 61, wherein the communication controller is adapted to:

wait a first pre-determined backoff time before sending a first request-to-send (RTS) signal, and

wait a second pre-determined backoff time, responsive to an acknowledgement to the first RTS signal, before sending a second RTS signal, in order to establish the communication link.

80. A transceiver according to claim 61, wherein the communication controller is adapted to send an RTS signal and wherein the first receiver is adapted to receive the RTS signal and acknowledge receipt by transmitting a clear-to-send (CTS) signal, and the communication controller is adapted to receive the CTS signal, so as to establish the communication link.

81. A transceiver according to claim 80, wherein the second receiver is adapted to transmit and to receive the CTS signal, and to begin a second-receiver-guard-time responsive to receiving the CTS signal, during which time the second receiver does not transmit.

82. A transceiver according to claim 81, wherein the second receiver is adapted to end the second-receiver-guard-time responsive to correct reception of the first signal by the second receiver.

83. A transceiver according to claim 80, wherein the communication controller is adapted to incorporate a value of a number of frames comprising the first signal in the RTS signal, and wherein transmitting the first signal comprises transmitting the number of frames.

84. A transceiver according to claim 80, wherein a first directed distance measured along the power lines from the transceiver to the first receiver is less than a second directed distance measured along the power lines from a the transceiver to the second receiver, and wherein a third receiver located at a third directed distance measured along the power lines substantially equal to a negative of the first directed distance is adapted to transmit, and to receive the RTS signal and to begin a third-receiver-guard-time responsive to receiving the RTS signal during which time the third receiver does not transmit.

85. A transceiver according to claim 84, wherein the communication controller is adapted to transmit the first signal as a multicast frame to the first receiver, and wherein the third receiver is adapted to receive the multicast frame during the third-receiver-guard-time.

86. A transceiver according to claim 61, wherein the communication controller and level-setting circuitry are adapted to operate as a power distribution and control module.

87. A transceiver according to claim 61, wherein the network of power lines operates at substantially one voltage.

88. A transceiver according to claim 61, wherein the network of power lines comprises lines operating at a plurality of voltages, and wherein the transceiver is coupled to a first line operating at a first voltage, and wherein at least one of the first and second receivers is coupled to a second line operating at a second voltage, different from the first voltage.

89. A method for communication over a network of power lines, comprising:

establishing an initial communication link within a selected frequency band over the network between a first transceiver coupled to the network and a second transceiver coupled to the network;

transmitting a signal over the initial communication link from the first transceiver to the second transceiver at a first power level sufficiently strong that the signal can be decoded by the second transceiver, but is attenuated sufficiently when it reaches a third transceiver coupled to the network so that the third transceiver is unable to decode the signal;

terminating the initial communication link;

establishing a re-transmission communication link between the second transceiver and the third transceiver; and

transmitting the signal from the second transceiver to the third transceiver over the re-transmission communication link at a second power level so that the signal can be decoded by the third transceiver.

90. A method for communication over a network of power lines, comprising:

establishing a communication link within a selected frequency band over the network of power lines between a first transceiver coupled to the network and a second transceiver coupled to the network;

transmitting a first signal over the link from the first transceiver to the second transceiver;

terminating the communication link;

establishing a re-transmission communication link between the second transceiver and a third transceiver coupled to the network; and

transmitting the first signal from the second transceiver to the third transceiver.

91. A method according to claim 90, wherein establishing the re-transmission communication link comprises transmitting a request-to-send signal from the second transceiver to the first and third transceivers, and preventing the first transceiver from receiving the first signal responsive to the first transceiver receiving the request-to-send signal.

92. A method according to claim 90, and comprising coupling further transceivers to the network of power lines, wherein establishing the re-transmission communication link comprises transmitting a request-to-send signal from the second transceiver to the first and third transceivers, and preventing all but the third transceiver from receiving the first signal responsive to the first and third transceivers receiving the request-to-send signal.

93. A method according to claim 90, wherein transmitting the first signal comprises transmitting the signal so that it is not received by the third transceiver.

94. A method according to claim 93, wherein transmitting the signal so that it is not received by the third transceiver comprises transmitting the signal at a power level sufficiently weak so that the signal is not received by the third transceiver.