Transmission system for transmitting data via current conducting branches

• US 7,327,222 B2
• Filed: 11/29/2001
• Issued: 02/05/2008
• Est. Priority Date: 11/29/2001
• Status: Expired due to Fees

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Peltonen, Pentti
• Primary Examiner(s): Pope; Daryl C
• Application Number:
  US10/496,266
• Publication Number:
  US 20040258165A1
• Time in Patent Office: 2,259 Days
• Field of Search: 340/310.11, 340/310.12, 340/310.16, 340/538, 340/533, 340/538.11, 340/538.15
• US Class Current: 340/12.32
• CPC Class Codes: H04B 2203/547 via DC power distribution
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines

Abstract

A system and method for transmitting and receiving data between a power supply and a remotely located load, by use of standard data communication cable has functional data transmitted via the power line of such data communication cable in order to decrease the number of required conductors. This auxiliary data is encoded by altering the current balance between two conductors, conducting a current I from the receiver to the transmitter or vice versa in two branches.

Claims

1. A transmitter for transmitting data to a receiver via a cable, comprising at least two current conducting branches, wherein said cable comprises at least two conductors respectively connectable with said branches for conducting a current either from said receiver to said transmitter or vice versa, said current being divided in said two branches, a first branch for a first one of said conductors and a second branch for a second one of said conductors, and means for encoding data to be transmitted via said cable to said receiver by altering the current balance between the currents in said two branches.

2. A transmitter according to claim 1, wherein said current is a power supply current being fed from a power supply to a load or returned from said load to said power supply and wherein said branches are capable to said power supply and wherein said branches are capable of feeding said current.

3. A transmitter according to claim 2, further comprising a power feed connector means for each branch for respectively connecting each branch with one of said conductors.

4. A transmitter according to claim 1, wherein said encoding means comprise a switchable element for each branch, respectively, each switchable element being connected in series in the respective branch.

5. A transmitter according to claim 4, wherein said encoding means further comprise a resistive element and/or a diode respectively coupled across said switchable elements.

6. A transmitter according to claim 4, wherein said switchable elements are coupled with a controller for controlling said switchable elements, said controller being designed for control-ling said switchable elements so that said switchable elements have in both branches either the same switching state or different switching states in order to generate one of three different current balance states.

7. A transmitter according to claim 6, wherein said three current balance states are:

a neutral current balance (n) state generated by same switching states in both branches in order to generate substantially equal currents in both branches, a negative current balance state generated by closing a first one of both switchable elements and by opening a second one of both switchable elements in order to generate a larger current in the first branch than in the second branch, and a positive current balance state generated by opening the first one of both switchable elements and by closing the second one of both switchable elements in order to generate a smaller current in the first branch than in the second branch.

8. A transmitter according to claim 6, wherein said switchable elements respectively comprise a transistor with its gate coupled to said controller.

9. A transmitter according to claim 8, wherein said transistor is an insulated gate field effect transistor.

10. A transmitter according to claim 9, wherein said insulated gate field effect transistor is a N-channel insulated gate field effect transistor.

11. A transmitter according to claim 9, wherein said insulated gate field effect transistor is a double N-channel insulated gate field effect transistor.

12. A transmission apparatus comprising a transmitter according to claim 1, an electrical unit comprising a load or a power supply, wherein said transmitter being connected in series between said at least two conductors and said electrical unit, and wherein said conductors are at least part of a positive power line feeding a current from said power supply to said load or at least part of a negative power line returning said current from said load to said power supply.

13. A transmission apparatus according to claim 12 further comprising a receiver connected in series between said conductors and said electrical unit, in order to enable half-duplex data transmission between said transmission apparatus and a receiving apparatus.

14. A transmission apparatus according to claim 12 further comprising a receiver connected in series between at least two further conductors and said electrical unit, in order to enable full-duplex data transmission between said transmission apparatus and a receiving apparatus, wherein said further conductors are at least part of said positive power line or at least part of said negative power line.

15. A transmission apparatus according to claim 12, wherein said transmission apparatus being a network interface and power supply unit.

16. A transmission apparatus according to claim 12, wherein said transmission apparatus being a router.

17. A transmission apparatus according to claim 16, wherein said router being a wireless router.

18. A receiver for receiving data from a transmitter via a cable, comprising at least two current conducting branches, wherein said cable comprises at least two conductors respectively connectable with said branches for conducting a current either from said receiver to said transmitter or vice versa, said current being divided in said two branches, a first branch for a first one of said conductors and a second branch for a second one of said conductors, and means for decoding data being transmitted via said cable from said transmitter by evaluating alterations of the current balance between the currents in said two branches.

19. A receiver according to claim 18, wherein said current is a power supply current being fed from a power supply to a load or re-turned from said load to said power supply and wherein said branches are capable to said power supply and wherein said branches are capable of feeding said current.

20. A receiver according to claim 19, further comprising a power feed connector means for each branch for respectively connecting each branch with one of said conductors.

21. A receiver according to claim 18, wherein said decoding means comprise current detection means for each branch, respectively, for detecting the currents in the respective branches.

22. A receiver according to claim 21, wherein said current detection means is a resistor connected in series in the respective branch.

23. A receiver according to claim 21, wherein said current detection means are coupled with comparator means for comparing values indicating the currents detected by said current detection means, said comparator means being designed for detecting one of three different current balance states.

24. A receiver according to claim 23, wherein said three different current balance states are:

a neutral current balance state detected if said values of both currents are substantially equal, a negative currents balance state detected if said value referring to a first one of both branches is larger than the value referring to a second one of both branches, and a positive current balance state detected if said value referring to said first branch is smaller than the value referring to said second branch.

25. A receiver according to claim 23, wherein said current detection means of both branches are coupled in series with each other and wherein said comparator means comprise a first comparator (C1;

N1) coupled across both current detection means, and a second comparator coupled across both current detection means, wherein each of both comparators comprises a first input and a second input, wherein said first inputs and said second inputs are coupled across both current detection means in opposite orientation to each other.

26. A receiver according to claim 25, wherein said first comparator outputs a high level signal if a voltage difference between its first and second inputs is above a first threshold value and outputs a low level signal if said voltage difference is below said first threshold value, and wherein said second comparator outputs a low level signal if a voltage difference between its first and second inputs is above a second threshold value and outputs a high level signal if said voltage difference is below said second threshold value.

27. A receiver according to claim 25, wherein said first comparator comprises an output coupled with a first indicator, and wherein said second comparator comprises an output coupled with a second indicator.

28. A receiver according to claim 27 wherein said first and second indicators integrate the outputs of said respective first and second comparators over two consecutive periods of time.

29. A receiver according to claim 28, wherein said indicators are light emitting diodes.

30. A receiver according to claim 29, wherein said light emitting diodes are driven with at least 50% duty cycle using a frequency which is seen as a constant light.

31. A receiver according to claim 30 wherein said duty cycle is below 100%.

32. A receiver according to claim 30, wherein said frequency is 50 Hz or higher.

33. A receiver according to claim 32, wherein said light emitting diodes are driven in order to generate flickering or flashing light.

34. A receiving apparatus comprising a receiver according to claim 18, an electrical unit comprising a power supply or a load, wherein said receiver being connected in series between said at least two conductors and said electrical unit, and wherein said conductors are at least part of a positive power line feeding a current from said power supply to said load or at least part of a negative power line returning said current from said load to said power supply.

35. A receiving apparatus according to claim 34, further comprising a transmitter connected in series between said conductors and said electrical unit, in order to enable half-duplex data transmission between said receiving apparatus and a further transmission apparatus.

36. A receiving apparatus according to claim 34 further comprising a transmitter connected in series between at least two further conductors and said electrical unit, in order to enable full-duplex data transmission between said receiving apparatus and a transmission apparatus, wherein said further conductors are at least part of said positive power line or at least part of said negative power line.

37. A receiving apparatus according to claim 34, wherein said receiving apparatus being a network interface and power supply unit.

38. A receiving apparatus according to claim 34, wherein said receiving apparatus being a router.

39. A receiving apparatus according to claim 38, wherein said router being a wireless router.

40. A transmission and receiving system for transmitting data, comprising

a transmission apparatus comprising a transmitter, an electrical unit comprising a load or a power supply, wherein said transmitter being connected in series between said at least two conductors and said electrical unit, and wherein said conductors are at least part of a positive power line feeding a current from said power supply to said load or at least part of a negative power line returning said current from said load to said power supply,

a receiving apparatus according to claim 34,

wherein said transmission apparatus and said receiving apparatus are connected with each other by said cable.

41. A system according to claim 40, wherein said cable is a data communication cable comprising at least two conductors as said positive power line, at least two conductors as said negative power line, and at least two conductors as a main data communication line, wherein said power lines are usable for supplying power from said power supply to said load as well as for data transmission.

42. A system according to claim 40, wherein said cable comprises a number of twisted pair conductors.

43. A system according to claim 42, wherein said number of twisted pair conductor is 3, 4 or 5 .

44. A method for transmitting data via a cable, said cable comprising at least two conductors for conducting a current either from a receiver to a transmitter or vice versa, said current being divided in two current conducting branches, a first branch for a first one of said conductors and a second branch for a second one of said conductors, comprising the step of encoding data to be transmitted via said cable by altering the current balance between the currents in said two branches.

45. A method according to claim 44, wherein said current is a power supply current, said method comprising the further step of feeding said power supply current from a power supply to a load or returning said current from said load to said power supply.

46. A method according to claim 44, wherein said current is fed via a power feed connector means for each branch for respectively connecting each branch with one of said conductors.

47. A method for receiving data via a cable, said cable comprises at least two conductors for conducting a current either from a receiver to a transmitter or vice versa, said current being divided in two current conducting branches, a first branch for a first one of said conductors and a second branch for a second one of said conductors, comprising a step of decoding data transmitted via said cable from said transmitter by evaluating alterations of the current balance between the currents in said two branches.

48. A method according to claim 47, wherein said current is a power supply current, said method comprising the further step of feeding said power supply current from a power supply to a load or returning said current from said load to said power supply.

49. A method according to claim 48, wherein said current is fed via a power feed connector means for each branch for respectively connecting each branch with one of said conductors.