Multi-subnet power line communications system and method

1. A system for providing power line communications over a power distribution system having a plurality of low voltage (LV) subnets that each supply power to a plurality of customer premises, comprising:

a power line communications device having a first modem communicatively coupled to a first LV power line subnet to communicate data signals therethrough;

a subnet coupler communicatively coupled to the first LV power line subnet and to a second LV power line subnet; and

wherein said subnet coupler is configured to substantially prevent the flow of power between the first and second LV power line subnets and to couple data signals between the first and second LV power line subnets.

2. The system of claim 1 , wherein said subnet coupler comprises a high pass filter.

3. The system of claim 1 , wherein the first and second LV power line subnets each include a first and second energized conductor, and said modem is configured to differentially transmit the data signals on the first and second energized conductor of the first power line subnet.

4. The system of claim 3 , wherein said subnet coupler is configured to couple the first energized conductor of the first LV power line subnet to the first energized conductor of the second LV power line subnet.

5. The system of claim 4 , wherein said subnet coupler is configured to couple the second energized conductor of the first LV power line subnet to the second energized conductor of the second LV power line subnet.

6. The system of claim 3 , wherein said subnet coupler comprises a first data path including a first high pass filter configured to couple the first energized conductor of the first LV power line subnet to the first energized conductor of the second LV power line subnet and further comprises a second data path including a second high pass filter configured to couple the second energized conductor of the first LV power line subnet to the second energized conductor of the second LV power line subnet.

7. The system of claim 6 , wherein said first data path further comprises a first fuse communicatively coupled to said first high pass filter and said second data path further comprises a second fuse communicatively coupled to said second high pass filter.

8. The system of claim 1 , wherein the power distribution system includes a medium voltage power line and said power line communications device further comprises a second modem in communication with said first modem and communicatively coupled to the medium voltage power line to communicate data signals therethrough.

9. The system of claim 1 , wherein said power line communications device is configured to communicate with a first user device coupled to the first LV power line subnet and a second user device coupled to the second LV power line subnet.

10. The system of claim 1 , further comprising a repeater coupled to the second LV power line subnet and configured to repeat the data signals.

11. The system of claim 1 , wherein said subnet coupler further comprises an amplifier.

12. A method for providing power line communications over a power distribution system having a medium voltage power line and a first and second low voltage (LV) subnet that each supply power to a plurality of customer premises, comprising:

receiving first data from the MV power line;

transmitting the first data over the first LV power line subnet;

coupling the first data from the first power line subnet to the second power line subnet; and

receiving the first data at a user device coupled to the second LV power line subnet.

13. The method of claim 12 , wherein said coupling includes communicating the first data through a high pass filter.

14. The method of claim 13 , wherein said coupling further includes communicating the first data through a fuse.

15. The method of claim 12 , wherein the first and second LV power line subnets include a first and second energized conductor, and said transmitting comprises differentially transmitting a data signal on the first and second energized conductors of the first LV power line subnet.

16. The method of claim 15 , wherein said coupling comprises first coupling of the data signal from the first energized conductor of the first LV power line subnet to the first energized conductor of the second LV power line subnet and second coupling of the data signal from the second energized conductor of the first LV power line subnet to the second energized conductor of the second LV power line subnet.

17. The method of claim 16 , wherein said first coupling includes communicating the data signal through a first high pass filter and said second coupling includes communicating the data signal through a second high pass filter.

18. The method of claim 17 , wherein said first coupling further includes communicating the data signal through a first fuse and said second coupling further includes communicating the data signal through a second fuse.

19. The method of claim 12 , further comprising:

transmitting second data from a user device coupled to the second LV power line subnet; and

coupling the second data from the second power line subnet to the first power line subnet.

20. The method of claim 19 , further comprising receiving the second data from the first power line subnet.

21. The method of claim 20 , further comprising transmitting the second data over the MV power line.

22. The method of claim 12 , wherein the coupling further comprises amplifying a data signal representing the first data.

23. A device for communicating data signals between first and second low voltage (LV) subnets that each supply power to a plurality of customer premises, each low voltage subnet having a first energized conductor and a second energized conductor, the device comprising:

a first data path comprising a first high pass filter configured to be communicatively coupled to the first energized conductor of the first LV power line subnet and to the first energized conductor of the second LV power line subnet to couple data signals therebetween while substantially preventing the flow of power;

said first data path further comprising a first fuse communicatively coupled to said first high pass filter;

a second data path comprising a second high pass filter configured to be communicatively coupled to the second energized conductor of the first LV power line subnet and to the second energized conductor of the second LV power line subnet to couple data signals therebetween while substantially preventing the flow of power; and

said second path further comprising a second fuse communicatively coupled to said second high pass filter.