GPON Rogue-ONU detection based on error counts

1. A system for identifying faults in a gigabit passive optical network that includes a central optical line terminal and a plurality of optical network units, the system comprising:

a grant-start error-counter, operationally connected to the optical line terminal, for counting grant-start errors, for each optical network unit, from a data stream from the gigabit passive optical network;

a grant-end error-counter, coupled to the optical line terminal, for counting grant-end errors for each optical network unit; and

a CPU, operationally connected to the optical line terminal, for identifying a faulty optical network unit, based on at least one parameter selected from the group consisting of said grant-start errors, said grant-end errors, and a combination thereof.

2. The system of claim 1 , the system further comprising:

a grant monitor operationally connected to, and operative to notify, said grant-start error-counter and said grant-end error-counter of an expected granted optical network unit.

3. The system of claim 2 , wherein said grant monitor is configured to send a pre-determined PRBS to the optical line terminal for determining locations of said grant-start errors and locations of said grant-end errors.

4. The system of claim 1 , the system further comprising:

an forward error correction decoder for calculating a bit error rate of said data stream, and for sending said bit error rate to said grant-start error-counter and said grant-end error-counter, wherein a bit error rate threshold is indicative of a transmission error.

5. The system of claim 1 , wherein said grant-start error-counter is configured to count errors in a first block of a forward error correction grant, and wherein said grant-end error-counter is configured to count errors in a last block of said forward error correction grant.

6. The system of claim 1 , wherein said grant-start error-counter is configured to count errors in a first N-bytes of a forward error correction grant, and wherein said grant-end error-counter is configured to count errors in a last N-bytes of said forward error correction grant.

7. A method for identifying faults in a gigabit passive optical network that includes a central optical line terminal and a plurality of optical network units, the method comprising the steps of:

counting grant-start errors, for each optical network unit, from a data stream from the gigabit passive optical network using a grant-start error-counter, operationally connected to the optical line terminal;

counting grant-end errors for each optical network unit using a grant-end error-counter, operationally connected to the optical line terminal; and

identifying a faulty optical network unit, based on at least one parameter selected from the group consisting of said grant-start errors, said grant-end errors, and a combination thereof, using a central processing unit that is operationally connected to the optical line terminal.

8. The method of claim 7 , the method further comprising the steps of:

prior to said step of counting grant-start errors, calculating a bit error rate of said data stream using an forward error correction decoder; and

sending said bit error rate to said grant-start error-counter and said grant-end error-counter, wherein a bit error rate threshold is indicative of a transmission error.

9. A system for identifying faults in a gigabit passive optical network that includes a central optical line terminal and a plurality of optical network units, the system comprising:

a grant-start error-counter, operationally connected to the optical line terminal, for counting grant-start errors, for each optical network unit, from a data stream from the gigabit passive optical network;

a grant-end error-counter, coupled to the optical line terminal, for counting grant-end errors for each optical network unit;

a CPU for identifying a faulty optical network unit, based on at least one parameter selected from the group consisting of said grant-start errors, said grant-end errors, and a combination thereof; and

a media access control unit operative:

to detect a delimiter, indicative of a grant start, in an input data stream,

to determine a timing of said grant start, and

to send said timing to said grant-start error-counter and said grant-end error-counter.

10. The system of claim 9 , wherein said input data stream is an optical data stream provided by an optical transceiver.

11. A method for identifying faults in a gigabit passive optical network that includes a central optical line terminal and a plurality of optical network units, the method comprising the steps of:

counting grant-start errors, for each optical network unit, from a data stream from the gigabit passive optical network using a grant-start error-counter, operationally connected to the optical line terminal;

counting grant-end errors for each optical network unit using a grant-end error-counter, operationally connected to the optical line terminal;

identifying a faulty optical network unit, based on at least one parameter selected from the group consisting of said grant-start errors, said grant-end errors, and a combination thereof;

prior to said step of counting grant-start errors, detecting a delimiter in an input data stream using a media access control unit, wherein said delimiter is indicative of a grant start;

determining a timing of said grant start using said delimiter; and

sending said timing to said grant-start error-counter and said grant-end error-counter.