Patent ID: 11909523
Assignee: NOKIA SOLUTIONS AND NETWORKS OY
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An upstream (US) optical line terminal (OLT) for a passive optical network (PON) having at least one downstream (DS) optical network unit (ONU), the OLT comprising a processor configured to control (i) transmit operations of a transmitter of the OLT and (ii) receive operations of a receiver of the OLT, wherein the OLT is configured to:
generate a trigger signal indicating a need to receive at least one US burst having a shortened codeword for a first forward error-correction (FEC) code;
based on the trigger signal, transmit, to the ONU, a DS message instructing the ONU to transmit, to the OLT, an US burst having a shortened codeword;
receive, from the ONU, the US burst having the shortened codeword; and
decode the US burst having the shortened codeword using the first FEC code, wherein at least one of (a)-(h):
(a) the trigger signal is configured to override normal bandwidth assignment processing by the OLT's Dynamic Bandwidth Assignment (DBA) engine;
(b) the OLT is configured to determine, based on zero, one, or more detected errors in the shortened codeword, to instruct the ONU to replace the first FEC code with a different FEC code for future US bursts;
(c) the shortened codeword comprises a maintenance message;
(d) the US burst comprises two or more shortened codewords;
(e) the US burst comprises a single codeword, wherein the single codeword is a shortened codeword;
(f) each shortened codeword has a codeword size that is smaller than a specified upper limit that is smaller than the codeword size of a full-size codeword;
(g) contents of the shortened codeword are known a priori by the OLT such that the OLT can detect errors in the shortened codeword without having to decode the shortened codeword; and
(h) the OLT is configured to maintain one or more of:
(1) a first counter value for a number of information bits plus parity bits in successfully corrected codewords; and
(2) a second counter value for a number of corrected information bits plus parity bits in successfully corrected codewords.