Method and apparatus for laser overlap detection

摘要

There are disclosed systems and methods for detecting whether an Optical Network Unit (ONU) in a network may be causing a communications interference due to laser overlap. In one embodiment, an Optical Line Terminal (OLT) selects a pair of ONUs suspected of possibly causing laser overlap. The OLT then grants a first window to a first ONU for transmitting a first message, and grants to another ONU different from the pair of ONUs a second window for transmitting a second message. If the first message is not received by the OLT, then the OLT indicates that the first ONU may be causing laser overlap. In another embodiment, the OLT grants to an ONU a window for transmitting a message to the OLT. If the message is not received by the OLT when expected, then the OLT indicates that the ONU may be causing laser overlap. Other embodiments are disclosed.

主权项

1. A method in an Optical Line Terminal (OLT), the method comprising:
granting to a pair of Optical Network Units (ONUs) a respective time window for transmitting data to the OLT, the pair of ONUs comprising a first ONU and a second ONU, and the time window granted to the second ONU scheduled, from the perspective of the OLT, adjacent to and later than the time window granted to the first ONU; receiving data from the first ONU that contains packet errors; if subsequent to said granting, one or both of the pair of ONUs is either suspected by the OLT of causing communications interference due to the packet errors, known by the OLT to be causing communications interference due to the packet errors, or is assumed by the OLT to be causing communications interference due to the packet errors, then subsequent to said granting performing (a) or (b) or both (a) and (b); wherein (a) comprises:
granting to the first ONU a first time window for transmitting a first message from the first ONU to the OLT, and granting to another ONU different from both the first ONU and the second ONU a second time window for transmitting a second message from the another ONU to the OLT, the second time window scheduled, from the perspective of the OLT, to begin at a select time later than the beginning of the first time window for the purpose of enabling communications interference detection;if the first message is not received by the OLT, then indicating that the first ONU may be causing communications interference, and otherwise if the first message is received by the OLT then indicating that the second ONU may be causing communications interference; and wherein (b) comprises:
granting to another ONU different from both the first ONU and the second ONU a third time window for transmitting a third message from the another ONU to the OLT, and granting to the second ONU a fourth time window for transmitting a fourth message from the second ONU to the OLT, the fourth time window scheduled, from the perspective of the OLT, to begin at a select time later than the beginning of the third time window for the purpose of enabling communications interference detection;if the third message is not received by the OLT, then indicating that the second ONU may be causing communications interference, and otherwise if the third message is received by the OLT then indicating that the first ONU may be causing communications interference.