Cortina Systems Corporation

Cortina Access, Inc.

Dongsheng Zhang

Eugene W Lee

Abhimanyu Das

Deyi Dong

Wei Yao

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.

Method and apparatus for laser overlap detection

There are disclosed systems and methods for detecting and controlling congestion in an Optical Line Terminal (OLT). The OLT has a plurality of ports. Each port of the plurality of ports communicates with at least one Optical Network Unit (ONU), and each port of the plurality of ports has a respective enforced maximum upstream bandwidth. For example, the maximum upstream bandwidth may be enforced by a Dynamic Bandwidth Allocation (DBA) algorithm. The OLT further includes an uplink port through which data received from each of the plurality of ports are transmitted. In one embodiment, if there is congestion of the data at the uplink port, then the enforced maximum upstream bandwidth for at least one port of the plurality of ports is modified.

Congestion control in an optical line terminal

A method of operation of a network transport system includes: determining a congestion mode based on a total bandwidth request meeting or exceeding a bandwidth threshold, where the congestion mode indicates a level of network traffic and the total bandwidth request is a sum of all bandwidth requests for accessing the network; calculating a fixed information rate schedule grant based on a fixed information rate list to create a bandwidth grant for a fixed information rate request; calculating a low latency schedule grant based on a low latency list to create the bandwidth grant for a low latency request; calculating a main schedule grant for allocating an available bandwidth based on the congestion mode, where the main schedule grant is calculated using a weighted maximum-minimum fairness method when the congestion mode indicates congestion; and generating a grant packet for defining a transmission schedule of a first network unit.

Network transport system with hybrid dynamic bandwidth allocation mechanism and method of operation thereof

There are disclosed techniques for power control in an Optical Network Unit (ONU) of a Passive Optical Network (PON). In one embodiment, the supply of power to an optical transmitter is controlled in accordance with information defining a plurality of transmission windows during which data can be transmitted from the ONU, in order to achieve the following: (1) to provide power to the optical transmitter beginning at a predetermined time in advance of a transmission window to ensure a laser in the optical transmitter is ready to begin transmitting the data at the start of the transmission window; and (2) to refrain from providing full power to the optical transmitter between transmission windows when the duration of time between the transmission windows is greater than a predetermined length.

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Fremont, CA, United States of America

Dongsheng Zhang