Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Shared memory management apparatus and techniques are disclosed. A shared memory provides queues for storing communication traffic that is to be scheduled for transmission. Based on amounts of communication traffic stored in the queues, a determination is made as to whether or not communication traffic is to be removed from the shared memory, and if so, communication traffic is removed. Traffic may be selected for removal based on one or more of: a scheduling algorithm for scheduling communication traffic out of the queues for transmission, thresholds associated with the queues, and latency of the communication traffic stored in the queues. Removal of communication traffic from the shared memory is coordinated with scheduling of communication traffic in some embodiments.

Abstract: An arbitration scheme is used for scheduling connections between input ports and output ports. Input ports request connections to the output ports for a next time slot. Arbitration parameters, such as priority and weight, are identified for the buffer requests. Output port arbitrations are conducted for each one of the output ports according to the arbitration parameters. If there are more than two input buffers with the same priority and weight, a round robin arbitration is used. Grants are issued to the input port buffers winning the output port arbitrations. Input port arbitrations are conducted using the same arbitration parameters for input ports receiving multiple grants. The grants are accepted by the input port buffers winning the input port arbitrations. The input port buffers accepting the grants are connected to the requested output ports.

Abstract: A data scrambler receives a parallel array of input bits. An array of previously scrambled output bits are stored from a previous clock period. The array of previously scrambled output bits are applied to the parallel array of input bits during a same current clock period to generate a current array of scrambled output bits.