Ethernet passive optical network with framing structure for native Ethernet traffic and time division multiplexed traffic having original timing

摘要

A passive optical network (PON) carries both telephony traffic and packet-based traffic, each in their native format i.e. without any processing (such as segmentation and reassembly) of either kind of traffic. Specifically, an optical line terminal (OLT) transmits in a time slot of fixed duration (e.g. 125 microseconds or a fraction thereof) a provisionable number (e.g. 0 to 8) frames of fixed size (e.g. T1 frames or E1 frames) in one portion of the time slot, and also transmits a number of frames of variable size in a remaining portion of the time slot. In several embodiments of the invention, the optical line terminal (OLT) determines in real time an integral number of variable size frames that can be transmitted, based on the size of each variable size frame that has been received and is awaiting transmission, and also based on the number of fixed size frames that have been provisioned for the time slot. If an Ethernet frame is still being received or if it has been received but does not fit into the current time slot, then it is not sent in the current time slot, and instead it is sent at the next opportunity (which can occur in the next time slot).