摘要:
A point-to-multipoint passive optical network transmits downstream data from an optical line terminal (OLT) to multiple optical network units (ONUs) in variable-length packets and upstream data from the ONUs to the OLT in variable-length packets utilizing time division multiplexing to avoid transmission collisions. In an embodiment, the variable-length downstream packets and the variable-length upstream packets are formatted according to IEEE 802.3. In an embodiment, the length of the variable-length downstream and upstream packets is related to the length of Internet protocol (IP) datagrams carried within the packets.
摘要:
An optical access network and method for transmitting optical data in the network utilizes an interleaved polling scheme to efficiently use the available bandwidth of the network. The use of the interleaved polling scheme allows a central terminal of the network to dynamically allocate upstream bandwidth from remote terminals of the network to the central terminal in response to the amount of data that is waiting at the remote terminals to be transmitted to the OLT. In one embodiment, the optical access network is based on Passive Optical Network (PON) technology. In another embodiment, the optical access network utilizes Ethernet protocol to encapsulate data in Ethernet frames for transmission. Thus, in these embodiments, the optical access network includes all of the advantages associated with the PON technology and/or the Ethernet protocol. In addition, since the allocation of upstream bandwidth is on an as needed basis, loss of bandwidth due to unfilled time slots is substantially eliminated.
摘要:
One embodiment provides a system for controlling flow rate in an EPON. The system includes an OLT, an ONUs coupled to the OLT via a passive optical splitter, a switch coupled to a port located on the ONU, and a flow-control mechanism. The ONU includes one or more queues corresponding to one or more classes of Services, and one or more ports. The switch includes a plurality of UNI ports, and the switch is configured to switch one or more upstream traffic flows belonging to the one or more classes of services from the plurality of UNI ports. The flow-control mechanism is configured to set a flow rate of an upstream traffic flow of certain class of service originated from a UNI port. The flow-control mechanism sets the flow rate based on status of an ONU queue corresponding to the class of service of the upstream traffic flow.
摘要:
One embodiment provides a media access control (MAC) module facilitating operations of an Ethernet passive optical network (EPON). The MAC module includes a frame formatter configured to generate a MAC control frame. The generated MAC control frame includes at least one of: an organizationally unique identifier (OUI) field, an OUI-specific operation code (opcode) field, and a number of fields associated with the OUI-specific opcode. Transmission of the MAC control frame facilitates realization of an EPON function based on the fields associated with the OUI-specific opcode.
摘要:
One embodiment provides a media access control (MAC) module facilitating operations of an Ethernet passive optical network (EPON). The MAC module includes a frame formatter configured to generate a MAC control frame. The generated MAC control frame includes at least one of: an organizationally unique identifier (OUI) field, an OUI-specific operation code (opcode) field, and a number of fields associated with the OUI-specific opcode. Transmission of the MAC control frame facilitates realization of an EPON function based on the fields associated with the OUI-specific opcode.
摘要:
One embodiment of the present invention provides a system for mitigating Raman crosstalk between downstream data and video transmission in an Ethernet passive optical network (EPON), wherein the EPON includes an optical line terminal (OLT) and one or more optical network units (ONU's). During operation, the system transmits a data stream from the OLT to the ONU's on a first wavelength that is substantially at 1490 nm. The system also transmits a video signal stream from the OLT to the ONU's on a second wavelength that is substantially at 1550 nm. The system modifies the bit sequence for the data stream to change the power spectral distribution (PSD) for the data stream, thereby reducing power spectral content in the frequency range where significant Raman crosstalk can occur between data and video signal streams.
摘要:
One embodiment of the present invention provides a system that reduces data burst overhead in an Ethernet passive optical network which includes a central node and at least one remote node, wherein downstream data from the central node is broadcast to the remote nodes, and wherein upstream data from a remote node is transmitted to the central node in a unicast manner. During operation, the central node transmits grant messages to a number of remote nodes, wherein a grant message for a specified remote node assigns a start time and a duration of a transmission timeslot in which the specified remote node may transmit an upstream data burst. In response to the grant messages, the central node then receives a number of upstream data bursts, wherein the time gap between two consecutive upstream data bursts is less than the summation of a default laser turn-on time, a default laser turn-off time, an AGC period, and a CDR period.
摘要:
A system is provided to reduce data burst overhead in an Ethernet passive optical network. During operation, the OLT transmits grant messages to a number of ONUs, wherein a grant message assigns a start time and a duration of a transmission timeslot in which an GNU may transmit an upstream data burst. In response to the grant messages, the OLT receives a number of upstream data bursts, wherein the time gap between two consecutive upstream data bursts is less than the summation of a default laser turn-on time, a default laser turn-off time, an AGC period, and a CDR period.
摘要:
One embodiment of the present invention provides a system that reduces data burst overhead in an Ethernet passive optical network which includes a central node and at least one remote node, wherein downstream data from the central node is broadcast to the remote nodes, and wherein upstream data from a remote node is transmitted to the central node in a unicast manner. During operation, the central node transmits grant messages to a number of remote nodes, wherein a grant message for a specified remote node assigns a start time and a duration of a transmission timeslot in which the specified remote node may transmit an upstream data burst. In response to the grant messages, the central node then receives a number of upstream data bursts, wherein the time gap between two consecutive upstream data bursts is less than the summation of a default laser turn-on time, a default laser turn-off time, an AGC period, and a CDR period.
摘要:
A system and method for applying an extended multipoint control protocols to wireless access systems. A medium-to-medium adaptor can be provided in an adaptor node that can interface with an upstream optical line terminal in a PON domain and a downstream device in a non-PON wireless domain. The medium-to-medium adaptor enables an implementation of end-to-end services across multiple quality of service (QoS) domains by passing all traffic with controlled delay and without contention.