616 results about "Ethernet passive optical network" patented technology

One embodiment provides a system for power saving in an Ethernet Passive Optic Network (EPON). The system includes an optical line terminal (OLT), an optical network unit (ONU), a traffic-detection module configured to detect status of traffic to and from the ONU, and a power-management module configured to place the ONU in sleep mode based on the detected traffic status. The ONU includes an optical transceiver that includes an optical transmitter configured to transmit optical signals to the OLT and an optical receiver configured to receive optical signals from the OLT.

One embodiment of the present invention provides a system that facilitates forwarding of packets in an Ethernet passive optical network (EPON), which includes a central node and at least one remote node. During operation, the system assigns a logical link identifier (LLID) to a remote node, wherein an LLID corresponds to a logical link between the central node and a remote node. The system also associates an LLID with a port of a switch within the central node, wherein the switch has a number of ports; wherein a port may be a physical port or a virtual port; and wherein the number of ports on the switch are divided into network-side ports and user-side ports. Upon receiving a downstream packet from a network-side port, the system searches a mapping table to determine whether one or more field values of the downstream packet correspond to any LLIDs or ports. If the one or more field values correspond to an LLID, the system assigns the LLID to the downstream packet and transmits the downstream packet to a remote node.

Embodiments of the present invention exploit the existing capabilities of the Ethernet Passive Optical Network (EPON) MAC layer, designed for fiber optics communications, to provide a low cost MAC layer with upper layer connectivity over a hybrid fiber coaxial (HFC) network. In particular, embodiments allow for the EPON MAC to be used end-to-end (i.e., from an optical line terminal (OLT) to a coaxial network unit (CNU)) in a HFC network, thereby fully leveraging the packet processing capabilities, QoS functions, and management features of the EPON MAC. Furthermore, embodiments enable unified provisioning and management for both fiber and coaxial network units in a HFC network.

An apparatus and method for providing a security function of frames transmitted between optical network terminals (OLTs) and optical network units (ONUs) in an Ethernet passive optical network (EPON) providing media access control (MAC) services are provided. The apparatus includes: a frame classifier distinguishing the type of a frame, and based on the logical link identifier (LLID) of the distinguished frame, determining whether or not the frame is a security link to which a security function is to be applied; a bypass unit delaying a no-security-function frame so that a processing time for converting the security-function-applied frame classified in the frame classifier into an encrypted frame is the same as a time for processing the no-security-function frame; and a parameter generation unit transmitting in relation to each of the LLIDs, a parameter set value including a security-function-application setting signal used in the encryption, decryption and authentication of the frame, a frame decryption signal, an encryption mode selection signal, and an authentication intensity adjustment signal.

One embodiment of the present invention provides a system that performs layer 3 (L3) aware switching in an Ethernet passive optical network (EPON) which includes a central node and at least one remote node. During operation, the system maintains a set of mapping information which indicates a correspondence relationship between a logical link identifier of a remote node, a medium access control (MAC) address for a subscriber coupled to the remote node, and an IP address for the subscriber. Upon receiving a packet which contains an IP address, the system selectively attaches a proper logical link identifier to the packet based on the mapping information and the IP address contained in the packet, thereby allowing only one proper remote node to receive the packet.

The present invention provides a small form factor, pluggable ONU, which includes a bi-directional optical transceiver configured to transmit optical signals to and receive optical signals from an OLT. The ONU further includes an ONU chip coupled to the optical transceiver and configured to communicate with the OLT. Also included is a pluggable interface configured to electrically interface between the ONU chip and a piece of subscriber premise equipment (SPE). The ONU includes a power management module to provide power to the ONU chip and the optical transceiver, using power delivered from the SPE through the pluggable interface. The ONU is enclosed a small form factor enclosure, thereby allowing the pluggable ONU to be directly plugged into the SPE and providing an Ethernet Passive Optical Network (EPON) uplink to the SPE without requiring an separate power supply.

Provided is a method of monitoring link performance and diagnosing an active link state without interrupting traffic in an Ethernet passive optical network (EPON) while the link is in the active state. The method of monitoring link performance and diagnosing an active link state without interrupting data flow to logic links which are in active states in the EPON, includes: a) allowing an operator of the EPON to select a link performance monitoring function or a link active state diagnosing function; b-1) if the link performance monitoring function is selected, setting a monitoring cycle timer and periodically transmitting a performance information request frame from a local node to a remote node; b-2) if the remote node receives the performance information request frame, collecting corresponding link performance information and transmitting a response frame from the remote node to the local node in a format which is predetermined in accordance with a corresponding frame format; b-3) if the local node receives the response frame from the remote node, analyzing the performance information of the response frame and determining whether the link performance has deteriorated or if a failure has occurred in the local node; b-4) if the deterioration of the link function or the degree of the failure reaches a predetermined threshold, reporting to an upper layer that a failure has occurred.

A dynamic bandwidth allocation method of an Ethernet passive optical network, comprises a predictor and a rule of QoS-promoted dynamic bandwidth allocation (PQ-DBA); the predictor predicts a client behavior and numbers of various kinds of packets by using a pipeline scheduling predictor consisted of a pipelined recurrent neural network (PRNN), and a learning rule of the extended recursive least squares (ERLS); the present invention establishes a better QoS traffic management for the OLT-allocated ONU bandwidth and client packets sent by priority.

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.

There is provided a method for supporting a multicast service in an Ethernet passive optical network system. Since an Optical Network Unit (ONU) system monitors an IGMP (Internet Group Management Protocol) message and informs the monitored result of an Optical Line Terminal (OLT) system so that the OLT system creates L2 multicast forwarding table using a multicast address and ONU ID information in a PON port, the ONU system transmits the multicast packet only to a corresponding subscriber on the basis of the L2 multicast forwarding table when receiving a multicast packet. Therefore, it is possible to transfer a multicast packet only to a specific ONU system belonging to a corresponding multicast address group among a plurality of ONU systems.

One embodiment of the present invention provides a method for facilitating asymmetric line rates in an Ethernet passive optical network (EPON) which includes a central node and at least one remote node. During operation, the system provides a downstream code-group clock, wherein each cycle thereof corresponds to a code group transmitted from the central node to a remote node. The system also provides an upstream code-group clock, wherein each cycle thereof corresponds to a code group received at the central node from a remote node. In addition, the system provides a multi-point control protocol (MPCP) clock, wherein the frequency ratio of the MPCP clock to the downstream code-group clock is different from the frequency ratio of the MPCP clock to the upstream code-group clock, thereby allowing the downstream transmission to be performed at a faster line rate than the upstream transmission line rate.

An Ethernet passive optical network provides a subscriber with a high speed and large capacity data service and a real time digital broadcast/video service. The network includes an optical line terminal for frame-multiplexing broadcast/video signals, which are obtained by performing a switching operation and a time-slot multiplexing with respect to a plurality of digital broadcast/video data delivered from external broadcasting vendors according to broadcast/video selection information delivered from each user, and communication data delivered through an Internet protocol network.

Carrying out marking service type/priority for data frame in Ethernet, request frame for allocating dynamic bandwidth of OAM (operation, administration and maintenance), and frame for authorizing bandwidth allocation, the method further provides method of dynamic bandwidth allocation, and processing method for transmitting and receiving multiple service data in use for EPON (Ethernet passive optical network). Features are: compatible to current format of standard frame in Ethernet, encapsulation and transmission of multiple services in MAC layer directly so as to raise transmission efficiency of network, as well as provide to realize differentiated services on EPON for different service types.

In a passive optical network, dynamic bandwidth allocation and queue management methods and algorithms, desgiend to avoid fragmentation loss, guarantee that a length of a grant issued by an OLT will match precisely the count of bytes to be transmitted by an ONU. The methods include determining an ONU uplink transmission egress order based on a three-stage test, and various embodiments of methods for ONU report threshold setting.

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.

A passive optical network (PON) in accordance with the invention uses a superframe having a number of subframes arranged in a two-dimensional array, wherein for normal data transfer subframes are allocated to each optical network unit (ONU) column by column, left to right, and within each column subframes are allocated from top to the bottom. Initially, for ranging, at least two subframes are allocated to an ONU, adjacent to a diagonal of the superframe (which may go from the top left corner of the superframe to the bottom right corner, or alternatively from the top right corner to the bottom left corner). In some embodiments, instead of allocating subframes column by column, the subframes are evenly spaced apart from one another, and conflicts with a previous allocation are resolved by adjustment, and optionally an evaluation function may be used to find an optimal allocation.

A method for registration of multiple entities belonging to a specific optical networks unit (ONU). In one embodiment, the multiple entity registration method comprises checking by an optical line terminal (OLT) if a registration request message received from the specific ONU belongs to a certain grant, and based on the check result, registering an entity as either a first or as an additional entity of the specific ONU. In another embodiment, the method comprises checking by an OLT of a reserved value of a flags field inside a registration request message, and based on the check result, registering an entity as either a first or as an additional entity of the specific ONU. The knowledge by an OLT that multiple entities belong to a specific ONU is used for grant optimization and packet data flow optimization.

This invention discloses a control method for purview of multicast service of Ethernet passive optical network, an optical network unit and an optical line terminal, in which, the control method includes: an ONU receives a joining request of a multicast set of a user with an ID of the identity of the user and sends the request to the optical line terminal, which enquires the visit purview of the user to the multicast set and sets up a multicast transmit item transmitting said multicast set data to the user in the ONU when determining that said user can visit said set, when the ONU receives the data, it transmits the data to the user according to the transmit item.

One embodiment provides a system for decrypting data frames in an Ethernet passive optical network (EPON). During operation, the system maintains a local cipher counter at a local node, and receives from a remote node a data frame which is encrypted based on a remote input block and a session key. The remote input block is constructed based on the remote cipher counter and a remote block counter. The system updates the local cipher counter based on a received field located in a preamble of the data frame, truncates the local cipher counter by discarding a number of least significant bits, and constructs for the received data frame a local input block based on the truncated local cipher counter, the received field, and a local block counter. The system then decrypts the data frame based on the local input block and the session key.

A system and method for assigning IP addresses in an Ethernet passive optical network which includes one OLT (Optical Line Terminal) and a plurality of ONTs (Optical Network Terminals) connected to the OLT are disclosed. The method includes the steps of including a dynamic host configuration protocol (DHCP) server in the OLT, establishing IP address pools including at least one IP address according to the ONTs, and searching for an ONT from a MAC processing section of the OLT by means of a MAC address from which IP address assignment is requested when IP address assignment is requested from one of the ONTs. The ONT is connected to a DHCP client. The DHCP server assigns an available IP address existing in an IP address pool established for the ONT having requested the IP address assignment according to ONTs.

One embodiment of the present invention provides a system that facilitates registration of remote nodes in an Ethernet passive optical network (EPON). The system includes a central node and at least one remote node, wherein a number of virtual remote nodes are coupled to a common physical remote node and transmit upstream data through a common transmitter within the common physical remote node. During an initial discovery cycle, the system receives a solicitation message from the central node at a remote node, wherein the solicitation message assigns a discovery slot in which an unregistered remote node may transmit a response message to the central node for registration. The system then transmits a response message from an unregistered remote node to register within the assigned discovery slot. If multiple virtual remote nodes coupled to the common physical remote node seek registration concurrently, the system controls the transmission of response messages from these virtual remote nodes to the central node so as to avoid collisions between response messages from different remote nodes.

Disclosed is a method and apparatus for controlling downstream traffic in an EPON (Ethernet Passive Optical Network). Individual tokens respectively for ONUs (Optical Network Units) are generated and stored, and a common token based on a total transfer rate of the EPON is generated and stored. In order to transmit downstream data, it is determined whether the downstream data is transmittable first by the corresponding individual token, and then second by the common token if the first determination is negative. In the case where traffic is concentrated on an ONU at a time, even if downstream data cannot be transmitted by an individual token for the corresponding ONU, the common token not used by other ONUs can be used to transmit the downstream data. It is thus possible to guarantee minimum/maximum transfer rates to all ONUs and ensure QoS against burst traffic in the EPON.