Abstract: An apparatus for sampling clock recovery (SCO) and methods for estimating and compensating SCO are provided. The apparatus comprises a symbol timing adjustment module for shifting forward or backward symbol timing of the transmitted OFDM symbols; a discrete Fourier transform (DFT) processor for performing DFT to an output from the symbol timing adjustment module; a channel estimator for undertaking a channel frequency response estimation based on a channel estimation sequence; a SCO phase rotator for receiving and performing phase shift on the transmitted OFDM symbols of a frame header and a frame payload; an SCO estimation stage for undertaking an SCO estimation based on a pilot-subcarrier-related output of the SCO phase rotator and the CFR estimation; and an SCO compensation distributor for dividing the SCO estimation into integer and fractional portions and then distributing them into the symbol timing adjustment module and the SCO phase rotator, respectively.

Abstract: Disclosed is a distributed controlled passive optical network system and bandwidth control method thereof. The system comprises an optical line terminal (OLT), plural optical network units (ONUs) and a splitter with combiner. Each ONU has a first Tx/Rx for respectively transmitting and receiving data packets on an upstream data channel and a downstream data channel, and a second Tx/Rx for transmitting and receiving control signals/commands on a control channel. Upstream data of each ONU is carried by the upstream data channel and sent to the OLT through the splitter with combiner. Downstream data of the OLT is carried by the downstream data channel and sent to corresponding ONUs through the splitter with combiner. With the control signals/commands carried by the control channel, the required information of network status among the ONUs is provided.

Abstract: A method comprises receiving packets; transferring the packets to an output circuit when aggregation of the packets is not enabled; transferring the packets to a queue when aggregation is enabled; enabling aggregation when a rate of receiving the packets into the queue is greater than a predetermined rate or a number of the packets in the output circuit>a first number; and generating aggregate packets each comprising packets in the queue, transferring each aggregate packet to the output circuit when a number of packets in the aggregate packet>a second number, and transferring the aggregate packet to the output circuit when a number of packets in the aggregate packet?the second number, when a predetermined interval elapses, wherein the interval begins when the queue is empty when receiving a packet or a number of aggregate packets in a device receiving the aggregate packets<a third number.

Abstract: Aspects of the invention include determining or choosing any usable media pair from all existing media pairs of a first device. Any channel may be selected from all existing channels and the selected channel is chosen so that it is different from a general channel assignment corresponding to the determined usable media pair. The selected channel may be assigned to the media pair. A second device may be notified of the assigned channel which corresponds to the media pair chosen from all the media pairs. The second device may cross-connect a corresponding equivalent channel and media pair. The first and second device may be adapted to negotiate the assignment of the selected channel to any one of the media pairs. Alternatively, a particular channel and media pair assignment may be selected from a plurality of predetermined channel and media pair assignments and utilized by the first and second device.

Abstract: In a network connection method for interconnecting a virtual LAN distributed over plural sites via a network formed by plural layer 2 switches, a layer 2 switch monitors a first virtual LAN configuring frame sent from a site in the plural sites for configuring the virtual LAN, a network virtual LAN identifier is assigned based on the monitored first virtual LAN configuring frame, and the layer 2 switch generates a second virtual LAN configuring frame based on the assigned network virtual LAN identifier, and transmits the second virtual LAN configuring frame to the plural layer 2 switches in the network so as to establish the virtual LAN distributed over the plural sites. Accordingly, configuration and operation of a virtual LAN in a network of the layer 2 switches can be performed efficiently according to the virtual LAN tag of the subscriber.

Abstract: Improved p-cycle restoration techniques using a signaling protocol are disclosed. For example, a technique for use in at least one node of a data communication network for recovering from a failure, wherein the data communication network includes multiple nodes and multiple links for connecting the multiple nodes, comprises the following steps/operations. Notification of the failure is obtained at the at least one node. A determination is made whether the failure is a single link failure or one of a node failure and a multiple link failure. A pre-configured protection cycle (p-cycle) plan is implemented when the failure is a single link failure but not when the failure is one of a node failure and a multiple link failure, such that two independent paths in the network are not connected when implementing the pre-configured protection cycle plan.

Abstract: The block #1 capsules a user IP layer by a UDP/IPv6, as well as detecting a destination IP address and specifying a QoS class from a DSCP embedded in a TOS field of an IP header of the user IP layer to transfer data to the block #2 through a UDP port correlated to a corresponding link. The blocks #2 and #3 execute processing of protocols divided into functional blocks with respect to a payload part of a UDP packet obtained from each UDP port to transfer the data to its subsequent block through a UDP port correlated to a corresponding link. The block #4 embeds, into a TOS field of an IP header of an IP packet obtained from each link, a DSCP value of a QoS class correlated to the link.

Abstract: Certain embodiments of the invention may be found in a method and system for a simplified user group selection scheme with finite-rate channel state information feedback for frequency division duplex (FDD) multiuser multiple-input-multiple-output (MIMO) downlink transmission. Aspects of the method may include selecting, from a plurality of users, a first user having a channel gain that is greater than a channel gain corresponding to a remaining portion of the plurality of users. At least a second user may be selected from a portion of the remaining portion of the plurality of users. The selected at least the second user has a channel direction that may be approximately orthogonal to that of the first user. The channel gain may be defined by a quantized channel gain. A quantized channel direction of the selected first user may be determined for the selecting the at least the second user.

Abstract: Session invitation method and system in a PTx communication system are disclosed. For session invitation, an inviting terminal adds first media information corresponding to session information in an invitation message and transmits it or transmits it through an RTP. Then, the first media information received by an invited terminal is checked and an invitee determines whether to accept the invitation before joining the session. When the invitation is rejected, the invited terminal adds second media information corresponding to a reason for rejection in a reject message and transmits it, or transmits it through the RTP.

Abstract: A router includes multiple routing engines. If the active routing engine fails, a backup one of the routing engines detects the failure and assumes the role of active routing engine. A redundancy controller circuit, connected to the multiple routing engines, facilitates the selection and switching of the routing engines. Portions of the packet forwarding engine, in addition to the routing engine, may be redundantly implemented. The active routing engine controls the selection of the redundant portion of the packet forwarding engine.

Abstract: Various embodiments of the invention relate to apportioning a total memory bandwidth available for a time period amongst a plurality of bandwidth requests according to a power managed profile. In addition, isochronous data transmission may be appended together and transmitted according to a data transmission policy, wherein the policy may include transmitting the appended isochronous data during an opportunistic data transmission, or during a time identified for transmitting a combined isochronous data transmission, but prior to a time delay compliance limit for isochronous requirements.

Abstract: A network tap device array capable of being powered by a power-over Ethernet (“POE”) supply is disclosed. The array enables data from multiple nodes in a communications network to be tapped and forwarded to a plurality of monitoring devices. In one embodiment the network tap device array includes a chassis that is configured to receive a plurality of network tap devices that are each powered by a POE supply. Each network tap device includes network ports for receiving and transmitting network data via communication cables and tap ports for forwarding the tapped network data to the monitoring device. In another embodiment, a sub-chassis includes a plurality of network tap devices and an aggregator that aggregates tapped data from each of the tap devices. The aggregator then forwards the aggregated data to the monitoring device. The sub-chassis can be included in a chassis that is configured to receive multiple populated chassis.

Abstract: A system includes a first network device and a second network device. The first network device includes a group of first logical portions and is configured to detect a problem with one of the first logical portions, and transmit a message identifying the one first logical portion. The second network device includes a group of second logical portions, where the group of second logical portions corresponds to the group of first logical portions. The second network device is configured to receive the message from the first network device, and activate the one second logical portion corresponding to the one first logical portion in response to receiving the message.

Abstract: In a first aspect, a first method is provided that includes the steps of (1) providing a pointer that includes a first keytype field and a second keytype field; and (2) assigning a value to the second keytype field of the pointer based on a tabletype field of an updated table. The updated table is an updated version of a first table written in a memory, and the first keytype field of the pointer has a value assigned based on a tabletype field of the first table. The first method further includes the step of employing the second keytype field of the pointer to point to the updated table. Numerous other aspects are provided.

Abstract: The present invention provides a method for route and resource allocation. One embodiment of the method includes determining at least one network variable associated with a network that includes a plurality of nodes connected by a plurality of links. The network variable(s) are determined based on a plurality of basic loads associated with the plurality of links and a plurality of data rates associated with the plurality of links. The method also includes determining at least one communication variable based on the determined network variable(s) and allocating at least one resource for communication over the network based on the determined network variable(s) and the determined communication variable(s).

Abstract: A network tap device that is configured for operation in a copper Gigabit Ethernet communications network using a power-over-Ethernet (“POE”) electrical supply is disclosed. In one embodiment, a network tap device powered by a POE supply is disclosed, comprising first and second network ports that are configured with receptacles for receiving communication cables. The communication cables are configured to carry both data signals and the POE supply to and from the network tap device. The network tap device further includes first and second tap ports that connect with additional communication cables to a monitoring device. The network tap device also includes control and regulation circuitry that is configured to receive the POE supply from the communication cables via the network ports and to enable components of the network tap device to be operated by the POE supply.

Abstract: The present invention provides receiving and transmitting devices for providing fragmentation at a transport level along a transmission path. The transmitting device comprises an interface and a control unit coupled to the interface. The control unit is adapted to negotiate a packet size with a remote device. The control unit is also adapted to transmit a data packet of up to the negotiated size. The control unit is further adapted to receive acknowledgments from the remote device associated with one or more fragments, fragmented at the transport-level, of the transmitted data packet. The receiving device comprises an interface and a control unit coupled to the interface. The control unit is adapted to receive two or more fragments of a data packet transmitted by a remote device. The control unit is also adapted to transmit one or more acknowledgments to the remote device based on the received fragments.

Abstract: A system for encoding data in a multilane communication channel may include at least one processor operable to generate, from existing control characters in a character set, expanded control characters utilized for controlling the data in each lane of the multilane communication channel. Each lane of the multilane communication channel may transport the data in a similar direction. The at least one processor is also operable to control at least one of the lanes of the multilane communication channel using at least one of the generated control characters. If a first control character of the existing control characters is a start-of-packet control character, the at least one processor is then operable to select a second control character from any other of the generated expanded control characters, and to indicate a start of a packet using the selected second control character for at least one of the lanes.

Abstract: An interface and related methods for rate pacing in an Ethernet architecture are described herein. In an embodiment, an effective data rate of communication channel with a remote network device is reduced based, at least in part, on an identified processing capability of the remote network device. In one embodiment, to reduce the effective data rate, one or more idle control elements are inserted between at least two frames of substantive content based, at least in part, on the processing capability of the remote network device. Other embodiments are also disclosed.

Abstract: An exemplary embodiment of the present invention may provide an arbiter, a demultiplexer, and a digital receiver. An exemplary embodiment of the demultiplexer may include packet identifier filters, first-in first-out memories, an arbiter, and a conditional access buffer. Another exemplary embodiment of the present invention provides a method for demultiplexing multiplexed broadcasting signals.