Abstract: A photodetector comprising: a first light-receiving surface configured to receive reflected light of zero-order light generated based on a laser beam, from one information recording layer of a multilayer optical disc; a second light-receiving surface that is adjacent to the first light-receiving surface with a predetermined interval, the second light-receiving surface being configured to receive reflected light of diffracted light generated based on the laser beam, from the one information recording layer; and a third light-receiving surface for canceling out reflected light of the zero-order light from other information recording layer of the multilayer optical disc, received by the first light-receiving surface or the second light-receiving surface, the third light-receiving surface being configured to receive the reflected light of the zero-order light from other information recording layer.

Abstract: A fluid dynamic-pressure bearing includes a rotatable shaft, a hub, a fixed portion, and a lubricating liquid. The hub includes a hub thrust bearing surface extending from the shaft outwardly in a radial direction and an annular surface. The fixed portion includes a fixed-portion upper thrust bearing surface facing the hub thrust surface and a flange surface facing the annular surface. The hub thrust bearing surface, the fixed-portion upper thrust bearing surface, and the lubricating liquid arranged therebetween form together an upper thrust dynamic-pressure bearing. The annular surface and the flange surface define an annular gap therebetween. An axial dimension of the annular gap is larger than a total of an axial dimension of an upper thrust gap between the hub thrust bearing surface and the fixed-portion upper thrust bearing surface and an average depth of upper thrust dynamic-pressure generating grooves of the upper thrust dynamic-pressure bearing.

Abstract: A typical dynamic bearing design comprises a ring shaped or circular thrust plate mounted at or near the end of a shaft, the shaft defining together with a surrounding sleeve a journal bearing by providing grooves on only one of the two surfaces facing the gap between the shaft and sleeve. On the ring shaped thrust plate supported by the shaft, the traditional upward thrust bearing defined between the lower face of the thrust plate and the facing surface of the sleeve is maintained; but no grooves are on the surface of the thrust plate distant from the shaft and a facing counterplate surface. Further, the journal bearing is defined to have an asymmetry so that a bias force pressure along the surface of the shaft toward the thrust plate is established.

Abstract: A recording medium has a user-data zone in which a plurality of fragments can be reserved by recording the start and end addresses of the fragments, and a management information zone in which management information having recorded-area-indicator (RAI) information indicating whether each of partial areas into which the user-data zone is divided by a fixed size is a recorded area and fragment information concerning each fragment reserved in the user-data zone is recorded. RAI information and fragment information are acquired from the management information zone. A recording end position in the reserved fragment is searched for using the entirety of an area in a reserved fragment as a search range. A search range in an unreserved fragment whose end address is not defined is determined on the basis of the RAI information, and a recording end position in the unreserved fragment is searched for within the determined search range.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An optical data storage medium is described. It comprises at least a substrate, having a surface with data stored in pits that are embossed into the substrate and in spaces separating the pits, a reflective layer covering the surface and having an intrinsic optical reflectivity R at a wavelength ?, a transparent cover stack formed on the reflective layer, the pattern of pits being readable through the cover stack by means of the focused radiation beam having the wavelength ?. The value of R on the spaces separating the pits is substantially different from the value of R on the bottom of the pits. An improved signal quality is achieved, e.g for BD-ROM discs. Further methods for manufacturing such a medium are described, e.g. inclined sputtering or selective etching.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: According to one embodiment, disclosed is an optical disc in which information is recorded by a pit pattern and which includes a reflection membrane. When concavities and convexities of the pits are opposite to those of a usual case, the reflection membrane is formed on the pits in the form of a two-layer membrane of silver or a silver alloy and aluminum or an aluminum alloy. The reflection membrane is formed with a two-layer structure including a first layer and a second layer different from the first layer. The material of the first layer is aluminum, an aluminum alloy or aluminum oxide. The second layer contacts the first layer and its material is silver or a silver alloy.

Abstract: A method for avoiding signal interference between a first RF device and a second RF device is provided. The first and second RF devices are co-located and the first RF device is configured to operate within a semi-stationary range of a frequency band. The second RF device is configured to operate by changing channels within the frequency band. The method initiates with a communication interface being provided between the first RF device and the second RF device. Then, the second RF device receives the semi-stationary range and a mode for the first RF device through the communication interface. Next, the second RF device is adapted to avoid the semi-stationary range of the frequency band of the first RF device when the mode of the first RF device is in an active mode. An apparatus where two RF devices are co-located without causing interference for each other is also provided.

Abstract: A blind carrier frequency offset estimator is based on a single-OFDM-symbol training sequence in multi-user OFDMA uplink. Through multiple access interference modeling and analysis, a virtual user is employed that occupies the all null sub-carriers. By minimizing the energy leakage on the virtual user in term of tentative frequency offsets, the estimator can approach the real frequency offset. The estimator performs only on frequency-domain, simplifies interference calculations, and lowers the rank of the matrix. An iterative computation method is used to approach the real frequency offset.

Abstract: A method for defining a valid set of sub-channels {1, 2, . . . , K} for transmission between a user device and a base station, where each sub-channel “k” has sub-carrier spacing s[k]. Sub-carriers of each sub-channel are equi-spaced. That is, for each sub-channel “k”, the distance between consecutive sub-carriers is maintained at a fixed level s[k]. Different sub-channels can have different sub-carrier spacing s[k]. Sub-channels are non-overlapping. A resource tree is used to select a valid set of sub-channels from a set of possible tone spacing's that include sequence {M1, M2, . . . , MN} of not necessarily different positive integers.

Abstract: A transmission/reception apparatus for transmitting packet data in an Orthogonal Frequency Division Multiplexing (OFDM) system. The apparatus includes a transmission module for generating a frame of an OFDM symbol including pilot tones using the packet data, and transmitting the frame to a wireless network; and a controller for changing at least one of a Pilot-to-Data Ratio (PDR) of the pilot tones and a density of the pilot tones based on a length of the frame. The reception apparatus includes a reception module for receiving a frame of an OFDM symbol including pilot tones from a wireless network, extracting the pilot tone from the received frame, performing channel estimation thereon, and demodulating the packet data; and a controller for receiving at least one of a PDR of the pilot tone and a density of the pilot tone, both of which are in proportion to a length of the frame, and controlling the reception module so that the channel estimation is performed, based on the received information.

Abstract: Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprising: a receiver configured to receive symbols from at least one of a plurality of spectrally overlapping carrier signals to produce an output; a transmitter configured to modulate symbols onto at least one of a plurality of the spectrally overlapping carrier signals; a processor coupled to the receiver, wherein the processor applies a Fourier transform to the output from the receiver; and a controller programmed to instruct the transmitter to transmit at least one symbol comprising a ranging pattern when a predetermined instruction is received by the receiver.

Abstract: The invention sets forth an approach for aggregating a plurality of NICs in a computing device into a single logical NIC as seen by that computing device's operating system. The combination of the single logical NIC and a network resource manager provides a reliable and persistent interface to the operating system and to the network hardware, thereby improving the reliability and ease-of-configuration of the computing device. The invention also may improve communications security by supporting the 802.1X and the 802.1Q networking standards.

Abstract: Method and system for providing continuous data forwarding during a failure mode in a wireless data network including detecting a control plane failure mode of a network switch, maintaining data path between one or more network entities with the network switch, detecting the network switch recovery from the control plane failure mode, and re-authenticating the one or more network entities over the data network is disclosed without disrupting data traffic forwarding.

Abstract: A method and system of transmit load balancing across multiple physical ports. At least some of the illustrative embodiments are methods comprising teaming a first and second communication ports to create a teamed communication port, creating a plurality of virtual ports which abstract the first and second communication ports (and wherein a number of virtual ports utilizing each communication port is based on parameters associated with the communication ports), selecting one of the plurality of virtual ports out which to send a message packet thus designating a select virtual port (the selecting implements transmit load balancing across plurality of virtual ports) and sending the message packets out the first or second communication port utilized by the selected virtual port.

Abstract: A method of operating a network computer system to manage failover in the network computer system comprising communicating traffic via the plurality of network resources, and failing over from a primary pathway to a secondary pathway of the pathway plurality based on failure to receive the user-specified traffic defined by the failover criteria in the primary pathway in combination with availability of the user-specified traffic via the secondary pathway.

Abstract: A method and apparatus for filtering a packet on a connection within a computing system. In one embodiment, the method includes: receiving the packet; delegating the packet to an offload unit for filtering the packet; and determining, by the offload unit, whether the connection is a delegated connection.

Abstract: Various embodiments are disclosed relating to congestion control in wireless networks. In an example embodiment, one or more trigger conditions may be determined relating to traffic congestion for one or more performance levels in a wireless network. One or more congestion control actions may be associated with each of the one or more performance levels. When a trigger condition at a wireless node is met, the associated congestion control actions may be performed.

Abstract: A method of managing a routing table by interoperating with a routing block and a radio resource management (RRM)/scheduling block in a plurality of nodes of a multi-hop system, the method including computing a traffic load rate of each path which transmits traffic and updating the routing table with the computed traffic load rate via the routing block; and updating a plurality of metrics included in the routing table based on the traffic load rate and information transmitted from a neighbor node via the RRM/scheduling block.

Abstract: A method to reconfigure a connection-oriented network from an existing configuration to a desired configuration includes generating a sequence of configuration specifications for the connection-oriented network. The sequence specifies a plurality of intermediate configurations between the existing and the desired configurations. The sequence of configuration specifications is implemented within the connection-oriented network by, for each configuration specification, issuing at least one instruction to an element of the connection-oriented network to modify configuration information maintained at the element to thereby instantiate respective configurations. The implementing includes issuing a specific instruction to instantiate a subsequent configuration specification only if an acknowledgment is received that a preceding configuration has been successfully instantiated.

Abstract: A method and apparatus for classifying video flows to minimize switching time at a user terminal is described. One aspect of the invention relates to classifying video for distribution. A plurality of classes associated with a respective plurality of network jitter measures is established. A jitter profile for a plurality of video flows is defined by associating each video flow of the plurality of video flows with one of the plurality of classes based on an estimated jitter measure of the video flow. The jitter profile is distributed towards at least one user terminal from a distribution facility. The user terminal may use the jitter profile to set the fill level of its jitter buffer dynamically according to the particular video flow being decoded.

Abstract: In a mobile communication system according to the present invention, a data transmitting-side apparatus is configured to retransmit a transmission data block according to a transmission acknowledgement signal transmitted from a data receiving-side apparatus. The data receiving-side apparatus includes: a maximum number-of-retransmissions manager unit configured to manage the maximum number of retransmissions of the transmission data block; and a transmission acknowledgement signal transmitter unit configured not to transmit the transmission acknowledgement signal, when the number of retransmissions of the transmission data block reaches the maximum number of retransmissions.

Abstract: Hybrid fiber/coax networks employ the existing cable plant used for cable TV and transmit data signals in a frequency bandwidth above that which is used for cable TV. As this cable plant was deployed in a tree and branch topology, data transmissions may be susceptible to noise, variable transmission loss and frequency dispersion, particularly in the upstream direction. Further, due to the tree and branch topology, homes at the far end of the network experience much greater loss than do the homes that are near to the headend/ONU. The present system, which uses point-to-point data links between intelligent network elements located in the feeder/distribution network to provide reliable, secure, bi-directional broadband access. Digital signals, or messages, are terminated at the intelligent network elements, switched and regenerated for transmission across additional upstream or downstream data links as needed to connect a home to a headend or router.

Abstract: Methods and products are disclosed for analyzing network traffic using an improved Markov Modulated Poisson Process Model with one bursty state and a plurality of idle states that include: establishing a time scale of operation for each state in the improved MMPP model; establishing a transition value for each state in dependence upon the time scale of operation for the state; measuring inter-arrival times between individual packets received in one or more network adapters; and determining a current state for the network traffic independence upon the measured inter-arrival time of a most recently received packet and the transition values.

Abstract: A method and system of network communication receive load balancing At least some of the illustrative embodiments are methods comprising determining communication path cost information by a computer system (the computer system coupled to plurality of clients over a network), configuring communications from the plurality of clients to the computer system such that the communications are distributed across a plurality of teamed communication ports (the distribution proportional to communication path cost information associated with each communication port), and receiving message packets distributed across the plurality of teamed communication ports.

Abstract: A wireless terminal concurrently associates with multiple wireless local area networks. The wireless terminal may operate in power save mode on both of the WLANs to prevent a disruption of communication on either WLAN. The wireless terminal may adjust the times at which it listens for beacons to enable reception of beacon information even though the beacons for different WLANs may overlap in time. Beacon transmission times also may be scheduled to avoid overlapping transmissions of beacons on different WLANs.

Abstract: A terminal regulation management device capable of flexibly managing terminals in times of unexpected incident, to ensure communications of users whose daily life zone overlaps with the site of the incident and of users whose daily life zone is outside the site. A priority information memory stores, with respect to each base station, priority information indicating priority levels as to subscribers' incoming/outgoing calls and including communication counts that the subscribers have communicated using their radio terminals. A communication information receiver receives communication information on the terminal communications from a radio network controller for controlling the base stations. A priority decision unit updates the communication counts stored in the memory, based on the received communication information, and determines the priority order of the priority information in accordance with the updated communication counts.

Abstract: A system is disclosed, that provides dynamic bandwidth sharing among a plurality of client nodes, which share network link resources in a communication network. Upon receipt of a bandwidth adjustment request from a requesting client node, the system adjusts bandwidth when network link capacity meets the bandwidth adjustment request, or when total amount of bandwidth offered to trade by any peers of the requesting client node meets the bandwidth adjustment request.

Abstract: During operation, each client device will be provided with a list of addresses for all nodes within a network. The addresses for all nodes will be unique to a particular client device such that {address(node 1), address(node 2), . . . address(node n)} for a first client does not equal {address(node 1), address(node 2), . . . address(node n)} for a second client. Each client's address for a particular node will preferably only be known by the client and a naming server. When sending a message to a destination node, a client device will create a source route consisting of the unique addresses. Because each client's address for a particular node will only be known to itself and the naming server, anyone who intercepts the route will not know what nodes along the route are used for routing the message.

Abstract: A weighting process may be used to select between alternate neighbors in a RAPID calculation to enable policy and/or traffic engineering considerations to affect the selection of an alternate path through the network. The information used to weight the neighbors may static administratively assigned weighting information or dynamic weighting information such as local statistical traffic condition information. The process may take into account the amount of traffic being handled by the current primary next hop for the destination, the available capacity of the available alternate neighbors, the ability of the alternate neighbors to handle the additional traffic, and other considerations. Weighting may occur after a set of available loop free alternate neighbors has been determined. Alternatively, weighting may occur before the RAPID calculation has been performed to cause the neighbors to be ordered prior to RAPID processing. This may enable RAPID calculation to stop without considering all available neighbors.

Abstract: A communication apparatus includes a determination portion determining a communication path over which first information to be communicated is routed, on the basis of second information corresponding to communication qualities of multiple communication paths provided between a first site and a second site.

Abstract: A debugging system running on a host device uses an embedded target-side network analyzer to acquire communications information such as packets. The target-side network analyzer logs and analyzes packets by obtaining data from the target's Internet Protocol (IP) stack when diagnostic functions are invoked at breakpoints. This allows display, logging, analysis and other uses of decoded network traffic. This approach can be used in applications (e.g., wireless or those using protocols such as RADIUS and PPP, etc.) where identifying and intercepting traffic to or from a specific target device may be difficult or impossible. With this approach developers can analyze network traffic in real time without any special hardware.

Abstract: A MIMO wireless data transmission system including a data arrangement in which data to be sent is divided for each transmission stream of MIMO with adding an error detection code thereto and thereby resending a subframe's worth of data when an error occurred at the time of resending. It therefore becomes to avoid the same frame being sent again at the time of resending.

Abstract: Method and system for providing network connectivity outage detection for MPLS cores based on service level agreement (SLA) parameters including receiving a service level agreement parameter, determining a probe interval associated with the service level agreement parameter, and performing network connectivity outage detection based on the service level agreement parameter, is disclosed.

Abstract: Disclosed are test methods for testing message paths in communication networks. Also disclosed are redundant network arrangements for rerouting information when faults are detected.

Abstract: When a wireless two-way communications device that has a plurality of user interfaces (and where at least two of these interfaces comprise different interface modalities) receives (101, 201) non-user input regarding an operational constraint (such as, but not limited to, an environmentally-sourced or an internally-sourced operational constraint), an automatic determination (102, 202) will follow regarding a plurality of differing user interface operational configurations as will comply with the operational constraint. One or more of these operational configurations are then presented (103, 203) to a user of the device in order to prompt provision of a user instruction regarding use of such operational configurations. Upon receiving (104, 204) a corresponding instruction from the user, the corresponding operational configuration is used (105, 205) to thereby accommodate the operational constraint in a manner that is relatively satisfactory to the user.

Abstract: A system for monitoring network performance includes a data collection system for obtaining data from event data records provided by the network. A data management system scores events experienced by a user within the network responsive to the data from the event data records. A graphical user interface may then display the data predicting future events of the network responsive to the scored events provided by the data management system.

Abstract: Systems and methods are described for transmitting audio and video messages between network terminals over a network. A communication link is established between a first network terminal and a second network terminal, and audio data and video data is transmitted concurrently over the link. During communication, the first network terminal acquires data representing the performance of the first network terminal and data representing the performance of the network. Based on the performance data, at least one audio buffering parameter is determined and, if the parameter is within a predetermined range, the audio buffering parameter of the first network terminal is modified.

Abstract: A computer implemented method, apparatus, and computer usable program code for identifying a maximum round trip time over a socket for use in transmitting data over a connection. During a beginning phase of a send operation through a socket, packets are sent on the connection as fast as possible. The as fast as possible value is determined by the network and an event is generated that flows back to the application. Sending of the packets is halted in response to this event. Round trip times for the packets sent are identified by waiting for the acknowledgement for the packets sent. The maximum round trip time from the various round trip times is identified, wherein the maximum round trip time used in an adaptive bandwidth control algorithm to determine the optimum rate of sending the data to the endpoint.

Abstract: A computer implemented method, apparatus and computer usable program code for identifying a minimum round trip time over a socket for use in transmitting data over a connection. Two packets are sent over the connection to an endpoint. Round trip times are identified for the two packets in response to receiving acknowledgments for the two packets. Two additional packets of the connection are sent after round trip times for the two packets have been identified. Additional round trip times for the two additional packets are identified in response to receiving additional acknowledgments for the two additional packets. The repeating and identifying steps are repeated for a selected period of time, wherein a lowest round trip time identified for packets sent over the connection during the selected period of time is used as the minimum round trip time for use in sending data over the connection.

Abstract: Wireless communication methods and apparatuses for reducing data retransmission are provided. One wireless communication apparatus performs one of the methods comprising the steps of determining whether a reset is triggered; if yes, receiving a status report and transmitting a datum having not been received successfully in response to the status report. Another wireless communication apparatus performs another method comprising the steps of receiving a trigger of a reset; determining what datum having been received successfully in response to the trigger; and generating a status report under a particular condition. The status report indicates the datum having been received successfully.

Abstract: A wireless mesh network enables multiple devices near each other to transmit simultaneously, thus allowing increased network bandwidth. Prior to transmitting, a device may determine various parameters of the wireless medium on which it desires to transmit. For example, the device may determine whether the intended recipient device is close enough, and verify that any other transmitting and receiving devices are far enough away. If these or any other suitable criteria are met, the device can transmit simultaneously with other devices in the vicinity.

Abstract: Disclosed is a method for setting configuration parameters for a communication network. Performance data is periodically obtained, the performance data including information concerning performance at least in some part of said communication network. On the basis of said performance data, an appropriate set of configuration parameters is automatically chosen for at least one network element of the communication network amongst at least two predefined sets of configuration parameters. The chosen appropriate set of configuration parameters is automatically provided for use in said at least one network element, if said appropriate set is not already in use in said at least one network element.

Abstract: Typically, paths in a network are set up via direct provisioning performed by an Element Management System/Network Management System/Operations Support System, i.e. a platform supporting multiple Wavelength Division Multiplexed spans in order to provide Network Management services/a system responsible for managing at least part of the network, and communicating with agents in order to help keep track of network resources, statistics, and performance. Alternatively, paths in the network are set up via automated nodal software that is capable of performing routing under EMS/NMS/OSS command. A relatively recent protocol, Session Initiation Protocol, has evolved for use in conjunction with multimedia devices in order to locate and connect devices together.

Abstract: A measurement data communication device of the present invention transmits, to an information acquisition device, a measured value which indicates the health condition of a measurement target. In this measurement data communication device, a communication section transmits, to the information acquisition device, communication information including a measurement name corresponding to the measured value and a code value corresponding to the measurement name. Also, a measurement data generation section generates measurement data from the code value and the measured value. The measurement data communication device of the present invention can therefore cause the information acquisition device to recognize the measurement name corresponding to the code value, when measurement data communication device transmits the measurement data to the information acquisition device.