Abstract: A network system and method include a wireless base station integrated at a central office of a service provider. The wireless base station is configured to provide portable and fixed services to customers. A passive optical network is coupled to the wireless base station at the central office to provide a link to extend an antenna for wireless operations of the wireless base station to a remote site such that a wireless signal from the wireless base station is transmitted in parallel with a passive fiber network signal through the link.

Abstract: A method of setting shared risk link group identification information (SRLG ID) which is one of link properties employed for calculating a route for a path in a communications network including nodes and links for interconnecting the nodes, and indicates a link group which shares resources, comprises the step of assigning a number of SRLG IDs to the link group in accordance with a failure rate of resources shared by that link group. A route calculating method for calculating routes for a working path and a standby path comprises the step of calculating the routes such that a minimum number of SRLG IDs duplicate between all links on the route of the working path and all links on the route of the standby path.

Abstract: To eliminate interruption of a service used by a user and reset of communication caused by switching of an operating server such as a process migration or the like. On receiving a session migration start request, server/network cooperation control means 2 issues an operating server-switching control start notification to an operating server switching control means 3 (step S702). On receiving the operating server switching control start notification, the operating server switching control means 3 switches an operating server. Next, on receiving an operating server switching control completion notification, the server/network cooperation control means 2 sends a connection destination target network-switching request to a connection control means 4 (step S707).

Abstract: A network element provides an interworking function between plural networks. The network element includes a first network forwarding function block for forwarding packets in a first network, a first network control function block for controlling the first network forwarding function block, a second network forwarding function block for forwarding frames along a connection-oriented path in a second network, and a second network control function block for controlling the second network forwarding function block.

Abstract: A hierarchized path setting system in a communication network efficiently contains lower order paths in higher order path. The communication network has a plurality of nodes capable to perform switching process and demultiplexing process not only for lower order paths in a predetermined hierarchical level among hierarchized paths but also for higher order paths in a hierarchical level higher than the predetermined hierarchical level, and a plurality of links connecting these nodes. The system is responsive to a new path setting demand for setting the lower order path, for setting the lower order path in the higher order path when a single higher order path is set from a predetermined transmitter node group, in which a transmitter node of the lower order path belongs, to a predetermined receiver node group including a receiver node.

Abstract: A source node of a network transmits a path setup message for requesting a traffic path to a destination node. First and second nodes, located between the source and destination nodes, establishes first and second parallel transport paths on a first fault recovery layer between them. The first node further includes a database for storing identities of the first and second paths as a single virtual link as viewed from the source node. The first node responds to the path setup message for accommodating the traffic path on a second fault recovery layer through the first transport path. Each node accommodates the traffic path through the second transport path when the first transport path fails. The first node advertises recovery type of the virtual link as equal to the recovery type of the first and second transport paths, and/or equal to most unreliable recovery type of its component links.

Abstract: This invention provides an optical path fault recovery method by which an end point node of an active path having received fault notification issues a resource securing request message transferred hop by hop to a start point node along the standby path. In the case where resources of the standby path are secured, when the resources are used by the extra traffic, the nodes on the standby path and the start point node that have received the message release the extra traffic and then secure the resources. When the resource securing request message reaches the start point node, the start point node issues a switch changeover request message, and the end point node, the start point node, and the nodes on the standby path set switches according to the secured resources.

Abstract: A communication system comprises a plurality of packet rings, each composed of a plurality of node devices, the node devices each transmitting and receiving a packet and being interconnected in a ring; two of the packet rings being interconnected via a pair of node devices each in each of the packet rings; the communication system further comprising: a table having recorded therein the correspondence between inter-ring service classes set between the packet rings and intra-ring service classes set in each packet ring; wherein the packet transferred in the packet ring includes information on the intra-ring service classes, as intra-ring header information, and information on the inter-ring service class, as inter-ring header information, the inter-ring service class(es) being correlated with the intra-ring service class(es), and being determined based on the table; the intra-ring header information being deleted when the packet is transferred from one of the packet rings to another.

Abstract: To prevent load of route calculation from being centralized in part of units. A node calculates routes of a primary path and an alternate path and sends them to a management center. The management center checks whether SRLGs of the two routes overlap, and instructs the node to perform calculation again if the routes overlap. The management center searches for an alternate path having a route overlapping the route of the above described alternate path. When an overlapping alternate path exists, and SRLGs of a primary path corresponding to the alternate path and the above described primary path do not overlap, a link is shared in an overlapping portion of the routes of the two alternate paths.

Abstract: In a communications network where first and second nodes are interconnected by communication links, a source node transmits a path setup message for requesting a traffic path to a destination node. Each of the first and second nodes includes routing control means for establishing first and second transport paths on a first fault recovery layer between the first and second nodes. The first node further includes a database for storing identities of the first and second paths as a single virtual link as viewed from the source node. The first node responds to the path setup message from the source node for establishing the traffic path on a second fault recovery layer through the first transport path. The first and second nodes accommodate the traffic path through the second transport path when the first transport path is not working properly.

Abstract: A hierarchized path setting system in a communication network efficiently contains lower order paths in higher order path. The communication network has a plurality of nodes capable to perform switching process and demultiplexing process not only for lower order paths in a predetermined hierarchical level among hierarchized paths but also for higher order paths in a hierarchical level higher than the predetermined hierarchical level, and a plurality of links connecting these nodes. The system is responsive to a new path setting demand for setting the lower order path, for setting the lower order path in the higher order path when a single higher order path is set from a predetermined transmiter node group, in which a transmiter node of the lower order path belongs, to a predetermined receiver node group including a receiver node.

Abstract: A network system and method include a wireless base station integrated at a central office of a service provider. The wireless base station is configured to provide portable and fixed services to customers. A passive optical network is coupled to the wireless base station at the central office to provide a link to extend an antenna for wireless operations of the wireless base station to a remote site such that a wireless signal from the wireless base station is transmitted in parallel with a passive fiber network signal through the link.

Abstract: [PROBLEMS] To enable automatic setting of corresponding relations between data links and bundled links thereof. [MEANS FOR SOLVING PROBLEMS] A temporary bundled link forming device (13) associates data links having the same port attributes within own communication apparatus with the identical temporary bundle link ID. A data link neighbor discovery device (11) obtains the neighboring node IDs of the data links. A bundled link forming device (14) automatically sets, as a bundled link, the data links having the same neighboring node IDs obtained by the data link neighbor discovery device (11), among the data links that are associated with the same temporary bundled link ID by the temporary bundled link forming device (13).

Abstract: A method of setting shared risk link group identification information (SRLG ID) which is one of link properties employed for calculating a route for a path in a communications network including nodes and links for interconnecting the nodes, and indicates a link group which shares resources, comprises the step of assigning a number of SRLG IDs to the link group in accordance with a failure rate of resources shared by that link group. A route calculating method for calculating routes for a working path and a standby path comprises the step of calculating the routes such that a minimum number of SRLG IDs duplicate between all links on the route of the working path and all links on the route of the standby path.

Abstract: In a communications network where multiple shared risk link groups are formed by links having a common risk, unreserved bandwidths are defined corresponding to all SRLG's and a maximum bandwidth of each link is set as an initial value of each of the defined unreserved bandwidths when a working path or a protection path of “1+1” or “1:1” recovery type is requested. When a protection path of “shared” recovery type is requested, unreserved bandwidths are defined corresponding to the SRLG's to which the links of its corresponding working path belong and a maximum bandwidth of each link is set as an initial value to each of the defined unreserved bandwidths. The bandwidth of the working or protection path is subtracted from each of the unreserved bandwidths. The request is rejected if a minimum of the subtracted values is smaller than a threshold.

Abstract: An optical cross-connecting device is small in scale of a switch even when a wavelength multiplexed signal to be transmitted through an optical fiber is high density and wide range. Switching of the wavelength multiplexed signals is performed in a first optical switch, switching per wavelength group in a second optical switch is performed for only signals required switching for smaller granularity, and switching per wavelength signals in a third optical switch is performed for only signals required switching for smaller granularity to from the opticall cross-connecting device. By this, even when the wavelength multiplexed signal to be transmitted through the optical fiber is high density and wide band, the optical cross-connecting device can be small in scale of a switch.

Abstract: An optical packet exchange apparatus and an optical switch in which search for a connection pattern between an input unit devoid of a packet to be transmitted and an output unit devoid of a packet to be received is reduced to enable fast switch control even in cases wherein the number of channels of the exchange apparatus is increased or network speed is higher. A plurality of input units, a plurality of output units and an optical switch are provided. Each input unit includes an input buffer unit, a parallel/serial conversion unit, an electrical/optical conversion unit, and a dummy packet insertion unit for sending a dummy packet if there is no packet to be transmitted. Each output unit includes an exchange counterpart contention resolution unit for controlling the exchange counterpart, an optical/electrical conversion unit, a serial/parallel conversion unit, and a packet eliminating unit. The exchange counterpart contention resolution unit controls the packet eliminating unit to eliminate a dummy packet.

Abstract: A packet switching network which allows the duration of guard time of each packet to be reduced to a minimum and the transmission efficiency of the network to be increased is disclosed. The sending nodes send the packet switch packets each having a guard time added thereto. The receiving nodes receive the packets from the packet switch. Each of the receiving nodes includes a switch timing detector for detecting switch timing of the packet switch based on a serial signal received from the packet switch, and a timing holder for holding the switch timing.

Abstract: An optical receiving circuit 1 is composed of a preamplifier circuit 2, an output differential amplifier 3 and a mean value holding circuit 4. The optical receiving circuit 1 is connected to a photodetector 5 for receiving an input optical signal and outputting current. For the preamplifier circuit 2, a transimpedance type circuit may also be used. The preamplifier circuit 2 comprises a feedback resistor 21 and a resistor for detecting output voltage 22, the transimpedance gain is 55 dB &OHgr; and 3 dB bandwidth when the photodetector 5 the capacity of which is 0.2 pF is connected to its output is 8 GHz. The output differential amplifier 3 discriminates and regenerates data by regulating reference voltage Vref between the high level and the low level of the amplitude of an input signal. The mean value holding circuit 4 includes a sample-hold circuit 41 and capacity 42 for holding the mean value of voltage output from the preamplifier circuit 2.

Abstract: In a communications network where multiple shared risk link groups are formed by links having a common risk, unreserved bandwidths are defined corresponding to all SRLG's and a maximum bandwidth of each link is set as an initial value of each of the defined unreserved bandwidths when a working path or a protection path of “1+1” or “1:1” recovery type is requested. When a protection path of “shared” recovery type is requested, unreserved bandwidths are defined corresponding to the SRLG's to which the links of its corresponding working path belong and a maximum bandwidth of each link is set as an initial value to each of the defined unreserved bandwidths. The bandwidth of the working or protection path is subtracted from each of the unreserved bandwidths. The request is rejected if a minimum of the subtracted values is smaller than a threshold.