Abstract: Network devices, systems, and methods, including executable instructions and/or logic thereon to achieve fiber channel one for N (1:N) redundancy. A network device includes a processing resource coupled to a memory. The memory includes program instructions executed by the processing resource to group a number of switches in a 1:N cluster and provide each switch with a (virtual) A_Port link to all members of the 1:N cluster. If a failure of a fiber channel over ethernet forwarder (FCF) occurs, the program instructions execute to re-establish or redirect a connection over an alternate path through a redundant FCF without having to synchronize a connection state across all switches in the cluster.

Abstract: Method and apparatus for optimizing a decision threshold of an optical receiver is used to solve a problem of affecting system stability and reliability. The method comprises: determining a maximum value and a minimum value of an adjustment range of the decision threshold, and determining an adjustment step of the decision threshold (10); adjusting a decision threshold value within the adjustment range of the decision threshold, and separately detecting pre-FEC BERs corresponding to different decision threshold values (11); and searching for a minimum value in the detected pre-FEC BERs, a decision threshold value corresponding to the minimum value being an optimal decision threshold value (12). The apparatus comprises a decision threshold adjusting unit, a pre-FEC BER detecting unit, a decision threshold control unit and an optimal decision threshold determining unit.

Abstract: A method for shared mesh restoration includes configuring a switch to allow sharing of a plurality of backup line cards across a plurality of node degrees associated with a reconfigurable optical add/drop multiplexer (ROADM). The switch is communicatively coupled to the ROADM. The method further includes configuring a number of backup line cards coupled to the switch. The number of backup line cards is based on determining a number of active backup lightpaths for each of a plurality of network failures associated with each of the plurality of node degrees of the ROADM, identifying which node degree and failure has the largest number of active backup lightpaths for all of the plurality of node degrees of the ROADM and for each of the plurality of network failures, and determining the number of backup line cards to configure based on the identified largest number of active backup lightpaths.

Abstract: The present disclosure describes methods and systems for the hierarchical mesh restoration of connections in an ASON or the like. These methods and systems provide a mesh restorable OTN server layer that carries an aggregate of mesh restorable SONET/SDH SNCs, without designating SONET/SDH/OTN hand-off ports or work/protect lines. Server layer SNCs are terminated on Virtual Trail Termination Points (VTTPs) on the NEs. These VTTPs maintain all of the attributes of physical Trail Termination Points (TTPs). The server routing protocol creates physical TTP interfaces at the server layer, and the server layer advertises bandwidth to the client layer routing protocol. A failure in the server layer results in the mesh restoration of an aggregate line, holding off the release of the individual client SNCs. Only when the server layer cannot restore are these individual client SNCs released.

Abstract: A time synchronization method for a communication system configured to perform protection switching, the communication system including a first network in which a master station and a slave station are connected via plural physical lines including a working line and a backup line and a second network connected to the slave station, the method including a time synchronization in which the slave station executes, when not detecting a communication failure of a downlink signal transmitted from the master station, synchronization processing for synchronizing, based on a clock of the slave station and timing information, time information transmitted to the second network with time information included in a time synchronization command and suppresses, when detecting a communication failure or receiving a switching notification from the master station apparatus, a synchronization error due to a difference between the clock of the slave station and the timing information.

Abstract: Switching process at the occurrence of a path trouble is performed more quickly to reduce the number of packet discards during a traffic transition from a currently used system path to a standby system path within a section to be protected. An OLT (210-W) refers to the DBA information of a PON section and, if receiving no CCM frame at a timing at which the same should be received, then determines that some trouble has occurred on the path (S801) and transmits, to an OAM-compliant NE (200-Z), an application-for-switching frame (1501) to notify the OAM-compliant NE (200-Z) of the abnormal condition. The OAM-compliant NE (200-Z) monitors the occurrence of the trouble within the PON section nearly in real time, starts a switching process (S802) and generates and transmits a standby-system delivery request (321) (S302, S803). An OAM-compliant NE (200-A) switches the communication path to the standby-system passing through an OLT (210-P).

Abstract: The present invention discloses a method and an apparatus for migrating a Sub-Network Connection Protection (SNCP) service. The method comprises: receiving a migration request of an SNCP service, wherein the migration request comprises one of: Permanent Connection (PC) to Soft Permanent Connection (SPC) migration, SPC to PC migration; respectively setting cross status control bits of a current operation connection and a correlative connection thereof according to the received migration request, and performing collective migration of the current operation connection and the correlative connection thereof according to the set cross status control bits; respectively modifying the cross status control bits of the current connection and the correlative connection thereof according to the migration result. The consistency of cross management authorities of a working connection and a protection connection of the SNCP service migration can be ensured by the present invention.

Abstract: Delivering multicast data traffic over a communication network includes a first network node delivering multicast data traffic to second network nodes. The first and second network nodes are connected by a transmission network in a ring architecture and implement a point-to-multipoint layer 2 protocol. A method includes at the first network node: collecting alarms signals indicative of a failure along the whole ring and of the second network nodes. Based on a current state of the alarm signals, delivering the multicast data traffic either in a first delivery direction along the ring, or in a second delivery direction along the ring opposite to the first delivery direction, or in both the first and second delivery directions. At each of the second network nodes: collecting alarm signals indicative of a failure of the transmission network locally to the second network node and of the second network node.

Abstract: An arrangement at a Remote Node, a Remote Node, a Central Office, a WDM-PON and a method in an arrangement at a Remote Node, and a method in a Central Office are provided for supervision of the WDM-PON. The arrangement comprises at least one filter connected to the feeder fibre links and adapted to separate a data signal and an original OTDR signal received on either of the feeder fibre links. Further, the arrangement comprises a first splitter adapted to receive, from the at least one filter, the original OTDR signal, to split the original OTDR signal into a plurality of OTDR sub-signals and to output, to an N*M AWG, the plurality of OTDR sub-signals. The at least one filter is further adapted to output the original OTDR signal to the first splitter and to output the data signal to the AWG, thereby enabling supervision of the WDM-PON.

Abstract: A passive optical network is provided which uses existing GPON OAM functionality and standard routing protocol messages to solve the downstream routing problem between an access service provider and one or more other communication provider networks.

Abstract: A peer network node, along with other peer network nodes, forms a higher-tiered optical network that transports wavelength division multiplexed traffic for multiple lower-tiered optical networks. The node comprises a plurality of dedicated bidirectional optical ports, including two or more lower-tiered ports and one or more peer ports. The node also comprises one or more hub-side bidirectional optical ports, and a switching circuit. The switching circuit is configured to distribute traffic received at the one or more hub-side ports to respective dedicated ports, for dedicated transport to one or more of the lower-tiered networks and peer network nodes. The switching circuit is also configured to direct any traffic received at the dedicated ports to the one or more hub-side ports for transport to a hub node, even if that traffic is actually destined for one of the lower-tiered networks to which a lower-tiered port is connected.

Abstract: Disclosed is a method and system for transmitting data on a data channel from a source to a destination. The data channel has a plurality of wavelength channels and a throughput. The system and method include a storage application for multicasting data on each of the plurality of wavelength channels, a storage protocol extension device using buffer credits to adjust the throughput during the multicasting, and an application optimization device for managing data channel latency to achieve asymmetric mirroring behavior at the same time as the multicasting.

Abstract: A node of an optical transport network system transmits optical wavelengths to an adjacent node through an operational line. An apparatus for protection switching of the optical transport network system transmits only an optical channel with a fault among a plurality of optical channels composed of flexible optical channel data units in an optical wavelength of the operational line, via a reserve line.

Abstract: A system and method for Passive Optical Networks (PON) providing integration (cross-correlation) of powersave and fiber protection, optionally with encryption, facilitating the successful operation and/or benefits that can be gained when operating a PON system with these features. A major problem with power save is the detection, since both the OLT and the ONUs rely on a valid signal in order to detect fiber failure. However, the OLT may not detect this for sleeping ONUs, and an ONU in Tx/Rx sleep-mode, may not detect a fiber failure, and may not be aware of the OLTs switchover. In addition to solving the problem of combined fiber protection and power savings, a solution is also needed for providing security for this combination. A current embodiment is a system and method for Passive Optical Networks (PON) providing integration (cross-correlation) of powersave and fiber protection, optionally with encryption.

Abstract: Optical networks occasionally experience a fault along a communications path. Service providers prefer to have an alternative communications path available to enable users to still communicate in a seamless manner. Accordingly, a method and corresponding apparatus for providing path protection for dedicated paths in an optical network is provided.

Abstract: A device may include a component, a first switch, a repeater, and a second switch. The component may configure optical paths between ports. The component may comprise a first pair of optical ports connected to a first pair of optical fibers, and a second pair of optical ports connected to a second pair of optical fibers. The first switch may be configured to output one of two optical signals received by the first pair of optical ports from the first pair of optical fibers. The repeater may reshape or amplify the outputted optical signal. The second switch may be configured to direct the reshaped or amplified signal to one of the second pair of optical ports.

Abstract: A node for an optical network has an electrical selector (30, 35) coupled to a first transponder for selecting which of first or second connections, is carried. A connection controller (80, 130) cooperates with other nodes to set up the first connection on a main path using a second transponder, and to reserve a first restoration path for the first connection. A second connection (best effort traffic) is set up on at least part of the reserved first restoration path by controlling the electrical selector. If the main path fails, the first connection is restored by controlling the electrical selector to select the first connection for the first restoration path in place of the second connection. By having an electrical selector, a change can be made more rapidly than if done only optically.

Abstract: In the field of optical communications technologies, a method and a system for optical network switching protection are provided, to solve the problem of long service interruption time during active-standby switching in the prior art. One optical terminal apparatus is selected as a ranging optical terminal apparatus after a service is switched from an active optical central office end apparatus to a standby optical central office end apparatus; a delay difference between delay from the ranging optical terminal apparatus to the standby optical central office end apparatus and delay from the ranging optical terminal apparatus to the active optical central office end apparatus respectively is obtained; and time at which data sent by all the optical terminal apparatuses reaches the standby optical central office end apparatus is synchronized according to the delay difference. The method and the system are mainly used in an optical communication system.

Abstract: Protection switching methods, systems, and architectures are provided for hybrid Ethernet Passive Optical Network (EPON)-Ethernet Passive Optical Network Over Coaxial (EPOC) networks. Protection switching embodiments enable protection of the EPON portion and/or the EPOC portion of the hybrid network. In embodiments, protection switching may be initiated by an Optical Line Terminal (OLT), a coaxial media converter (CMC), or an optical network unit (ONU)/coaxial network unit (CNU) in the hybrid network.

Abstract: A system for redundancy in Ethernet passive optical networks (EPONs) facilitates fast recovery from failure (less than 50 msec), path redundancy of the fiber optic network, and location redundancy of the OLTs. An optical networking unit (ONU) in a normal state monitors input communications, and when the input communications are quiet for a predetermined minimum length of time, the ONU transitions to a lenient state in which: the ONU accepts old and new security keys; upon receiving a packet: the ONU updates an ONU timestamp based on the packet's timestamp; and the ONU transitions to the normal state of operation. While the ONU is in the lenient state if a packet is not received for a predetermined given length of time the ONU transitions to a deregistered state. In this system, main and standby OLTs do not require synchronization of security parameters or synchronization for differences in fiber lengths.

Abstract: A method and system of determining a new path through an optical network from a source node to a destination node when a link in an original path fails are disclosed. When a fault on a link is detected, adjoint weights are assigned to each operational link for each node on the original path. A connection cost is determined for each node based on the adjoint weights of the links connected to the node. A new path through the optical network is determined based at least in part on the adjoint weights and the connection costs.

Abstract: In an optical communication system containing a primary line and backup line card, a method includes providing interfaces for the primary and backup line card, each line card including a transmitter and receiver; and selecting output from the transmitter from either the primary or back up line card including selecting the backup line card when the primary line card encounters a failure.

Abstract: A system includes one or more active/working circuit groups to transfer information through a protection domain, the protection domain defined by a plurality of network devices and a plurality of links connecting the network devices between a start point and an end point; and a protection circuit group through the protection domain, the protection circuit group being disjoint from the one or more active/working circuit groups to provide shared protection for the one or more active/working circuit groups, where the protection circuit group is comprised of an individual protection circuit and where a capacity of the protection circuit group is dynamically adjusted based on a capacity of the one or more active/working circuit groups.

Abstract: An optical splitter/coupler may be disposed at a subscriber network access location to provide primary and back-up service to the subscriber network access location. The optical splitter/coupler includes first and second optical fibers that are optically coupled to a third optical fiber. The first and second optical fibers of the optical splitter/coupler are optically coupled to a service provider location. The third optical fiber is optically coupled to the subscriber network access location.

Abstract: A three-way handshake method for optical messaging in a multi-domain optical network that includes a first pass from a source domain to a destination domain through intermediate domains on candidate working paths, collecting information identifying available routing resources for each working path, calculating a working path metric and storing each of the metrics at the respective border node, determining a path key of the topology of each domain working path and using the path key to identify the path outside its domain and determining the best working paths and border nodes to use. A second pass using the path keys for identifying the working path in each domain and reserving the identified routing resources and selecting which routing resources to use. A third pass identifying the selected routing resources and establishing an optical signaling message path between the source node and the destination node.

Abstract: An optical fiber transmission switching device includes a first transmission port; a second transmission port; a terminal-end input port; a terminal-end output port; a first and a second optical module respectively including an electrical input port, an electrical output port, and a bi-directional optical port, wherein the two bi-directional optical ports are coupled to the first and the second transmission port respectively; a first and a second laser driver circuit respectively coupled to the first and the second optical module; a first and a second electrical amplifier respectively coupled to the first and the second optical module; a first switching module coupled to the terminal-end input port and the first and the second laser driver circuit; a second switching module coupled to the first and the second electrical amplifier and the terminal-end output port.

Abstract: A method for realizing service protection in the automatically switched optical network includes following steps: after any defect occurs on the working paths that carry the service, the first node and the last node of the working paths sends the requests to restore the paths setup in opposite directions, respectively; at least one intermediate node in the restoration path establishes a connection according to the restoration path setup request, and forwards the restoration path setup request hop by hop, until the setup of the recovering path is finished; the service is switched from the working paths to the restoration paths. A system for realizing service protection and a node device in an ASON is also provided. The paths restoration process can be faster obviously using this invention, and the restoration time can be shortened, and the work efficiency and reliability can be improved, and the service can be ensured to be restored.

Abstract: A system for serving N optical communication lines by a redundant set of modules in an optical network; where the set of modules comprises N>1 main modules and one backup module, N optical splitters, 2N fiber connections and a control means. In the system, each of the N optical splitters is connected to two different modules of the set by two respective fiber connections out of the 2N connections, while each of the N optical splitters is also coupled to one of the N optical communication lines. The arrangement is such that the control means selectively activates/inactivates any of the fiber connections for respectively enabling/blocking transfer of data there-along; the control means thus ensures that each specific line of the N optical communication lines is always served by either one or another of two different modules.

Abstract: Various example embodiments are disclosed. According to an example embodiment, a method may include determining that a transmission of a data signal over a path of a wavelength division multiplexed (WDM) optical network using a group of optical subcarriers is not optically feasible; determining that the transmission of the data signal over the path using a subset of the group of optical subcarriers is optically feasible; activating subcarriers for the subset of optical carriers while deactivating one or more optical subcarriers of the group, at least one deactivated subcarrier provided between at least two activated subcarriers of the group; and transmitting the data signal over at least a portion of the path using the activated subcarriers of the group.

Abstract: Optical safety functions are incorporated into protection switching modules which maintain redundant pathways to avoid interruptions in optical network connections. The optical safety functions which lower optical power levels upon interruptions of optical connections are effectively combined with protection switching procedures which are also triggered by interruptions in optical network connections. The interoperation of protection and safety processes keep optical power levels below hazardous levels at system points which might be accessible to human operators.

Abstract: A wireless communications link comprising an RF link and a free space optics (FSO) link, a switch, an RF signal monitoring apparatus, an optical signal monitoring apparatus, alarm apparatus and a controller. The switch operates in a normal mode to aggregate the links to form a link aggregation group and to route traffic on the link aggregation group, a first protection mode to route traffic on the FSO link, or a second protection mode to route traffic on the RF link. The controller is arranged to receive an alarm signal and to generate and transmit a control signal to cause the switch to operate in the first protection mode when a first alarm signal is received, the second protection mode when a second alarm signal is received, and the normal mode when an indicator is received indicating that both signal quality parameters are above their threshold values.

Abstract: Due to demand for more network bandwidth, a need for multi-user optical network topologies has, and will continue to, increase. A method or corresponding apparatus in embodiments of the present invention provide for an availability determination tool for determining and displaying wavelength and subrate availabilities within a network. Benefits of embodiments of a tool include allowing a user to identify the availability and capacity of any wavelength on any network, via an interactive graphical user interface, such as by using three-dimensional representations. In one embodiment, the disclosed availability determination tool allows users to locate and view any combination of available wavelengths between nodes in an optical network topology, and generate graphical and tabular reports of the availability in order to maintain an efficient and organized method or apparatus for determining and controlling wavelengths in a network.

Abstract: An apparatus and method for cost-effectively providing protection in a PON. Protection ports, usually on a protection LT card, are configured to communicate with a selectable one of the downstream ODN splitter/combiners associated with the primary ports on the remaining LT cards of the OLT. Each protection port includes at least a splitter for distributing a transmitted signal from a light source to a plurality of switched protection fibers, and may have an optical amplifier to provide for lossless or low-loss distribution. Each port may also have a combiner for combining received signals from a plurality of switched protection fibers. When a failure is detected at a primary port, traffic is re-directed from the primary port to the protection port after the protection port has been configured to communicate with the same ODN splitter/combiner as the failed primary port.

Abstract: The present disclosure provides Optical Transport Network (OTN) port protection systems and methods using flexible switch criteria. Specifically, the OTN port protection systems and methods provide linear protection in OTN such as 1+1 Protection with Automatic Protection Switching (APS) and/or 1+1 Subnetwork Connection Protection (SNCP) Protection. The OTN Port Protection with flexible switch criteria allows a user to provision a protection application on an OTN Port and select a switch criteria, Section Monitoring, Path Monitoring, or Tandem Connection Monitoring, without considering the provisioning state of an Optical channel Data Unit level k (ODUk) entity. The ODUk entity may either be cross-connected in the LO case or terminated in the HO case. The ODUk entity may be provisioned independently, after the port protection has been established.

Abstract: An optical ring network has one or more working wavelengths and multiple protection wavelengths adapted to support the working wavelength(s). Routing tables may be used in network nodes to assign traffic of a failed working wavelength to a protection wavelength. The protection technique may be applied to networks employing, for example, Dense Wave Division Multiplexing (DWDM).

Abstract: A PON in which parallel optical fiber paths are provided between dual OLTs and the ONTs, one of the optical fiber paths providing an active connection and the other optical fiber path providing a standby connection. Respective VLANs may be formed over the parallel optical fiber paths. If performance indicators, for example Ethernet continuity check messages, indicate that an ONT is no longer in communication with the OLT then data may be sent via the VLAN associated with the standby connection.

Abstract: An amplifier node, in an optical network, includes a first switch connected to a working path from which network traffic is received; a second switch connected to the working path to which the network traffic is transmitted; and two amplifiers that interconnect the first switch and the second switch, where the network traffic travels from the first switch to the second switch via a first amplifier. The amplifier node also includes a controller to receive an instruction to switch the network traffic from the first amplifier to a second amplifier that enables the first amplifier to be repaired; send, to the first switch and the second switch, another instruction to switch the network traffic from the first amplifier to the second amplifier; receive an indication that the network traffic is traveling via the second amplifier; and send a notification that the first amplifier can be repaired based on the indication.

Abstract: The present invention discloses a linear protection method for an optical network, used for protecting a failed service path in the optical network, and the method comprises: setting priorities of services carried on service paths participating in linear protection of the optical network as service priorities; selecting, from the service paths participating in the linear protection, a service path of which the service priority is lower than that of the failed service path as a protection path, and bridge switching the service on the failed service path to the protection path. The present invention implements protection of service paths according to the priority of the service carried on the failed service path, and enhances the security of service paths.

Abstract: The present invention discloses a passive optical network (PON) protection method, a switchover control device, and a PON protection system. In embodiments of the present invention, a protection optical line terminal (OLT) is connected to optical links of at least two working OLTs through the switchover control device; when a working OLT or working optical link fails, the switchover control device replaces the working OLT through the protection optical link, thus ensuring smooth communication. In addition, by using the networking mode of multiple working OLTs and one protection OLT, the embodiments of the present invention greatly saves the networking cost and facilitates the application of the PON technology.

Abstract: A switching method is provided having improved accuracy in monitoring a network to determine when to switch. The method collects and stores a plurality of bit error rate (BER) values. The BER values are analyzed using a BER hysterisis algorithm to check BER degradation. Thereafter, the method switches a transmission port when the degradation exceeds a predetermined BER threshold level for a predetermined period of time. In another embodiment, a feature which transmits a switch polling signal for a predetermined duration is used with the above switching method.

Abstract: Systems, methods, and devices are disclosed for monitoring optical communications between a managed location and a remote location. In particular, an optical signal is transmitted over an optical fiber and passed-through a test device. A portion of the optical signal is filtered from the original optical signal and passed to a monitoring unit. The monitoring unit may instruct one or more switches in the test device to loop the optical signal back toward the managed location. Subsequently, testing and monitoring may be performed at the managed location. The device may provide a test output or may transmit the information to the managed location.

Abstract: An optical transmission device includes a wavelength multiplexing/demultiplexing unit, a plurality of transponders, an optical switch unit and a controller. The controller includes a table in which a plurality of items at least including priority order, a transmission label, a receiving label and a receiving label expected value correspond to the respective transponders. And the controller rewrites the transmission label of the transponder corresponding to the client device of the lower priority order than the priority order of the client device connected to the transponder of the irregular input, upon the optical signal provided by the wavelength multiplexing/demultiplexing unit to one of the transponders being irregular, and controls the label-changed transponder for which the transmission label has been rewritten so that the label-changed transponder provides the wavelength multiplexing/demultiplexing unit with the optical signal including the rewritten transmission label.

Abstract: Optical By-Pass (OBP) links may be created by adding wavelengths between nodes on the network. The OBP may extend between any pair of nodes on the network. Intermediate nodes on the OBP are transient nodes and simply forward traffic optically. An OBP extends between a pair of nodes and, unlike express links, is created in such a manner that it does not affect the previous allocation of resources on the network. This enables capacity to be added between pairs of nodes on the network to alleviate congestion at a portion of the network, without changing other traffic patterns on the network. This enables inclusion of an OBP to be deterministic and of linear impact on the network. The OBP links may be statically provisioned or created on demand. Optionally, the OBP links may be crated to coincide with PBB-TE tunnels on the network.

Abstract: The present invention discloses a passive optical network (PON) protection method, a switchover control device, and a PON protection system. In embodiments of the present invention, a protection optical line terminal (OLT) is connected to optical links of at least two working OLTs through the switchover control device; when a working OLT or working optical link fails, the switchover control device replaces the working OLT through the protection optical link, thus ensuring smooth communication. In addition, by using the networking mode of multiple working OLTs and one protection OLT, the embodiments of the present invention greatly saves the networking cost and facilitates the application of the PON technology.

Abstract: A method for protecting a passive optical transmission network comprising an optical line terminal (OLT) at least one remote node (RN), and a plurality of network termination nodes (ONU) A bidirectional optical signal transmission can be established between each ONU and the OLT via a first bidirectional optical transmission route by means of which an optical wavelength-multiplexed signal is transmitted in the downstream direction from the OLT to the one or more RNs and in the upstream direction from the one or more RNs to the OLT. A second bidirectional optical transmission route is provided between the OLT and the RNs where the wavelength-multiplexed signal is fed in the upstream direction both to the first and second optical transmission routes. On the detection of a fault state on the first or second optical transmission route, the OLT is switched to the other corresponding optical transmission route.

Abstract: An optical signal division transmission system in which an input optical signal is divided into N parts (termed as “N-part optical signals”) and transmitted at a transmission rate of 1/N, wherein an additional optical wave path is provided separately from an optical wave paths for transmitting said N-part optical signals, and even if a malfunction occurs in any one of said optical wave paths for transmitting said N-part optical signals, transmission of said N-part optical signals is continued, using said additional optical wave path.

Abstract: First and second switching device are connected by a number of signal paths. The first switching device receives an instruction to switch from a first one of the signal paths to a second one of the signal paths. The first switching device performs, in response to the received instruction, a first switching operation to connect the first path, at an input of the first switching device, to the second path, at an output of the first switching device. The second switching device receives the instruction to switch from the first path to the second path and detects a loss of signal on the first path as a result of the first switching operation performed by the first switching device. The second device performs, in response to detecting the loss of signal on the first path, a second switching operation to connect the first path, at an output of the second switching device, to the second path, at an input of the second switching device.

Abstract: This invention discloses a method and an apparatus for transmitting/receiving signals in a microwave system, and pertains to the field of communications. The transmitting method comprises receiving and modulating a transmission signal transmitted via an optical fiber; processing the modulated transmission signal to generate RF signal; and separating the RF signal to be transmitted from a signal received via an antenna, and transmitting the separated RF signal via the antenna. The receiving method comprises separating a signal received via an antenna from a signal to be transmitted; processing the received signal after being separated to generate IF signal; demodulating the generated IF signal; and transmitting the received signal after being demodulated via an optical fiber. The transmitting/receiving apparatus comprises an optical fiber signal interface, a signal reception module, a modulation module, an IF-RF transmission module, a duplexer, a control module and a power interface.

Abstract: An apparatus switches paths in a wavelength-multiplexing network in which a first number of wavelengths each used for a path to transmit an optical signal are multiplexed into an optical fiber. The apparatus includes an entire switching unit and a second number of individual switching units where the second number is smaller than the first number. The entire switching unit is configured to perform a path-switching process for switching a path, simultaneously on all the first number of wavelengths when failures have occurred for all the first number of wavelengths. The second number of individual switching units are each configured to perform the path-switching process individually on one of a third number of wavelengths included in the first number of wavelengths when at least one failure has occurred for the third number of wavelengths where the third numbers is smaller than the first number.

Abstract: A network protection switching mechanism comprises a plurality of optical switches located at a plurality of nodes; a plurality of optical communication paths between said switches; switch based fault detectors located as part of at least two switches which generate detection results representative of the identification of a fault; switch based controllers located as part of said at least two switches; and internal switch-communication means between said fault detectors and said controllers which facilitate the transmission of detection results from said fault detectors to said controllers; wherein said controllers directly cause switching to an alternative optical communication path dependent upon the receipt of said detection results; whereby autonomous switch based protection without dependence on either inter-switch control communication or higher level network control communication is achieved.