Abstract: In a WDM optical communication system that includes a plurality of nodes interconnected by communication links, a node is provided that includes a first plurality of transponders each generating and/or receiving an information-bearing optical signal at a different channel wavelength from one another. An optical coupling arrangement, which may include one or more reconfigurable optical switches, transfers the channel wavelengths between a link connected to the node and the first plurality of transponders. The arrangement is adaptable to reconfigure its operational state to selectively direct different ones of the channel wavelengths from the link to different ones of the transponders without disturbing the optical path through the node traversed by any other channel wavelengths. A communications and configuration arrangement is provided, which transfers data identifying the respective channel wavelengths at which the transponders operate from the transponders to the optical coupling arrangement.

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: A method of processing data for computing alternative paths in an optical network (10, 40) including making a list of groups (12, 14, 16, 18, 20, 22, 24, 26) that comprise links wherein the links in a group share a risk of being affected by the same fault, comparing each group (12, 14, 16, 18, 20, 22, 24, 26) with other groups (12, 14, 16, 18, 20, 22, 24, 26) in the list to determine whether each group includes the same links as another group, and deleting the groups (16, 26, 20, 22) that comprise links which are a subset of the links in another group.

Abstract: An optical network includes an optical ring that is capable of transmitting, between two or more nodes, a plurality of working traffic streams that include traffic transmitted in one of a plurality of wavelengths. A node is capable of transmitting, in a first wavelength, a first protection traffic stream associated with a first working traffic stream, in response to an interruption of the first working traffic stream. A node is also capable of transmitting, in a second wavelength, a second protection traffic stream associated with a second working traffic stream, in response to an interruption of the second working traffic stream. The optical network also includes a regeneration element capable of selectively regenerating the first protection traffic stream. The regeneration element is also capable of tuning the regeneration element to receive traffic in the second wavelength and of selectively regenerating the second protection traffic stream.

Abstract: The invention relates to a communications node (10, 90, 100) for routing a plurality of Wavelength Division Multiplexed (WDM) optical signals, the node having a plurality of line units (12) between its inputs and outputs, each line unit including a splitter (14) and a Wavelength Selective Switch (WSS) (16), wherein the splitter (14) is arranged to split an incoming WDM signal into a plurality of WDM signals and to pass them to each WSS in the plurality of line units, each WSS (16) being arranged to selectively route any one or more channels of its received WDM signals to its associated output. Such an arrangement has the advantage of providing a more cost effective realisation of a node with a high nodal degree. The invention provides a technical solution to the problem of connecting a plurality of inputs to a plurality of outputs in a multi-port WDM node. The node has particular application in a mesh network where the nodal degree may be high.

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.

Abstract: A system and method for providing a network that includes at least two microprocessor-controlled devices that include a first microprocessor-controlled device and a distinct second microprocessor-controlled device, and at least two bi-directional fiber optic cables to provide a communicative ring amongst the at least two microprocessor controlled devices by connecting the at least two microprocessor-controlled devices in a daisy-chain, where the first microprocessor-controlled device and the distinct second microprocessor-controlled device communicate via at least two of the bi-directional fiber optic cables.

Abstract: A restoration path planner minimizes cost while meeting restoration-time constraints of a network by reducing the worst-case number of cross-connections that must be performed in a network in the event of a single element failure. The planner involves optimization that identifies primary and restoration path plans for demands within the network such that the worst-case number of cross-connections at any node within the network is minimal and/or bounded. Embodiments further constrain the cost of the path plan. In one embodiment, restoration time is bounded and cost is relaxed until a solution is found. In another embodiment, the restoration time bound is relaxed to a limit while path plans and their costs are stored. These plans can later be chosen amongst for the desired balance of cost and restoration time. At least one approach to minimization of network cost involves maximizing sharing within restoration path plans.

Abstract: An active/standby switchover device and an active/standby switchover method of an asynchronous backplane in a transport network are provided. A local oscillator clock is adopted to obtain a clock of a working path, so as to replace the clock of the working path tracked in a phase-locked loop mode. An active/standby switchover operation is realized by using the local oscillator clock, so that the implementation cost is greatly reduced, and the hysteresis problem of the phase-locked loop tracking clock during the active/standby clock switchover is eliminated, thereby effectively achieving the lossless switchover of services.

Abstract: The present invention provides multi-channel protection switching systems and methods for increased reliability and reduced cost. Advantageously, the multi-channel protection switching systems and methods of the present invention use pre-FEC rate measurements, and changes in pre-FEC rate measurements, to detect and avoid potential link failures before they occur. The multi-channel protection switching systems and methods of the present invention also use “wavelength-hopping” and other protection schemes to alleviate wavelength and time-dependent optical propagation impairments.

Abstract: A method for remotely restoring inoperative data communications is disclosed. The method includes generating a predetermined sequence of signals at a first Communications unit. The method further includes keying an output of a transmitter on and off at the first communications unit with the predetermined sequence of signals and conveying a transmission of the predetermined sequence of signals to a second communications unit. The method also includes recognizing the predetermined sequence of signals at the second communications unit as indicative of inoperability of the second communications unit and, responsive to the recognized predetermined sequence of signals, outputting a signal to attempt to restore inoperative data communications at said second communications unit.

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 protection switch and a method for optical protection switching are provided. The optical protection switch includes a loop mirror-based optical switch with two circulators and a direction-dependent phase shifter in the loop mirror. The direction-dependent phase shifter introduces phase shifts in counter-propagating optical signals in the loop mirror such that either one of a first optical signal and a second optical signal are switched as an output optical signal. The direction-dependent phase shifter is controlled by a controller which initiates switching from the first optical signal to the second optical signal if a drop in power level is detected in the first optical signal and a corresponding drop in power level is not detected in the second optical signal and vice versa.

Abstract: In a WDM optical communication system that includes a plurality of nodes interconnected by communication links, a node is provided that includes a first plurality of transponders each generating and/or receiving an information-bearing optical signal at a different channel wavelength from one another. An optical coupling arrangement, which may include one or more reconfigurable optical switches, transfers the channel wavelengths between a link connected to the node and the first plurality of transponders. The arrangement is adaptable to reconfigure its operational state to selectively direct different ones of the channel wavelengths from the link to different ones of the transponders without disturbing the optical path through the node traversed by any other channel wavelengths. A communications and configuration arrangement is provided, which transfers data identifying the respective channel wavelengths at which the transponders operate from the transponders to the optical coupling arrangement.

Abstract: A communication network comprising at least one first terminal, at least one second terminal, a plurality of links, and at least first and second nodes. The first node is bidirectionally coupled to the first terminal through at least a first one of the links, and also is bidirectionally coupled to the second terminal through at least a second link and the second node. Preferably, the first node comprises a plurality of communication paths, each of which is coupled at a first end thereof to at least one corresponding first link. Second ends of the communication paths are all coupled to the second link, through a multiplexing device, and route signals between the first and second links. The first node also preferably comprises at least one alternate communication path having a first end coupled through the multiplexing device to the second link, at least one switch that is coupled to the alternate communication path, and a detector for detecting a failure in at least one of the communication paths.

Abstract: A method and system for providing joint IP/Optical Layer restoration mechanisms for the IP over Optical Layer architecture, particularly for protecting against router failure within such architecture, includes any one of plural node elements participating in the detection and restoration of the joint IP/Optical Layer architecture upon the failure of a router in one of the nodes. The plural node elements may include, but are not limited to, one of plural routers and an optical cross-connect.

Abstract: A system and method for configuring a network element to support protection switching in an optical network are described. The network element can operate according to the SONET, SDH, or both optical transport standards. Each tributary card of the network element has a baseline set of triggering parameters for supporting each protection scheme of both optical transport standards. A baseline parameter set for a given protection scheme has those triggering parameters that are common to SDH and SONET optical transport standards. One or more additional triggering parameters may be needed by a tributary card to complete the implementation of a particular protection scheme. These additional triggering parameters can be sent to the tributary cards, as needed, to supplement the baseline parameter sets.

Abstract: A method and system for protecting integrated optoelectronic devices are disclosed. The method includes (1) providing standby light source links of fixed wavelength and their corresponding standby data channel in a transmitting-end integrated optoelectronic device; (2) detecting whether there is failure in each active light source link in the transmitting-end integrated optoelectronic device; and (3) selecting a standby light source link having a fixed wavelength and its corresponding standby data channel for accomplishing service transmission of failed active light source link and its corresponding active data channel when detecting failure of an active light source link. The system includes a transmitting-end integrated optoelectronic device and a receiving-end integrated optoelectronic device.

Abstract: A transceiver module having intergrated eye diagram opening functionality for reducing jitter is describe. The transceiver module may transmitter eye opener and a receiver eye opener integrated in a single circuit. The transceiver module may also include serial control and various other integrated components. Other functionalities that may be integrated on the transceiver module include loopback modes, bypass features, bit error rate testing, and power down mode.

Abstract: An optical path switching device includes compact and unpackaged components; the components are mounted onto a single platform; and the components are coupled by luminous flux. Connection between optical fibers is negated. In particular the optical path switching device includes an optical input, an optical output, an optical branching device and an optical signal detection device. At least two of the optical input, the optical output, the optical branching device and the optical signal detective device are mounted onto a single platform.

Abstract: The present invention relates to a method for protecting an optical telecommunication network against possible failures and signal degrades, the network comprising at least two nodes; working resources and protecting resources connecting the nodes; a first protection mechanism operating at a first protection layer; and a second protection mechanism operating at a second protection layer, characterized by a) the step, carried out by a node detecting a failure that could be managed by said first mechanism, of sending downstream an in-band Forward Protection Indication signalling in order to instruct the second protection mechanism not to operate, or b) the step, carried out by a node detecting a Bit Error Rate between a certain range, of sending downstream an in-band Link Degradation Indication signalling in order to instruct the second protection mechanism to operate.

Abstract: A method is disclosed for providing highly available, redundant optical modules using a single network connection in a data processing system. An embedded network interface or network adapter card that occupies one network slot is included and includes a plurality of optical modules. The embedded network interface or network adapter card is used to communicate with a network utilizing one of the optical modules. One of the optical modules is currently designated as an active module. A redundancy controller is included on the network adapter card. The redundancy controller detects a failure of the optical module that is currently designated as the active module and changes the active module designation from the failed optical module to a remaining one of the optical modules such that the remaining one of the optical modules becomes designated as the active module. The embedded network interface or network adapter card then begins utilizing the newly designated optical module to communicate with the network.

Abstract: Systems and methods for conditioning an optical signal are provided for applications which require management of both low and high-data-rates. Upon receipt of a data signal, a determination is made as to whether the data signal is a high or low-data-rate signal. If the data signal is a high-data-rate signal, a clock and data recovery circuit is activated along the data path. If the data signal is a low-data-rate signal, the clock and data recovery circuit is bypassed. When activated, the clock and data recovery circuit conditions the data signal to reduce jitter and other distortion effects which tend to produce larger detrimental effects as data rates increase.

Abstract: Each network device holds as a database parameters relating to the size of a factor of signal degradation of the device, and relays the parameters according to a path through which a signal passes. When each network device receives a relayed parameter, it accumulates the parameter of the device to the received parameter value, and transmits the result to the network device at the next stage. The network device on the terminating side of the path estimates the size of the degradation of the signals in the entire path using the received parameter, thereby determining the reachability as to whether or not a signal can be transmitted through the path.

Abstract: In an optical network a 1+1 bidirectional protection system is presented. Each node across a link has photodiodes to monitor the power of signals received by the node on receiving working and protection optical fibers and also optical switches connected to transmission working and protection optical fibers to modulate signals to its counterpart node across the link. When a node detects a fault in the receiving working optical fiber, not only does the node switch to the receiving protection optical fiber, but it also switches to the transmission protection optical fiber to signal the fault to the node across the link. The optical switches on transmission working and protection optical fibers allow the two nodes across the link to signal each other at a protocol-less or primary protocol level for the link to revert back to its initial state.

Abstract: Disclosed is a secure/non-secure bypass switch, including at least one input port for receiving signals; a control module for determining if a secure or a non-secure operating mode is selected; if a non-secure mode is selected, configuring at least one relay to route the signals through at least two fiber optic modems; and if a secure mode is selected, configuring the at least one relay to route the signals through an encryption device.

Abstract: A method and apparatus for fault notification in an optical network are described herein. In one embodiment, an exemplary process includes detecting at a node that at least a portion of a first unidirectional path of an optical circuit is down, where the first unidirectional path is originated from a first terminating node. In response to the detection, the node signals the first terminating node by removing at least a portion of light of a second unidirectional path in an opposite direction of the first unidirectional path of the optical circuit, to indicate a path between the node and the first terminating node is down. Other methods and apparatuses are also described.

Abstract: This invention pertains to optical fiber transmission networks, and is particularly relevant to transmission of high volume of data and voice traffic among different locations. In particular, the improvement teaches improvements to an optical transport system to allow for efficient and flexible network evolution.

Abstract: The present invention provides a network at a low cost with a reduced number of components and simple management among networks anticipated to become more and more complicated, the network being capable of quick pass change upon service addition/change and failure occurrence. Namely, the present invention realizes a network configuration unnecessary for replacement of interface panels upon pass change, by using a multi-rate compatible interface panel capable of freely changing a signal type to be processed, under control of an upper level operation.

Abstract: A drive shelf includes an embedded switching hub (ESH) that monitors Fibre Channel Arbitrated Loop (FC-AL) traffic, including loop initialization requests (LIRs), coming from drives attached to the ESH. When a number of LIRs issued by a single drive within a certain amount of time exceeds a threshold, the drive is bypassed. One threshold (a “burst” threshold) measures the number of LIRs issued within a short period of time. If the number exceeds a threshold that would prevent other data from circulating through the loop, the drive is bypassed. A second threshold (a long-term threshold) measures the number of LIRs issued within a longer period of time. If the drive issues a number of LIRs at a slower rate than the burst threshold, but still above the long-term threshold, the drive is bypassed.

Abstract: Optical transceivers have loopback and pass-through paths for diagnosing transceiver components and optical networks connected to the optical transceiver or for routing data out of the transceiver in a pass-through mode. The loopback paths are selectively configured so that a selected number of the components in the transceiver are included in the loopback path. Where more than one loopback path is present, a network administrator can select which components will be included in a particular test so that, depending on whether a signal is returned on the loopback path as intended, the network administrator can determine which components are operating correctly and which are faulty. The loopbacks can be configured to run on the electrical side of the transceiver from input port to output port or on the optical side from receiver to transmitter. The pass-through paths can be used to connect the transceiver to other devices.

Abstract: Reroutable protection schemes of an optical network are described herein. In one embodiment, an access node detects that at least a portion of a first path of an optical circuit fails based on a loss of a light of the at least a portion of the first path. In response to the detection, the access node provisions a second path leading to a destination node of the first path without waiting for an update of a routing database regarding the failure of the first path, where the second path satisfies a set of disjointness requirements with respect to the first path. Other methods and apparatuses are also described.

Abstract: In an OTN (Optical Transport Network), an OTN interface of a network element may receive a BDI (Backwards Defect Indicator) signal from a far end network element to which OTN frames are being transmitted. A BDI signal indicates the occurrence of a unidirectional failure in the transmission of OTN frames to which the far end network element responds by switching its routing to the network element. The OTN interface generates an AIS (Alarm Indication Signal) for its network element so that the network element switches network communication channels to the far end network element to ensure bidirectional switching upon a unidirectional failure.

Abstract: In a broadband access network, calls can be kept active even when a telephone network fails. A voice gateway function captures callee telephone number information sent from a caller subscriber telephone to the telephone network and, when the telephone network fails, keeps the call active by retaining the connection between the caller and the callee. Furthermore, when the telephone network fails, the operation mode of the voice gateway and all ONTs is switched from an H.248 gateway mode to an SIP softswitch mode, allowing the voice gateway function to relay communication packets between ONTs and new call connections to be made in the broadband access network.

Abstract: Method and apparatus for dynamic provisioning of reliable connections in the presence of multiple failures in optical networks are described. One embodiment is a method for allocation of protection paths after a failure in an optical network. The method comprises, responsive to a failure in an active lightpath, switching traffic on the active lightpath to a protection path; subsequent to the switching, identifying all active lightpaths in the network that no longer have an available protection path; and attempting to allocate a protection path to each of the identified active lightpaths.

Abstract: A method for processing fault dependency of different levels of tandem connection monitoring is provided. The method comprises obtaining monitored coverage scopes of the different levels of tandem connection monitoring (TCM); locating a fault section according to an overlapping relationship between monitored coverage scopes of the at least two different levels of TCM at which the warnings are reported and performance degradation degrees of the at least two different levels of TCM, the fault section being located when warnings are reported in at least two different levels of TCM; and outputting location-related information that includes information of the fault section to a user.

Abstract: The invention discloses a method and device for data-flow protection of an optical interface in data communication equipment. First, receiving an optical-signal from a source-neighboring device, then duplicating the received optical signal into two duplicated optical signals. One of them is sent to a protected device for processing. According to the protected device working status, either the optical signal having been processed by the protected device or the second duplicated optical signal is selected and sent to a destination-neighboring device. The device of the invention includes a first optical-signal duplicating unit and an optical-signal selecting unit. The first optical-signal duplicating unit is used for duplicating an optical signal, and the optical-signal selecting unit is used as a selector. The method and device proposed by the invention are independent to network topology and can protect data-flow reliably.

Abstract: An apparatus has a cross connection circuit, first switching sections located on the input side of the cross connection circuit to switch a presently-used transmission path and a reserve transmission path, and second switching sections located on the output side of the cross connection circuit to switch the presently-used transmission path and the reserve transmission path and comprises slot sections, first selecting section selectively connecting any one of the slot sections to the input side of the first switching section, second selecting section connecting the output side of the first switching section to the input side of the cross connection circuit, third selecting section selectively connecting the output side of the cross connection circuit to the input side of any of the second switching sections, and fourth selecting section connecting the output side of the second switching section to any one of the slot sections.

Abstract: A telecommunication switch and an operating method for handling SDH signals transmitted by a protection SDH link associated to a working SDH link of an SDH hardware interface of the telecommunication switch. The telecommunication switch comprises a plurality of SDH hardware interfaces and an equipment protection arrangement. Each of the SDH hardware interfaces is connected to the equipment protection arrangement by a first and a second SDH connection. A protection SDH link of a first SDH hardware interface is connected to a second SDH hardware interface. The second SDH hardware interface is designed to forward protection SDH signals transmitted by the protection SDH link to the equipment protection arrangement using its first SDH connection. The equipment protection arrangement switches the protection SDH signals to a spare SDH termination module or an SDH termination module connected to the first SDH hardware interface according to a protection switching control signal.

Abstract: A data communication apparatus having a plurality of working ports for exchanging data traffic with a network element and at least one protection port. The communication apparatus also has a protection switching functional element to switch data traffic from a failed working port to the at least one protection port. The protection switching functional element is capable to acquire either one of a first mode of operation and a second mode of operation. The first mode of operation is an 1:Q mode using a single protection port where Q is the number of working ports and Q is equal or greater than 1. The second mode of operation is an M:N mode where M is the number of protection ports and N is the number of working ports, where M and N are greater than 1.

Abstract: Apparatus is disclosed for connecting at least a first Fibre Channel device to at least a second Fibre Channel device. The apparatus includes ports, buffers and bypass buffers that are arranged so that the second Fibre Channel device can operate at a physical link rate that is higher than the physical link rate of the first Fibre Channel device regardless of whether or not the first Fibre Channel device is sending data words to the second Fibre Channel device and regardless of whether or not the second Fibre Channel device is sending data words to the first Fibre Channel device.

Abstract: A system and method for permitting a customer of a telecommunication company, for whom fiber to the premises (FTTP) has been installed, to continue to use the telephone during utility company power failure, by powering both the optical network terminal (ONT) and the customer's telephone(s). The battery backup unit (BBU) maintains telephone usage for a pre-determined period of time after power failure, e.g., two hours, consistent with duration of most utility company power outages. This permits non-interrupted telephone service for most outages and, after that period of time, if utility company power has not been restored, the BBU provides power in order to provide telephone service only on demand by the customer, for up to approximately two more cumulative hours of usage. At the end of each usage on demand, the BBU powers the telephone for approximately five more minutes to permit return phone calls, if any, after which telephone service is shut off until any next usage on demand.

Abstract: A wavelength division multiplexed self-healing passive optical network using a wavelength injection method includes a central office for coupling modulated multiplexed optical signals (MMOS) and broadband optical signals (BOS)for an upstream light source into one signal transmitted to a plurality of optical network units (ONUs) through a working main fiber and a protection main fiber. A remote node connects to the central office via the main fiber and protection main fiber and to the ONUs through working distribution fibers and protection distribution fibers. The remote node demultiplexes the MMOS and the (BOS) for an upstream light source. The remote node transmits demultiplexed signals to the ONUs, which receive the modulated optical signals and the BOS for an upstream light source which corresponds to predetermined ONUs, and demodulate the modulated optical signals, and modulate upstream optical signals via demultiplexed BOS for an upstream light source.

Abstract: An optical, multi-channel, Differential Phase Shift Keying (DPSK) receiver demodulates multiple Wavelength Division Multiplexed (WDM) channels using at least one interferometer. This distributes expense of the interferometer(s) over all channels of an optical signal, allowing for deployment of cost-effective, scalable, wideband, WDM DPSK systems. For example, for an 80 channel WDM link, the receiver uses a single interferometer instead of eighty interferometers and associated stabilization hardware, dramatically reducing size, weight, power, and cost. The receiver is architecturally compatible with existing interferometer technologies so previous development and qualification efforts can be leveraged. This allows for expedited technology insertion into existing optical communications networks, including terrestrial and space-based optical networks.

Abstract: Embodiments of the present invention compensate for skew across a wavelength division multiplexed network. The network is a wavelength division multiplexed optical transport network. The skew compensation can be performed electrically or optically. It can be performed on the transmission side of the network, the receiver side of the network or at any intermediary node on the network.

Abstract: Current network switching architectures require communication with a higher level network control plane, which can be slow to reroute communications, resulting in unacceptable losses of communications for customers. Examples embodiments of the present invention reroute communications faster detecting optical power of an optical signal at optical switches coupled via optical communication paths, and causing at least one optical communication path between a first optical switch and second optical switch to switch to an alternative optical communication path, in part, through physical layer triggering in an event optical power at at least one of the first or second optical switches falls below a threshold level. Switching in response to physical layer triggering may result in reduced switching times and, consequently, faster restoration of communications to customers after a network fault interruption.

Abstract: A transmission apparatus that receives an optical signal by selecting any one of a plurality of provided optical signal transmission paths through protection control is configured to include a plurality of optical signal outputting sections that output the optical signals transmitted through said optical signal transmission paths respectively as optical signals having wavelengths that are different from each other, a wavelength selective optical switch capable of selectively outputting light of a wavelength corresponding to any one of the optical signals coming from the optical signal outputting sections on the basis of the frequency of a controlling frequency signal, and an optical switch controlling section that supplies said controlling frequency signal to the wavelength selective optical switch so as to output the optical signal coming from the optical signal transmission path side that is selected by said protection control among the optical signals coming from the optical signal outputting sections.

Abstract: An optical network transmission channel failover switching device is proposed, which is designed for use in conjunction with an optical network for providing a transmission channel failover switching function, which is characterized by the provision of a pair of two-to-two (2×2) optical switches and an optical transceiver module for providing a backup channel monitoring function that can be used to activate the failover switching action. This feature allows the utilization of the optical network system to have enhanced reliability, serviceability, and security.

Abstract: An optical network transmission channel failover switching device is proposed, which is designed for use with an optical network for providing the optical network with a transmission channel failover switching function, and which is characterized by the provision of a pair of one-to-two (1×2) type of optical switch and a monitoring beam generating module for providing a backup channel monitoring function that can be used to activate the switching action. This feature allows the utilization of the optical network system to have enhanced reliability, serviceability, and security.

Abstract: A system, method and computer readable medium comprising instructions for sending a message from an Optical Network Terminal (ONT) to an Optical Line Terminal (OLT), if the ONT does not receive an expected OLT action or an expected OLT response to the message within a period, considering the non-receipt of the expected OLT action or the expected OLT response a failure, and if a certain number of consecutive failures have occurred, considering by the ONT that it has entered an uncontrolled state.