The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is one of the slave station devices, and a second slave station device is a slave station device that cannot perform communication via the normal path. If a second slave station device is detected, the master station device calculates a second backup path RTT for the second slave station device based on the first normal path RTT and the first backup path RTT for the first slave station device and a second normal path RTT for the second slave station device. The master station device then resumes communication control processing for the second slave station device based on the calculated second backup path RTT.

An optical component includes a light emitter; an optical receiver; first and second electro-optical crystal layers configured to intersect with each other; and a control line configured to supply a signal for changing refractive indexes of the first and second electro-optical crystal layers, wherein the first and second electro-optical crystal layers are switched according to the signal between a first state where light from the light emitter is transmitted through the first electro-optical crystal layer and a second state where the light is reflected by the first and second electro-optical crystal layers and the reflected light is incident on the optical receiver.

An optical component includes a light emitter; an optical receiver; first and second electro-optical crystal layers configured to intersect with each other; and a control line configured to supply a signal for changing refractive indexes of the first and second electro-optical crystal layers, wherein the first and second electro-optical crystal layers are switched according to the signal between a first state where light from the light emitter is transmitted through the first electro-optical crystal layer and a second state where the light is reflected by the first and second electro-optical crystal layers and the reflected light is incident on the optical receiver.

Time taken for resuming communication in a protection scheme using a backup path in an optical communication system including a master station device and a plurality of slave station devices is decreased. The plurality of slave station devices are connected in parallel to a looped path. A communication path between the master station device and each of the slave station device includes a normal path and a backup path. The master station device performs communication control processing for each of the slave station device based on RTT. A first slave station device is a slave station device with which communication through the normal path has become impossible. First backup path RTT of the first slave station device is calculated based on first normal path RTT of the first slave station device, first partial RTT between the master station device and the looped path, and loop propagation time necessary for one trip through the looped path. The communication control processing for the first slave station device is resumed based on the calculated first backup path RTT without measurement of the first backup path RTT when the first slave station device is sensed.

Time taken for resuming communication in a protection scheme using a backup path in an optical communication system including a master station device and a plurality of slave station devices is decreased. The plurality of slave station devices are connected in parallel to a looped path. A communication path between the master station device and each of the slave station device includes a normal path and a backup path. The master station device performs communication control processing for each of the slave station device based on RTT. A first slave station device is a slave station device with which communication through the normal path has become impossible. First backup path RTT of the first slave station device is calculated based on first normal path RTT of the first slave station device, first partial RTT between the master station device and the looped path, and loop propagation time necessary for one trip through the looped path. The communication control processing for the first slave station device is resumed based on the calculated first backup path RTT without measurement of the first backup path RTT when the first slave station device is sensed.

An indexing system includes an indexing component; a redundant optical path; and a fiber tap arrangement. Multiple indexing components can be daisy-chained together in the indexing system. The redundant optical path is created between any forward port and any rearward port in the network. Multiple redundant optical paths can be created within the network. One or more tap arrangements can be disposed along each redundant optical path. Accordingly, feed signals in a bidirectional indexing environment can be supplied to each drop line along the redundant optical path from either direction without recabling.

An indexing system includes an indexing component; a redundant optical path; and a fiber tap arrangement. Multiple indexing components can be daisy-chained together in the indexing system. The redundant optical path is created between any forward port and any rearward port in the network. Multiple redundant optical paths can be created within the network. One or more tap arrangements can be disposed along each redundant optical path. Accordingly, feed signals in a bidirectional indexing environment can be supplied to each drop line along the redundant optical path from either direction without recabling.

The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is one of the slave station devices, and a second slave station device is a slave station device that cannot perform communication via the normal path. If a second slave station device is detected, the master station device calculates a second backup path RTT for the second slave station device based on the first normal path RTT and the first backup path RTT for the first slave station device and a second normal path RTT for the second slave station device. The master station device then resumes communication control processing for the second slave station device based on the calculated second backup path RTT.

The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is one of the slave station devices, and a second slave station device is a slave station device that cannot perform communication via the normal path. If a second slave station device is detected, the master station device calculates a second backup path RTT for the second slave station device based on the first normal path RTT and the first backup path RTT for the first slave station device and a second normal path RTT for the second slave station device. The master station device then resumes communication control processing for the second slave station device based on the calculated second backup path RTT.

Dynamic error-quantizer tuning systems and methods prevent misconvergence to local minima by using a dynamic quantizer circuit that controls reference voltages of three or more comparators that are independently adjusted to modify the transfer function of the dynamic quantizer circuit. A weighted sum of the comparator outputs is subtracted from the input to form an error signal in a control loop. The ratio of the reference voltages is chosen to reduce or eliminate local minima during a convergence of the control loop and is set to values that minimize a mean squared error signal with respect to discrete modulation states of the input after the convergence of the control loop is complete.