Abstract: A flexible open ring optical network includes a plurality of nodes connected by twin or other suitable optical rings. Each node is operable to passively add and passively drop traffic from the rings. The nodes may include a transport element for each ring. The transport elements include an optical splitter element and an optical combiner element. The optical splitter element is operable to passively combine an add signal including local add traffic and a first transport signal including ingress traffic from a coupled optical ring to generate a second transport signal including egress traffic for transmission on the coupled optical ring. The optical combiner element is coupled to the optical splitter element and is operable to passively split a third transport signal including the ingress traffic to generate a drop signal including local drop traffic and a fourth transport signal including the ingress traffic.

Abstract: There is provided a terminal apparatus including a message monitor to gather transmission request information from each of first and second terminating apparatus, a dynamic bandwidth allocation unit to allocate each transmission band in accordance with the gathered transmission request information, determine a size and an alignment position of a time slot in accordance with the allocated transmission band, determine a transmission start time of the time slot, and allocate an extinction period so as to stop a transmission of an optical signal between a time slot of the optical signal with the second transmission rate and a time slot following the time slot of the optical signal with the second transmission rate, and a MAC controller to generate a control frame for notifying each of the first and second terminating apparatus of the transmission start time and the size of the time slot.

Abstract: An optical amplification device which includes first and second optical amplifiers, and a controller. The first optical amplifier receives a light and amplifies the received light. The second optical amplifier receives the light amplified by the first optical amplifier, and amplifies the received light. When a level of the light received by the first optical amplifier changes by ?, the controller controls a level of the light received by the second optical amplifier to change by approximately ??. In various embodiments, the controller causes the sum of the gains of the first and second optical amplifiers to be constant. In other embodiments, the optical amplification device includes first and second optical amplifier and a gain adjustor. The gain adjustor detects a deviation in gain of the first optical amplifier from a target gain, and adjusts the gain of the second optical amplifier to compensate for the detected deviation.

Abstract: An optical network includes an access ring, a local ring, one or more add/drop nodes (ADNs), a first gateway and a second gateway. The access ring couples the plurality of gateways and transmits optical signals to and from the gateways, the optical signals comprising multiple wavelengths each wavelength operable to carry traffic. The local ring couples one or more of the ADNs and transmits optical signals to and from the ADNs. Additionally, the ADNs are capable of adding and dropping traffic to and from the local ring in one or more wavelengths. The first gateway is capable of receiving broadcast traffic on the access ring, the broadcast traffic transmitted in one or more wavelengths of the optical signals transmitted on the access ring and forwarding, on the access ring, a first copy of the broadcast traffic received on the access ring.

Abstract: An optical amplification device which includes first and second optical amplifiers, and a controller. The first optical amplifier receives a light and amplifies the received light. The second optical amplifier receives the light amplified by the first optical amplifier, and amplifies the received light. When a level of the light received by the first optical amplifier changes by ?, the controller controls a level of the light received by the second optical amplifier to change by approximately ??. In various embodiments, the controller causes the sum of the gains of the first and second optical amplifiers to be constant. In other embodiments, the optical amplification device includes first and second optical amplifier and a gain adjustor. The gain adjustor detects a deviation in gain of the first optical amplifier from a target gain, and adjusts the gain of the second optical amplifier to compensate for the detected deviation.

Abstract: A relay apparatus including: a first interface 11 that branches an optical signal that is input in a first direction from one side of the optical transmission line, and directs the optical signal to a first path and a second path, the first path being a processing path of an optical signal having a first transmission speed, the second path being a processing path of an optical signal having a second transmission speed that is different from the first transmission speed; a processing section 12 that executes processing on an optical signal propagating through each of the paths in accordance with a corresponding transmission speed; and a second interface 13 that binds the first path and the second path of the optical signal on which the processing is executed by the processing section, by means of wavelength multiplexing and directs to the other end of the optical transmission line.

Abstract: Providing protection for a network includes establishing a light-trail through a sequence of nodes of an optical network, where the sequence of nodes is coupled by a first fiber and by a second fiber. Traffic is communicated through a plurality of connections of the light-trail, where a connection is operable to communicate traffic from a source node of the sequence of nodes to one or more destination nodes of the sequence of nodes. A failure of the light-trail is detected. A protection light-trail corresponding to the light-trail is established. The traffic of the plurality of connections is communicated through the protection light-trail.

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: An optical amplification system includes a wavelength filter that divides a wavelength multiplexing optical signal into a plurality of wavelength multiplexing optical signals having wider wavelength intervals than wavelength intervals of the wavelength multiplexing optical signal, and a first optical amplifier that performs optical amplification on the plurality of divided wavelength multiplexing optical signals independently of one another.

Abstract: An optical communicating apparatus that is connected to another optical communicating apparatus by a two-core optical transmission path includes: a one-core optical transmission path that passes an optical signal transmitted from an optical transmitter/receiver performing one-core bilateral communication and an optical signal transmitted to the optical transmitter/receiver in an opposite direction; a transmitting unit that transmits the optical signal transmitted from the optical transmitter/receiver through the one-core optical transmission path, to the other optical communicating apparatus through a first core of the two-core optical transmission path; and a receiving unit that receives the optical signal transmitted from the other communicating apparatus through a second core of the two-core optical transmission path, and passes the received optical signal to the one-core optical transmission path.

Abstract: An optical network is provided that carries optical traffic in multiplexed wavelengths between a number of nodes. The network includes at least one light-trail associated with one of the wavelengths and established between a subset of the nodes in the network. The network also includes an out-of-band control channel that is associated with a different wavelength than the light-trail. The control channel is used to communicate control messages to establish the light-trail and to allocate use of the light-trail by the subset of nodes. Each of the subset of nodes comprises a burstponder operable to receive data traffic from one or more client devices of the associated node to be communicated over the light-trail and to buffer the received data traffic and assemble the data traffic into an optical payload.

Abstract: An optical communication system includes an optical ring that couples a hub node and a plurality of local nodes. The hub node is capable of receiving traffic over the optical ring from the plurality of local nodes on a transmitting wavelength and transmitting traffic over the optical ring to the local nodes on a receiving wavelength. At least one local node is capable of adding traffic to the optical ring by determining whether any other local node is transmitting at the transmitting wavelength and, in response to determining that no other local node is transmitting at the transmitting wavelength, transmitting a request message to the hub node requesting use of the transmitting wavelength. The local node adding traffic is further capable of receiving a grant message from the hub node and, in response to receiving the grant message from the hub node, transmitting traffic at the transmitting wavelength.

Abstract: A method for compensating for optical dispersion in an optical signal includes receiving an optical signal comprising a plurality of channels. The information being communicated in a first set of channels is modulated using a first modulation technique, and the information being communicated in a second set of channels is modulated using a second modulation technique. The method also includes compensating for optical dispersion in the optical signal such that dispersion compensation for the first set of channels is complete and such that dispersion compensation for the second set of channels is incomplete. In addition, the method includes splitting the optical signal into a first copy and a second copy, terminating the second set of channels in the first copy, performing additional dispersion compensation on the second copy such that dispersion compensation for the second set of channels is complete, and terminating the first set of channels in the second copy.

Abstract: A method and system for a data centric architecture in an optical network are provided. In one embodiment, a method and system for a data centric architecture in an optical network includes an optical ring. A number of local nodes are coupled to the optical ring and are configured to receive traffic at a receiving wavelength by optically broadcasting with electrical tag discrimination. Each local node is also configured to transmit traffic at an assigned wavelength different from the transmitting wavelengths assigned to the other local nodes. The transmitting wavelengths are each transmitted at a bandwidth less than the receiving wavelength. A data center node is coupled to the optical ring and operable to receive traffic from the local nodes, sort at least some of the traffic based on the destination of the traffic, and transmit the traffic at the receiving wavelength to the destination.

Abstract: A communication unit inhibits delay and jitter during network communication, improving the communication quality. For this purpose, the communication unit includes: a first terminator that terminates a communication channel in the first optical communication scheme established between the communication unit and another communication unit; a second terminator that terminates a signal in the second optical communication scheme; and a path setting switch that switches between a first signal path setting and a second signal path setting.

Abstract: The present invention aims at providing a method for controlling wavelength characteristics of optical transmission powers by Raman amplification, in which the wavelength characteristics of optical transmission powers are automatically compensated without giving any losses to channel lights to thereby improve transmission characteristics, and an apparatus adopting the same. To this end, the method for controlling wavelength characteristics of optical transmission powers by Raman amplification according to the present invention supplies Raman pump light to an optical transmission path (Raman amplifying medium); compensates the wavelength characteristics of optical transmission powers caused by transmission of WDM signal light through the optical transmission path, by gain wavelength characteristics of generated Raman amplification; and monitors the wavelength characteristics of optical transmission powers after Raman amplification to thereby control the gain wavelength characteristics of Raman amplification.

Abstract: A multi-wavelength light amplifier includes a first-stage light amplifier which has a first light amplifying optical fiber amplifying a light input, a second stage light amplifier which has a second light amplifying optical fiber amplifying a first light output from the first-stage light amplifier, and an optical system which maintains a second light output of the second-stage light amplifier at a constant power level. The first-stage and second-stage light amplifiers have different gain vs wavelength characteristics so that the multi-wavelength light amplifier has no wavelength-dependence of a gain thereof.

Abstract: An optical apparatus receives an upward signal light from a plurality of subscriber units, where the upward signal light is composed of a plurality of time slots corresponding to the plurality of optical subscriber units. The optical apparatus includes a driving unit configured to determine a respective required gain for light from each of the plurality of optical subscriber units, an amplifying section configured to amplify the upward signal light with the required gain corresponding to the time slots of the upward signal light, and a receiver configured to receive the amplified upward signal light.

Abstract: An optical line terminal receives an optical signal transmitted by time division multiple access from plural optical network units among which are an optical network unit performing communications at a first bit rate and an optical network unit performing communications at a second bit rate. The optical line terminal includes a branching unit, a first receiving unit, and a second receiving unit. The branching unit branches the optical signal into branches, at an asymmetrical branching ratio. The first receiving unit receives a branch having the first bit rate, among the branches of a greater branched proportion. The second receiving unit receives a branch having the second bit rate, among the branches of a lesser branched proportion.

Abstract: An optical network is disclosed that carries optical traffic in multiplexed wavelengths between a number of nodes. The network includes at least one light-trail associated with one of the wavelengths and established between a convener node and an end node, and including one or more intervening nodes. The network also includes an out-of-band control channel that is associated with a different wavelength than the light-trail. The control channel is used to communicate control messages to establish the light-trail and to allocate use of the light-trail by the convener node and the intervening nodes. Each of the convener node, the one or more intervening nodes, and the end node is operable to receive optical traffic in a number of multiplexed wavelengths from the optical network, drop a first copy of the multiplexed optical traffic from the optical network, and forward a second copy of the multiplexed optical traffic on the optical network.