[Problem] whether optical input interruption detected by an OXC device is due to an external failure from an upstream side or an internal failure of the OXC device in a transponder device connected to the OXC device using an optical transmission line, and this determination is implemented at low cost. [Solution] An optical transmission system (10A) is configured by connecting a plurality of OXC devices (14A) using optical fibers (16) between transponder devices (15A1) that relay optical signals transmitted to/from terminals (19a, 19b). The OXC device (14A) includes an OSC part (4d1) and a monitoring control part (4e1). The OSC part (4d1) outputs wavelength information on an optical signal in which optical input interruption has occurred and path information on a path of an optical fiber (16) in which the optical input interruption has occurred, at the time of detecting the optical input interruption from the optical fiber (16). In accordance with the wavelength information and the path information that have been output as above, the OXC device (14A) includes an AIS generation part (4j) that generates an AIS signal including both pieces of information on the wavelength and the path of the optical signal relating to the optical input interruption and alarm information relating to both the pieces of information.

[Problem] To determine a time difference between clocks which, for example, are placed far apart from each other with high accuracy at low cost. [Solution] In a time comparison system 20, an intermediate station 21 disperses a single optical signal 21c in the spatial region using the optical complex amplitude modulation to simultaneously transmit the optical signal 21c to a plurality of comparative stations 22 and 23 apart from each other. The intermediate station 21 transmits the optical signal 21c while changing the transmission angle using phase modulation, performs intensity scanning for the reflected light c1 of the optical signal 21c, and detects the peak intensity to determine the directions of the comparative stations 22 and 23. The reflected light c1 of the optical signal 21c transmitted to the comparative stations 22 and 23 of which the direction have been determined, is detected to determine a round-trip propagation delay time between the intermediate station 21 and each of the comparative stations 22 and 23. The difference calculation unit 25 calculates a sum of time difference between each of times to and tb associated with the comparative stations 22 and 23 and the time tc associated with the intermediate station 21, and the determined propagation delay time to determine time information of each of the comparative stations 22 and 23. Based on the result of subtracting, from the time information of the comparative stations 22, the time information of the comparative stations 23, the time difference between the comparative stations 22 and 23 is determined.

An asynchronous adaptation process includes receiving a first plurality of frames of a first interface group at a first rate, determining idle/stuffing data to be added in each of the first plurality of frames based on a second rate associated with a second plurality of frames of a second interface group, adding information about the idle/stuffing data in each frame of the first plurality of frames in a preceding frame, and transmitting the second plurality of frames of the second interface group with the idle/stuffing data included therein, wherein the second plurality of frames includes the first plurality of frames with the idle/stuffing data.

An asynchronous adaptation process includes receiving a first plurality of frames of a first interface group at a first rate, determining idle/stuffing data to be added in each of the first plurality of frames based on a second rate associated with a second plurality of frames of a second interface group, adding information about the idle/stuffing data in each frame of the first plurality of frames in a preceding frame, and transmitting the second plurality of frames of the second interface group with the idle/stuffing data included therein, wherein the second plurality of frames includes the first plurality of frames with the idle/stuffing data.

An asynchronous adaptation process includes receiving a first plurality of frames of a first interface group at a first rate, determining idle/stuffing data to be added in each of the first plurality of frames based on a second rate associated with a second plurality of frames of a second interface group, adding information about the idle/stuffing data in each frame of the first plurality of frames in a preceding frame, and transmitting the second plurality of frames of the second interface group with the idle/stuffing data included therein, wherein the second plurality of frames includes the first plurality of frames with the idle/stuffing data.

An asynchronous adaptation process includes receiving a first plurality of frames of a first interface group at a first rate, determining idle/stuffing data to be added in each of the first plurality of frames based on a second rate associated with a second plurality of frames of a second interface group, adding information about the idle/stuffing data in each frame of the first plurality of frames in a preceding frame, and transmitting the second plurality of frames of the second interface group with the idle/stuffing data included therein, wherein the second plurality of frames includes the first plurality of frames with the idle/stuffing data.

A communication control device that controls setting of an optical path between a first communication device and a second communication device includes: a detection unit that detects a main signal on which an uplink control signal transmitted from the first communication device is superimposed and detects a transmission timing of the uplink control signal; a determination unit that determines a transmission timing of a downlink control signal so as not to overlap with the transmission timing of the uplink control signal on the basis of the transmission timing of the uplink control signal detected by the detection unit and a predetermined control signal transmission rule; and a transmission unit that transmits the downlink control signal to the second communication device at the transmission timing of the downlink control signal determined by the determination unit.

A communication control device that controls setting of an optical path between a first communication device and a second communication device includes: a detection unit that detects a main signal on which an uplink control signal transmitted from the first communication device is superimposed and detects a transmission timing of the uplink control signal; a determination unit that determines a transmission timing of a downlink control signal so as not to overlap with the transmission timing of the uplink control signal on the basis of the transmission timing of the uplink control signal detected by the detection unit and a predetermined control signal transmission rule; and a transmission unit that transmits the downlink control signal to the second communication device at the transmission timing of the downlink control signal determined by the determination unit.

Novel tools and techniques are provided for implementing network experience shifting, and, in particular embodiments, using either a roaming or portable hypervisor associated with a user or a local hypervisor unassociated with the user. In some embodiments, a network node in a first network might receive, via a first network access device in a second network, a request from a user device to establish roaming network access, and might authenticate a user associated with the user device, the user being unassociated with the first network access device. Based on a determination that the user is authorized to access data, content, profiles, and/or software applications that are accessible via a second network access device, the network node might establish a secure private connection through a hypervisor or container communicatively coupled to the first network access device to provide the user with access to her data, content, profiles, and/or software applications.

Novel tools and techniques are provided for implementing network experience shifting, and, in particular embodiments, using either a roaming or portable hypervisor associated with a user or a local hypervisor unassociated with the user. In some embodiments, a network node in a first network might receive, via a first network access device in a second network, a request from a user device to establish roaming network access, and might authenticate a user associated with the user device, the user being unassociated with the first network access device. Based on a determination that the user is authorized to access data, content, profiles, and/or software applications that are accessible via a second network access device, the network node might establish a secure private connection through a hypervisor or container communicatively coupled to the first network access device to provide the user with access to her data, content, profiles, and/or software applications.