Abstract: A visible light communication method includes: obtaining a first ID identifying an area in which a receiver is present; obtaining a second ID by the receiver through visible light communication; and obtaining information corresponding to a third ID which is a combination of the first ID and the second ID. For example, in the obtaining of a first ID, the first ID may be obtained by referring to a table showing correspondence between the first ID and location information obtained by the receiver and indicating a location of the receiver.

Abstract: A clock at a first network element that is connected to a second network element over an optical fiber link is aligned in time/phase using packet protocols such as PTP. The invention discloses how to correct the asymmetry error inherent in traditional packet-based time-transfer methods.

Abstract: A network comprising at least one host device having an interface card connected to a backplane of said host device, wherein said interface card comprises at least one cage for receiving a pluggable module which provides at least one embedded communication channel which exchanges performance monitoring data and configuration data between said pluggable module and a far end device.

Abstract: A method and system for compensating residual dispersion curvature in an optical communication network is disclosed. One embodiment employs two types of dispersion compensating fiber to reduce higher order terms in a residual dispersion profile. The two types of dispersion compensating fiber may be co-located in a dispersion compensation module positioned in each transmission fiber link. Alternatively, the two types of dispersion compensating fiber may be distributed across a span of the optical communication network.

Abstract: A network diagnostic system is provided for an optical transport network having a plurality of network elements. The network diagnostic system includes at least one network element having a network diagnostic operation integrated therein and operable to perform the network diagnostic operation, thereby determining a network performance characteristic associated with the optical transport network; a wayside communication subsystem interconnecting the network elements residing in the optical transport network; and a network diagnostic device in data communication with the at least one network element and operable to initiate the network diagnostic operation at the network element.

Abstract: To optimize the number of optical gate switches required by an optical switching apparatus which comprises an optical space switch and wavelength selectors, the following process as a preliminary process of introducing optical signals into the optical space switch, is carried out. In detail, the preliminary process is optically converting the optical signals in relation to the number of input ports of the optical space switch, by optically processing the optical signals. As the results, the number of processed optical signals responding to the input ports and the processed number of wavelengths of each processed optical signal is equal to each other, and thereby, the optimization is achieved.