A method includes: generating indication information, where the indication information is used to indicate a resource allocation table corresponding to a first data unit in the plurality of data units; sending the indication information in a timeslot previous to a timeslot used to send the first data unit; and sending the plurality of data units, where a resource allocation table corresponding to each data unit is selected from a plurality of resource allocation tables in a cyclic manner, and a cyclically initial resource allocation table is the resource allocation table indicated by the indication information.

A service data processing method and apparatus is disclosed. A data frame is divided into code blocks with smaller granularity, and service data is mapped to a corresponding quantity of code blocks in the data frame based on a service requirement. In addition, the data frame is used to indicate a location of a code block carrying the service data. In one manner, a code block in a payload area of the data frame is divided into a data code block and an overhead code block, and the overhead code block is used to indicate a location of a data code block carrying the service data. In the another manner, an indication field is configured in an overhead area of the data frame to indicate a location of a code block that carries the service data and that is in the payload area of the data frame.

An example frequency converter includes a drift canceling loop with a balanced delay and a linear signal path (e.g., linear with respect to frequency scaling, amplitude modulation, and/or phase modulation). One side of the drift canceling loop includes a fixed delay, and the opposite side includes an adjustable, complementary delay. The adjustable, complementary delay facilitates precision matching of the signal delays on each side of the loop over a range of frequencies, which results in a significant improvement in noise cancelation, particularly at large offsets to the carrier, while permitting the use of a higher noise, but very fast tuning course scale oscillator. The linear signal path from the signal generator to an RF output facilitates modulation of the signal by the signal generator. A modular format is an advantageous embodiment of the invention that includes the removal of the frequency synthesizer's low phase noise reference into a separate module.

A method includes: generating indication information, where the indication information is used to indicate a resource allocation table corresponding to a first data unit in the plurality of data units; sending the indication information in a timeslot previous to a timeslot used to send the first data unit; and sending the plurality of data units, where a resource allocation table corresponding to each data unit is selected from a plurality of resource allocation tables in a cyclic manner, and a cyclically initial resource allocation table is the resource allocation table indicated by the indication information.

An example frequency converter includes a drift canceling loop with a balanced delay and a linear signal path (e.g., linear with respect to frequency scaling, amplitude modulation, and/or phase modulation). One side of the drift canceling loop includes a fixed delay, and the opposite side includes an adjustable, complementary delay. The adjustable, complementary delay facilitates precision matching of the signal delays on each side of the loop over a range of frequencies, which results in a significant improvement in noise cancellation, particularly at large offsets to the carrier, while permitting the use of a higher noise, but very fast tuning course scale oscillator. The linear signal path from the signal generator to an RF output facilitates modulation of the signal by the signal generator. A modular format is an advantageous embodiment of the invention that includes the removal of the frequency synthesizer's low phase noise reference into a separate module.

If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.

If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.

An optical transmission apparatus includes a detecting circuit configured to detect one or more empty slots in which a data signal is not accommodated in a plurality of slots included in a frame, a frame processing circuit configured to reduce size of the frame by deleting the one or more empty slots from the frame based on a detection result of the one or more empty slots and closing up gaps between remaining slots in the plurality of slots, and an optical modulation processing circuit configured to carry out multi-level modulation of the frame at a bit rate according to size of the frame after reduction.

An example frequency converter includes a drift canceling loop with a balanced delay and a linear signal path (e.g., linear with respect to frequency scaling, amplitude modulation, and/or phase modulation). One side of the drift canceling loop includes a fixed delay, and the opposite side includes an adjustable, complementary delay. The adjustable, complementary delay facilitates precision matching of the signal delays on each side of the loop over a range of frequencies, which results in a significant improvement in noise cancelation, particularly at large offsets to the carrier, while permitting the use of a higher noise, but very fast tuning course scale oscillator. The linear signal path from the signal generator to an RF output facilitates modulation of the signal by the signal generator. A modular format is an advantageous embodiment of the invention that includes the removal of the frequency synthesizer's low phase noise reference into a separate module.

An example frequency converter includes a drift canceling loop with a balanced delay and a linear signal path (e.g., linear with respect to frequency scaling, amplitude modulation, and/or phase modulation). One side of the drift canceling loop includes a fixed delay, and the opposite side includes an adjustable, complementary delay. The adjustable, complementary delay facilitates precision matching of the signal delays on each side of the loop over a range of frequencies, which results in a significant improvement in noise cancelation, particularly at large offsets to the carrier, while permitting the use of a higher noise, but very fast tuning course scale oscillator. The linear signal path from the signal generator to an RF output facilitates modulation of the signal by the signal generator. A modular format is an advantageous embodiment of the invention that includes the removal of the frequency synthesizer's low phase noise reference into a separate module.