OVERVIEW
Fig1. Service diversification on the software-defined network.
Fig2. Example of the burst-mode receiver for linear operation.
Fig3. Adaptive modulation and fairness control scheme on the dynamic bandwidth allocation in elastic optical access network.
Internet traffic is steadily increasing, and the transmission speed of optical communication is required to be further increased in order to transmit enormous traffic.
At the same time, the services provided on the optical network are increasingly diversified. In particular, when the fifth generation mobile communication (5G) service is introduced, the diversification will continue to progress on the fusion network of the fixed and mobile ones.
In order to meet these various-service requirements, network-function virtualization or software-defined network technologies are now being investigated to realize the coexistence of multiple logical networks on a physical optical network. To achieve this, the physical layer components of the network will need to be flexible enough to change its performance balance according to various service requirements on each logical network.
In this laboratory, we are researching on the high-speed integrated circuits for optical transceiver, that can change their specifications flexibly to suit the various service requirements for the bit rate (time, wavelength, sub-carrier, and modulation format), power consumption and digital-signal processing delay.
Furthermore, the optical burst-mode transmission technique is also investigated to applied the elastic transceiver to the optical access services. A new circuit configuration that makes flexibility without a degradation of the instantaneous response will be examined. In addition, a circuit configuration that allows flexible selection of the combination of the bit-rate and power consumption according to traffic conditions while maintaining the fairness between users will be studied.
