Research On Ethernet Technologies Of100GBASE-LR4Based On Optical Duo-Binary Modulation

Internet IP traffic has been increased in a speed which doubles in everyyear for more than20years, and now it’s still continuing, which becomeimpossible to meet the application requirement with current technology. Sothe research on100G Ethernet technology is well under way now.100GBASE-LR4which is an important part of100G Ethernet technologyrequires for40km transmission. Currently, the challenge for100GBASE-LR4transmission at1310nm is loss. For compensating theextra loss, optical amplifier is required. While at1550nm, the challenge forthe transmission is chromatic dispersion. If using NRZ, for40kmtransmission, extra dispersion compensation is required, which cause thesystem more complex and more expensive. Therefore, the main challengenow for100GBASE-LR4is to accomplish40km transmission withoutoptical amplifier or dispersion compensation.This paper is supported by the National863Program Keytechnologies for100GE and transmission systems, and the main research including:1) VPI simulation for100GBASE-LR4Model the100GBASE-LR4transmission system based on OpticalDuo-Binary (ODB) modulation. Set the simulation parameters according tothe actual transmitter, and simulate the Bit Error Rate (BER) for thetransmission system via VPI. A WDM transmission over G.652SMFs at1550nm with fixed channel spacing of50GHz is simulated, and for differenttransmission distance, VPI simulation results show the eye diagrams, BERperformance and also simulate the limitation distance for transmissionunder10-12.2)4×25Gbps PRBS generation and BER testFour25Gbps PRBS generators and one BER testing system are neededfor100GBASE-LR4experimental platform, and the platform setup is basedon a14Gbps BER testing system in lab. We accomplish25Gbps BERtesting system by using4:1electrical Mux,1:4electrical Demux and somesignal splitting technologies.3) Designs for25Gbps ODB transmitterIn experiment, we design the25Gbps ODB transmitters in two ways.One is single-ended driving with narrow-band driver, another is differentialdriving with broadband driver and low-pass filters. For both designs, we test the eye diagrams and BER performance for different distance. According tothe experiment results, we accomplish the100GBASE-LR4transmissionsystem.4) Experiment for100GBASE-LR4Complete the experiment for100GBASE-LR4on the base of platformsetup. The experiment results verify an amplifier-less40km G.652SMFstransmission for100GBASE-LR4based on Optical Duo-Binary modulationat1550nm.5)100GBASE-LR4sampleOn the base of experiment, we design a100GBASE-LR4sample forimproving the system stability and anti-interference ability, which includingsignal generator sample, transmitter sample and receiver sample.