Study On Optical Virtual Private Networks In A Wavelength Division Multiplexing Passive Optical Network

With the rapid development of optical access networks, the number of users and the demandof bandwidth are increasing. Users in the same PON may need to communicate directly witheach other for various services, such as high-definition video, teleconferencing. WDM-PON isone of the mainstream technologies for next-generation optical access networks with highreceiver sensitivity, large bandwidth and protocol transparency. Therefore, the study on how tobuild optical virtual private networks (OVPN) in a WDM-PON has theoretical and practicalsignificance.This paper mainly studies on optical virtual private networks in a WDM-PON. For thestructure of traditional PON, communications among ONUs must go through OLT. This paperpresents a new OVPN architecture with ONU-ONU direct communication capability, which usesarrayed waveguide gratings in ODN to add routing function among ONUs. Compared withtraditional ONU-ONU communication, it decreases the network latency, increases thecommunication security and improves the wavelength utilization, which also achieves highsurvivability and good anti-interference ability. The simulation results show that when the BERis set at 1×10^-9 and multiple signals coexist, the receiver's power penalty is only 0.5dB, whichmeans a good anti-crosstalk ability.Then the problems in the original scheme are pointed out. Through the analysis of existingcolorless ONU and remodulation techniques, a remodulation scheme based on RSOA is designedin ONUs, which makes the ONU be the colorless ONU and improves the downlink performance.Compared with the original scheme, it simplifies the network construction, reduces the cost ofequipments'operation and maintenance. The simulation results demonstrate its feasibility. Underthe cost budget permitting, the BER performance of remodulated signals can be improved 3.4dBby adding an EDFA in the ODN.