All-optical virtual private network utilizing bit allocation in OFDM-PON system

We propose a new all-optical virtual private network (AOVPN) using bit allocation technique in an orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) for the first time. The proposed system makes full use of the fundamental advantages of OFDM such as high spectral efficiency, dispersion tolerance, and flexibility in bandwidth allocation. It enables the simultaneous transmission of upstream (U/S) data and VPN data by multiple users. Since the U/S signal and the VPN signal are separated into bits within a high-order symbol, flexible resource management is possible according to real-time requirements. The feasibility of the proposed system is demonstrated in a 20-km single-fiber loopback link as a proof of concept. The experiment is focused on the optical transmission of VPN and U/S data. The results include performance variations of VPN transmission according to the bit allocation in a full-band uplink without multiple access and verification of dynamic bandwidth allocation (DBA) considering the multiple access by multi-users