Upstream access and local customer networking in passive optical networks using a single wavelength-seeded reflective semiconductor optical amplifier

All‐optical virtual private network in passive optical networks

“…Some previous schemes employed different wavelengths for the private VPN networking and public communication, respectively [24,28,31,[33][34][35][36][39][40][41][42]. With a wavelength-sensitive component such as an optical filter or wavelength-division multiplexing (WDM) Mux/Demux equipped at the remote node or the ONU side, VPN data can be separated from the conventional downstream and upstream traffic.…”

“…Hybrid orthogonal modulation formats are also used to differentiate the private and public communications [38,43,44]. In addition, specific sub-carrier bands [29,30] or time slots [26,27,34,35,37] can be assigned to the different types of connections.…”

“…The wavelength-selective reflection using fiber Bragg grating (FBG) is a good candidate for establishing all-optical VPN with specific wavelengths [24,29,30,[36][37][38][42][43][44]. A star-coupler can directly route the private traffic to the ONUs with relatively low insertion loss [25][26][27][28][29][30][31][33][34][35]. A cyclic N×N array waveguide grating (AWG) can efficiently route the communications among ONUs in a WDM-PON [39][40][41].…”

“…A cyclic N×N array waveguide grating (AWG) can efficiently route the communications among ONUs in a WDM-PON [39][40][41]. Reflective semiconductor amplifier (RSOA) [33][34][35] at the ONU side or fiber amplifier at the OLT side [43,44] can be used to boost the VPN and/or upstream signals to enhance the scalability of the network.…”

“…Another RSOA based architecture similar to [33] is depicted and discussed in [34], in which the separation of VPN and upstream traffic is completed in the remote node instead of in each ONU.…”