Reconfigurable Coded WDM with Arrayed-Waveguide-Gratings to Enhance Confidentiality on Fiber-to-the-Home Networks

In order to enhance the degree of confidentiality in the last mile access network, a reconfigurable coded wavelength-division-multiplexing Ethernet passive optical network scheme (reconfigurable coded WDM-EPON) is presented to protect against eavesdropper on fiber to the home (FTTH) network. Rather than employing wavelength-hopping, time-spreading or spectral phase coding approaches, which all involve huge code space, this study applies spectral amplitude coding (SAC) with unipolar maximal-length sequence (M-sequence) as signature address code. By exploiting the inherent cyclic properties in arrayed-waveguide-grating (AWG) routers, the AWG-based reconfigurable encoder/decoder (codecs), which requires minimal code space but additional optical switches and controller units, is demonstrated. Furthermore, both qualitative and quantitative analyses of protecting against eavesdropping are investigated. Under eavesdropping with a series of photo-detection strategy, the proposed reconfigurable coded WDM-EPON scheme in terms of the degree of confidentiality (DOC) is improved 673 times compared to the conventional wavelength-division-multiplexing EPON (WDM-EPON) for system capacity of N=127