Confidential enhancement with reconfigurable AWG-based optical CDMA codec over fiber-to-the-home access network

By extending a protecting mechanism called anticipative warning time policy to improve previous coded-WDM scheme, the reconfigurable arrayed-waveguide grating (AWG)-based coder/decoder (codec) architecture is presented to enhance data confidentiality over fiber-tothe-home (FTTH) access networks. To avoid the huge code space requirements of wavelength hopping, time spreading, or spectral phase coding approaches, this study applies a spectral amplitude coding (SAC) technique and constructs signature address codes using unipolar maximal-length sequence (M-sequence) code. Exploiting the inherent cyclic properties of AWG routers, additional anticipative-warning-time policy is integrated to previous degree of weighted load balance (DWLB) policy and performs the changing codeword algorithm to thwart network attacks by eavesdroppers. Furthermore, the qualitative and quantitative evaluations of the system's network protection performance are investigated by assessing the attained degree of confidentiality (DOC). Under the assumption of the brute-force searching attacking, the proposed active changing codeword scheme shows that for a system capacity of N = 127, the proposed system enhances data network confidentiality by a factor of 8063 times that provided by conventional wavelengthdivision multiplexed PON (WDM-PON) scheme.