Design of Reconfigurable Multiweight Wavelength-Time Optical Codes for Secure Multimedia Optical CDMA Networks

Multiweight optical codes are one of the alternative designs for differentiated quality-of-service (QoS) in multimedia optical CDMA (OCDMA) networks. In this paper, we address the design of reconfigurable multiweight wavelength-time optical codes that lead to secure multimedia transmission in OCDMA networks. The proposed multiweight wavelength-time optical codes are constructed based on quasigroups (QGs) for wavelength hopping and one-dimensional multiweight optical orthogonal codes (MWOOCs) for time spreading, then called QG/MWOOCs. Both QGs and MWOOCs are randomly generated by computer search. As a result, the proposed QG/MWOOCs have many different code set groups which differ in both time and wavelengths positions. Furthermore, a secure network is suggested by employing reconfigurable encoders/decoders array waveguide gratings (AWGs)-based, which allow the users to change their codewords patterns to protect against eavesdropping. Finally, the degree of security which may provide by the proposed scheme is analyzed. The results show that the proposed scheme offers both differentiated QoS and differentiated quality-of-security (QoSec) in multimedia OCDMA networks.