Abstract: This paper focuses on the research on conventional p-cycle algorithms’ performance degradation while there is not any wavelength converter in optical networks. Further, two improved strategies of p-cycle algorithms, viz. FPLC (Fixed Paths Least Congestion) pre-routing algorithm and wavelength complement configuration method, are proposed. Based on our extensive simulations, it can be concluded that the improved p-cycle algorithms can well satisfy the wavelength continuity requirement when the protection switch is being performed compared with the conventional p-cycle algorithms, in spite of a little higher block probability of dynamic traffic. Thus our work is contributive to applying p-cycle protection to present optical networks.

Key words: optical networks, p-cycle algorithm, wavelength continuity, wavelength complement configuration, FPLC