Adaptive wavelength allocation in GMPLS controlled optical network

Different wavelength assignment schemes have been proposed in the literature for improving the blocking performance in optical networks. In this paper we analyze first fit and random wavelength assignment techniques. In the first fit case, the destination node selects the least indexed wavelength from the set of available wavelengths, whereas in random assignment the wavelength is selected randomly from the set of available wavelengths. In this paper, we propose a new wavelength assignment scheme that is highly adaptive. We begin by comparing the blocking performance of two schemes and observing that the first fit scheme outperforms the random assignment scheme if link utilization is high. In any network, link utilization varies from time to time; it is therefore desirable to switch between the wavelength assignment techniques depending on the link utilization so as to attain optimal blocking performance. Here, we propose an adaptive wavelength assignment (AA) technique that can dynamically switch between different wavelength assignment schemes based on link utilization. Our performance study indicates that, as the link utilization changes, the nodes adaptively select the best wavelength assignment technique in real time so as to improve the blocking performance.