Split reservation protocols using multiple wavelengths (SRPM) in dense WDM optical networks

In GMPLS based WDM optical networks, a suitable signaling protocol is used to dynamically set up lightpaths. An important step, apart from routing and wavelength selection, in lightpath establishment is wavelength reservation. Protocols for wavelength reservation, as a part of signaling protocols, aim to minimize the blocking of lightpaths, which arises due to unavailability of wavelengths resulting from scarcity of wavelengths and/or collision of wavelengths. Since uni-wavelength reservation techniques attempt to reserve single wavelength, probability of blocking is more in them, compared to multi-wavelength reservation methods that scouts multiple wavelengths for reservation. In this work, we combine multi-wavelength reservation with dynamic splitting (at intermediate nodes) to propose two new protocols: Multi-wavelength Split Reservation Protocol with aggressiveness (SRPM-a) and Multi-wavelength Split Reservation Protocol with retry (SRPM-r). A comparative study with other analogous wavelength reservation protocols reveals that the proposed two protocols perform better than their peers. However, between them, SRPM-r performs considerably better than SRPM-a typically in dense WDM networks.