Optical burst Grooming, Routing and wavelength assignment in OBS networks

In this paper, we address the problem of routing and wavelength assignment (RWA) and optical grooming of data bursts in segment-based traffic of Optical Burst Switching (OBS) networks. This problem has been extensively treated in circuit based WDM networks, but not in the context of OBS networks. We propose a novel formulation of this problem and we develop an optimization algorithm for optical path determination taking into consideration burst grooming process that aggregate in one burst different overlapping bursts transmitted to the same destination. This process is executed in the core node and is based on the availability of Virtual Optical Memory (VOM©) resources. Hence, these two mechanisms can reduce burst contention and improve bandwidth utilization on the optical fiber. A performances study was performed by evaluating, burst blocking and average transmission delay according to wavelength availability, traffic loads, and VOM© characteristics.