Optical burst switching (OBS) has been paid increasing attention as an attractive alternative for building future photonic Internet. Besides pure theoretical research, experimental prototype and proof-of-concept demonstration are also significant parts toward practical burst switched WDM optical networks. This paper describes hardware architecture, software module and experimental results of optical burst switching nodes using a just-enough-time (JET) protocol and contention resolutions. The core node forwards bursts in the optical domain with deflection routing resolution. It is designed to be transparent to the format, the protocol and the bit rate of traffic. The edge node performs burst assembly/disassembly, as well as burst forwarding, which makes it flexible to be applied to various topologies. The related control protocols and algorithms are implemented taking into account characteristics of being used commercial off-the-shelf devices. By the experiments, the basic function of optical burst switching is demonstrated, the delay measurement result is analyzed, and the effort direction is given.
In WDM wavelength routed networks, prior to a data transfer, a call setup procedure is required to reserve a wavelength path between the source-destination node pairs. A distributed approach to a connection setup can achieve a very high speed, while improving the reliability and reducing the implementation cost of the networks. However, along with many advantages, several major challenges have been posed by the distributed scheme in how the management and allocation of wavelength could be efficiently carried out. In this thesis, we apply a distributed wavelength assignment algorithm named priority based wavelength assignment (PWA) that was originally proposed for the use in burst switched optical networks to the problem of reserving wavelengths of path reservation protocols in the distributed control optical networks. Instead of assigning wavelengths randomly, this approach lets each node select the “safest” wavelengths based on the information of wavelength utilization history, thus unnecessary future contention is prevented. The simulation results presented in this paper show that the proposed protocol can enhance the performance of the system without introducing any apparent drawbacks.