Performance Analysis of Smart Optical Burst Switching Networks for Different Signaling Protocols

Abstract

A future optical transport network needs an extremely high capacity to satisfy the rapid increase in traffic. Many technologies have been developed to increase throughput and energy efficiency and simplify the deployment of optical transport networks. Internet Protocol traffic transmission precedes optical transport networks in requiring new approaches for network nodes. Although optical fiber has a tremendous capacity, switching nodes limit the performance of optical networks. An optical burst switched network concept has been introduced as a promising solution to overcome this problem. Optical burst switched technology effectively utilizes the advantages of both circuit switching and packet switching networks, and also eliminates their drawbacks. Two important issues in achieving the best performance in optical burst switched networks are scheduling bursts and signaling protocols. In this paper, we provide a comprehensive analysis of optical burst switched signaling protocols. We study three protocols for signaling in optical burst switched networks that are used for various traffic types. The Tell-and-Wait and Just Enough Time protocols are used in extreme cases of loss-sensitive and delay-sensitive traffic, respectively. The third signaling protocol, called Intermediate Note Initiation, is a promising solution with an ability to adjust parameters depending upon traffic requirements. We analyze the blocking probability of core nodes with respect to the number of buffers and wavelengths for each signaling protocol. The simulation results show that when the number of optical buffers are five or higher, blocking probability tends to be zero, regardless of the number of wavelengths. Therefore, this tends to decrease loss due to a burst, and improves the overall performance of optical burst switched networks. The burst outstripping problem in optical fiber has been solved by determining a proper buffering policy for each burst, after considering the burst priorities and time delays between consistent bursts.