Novel resource reservation schemes for optical burst switching

Abstract

We propose to improve the throughput performance of optical burst switching by using regional controller nodes and window-based reservation. Both methods increase the information available to the intermediate nodes during scheduling decisions. Simulations show that the proposed reservation schemes provide significant improvement in the throughput performance compared with the original optical burst switching when the network is heavily loaded.

Performance Improvement Methods for Burst-Switched Networks

“…First, the additional T wd time delay of the control packet in OBS will increase the equivalent control packet processing time to T c p + T wd . Note that a normal JET system with control packet processing time T c p + T wd will have larger blocking probability than that with control packet processing time T c p unless T c p is much larger than the average data burst transmission time L. Similarly, a WBS OBS scheme can have even lower throughput if T c p is not much larger than L. Therefore, for the WBS OBS schemes, we can assume that T c p is much larger than L [19] or the T wd delay time is compensated [8,20]. WBS OBS assuming large T c p does not require any additional hardware and only needs to extend the initial offset time at the source, i.e., T off = H × (T c p + T wd ) + T sw .…”

“…A common approach is to virtually assign output channels to CP x and other control packets that have arrived in the T wd time period according to the arrival sequence of their associated data bursts [8,19,20]. The data burst DB x of CP x will get the channel that is assigned to DB x in the virtual channel assignment.…”

VB-Rescheduling: An Efficient Data Channel Rescheduling Algorithm Based on Virtual Burst for OBS Networks

“…For example, the offset time has been lengthened in order to provide QoS classes to the data bursts [2]. As a consequence, the variation of the offset times can be large, and the arrival sequence of the data bursts at a node can often be different from that of the control packets, leading to inefficient resource scheduling [3].…”

“…Therefore, in order to solve such problems and improve network performance, there are many data channel scheduling algorithms proposed [3]- [8]. We can classify them into two types based on different basic ideas.…”

“…We can classify them into two types based on different basic ideas. One aims at adjusting the sequence of scheduling data bursts and make the data channel scheduling more reasonable [3]- [4]. The other considers how to make better use of the voids on data channels [5]- [6].…”