A Data Burst Assembly Algorithm in Optical Burst Switching Networks

Abstract

Presently, optical burst switching (OBS) technology is under study as a promising solution for the backbone of the optical Internet in the near future because OBS eliminates the optical buffer problem at the switching node with the help of no optical/electro/optical conversion and guarantees class of service without any buffering. To implement the OBS network, there are a lot of challenging issues to be solved. The edge router, burst offset time management, and burst assembly mechanism are critical issues. In addition, the core router needs data burst and control header packet scheduling, a protection and restoration mechanism, and a contention resolution scheme. In this paper, we focus on the burst assembly mechanism. We present a novel data burst generation algorithm that uses hysteresis characteristics in the queueing model for the ingress edge node in optical burst switching networks. Simulation with Poisson and self‐similar traffic models shows that this algorithm adaptively changes the data burst size according to the offered load and offers high average data burst utilization with a lower timer operation. It also reduces the possibility of a continuous blocking problem in the bandwidth reservation request, limits the maximum queueing delay, and minimizes the required burst size by lifting up data burst utilization for bursty input IP traffic.

A model of optimal burst assembly for delay reduction at ingress OBS nodes

“…Comparing the distribution of the estimation error rate between the OBADR model and Jiang's model, which are the best among the previous models; and 3. Comparing the OBADR model and the previous models in terms of number of excess packets in 100 consecutive burst assemblies.…”

“…As shown in Figure 2, the arriving electronic packets are classified based on their destinations. There are two basic models of burst assembly: the time-based model [2] and the length-based model [3]. In the time-based model, a timer is initiated when the first packet arrives at an empty queue, and a burst is completed when the timer reaches a predefined time threshold ( T a ) .…”

“…The basic models of burst assembly, namely the timer-based model [2], the length-based model [3], and the hybrid model [4,5], do not study reducing the buffering delay; however, the models of burst assembly for delay reduction [6][7][8][9][10][11] try to eliminate the offset time by sending the BCP early, before the completion of its * Correspondence: vvmnhat@hueuni.edu.vn burst. However, it needs to estimate the length of the completed burst, because this information must be carried in the BCP.…”

Delay-throughput curves for timer-based OBS burstifiers with light load

“…Precisely, a number of burstification algorithms have been proposed and analyzed [1], [2], [3], [4], [5], [6]. In [5], three categories are identified: i) timebased algorithms, ii) burst-length-based algorithms and mixed time/burst-length algorithms.…”

A hybrid optical network architecture consisting of optical cross connects and optical burst switches

“…Current research on OBS focuses on a number of areas, which include OBS network architecture [Tur99], [YQ99], [XVC00], [DB02], resource allocation and reservation mechanisms [DGSB01], burst aggregation mechanisms [OK02], burst shaping [CVR02], Quality of Service (QoS) support [YQD00], [YQD01], labeled switched OBS [Qia00], performance of TCP over OBS [DL02] and many others. All of these studies assume a network consisting of OBSes alone.…”