Hybrid Burst Assembly Research Articles

A Hybrid Burst Assembly Algorithm Based on Transition Count Number for OBS Network

Background: Optical transport has emerged as a candidate solution to cope with the rising data transmission challenges of enormously evolving data. In Optical Burst Switching (OBS) networks, determining an adaptive burst size is a difficult task that must be performed efficiently during burst assembling. Methods: This research proposes a hybrid burst assembly algorithm that determines the optimal burst size during the burst creation time. The proposed algorithm uses the Transition Count Number (TCN) based method to maintain the optimal burst size when the incoming traffic is unpredictable. The efficiency of the proposed approach is investigated in terms of queuing delay, burst utilization, burst size, and burst size consistency. Findings: Three types of traffic variations (H = 0.5, H = 0.6, and H = 0.7) are imposed to evaluate the performance of the proposed burst assembly approach. As compared to the E-hybrid (time/length) strategy, the research outcomes demonstrate a 13.15% reduction in average queuing latency and a 21.26% improvement in average burst utilization. Novelty: A new burst assembly approach (hybrid burst assembly) has been proposed for OBS networks. Keywords: Burst assembly, Optical Burst Switching (OBS), burstification, burst consistency

Channel Scheduling Based on Orchestrator Live Node-Wavelength Reservation for Optical Burst Switching Networks

Background: Dedicated wavelength utilization and the isolation of control plane from the data plane are the important features in the design of Optical Burst Switching (OBS). The contention in bursts, link congestion and the reservation cause the burst dropping in optical networks. The slotted time and the burst assembly models incorporate the wavelength assignment and the channel reservation schemes to reduce the dropping probability. The reservation of resources prior to burst arrival and the additional delay due to the burst assembly and the offset time are the major issues in the reduction of probability. Besides, the traditional one-to-one packet transmission consumes more time due to a large number of packets handling. Materials and Methods: This paper proposes the novel OBS model that incorporates the three processes such as Open-Flow (OF)-based Orchestrator Live Node (OLN) modeling, fuzzy logic based ranking and the offset time-based reservation (without/with void filling) to overcome the issues in the traditional methods. Initially, the OLN modeling based on OF analysis includes the Flow Information Base (FIB) table for the periodical update of the link information. The fuzzy logic- based ranking of channels followed by OF-OLN predicts the status of the wavelength such as free, used and conversion. Based on the status, the channels are reserved without and with void filling to schedule the bursts effectively. The reservation scheme employs the Offset-Time Burst Assembly algorithm to allow the resource reservation prior to burst arrival. Through these processes, the reuse of wavelength and the reallocation of resources are possible in OBS. Results & Conclusion: The controlling of maximum burst transfer delay by the OTBA efficiently reduces the end-to-end delay for data traffic. The comparative analysis between the proposed OLN-WR with the existing Hybrid Burst Assembly (HBA), Fuzzy-based Adaptive Threshold (FAT) and Fuzzy-based Adaptive Hybrid Burst Assembly (FAHBA) in terms of end-to-end delay and transmitted amount of bursts assures the applicability of OLN-WR in scheduling and communication activities in OBS networks.

Fuzzy-Based Adaptive Hybrid Burst Assembly Technique for Optical Burst Switched Networks

The optical burst switching (OBS) paradigm is perceived as an intermediate switching technology for future all-optical networks. Burst assembly that is the first process in OBS is the focus of this paper. In this paper, an intelligent hybrid burst assembly algorithm that is based on fuzzy logic is proposed. The new algorithm is evaluated against the traditional hybrid burst assembly algorithm and the fuzzy adaptive threshold (FAT) burst assembly algorithm via simulation. Simulation results show that the proposed algorithm outperforms the hybrid and the FAT algorithms in terms of burst end-to-end delay, packet end-to-end delay, and packet loss ratio.

Hybrid approach for loss recovery mechanism in OBS networks

This letter reports a study of a hybrid burst assembly and a hybrid burst loss recovery scheme (delay-based burst assembly and hybrid loss recovery (DBAHLR)) which selectively employs proactive or reactive loss recovery techniques depending on the classification of traffic into short term and long term, respectively. Traffic prediction and segregation of optical burst switching network flows into the long term and short term are conducted based on predicted link holding times using the hidden Markov model (HMM). The hybrid burst assembly implemented in DBAHLR uses a consecutive average-based burst assembly to handle jitter reduction necessary in real-time applications, with variations in burst sizes due to the non-monotonic nature of the average delay handled by additional burst length thresholding. This dynamic hybrid approach based on HMM prediction provides overall a lower blocking probability and delay and more throughput when compared with forward segment redundancy mechanism or purely HMM prediction-based adaptive burst sizing and wavelength allocation (HMM-TP).

On Delay Performance and Burst Assembly for Wireless Mesh and Optical Burst Switching Converged Metro Area Network

Wireless Mesh Networks (WMN) have attracted increasing attention from the research community as a high-performance and low-cost solution to last-mile broadband Internet access. On the other side, Optical Burst Switching (OBS) is a promising access technology that uses optical fiber with burst switching paradigm. In this paper, we propose a novel Metropolitan Area Network (MAN) architecture, called Optical Burst Wireless Mesh Architecture (OBWMA) which integrates WMN at the user access side and OBS at the core of the MAN. OBWMA aims to combine advantages of both WMNs and OBS networks, such as large coverage at low cost and bandwidth availability. We specify the details of the interconnection and the internetworking of WMNs and the OBS network in OBWMA. Moreover, we develop an analytical model to compute the end-to-end delay in OBWMA in order to support flow requests with delay constraints. Furthermore, we propose a Control Bridge (CB) that ensures Quality of Service (QoS) mapping at the border between the WMN and the OBS parts. Also, we propose a burst assembly scheme, called Adaptive Hybrid Burst Assembly scheme (AHBA). Simulation results using ns-2 demonstrate the feasibility of OBWMA and the validity of our analytical model.

An Efficient Network Utilization Scheme for Optical Burst Switched Networks

Optical Burst Switching (OBS) is one of the most important switching technologies for future IP over wavelength division multiplexing (WDM) networks. In OBS Network, the burst assembly technique is a challenging issue in the implementation of the system. Burst assembly influences burst characteristics, which negatively impacts network performance. In this paper, the authors propose an efficient hybrid burst assembly approach, which is based on approximate queuing network model. To reduce the time complexity, an approximate queuing network model has been considered. Throughput performance has been investigated, taking into account both burst loss probability and time complexity. Simulation results have shown that the proposed hybrid approach based on variable burst length threshold and fixed maximum time limitation provides Simulation results have also shown a good trade-off between burst blocking performance and scheduling time.

Loss rate-based burst assembly to resolve contention in optical burst switching networks

Two loss rate-based optical burst assembly techniques addressing contention resolution are studied. These techniques stem from the burst assembly schemes using adaptive thresholds, which have been introduced earlier by the authors. The loss rates on the links/paths leading to the destination nodes are used to estimate congestion levels. Three alternative time and size threshold value pairs are employed based on the congestion level observed. Here, the aim is to generate short bursts under heavy traffic and long bursts under light traffic conditions in order to enhance performance. The results that are obtained in terms of byte loss rate and delay are compared with those of the hybrid burst assembly. It is observed that the adaptive techniques significantly enhance the byte loss rate as traffic gets heavier while keeping end-to-end delay in a feasible range.

Performance of OBS techniques under self-similar traffic based on various burst assembly techniques

In this paper, the performance of some well-known Optical Burst Switching (OBS) techniques is analyzed under self-similar traffic using the time threshold based burst assembly and the hybrid burst assembly techniques. The characteristics of the optical bursts formed at ingress nodes by the burst assembly techniques are studied extensively by changing input traffic load and the time threshold value. The performance of the OBS techniques, which are the horizon scheduling technique, two void filling techniques, and the group scheduling technique, are evaluated in terms of burst loss rate and byte loss rate. Although, in the OBS literature, burst loss rate is a commonly employed metric, it is observed that the burst loss rates obtained are different than the corresponding byte loss rates. Such a result is caused by variable burst sizes. It is also seen that the performance ranking using burst loss rate is not the same as the performance ranking using byte loss rate for some cases due to the characteristics of the OBS techniques. Moreover, the traffic characteristics of the optical bursts at ingress and egress nodes are examined in terms of the Hurst parameter values. It is observed that the self-similarity of the incoming traffic is mainly affected by the burst assembly techniques. It is shown that when the TTh based burst assembly is used, the Hurst parameter of the traffic degrades drastically. However, when the hybrid burst assembly is employed, the Hurst parameter of the traffic remains closer to the Hurst parameter of the original self-similar IP traffic.

A Novel Contention Resolution Scheme for Optical Burst Switching Network

Optical burst switching (OBS) is a promised newly technology to implemented the all-optical transmission for Internet protocol (IP) traffic. How to effectively resolve the burst contention at the core router and propose a QoS (Quality of Service) supported burst assembly technique is a critical issue in nowadays. In this paper, a novel burst contention resolution scheme for OBS network has been proposed, this scheme based on two main aspects. Firstly, we propose a new burst segmentation approach named both-direction-segmentation (BDS), which could subtly take the advantages of burst head-segmentation and burst tail-segmentation approach. Secondly, corresponding to BDS, a novel burst assembly technique, which we called hybrid burst assembly (HBA) also has been proposed. Different from several existing burst assembly techniques, which only protect high-priority bursts. HBA has also been considered to protect the relatively high-class packets in low-priority bursts. A simulation is given out at the end of this paper, we observe that the proposed contention resolution scheme not only could minimize the losing of packets remarkably but also could efficiently and veritably support QoS for OBS network. The results have some valuable theoretic significances to design the real network in practice.