Burst Loss Research Articles

QoS aware routing and wavelength allocation in optical burst switching networks using differential evolution optimization

The issue of burst losses imposes a constraint on the development of Optical Burst Switching (OBS) networks. Heavy burst losses strongly affect the Quality of Service (QoS) intended by end users. This article presents a QoS aware Routing and Wavelength Allocation (RWA) technique for burst switching in OBS networks. The RWA problem is modeled as a bi-objective Integer Linear Programming (ILP) problem, where objective functions are based on minimizing the number of wavelengths used and the number of hops traversed to fulfill the burst transmission requests for a given set of node pairs. The ILP model is solved using a novel approach based on a Differential Evolution (DE) algorithm. Analytical results show that the DE algorithm provides a better performance compared to shortest path routing, which is a widely accepted routing strategy for OBS networks.

Blocking Evaluation and Wavelength Dimensioning of Dynamic WDM Networks Without Wavelength Conversion

In this paper, a new fast and accurate methodology to evaluate the blocking probability (burst loss probability) in dynamic WDM networks without wavelength conversion is presented. The proposed model considers different traffic loads at each network connection (heterogeneous traffic). To take into account the wavelength continuity constraint, the method sees the network as a sequence of networks where all the links have capacity 1. Every network in the sequence is evaluated separately using a heuristic-based analytical technique. Then, a procedure combines the results of these evaluations in a way that captures the dependencies that occur in real systems due to the competition for bandwidth between the different connections. The method efficiently achieves results very close to those obtained by simulation, but orders of magnitude faster, allowing the evaluation of the blocking probability of all users (connections) for mesh network topologies. We illustrate the use of this procedure in the dimensioning of a WDM network, that is, in calculating the number of wavelengths on every network link, by considering the traffic load of every user, the routing algorithm and the maximum connection blocking probability acceptable by every user (quality of service) are determined.

Interleaved coding and sequential transmission scheme for packet‐level forward error correction over burst loss channels

SummaryBurst packet loss is a common problem over wired and wireless networks and leads to a significant reduction in the performance of packet‐level forward error correction (FEC) schemes used to recover packet losses during transmission. Traditional FEC interleaving methods adopt the sequential coding‐interleaved transmission (SCIT) process to encode the FEC packets sequentially and reorder the packet transmission sequence. Consequently, the burst loss effect can be mitigated at the expense of an increased end‐to‐end delay. Alternatively, the reversed interleaving scheme, namely, interleaved coding‐sequential transmission (ICST), performs FEC coding in an interleaved manner and transmits the packets sequentially based on their generation order in the application. In this study, the analytical FEC model is constructed to evaluate the performance of the SCIT and ICST schemes. From the analysis results, it can be observed that the interleaving delay of ICST FEC is reduced by transmitting the source packets immediately as they arrive from the application. Accordingly, an Enhanced ICST scheme is further proposed to trade the saved interleaving time for a greater interleaving capacity, and the corresponding packet loss rate can be minimized under a given delay constraint. The simulation results show that the Enhanced ICST scheme achieves a lower packet loss rate and a higher peak signal‐to‐noise‐ratio than the traditional SCIT and ICST schemes for video streaming applications.

Perfecting Protection for Interactive Multimedia: A survey of forward error correction for low-delay interactive applications

Many current and emerging applications require low-latency communication, including interactive voice and video communication, multiplayer gaming, multiperson augmented/virtual reality, and various Internet of Things (IoT) applications. Forward error correction (FEC) codes for low-delay interactive applications have several characteristics that distinguish them from traditional FEC. The encoding and decoding operations must process a stream of data packets in a sequential fashion. Strict latency constraints limit the use of long block lengths, interleaving, or large buffers. Furthermore, these codes must achieve fast recovery from burst losses and yet be robust to other types of loss patterns.

Traffic-aware congestion control (TACC) for wireless multimedia sensor networks

Wireless multimedia sensor networks (WMSNs) have emerged as a revolutionary technology, that has shifted the focus of low power wireless sensor networks (WSNs). These networks are aimed at gathering and delivering both scalar and multimedia data from the environment. WMSNs inherit the miniature size, low power, low processing and short range wireless communication traits from WSNs. Addition of multimedia content in WMSNs demands fulfillment of various QoS parameters like low end-to-end delay, acceptable jitter rate, low packet loss rate and higher throughput. Over the past few years, considerable research efforts have been directed towards the fulfillment of these QoS requirements; by proposing new traffic-aware medium access and routing algorithms. However, the issues of rate adaptation and congestion control are still largely unexplored. Congestion in wireless networks is a major cause of packet loss resulting in degraded network performance. In WMSNs congestion is a common occurrence, due to the communication of high data rate, bursty video traffic over lossy wireless link. Therefore, it is critical to adjust the sending rate of source nodes based on network conditions. This work investigates the issue of rate adaptation and congestion control in WMSNs. A traffic-aware congestion control protocol (TACC) is proposed that operates on end-to-end principle at the transport layer. The proposed protocol uses burst loss information to detect congestion at the destination and directs source nodes to adjust reporting rate accordingly. The proposed protocol is evaluated using simulation analysis which shows significant improvement in terms of packet losses, end-to-end delay, packet delivery ratio and received picture quality.

Fuzzy-Based Adaptive Length Burst Assembly Technique for Loss Reduction in Optical Burst Switched Networks

Optical burst switching (OBS) is a type of optical switching technology that harnesses the enormous bandwidth potential of the optical fiber to transport huge amounts of data in the form of jumbo packets which are mainly known as bursts. An important issue in OBS is high burst loss resulting from high number of burst contentions. In order to address this issue, an intelligent burst assembly algorithm named Fuzzy-based Adaptive Length Burst Assembly (FALBA) algorithm is proposed. FALBA uses fuzzy logic to intelligently adjust the burst assembly parameter using the incoming traffic load and the current burst size parameter. Simulation results have shown that FALBA out performs the fuzzy adaptive threshold algorithm in terms of burst loss ratio.

Adaptive Flow Assignment and Packet Scheduling for Delay-Constrained Traffic Over Heterogeneous Wireless Networks

Flow assignment and packet scheduling are two processes of deploying limited wireless resources to support high-data-rate transmissions. Optimizing these processes is critical in improving the traffic performance and network utilization. In this paper, we investigate the flow assignment and packet scheduling for multihomed communication of delay-constrained traffic over heterogeneous wireless networks. With regard to the inherent channel diversity and unreliability, large end-to-end delay and burst packet losses pose crucial challenges to guarantee goodput performance of real-time traffic. To address these critical issues, we present an Adaptive Flow Assignment and Packet Scheduling (AFAPS) framework. First, we introduce a “horizontal water filling” algorithm, which effectively integrates the channel resources in heterogeneous wireless networks to maximize the aggregate goodput. Second, we propose an alternative path interleaving scheme, which spreads out the packets' departures over multiple communication paths within the delay constraint to mitigate burst losses. The performance of the proposed AFAPS framework is evaluated through semi-physical emulations in EXata involving real Internet traffic traces. Experimental results show that AFAPS outperforms existing multipath data distribution models, in terms of goodput and end-to-end delay.

On the Highly Stable Performance of Loss-Free Optical Burst Switching Networks

Increase of bandwidth demand in data networks, driven by the continuous growth of the Internet and the increase of bandwidth greedy applications, raise the issue of how to support all the bandwidth requirements in the near future. Three optical switching paradigms have been defined and are being investigated: Optical Circuit Switching (OCS); Optical Packet Switching (OPS); and Optical Burst Switching (OBS). Among these paradigms, OBS is seen as the most appropriate solution today. However, OBS suffers from high burst loss as a result of contention in the bufferless mode of operation. This issue was investigated by Coutelen et al., 2009 who proposed the loss-free CAROBS framework whereby signal convertors of the optical signal to the electrical domain ensure electrical buffering. Convertors increase the network price which must be minimized to reduce the installation and operating costs of the CAROBS framework. An analysis capturing convertor requirements, with respect to the number of merging flows and CAROBS node offered load, was carried out. We demonstrated the convertor location significance, which led to an additional investigation of the shared wavelength convertors scenario. Shared wavelength convertors significantly decrease the number of required convertors and show great promise for CAROBS. Based on this study we can design a CAROBS network to contain a combination of simple and complex nodes that include none or some convertors respectively, a vital feature of network throughput efficiency and cost.

Software-Defined Optical Burst Switching for HPC and Cloud Computing Data Centers

In this paper, we assess the performance of techniques for optical burst switching (OBS) designed for high performance computing (HPC) and cloud computing data center networks (DCNs) by using network-level simulation. We consider short-duration bursts using the faster switching technologies that are now available. The modeled switch architecture features fast optical switches in a single-hop topology with a centralized, software-defined optical control plane. Instead of using OBS with traditional methods (i.e., one-way reservation), we consider OBS with a two-way reservation protocol that results in zero burst loss. We model different workloads with various data rates by considering different edge-to-core network oversubscription ratios to investigate the performance of such designs across usage patterns. Our results reveal that the proposed technique shows considerable improvement in terms of throughput and packet loss ratio and comparable performance in terms of delay when compared to traditional methods of OBS.

Best Fit Void Filling Segmentation Based Algorithm in Optical Burst Switching Networks

<p>Optical Burst Switching (OBS) is considered to be a promising paradigm for bearing IP traffic in Wavelength Division Multiplexing (WDM) optical networks. Scheduling of data burst in data channels in an optimal way is one of a key problem in Optical Burst Switched networks. The main concerns in this paper is to schedule the incoming bursts in proper data channel such that more burst can be scheduled so burst loss will be less. There are different algorithms exists to schedule data burst on data channels. Non-preemptive Delay-First Minimum Overlap Channel with Void Filling (NP-DFMOC-VF) and Non-preemptive Segment-First Minimum Overlap Channel with Void Filling (NP-SFMOC-VF) are best among other existing segmentation based void filling algorithms. Though it gives less burst loss but not existing the channel utilization efficiently. In this paper we propose a new approach, which will give less burst loss and also utilize existing channels in efficient way. Also analyze the performance of this proposed scheduling algorithm and compare it with the existing void filling algorithms. It is shown that the proposed algorithm gives some better performances compared to the existing algorithms.</p><p><em>Journal of Advanced College of Engineering and Management, Vol.1, 2015,</em> pp. 1-10</p><p> </p>

Binary Heap Based Fair Scheduling Algorithm in Optical Burst Switching Networks

In this paper, a binary-heap based fair scheduling algorithm (BFSA) for optical burst switching (OBS) networks is proposed. BFSA calculates the cost function (CF) for every generated burst at edge nodes. CF is calculated using four fair parameters associated with each burst and it is updated at every hop until reaching the destination node. Moreover, a minimum priority queue is implemented using a binary heap tree for all incoming bursts at each code node. In contention case, the minimum cost burst that occupies the root node of the heap is considered as a victim and it is replaced by the new arriving high priority burst flow. BFSA is a fast scheduling scheme that is easily implemented at core nodes with no extra hardware components. BFSA is evaluated in terms of burst loss ratio and throughput using NS-2 simulator. Results reveal that BFSA is able to address fairness in OBS networks as it achieves better burst loss ratio and better throughput. BFSA performs much better than other fairness schemes such as the last hop pre-emption (LHP) and the fair prioritized pre-emption (FPP) schemes. In addition, it shows better fairness performance for higher priority traffic flows.

Flow Scheduling in OBS Networks Based on Software-Defined Networking Control Plane

The separated management and operation of commercial IP/optical multilayer networks makes network operators look for a unified control plane (UCP) to reduce their capital and operational expenditure. Software-defined networking (SDN) provides a central control plane with a programmable mechanism, regarded as a promising UCP for future optical networks. The general control and scheduling mechanism in SDN-based optical burst switching (OBS) networks is insufficient so the controller has to process a large number of messages per second, resulting in low network resource utilization. In view of this, this paper presents the burst-flow scheduling mechanism (BFSM) with a proposed scheduling algorithm considering channel usage. The simulation results show that, compared with the general control and scheduling mechanism, BFSM provides higher resource utilization and controller performance for the SDN-based OBS network in terms of burst loss rate, the number of messages to which the controller responds, and the average latency of the controller to process a message.

Packet dispersion strategy evaluation from the perspective of packet loss pattern and VoIP quality

The appearance of burst packet losses and its devastating effect on Voice over IP (VoIP) service have imposed a requirement for the implementation of loss recovery mechanisms to address VoIP quality during periods when high packet loss is exhibited. Existing loss recovery mechanisms are dependent on end point capabilities, whereas Quality of service (QoS) routing protocols suffer from complexity and scalability issues. In this paper, we examine packet dispersion?s ability to address burst losses and provide a computational model, which is verified using real network testing. A study has been carried out to investigate the effect of different packet dispersion strategies on burst losses, which clearly shows dispersion?s qualitative superiority over single path routing. Furthermore, an analytical approach is proposed resulting in quality estimation obtained by individual strategies. Practical evaluation has shown that each strategy copes differently with various burst scenarios in order to maximize VoIP quality.

Blocking evaluation and analysis of dynamic WDM networks under heterogeneous ON/OFF traffic

This paper presents an efficient and accurate mathematical method to evaluate the blocking probability of burst loss in dynamic WDM networks with wavelength conversion. The proposed model allows different traffic loads to each network connection (heterogeneous traffic). It is shown that the traffic load heterogeneity on a network significantly affects the blocking probability of the connections, and for this reason, it should be considered in the network design and operation. The mathematical solution is efficient, allowing us to obtain the blocking probability of all users (connections) in less than a second for mesh network topologies. Another desirable characteristic of the proposed method is that it gets results very close to those obtained by simulation, but orders of magnitude faster.

How to Enhance the Efficiency of Loss-Less Optical Burst Switching Networks with the Streamline Effect

With the ongoing steady traffic increase in the Internet, the wavelength usage of the supporting optical networks is a critical network efficiency parameter. Therefore, this paper suggests a way how to efficiently and economically achieve this goal in the context of optical burst switching, a very promising technology that has been proposed to overcome the shortcomings of conventional WDM deployment, such as lack of fine bandwidth granularity in wavelength routing and electronic speed bottlenecks in the presence of bursty traffic. In order to mitigate the burst loss and achieve high network efficiency we adapt the loss-less paradigm defined by Coutelen et al. (2010), i.e., the CAROBS framework. In classical OBS networks, the streamline effect ensures a very low level of contention, i.e., efficient transmission, hence we define a routing guided only by the streamline effect. The resulting routing problem is formulated as an optimization model which is solved using a decomposition technique to increase the scalability of the solution process.

Reduced Cortical Activity Impairs Development and Plasticity after Neonatal Hypoxia Ischemia.

Preterm birth and term birth asphyxia result in brain injury from inadequate oxygen delivery and constitute a major and growing worldwide health problem. Poor outcomes are noted in a majority of very premature (<25 weeks gestation) newborns, resulting in death or life-long morbidity with motor, sensory, learning, behavioral, and language disabilities that limit academic achievement and well-being. Limited progress has been made to develop therapies that improve neurologic outcomes. The overall objective of this study is to understand the effect of early brain injury on activity-dependent brain development and cortical plasticity to develop new treatments that will optimize repair and recovery after brain injury.

Exploring parallelism and desynchronization of TCP over high speed networks with tiny buffers

The buffer sizing problem is a big challenge for high speed network routers to reduce buffer cost without throughput loss. The past few years have witnessed debate on how to improve link utilization of high speed networks where the router buffer size is idealized into dozens of packets. Theoretically, the buffer size can be shrunk by more than 100 times. Under this scenario, widely argued proposals for TCP traffic to achieve acceptable link capacities mandate three necessary conditions: over-provisioned core link bandwidth, non-bursty flows, and tens of thousands of asynchronous flows. However, in high speed networks where these conditions are insufficient, TCP traffic suffers severely from routers with tiny buffers.To explore better performance, we propose a new congestion control algorithm called Desynchronized Multi-Channel TCP (DMCTCP) that creates a flow with parallel channels. These channels can desynchronize each other to avoid TCP loss synchronization, and they can avoid traffic penalties from burst losses. Over a 10 Gb/s large delay network ruled by tiny buffer routers, our emulation results show that bottleneck link utilization can reach over 80% with much fewer number of flows. Compared with other TCP congestion control variants, DMCTCP can also achieve much better performance in high loss rate networks. Facing the buffer sizing challenge, our study is a new step towards the deployment of optical packet switching networks.

QuGu

Video dissemination over Vehicular Ad Hoc Networks is an attractive technology that supports many novel applications. The merit of this work lies in the design of an efficient video dissemination protocol that provides high video quality at different data rates for urban scenarios. Our objective is to improve received video quality while meeting delay and packet loss. In this work, we first employ a reliable scheme known as connected dominating set, which is an efficient receiver-based routing scheme for broadcasting video content. To avoid repeated computing of the connected dominating set, we add three statuses to each node. In nonscalable video coding, the distribution of lost frames can cause a major impact on video quality at the receiver's end. Therefore, for the second step, we employ Interleaving to spread out the burst losses and to reduce the influence of loss distributions. Although Interleaving can reduce the influence of cluster frame loss, single packet loss is also a concern due to collisions, and to intermittent disconnection in the topology. In order to fix these single packet losses, we propose a store-carry-forward scheme for the nodes in order to retransmit the local buffer stored packets. The results, when compared to the selected base protocols, show that our proposed protocol is an efficient solution for video dissemination over urban Vehicular Ad Hoc Networks.

Dynamic Home Circuit Construction for Datacenter Networks Using LOBS-HC Ring

Optical switching will be applied in datacenter networks because electronic switching is costly and power-consuming. In this paper, considering the ring-based interconnection using optical switching in the core of a datacenter, we study the home circuit (HC) construction for the labeled optical burst switching with home circuit (LOBS-HC), a new paradigm trying to share wavelengths among the HCs from the same source. In particular, aiming to construct HCs dynamically and properly, a scheme named optimal path matching and symmetric HC matching (OPM-SHM) is proposed. The main idea of OPM-SHM is to dynamically construct HCs by sharing wavelength(s) not only among the same-source HCs but also with symmetric HCs which have different sources other than the original LOBS-HC features. The simulation results demonstrate that OPM-SHM achieves better performance than some other methods in terms of burst loss rate and wavelength utilization of physical links. More specially, it maintains good load balancing for the datacenter network using an LOBS-HC ring. In addition, due to the symmetric feature of SHM, the proposed scheme can decrease the upper bound of the average hop count of the routing paths to half of the ring size.

Combined probabilistic deflection and retransmission scheme for loss minimization in OBS networks

Optical burst switching (OBS) is an appropriate optical switching technology for optical internet considering the bandwidth requirements and technological constraints. However, burst loss remains to be the critical issue in the bufferless OBS network. Many contention resolution schemes were proposed in the literature to address this issue. Deflection routing is regarded as an attractive method for contention resolution in OBS networks. To further reduce the loss, hybrid schemes combining deflection and retransmission were proposed. In this paper, a new hybrid scheme combining the limited retransmission and deflection namely combined probabilistic deflection and retransmission (CPDR) is proposed to achieve loss minimization, overcoming the adverse effects of pure deflection and pure retransmission. The proposed protocol is found to provide 25 percent to 60 percent reduction in burst loss with respect to other similar protocols at higher load conditions. An analytical model is also developed to estimate the burst loss probability of the proposed protocol and the predicted results are found to be in good agreement with simulation based results.