Services For Real-time Applications Research Articles

Reliable Bidirectional Data Transfer Approach for the Internet of Secured Medical Things Using ZigBee Wireless Network

Nowadays, the Internet of Things (IoT) performs robust services for real-time applications in monitoring communication systems and generating meaningful information. The ZigBee devices offer low latency and manageable costs for wireless communication and support the process of physical data collection. Some biosensing systems comprise IoT-based ZigBee devices to monitor patient healthcare attributes and alert healthcare professionals for needed action. However, most of them still face unstable and frequent data interruption issues due to transmission service intrusions. Moreover, the medical data is publicly available using cloud services, and communicated through the smart devices to specialists for evaluation and disease diagnosis. Therefore, the applicable security analysis is another key factor for any medical system. This work proposed an approach for reliable network supervision with the internet of secured medical things using ZigBee networks for a smart healthcare system (RNM-SC). It aims to improve data systems with manageable congestion through load-balanced devices. Moreover, it also increases security performance in the presence of anomalies and offers data routing using the bidirectional heuristics technique. In addition, it deals with more realistic algorithm to associate only authorized devices and avoid the chances of compromising data. In the end, the communication between cloud and network applications is also protected from hostile actions, and only certified end-users can access the data. The proposed approach was tested and analyzed in Network Simulator (NS-3), and, compared to existing solutions, demonstrated significant and reliable performance improvements in terms of network throughput by 12%, energy consumption by 17%, packet drop ratio by 37%, end-to-end delay by 18%, routing complexity by 37%, and tampered packets by 37%.

On the Usage of Multilink Access Methods for Service of Real-Time Applications in Wi-Fi Networks

On the Usage of Multilink Access Methods for Service of Real-Time Applications in Wi-Fi Networks

Multicriteria Handover Management by the SDN Controller-based Fussy AHP and VIKOR Methods

A wireless environment is characterized by its dynamic nature, inherent uncertainty, and imprecise parameters and constraints. Network settings such as speed, RSS, network delays, etc. are inherently imprecise. Due to this vagueness, accurately measuring these network parameters in a wireless environment is a difficult task. As a result, a fuzzy logic approach appears to work best when used to design systems in such environments. Although conventional techniques based on precise values can be used to reduce transmission delay, they cannot produce intelligent and efficient transfer decisions that take into account all the constraints of the network. Thus, using one criterion only can lead to service disruption, unbalanced network load, and inefficient handoff. Therefore, to guide the Horizontal handover process in wireless networks towards making a better choice for VoIP in congested environments, we propose the integration of the Fuzzy-AHP and VIKOR method in SDN (Software Defined Networking) controller on several criteria (the signal-to-noise ratio plus interference (SNIR), packet loss, jitter, delay, throughput). However, the results of this work show that our contribution maintains a good quality of service for real-time applications.

Energy efficient clustering and routing optimization model for maximizing lifetime of wireless sensor network

Recently, the wide adoption of WSNs (Wireless-Sensor-Networks) is been seen for provision non-real time and real-time application services such as intelligent transportation and health care monitoring, intelligent transportation etc. Provisioning these services requires energy-efficient WSN. The clustering technique is an efficient mechanism that plays a main role in reducing the energy consumption of WSN. However, the existing model is designed considering reducing energy- consumption of the sensor-device for the homogenous network. However, it incurs energy-overhead (EO) between cluster-head (CH). Further, maximizing coverage time is not considered by the existing clustering approach considering heterogeneous networks affecting lifetime performance. In order to overcome these research challenges, this work presents an energy efficient clustering and routing optimization (EECRO) model adopting cross-layer design for heterogeneous networks. The EECRO uses channel gain information from the physical layer and TDMA based communication is adopted for communication among both intra-cluster and inter-cluster communication. Further, clustering and routing optimization are presented to bring a good trade-off among minimizing the energy of CH, enhancing coverage time and maximizing the lifetime of sensor-network (SN). The experiments are conducted to estimate the performance of EECRO over the existing model. The significant-performance is attained by EECRO over the existing model in terms of minimizing routing and communication overhead and maximizing the lifetime of WSNs.

A Novel Analysis of Advanced Visual Cryptography Techniques for Providing Security Against Web Attacks Using Support Vector Machine Technique

In today’s internet applications such as some real time application services like core banking and other public service oriented application have been major issue in authentication of user specification. To perform online dictionary attacks, passwords have been used for security and authentication mechanism. Present days, hacking of databases on web oriented applications is unavoidable to access them easily. Data maintenance is a complex task in internet applications. To solve these type of problems in internet applications, in this paper, we proposed a novel Integrated and Dynamic CAPTCHA (Completely Automated Public Turing Test to Tell Computers and Humans Apart) (I&D CAPTCHA), which is extension version of existing CAPTCHA that valuated third party human attacks in internet applications based Visual Cryptography approach to discuss about authentication problem in real time applications. There is more number of methods presented for security in advanced pictures for insurance from inventive uninvolved or dynamic assaults in system correspondence environment. Like insightful Visual Cryptographic (VC) is a cutting edge strategy, which is utilized to mystery picture safely impart furthermore keep up to privacy. To proceed with difficulties of security in advanced picture information sharing, so in this paper we break down various VC security instruments for computerized picture information offering to regard tomystery information secrecy. Our examination give effective security answers for relative mystery advanced picture information imparting to correspondence progressively environment. Security aspects are main concepts in present days because of increasing statistical data storage. In Artificial Intelligence (AI) oriented applications, it is very difficult in terms of protection to increasing new aspects in real time world. So we also plan a Novel and Advanced Security system to enable solution for basic AI problems in this paper. This framework mainly works based on Captcha as visual security passwords (CaRP); it is two way communication plan which means that, it is the combination of Captcha and visual security plan. Our approach mainly worked with image security with respect to selection of passwords based on random way. In this paper, we also propose AMODS, an adaptive system that periodically updates the detection model to detect the latest unknown attacks. We also propose an adaptive learning strategy, called SVM HYBRID, leveraged by our system to minimize manual work. Our system out performs existing web attack detectionmethods, with an F-value of 94.79% and FP rate of 0.09%. The total number of malicious queries obtained by SVM HYBRID is 2.78 times that by the popular Support Vector Machine Adaptive Learning (SVMAL) method. The malicious queries obtained can be used to update the Web Application Firewall (WAF) signature library.

Neural adaptive admission control framework: SLA-driven action termination for real-time application service management

Currently, data centres employ much more computational power, machines and energy than it is really needed to provide the required level of service and ensure customer satisfaction. This is a resul...

A QoS-aware I/O mechanism for jitter-free multimedia playing in smart devices

As multi-tasking has become the common feature of modern smart devices, providing QoS (quality of service) guarantees for heterogeneous applications becomes challenging. For example, if a real-time application like a movie player is executed simultaneously with other applications, jitters may be experienced due to resource contention among the concurrent processes. This paper presents a novel I/O mechanism to provide jitter-free multimedia playing in smart devices. To this end, the I/O paths of smart devices were explored and two sources of unpredictable latency were discovered. The first one is the garbage collection overhead of flash memory and the second one is the non-preemptive scheduling used in the software platform of smart devices. This paper resolves these problems by adopting non-volatile memory as the storage of real-time applications, and then performing non-blocking I/O for them. This mechanism completely prevents all possible run-time delays due to the interferences of other processes, providing QoS-guaranteed services for real-time applications. Tracedriven simulations show that the proposed scheme reduces the deadline miss ratio of a movie player by 40% on average.

A Distributed Sequential Link Schedule Combined with Routing in Wireless Mesh Networks

This letter proposes a new distributed scheduling scheme combined with routing to support the quality of service of real-time applications in wireless mesh networks. Next, this letter drives average end-to-end delay of the proposed scheduling scheme that sequentially schedules the slots on a path. Finally, this letter simulates the time division multiple access network for performance comparison. From the simulation results, when the average number of hops is 2.02, 2.66, 4.1, 4.75, and 6.3, the proposed sequential scheduling scheme reduces the average end-to-end delay by about 28%, 10%, 17%, 27%, and 30%, respectively, compared to the conventional random scheduling scheme.

Workflow management for soft real-time interactive applications in virtualized environments

Many applications, especially the ones implementing multi-user collaborative environments, fall within the context of soft real-time systems in which only small deviations from timing constraints are allowed. The advancements in distributed computing have made it possible to follow a service oriented approach, taking advantage of the benefits this provides. In this context, applications consist of soft real-time critical application service components that interact with each other to provide the corresponding application functionality, forming application workflows. In this paper we present a new architectural design and implementation of a Workflow Management approach. This approach covers enacting soft real-time application service components according to a workflow description language, synchronizing the application components, monitoring the execution and reacting to events within a distributed virtualized environment. We also demonstrate the operation of the implemented mechanism and evaluate its effectiveness using an application scenario with soft real-time interactivity characteristics, namely Film post-production, under realistic settings.

Analysis and optimization of a cross-layer adaptation mechanism for real-time applications in wireless networks

The theoretical analysis of a cross-layer mechanism for improving the quality of service of real-time applications in wireless networks is presented. The mechanism coordinates adaptations of the modulation order at the Physical layer and the media encoding mode at the Application layer, to improve packet loss rate, throughput and mean delay. With the use of Continuous Flow Modeling, the system is considered as a "fluid" queue with inflow and outflow rates representing its traffic generation and service rates, respectively. Each data source is modeled as a Markov chain, from the steady-state of which the optimal adaptation thresholds of the cross-layer mechanism are derived. Extensive performance evaluation results show that the optimized operation of the mechanism attains a significant performance improvement compared to both the sub-optimal case, and a legacy system, which adjusts the modulation order and encoding mode separately and independently of each other.

Network-aware, energy-conscious, fair service for real-time applications on multiprocessor SoC

We consider systems consisting of wireless nodes that execute CPU intensive applications on multiprocessor systemon- a-chip (MPSoC) and must transmit packets over the network in a timely manner. Existing methods do not consider packet deadlines in conjunction with energy and real-time task performance, making it hard to predict system behavior. We present an energy-aware adaptive CPU scheduling algorithm to maximize the number of packet deadlines met in a fair manner and discuss future work.

A two-phase scheduling strategy for real-time applications with security requirements on heterogeneous clusters

Nowadays, increasing attention has been directed towards the issue of security service for real-time applications with security requirements on clusters. However, the study of integrating security demands of real-time applications into scheduling is rare. In this paper, we propose a novel two-phase scheduling strategy TPSS which takes timing constraints and security needs into consideration for security-critical real-time applications on heterogeneous clusters. In the first-phase, a novel algorithm DSRF is proposed to schedule real-time tasks. When the system is in heavy burden, DSRF is able to degrade the security levels of new tasks and tasks waiting in local queues so as to enhance guarantee ratio. On the contrary, when the system is in light burden, DSRF is capable of employing slack time to improve the security quality of new tasks and adequately utilize the system resource. The minimal security level can guarantee the system security, and higher security level is able to make the system more secure. In the second-phase, a new algorithm FMSL is proposed to minimize the difference of security levels of accepted tasks and further improve the security levels of accepted tasks on the whole, which degrades the probability of the applications being attacked. We compare TPSS, DSRF, SAEDF and RF by extensive simulations. The experimental results indicate that TPSS significantly improves the flexibility of scheduling and outperforms other algorithms.

Analysis of QoS in cooperative services for real time applications

Future complex architectures for Web-Services-based delivery of services and objects require applications able to deal with different levels of Quality of Service (QoS) and able to describe also the quality of the associated object. In order to allow applications adapting in front of degraded quality in a pre-determined way, all the nodes participating in a given business process shall coordinate their efforts in (i) deciding how to deal with service degradation/disruption, and in (ii) managing the overall quality (i.e., not only the Web-Service QoS but also the quality of the objects being delivered through the cooperative process). According to this rationale, one of the main goals of the Quadrantis project has been to investigate how to provide combined quality measurement of services and delivered objects, such as videos, voice, texts, or images. QoS modelling and management according to users’ needs are presented. Users will access services according to QoS Contracts negotiated with service providers, while the streaming content is based on user profiles, to face a more dynamic management of QoS deviations in the Real Time provisioning level. In our approach, applications can request QoS, and react and repair to violations of the terms set forth in contracts or in expected delivery parameters, such as bandwidth or frame rate. To this extent, we present a framework for providing applications and services with QoS adaptation functionality, through the step-wise induction of a monitoring and recovery solutions at both Web-Services and streaming layers. The foundations of the merging between the two layers, which deal with very different aspects and protocols, are based on quality.

High-performance packet scheduling to provide relative delay differentiation in future high-speed networks

Due to significant advances in interconnection networks and optical technologies, line rate for future high-speed networks can upgrade to terabits per second (Tb/s). Reduction of computational overhead and decrease of packet queueing delay are two critical issues in the design of a packet scheduler for efficiently delivering relative differentiated services over such high-speed networks. In this paper, we propose a new packet scheduler called multi-level dynamic deficit round-robin (MLDDRR). MLDDRR considers packet size and priority at the same time in making scheduling decision. Thus, MLDDRR can deliver relatively small delays not only for traffic of high priority but also for short packets of each class. Because MLDDRR acts like the shortest job first scheduler, MLDDRR can reduce average queueing delay for each class and also provide a better service for real-time applications with a large amount of short packets. MLDDRR also exploits concurrency and pipelining approach to speedup scheduling decision. Furthermore, MLDDRR can protect the traffic of the highest priority from serious performance degradation due to bursts of low priority traffic or high link utilization, and simultaneously prevent the traffic of the lowest priority from starvation. MLDDRR allows network operators to simply change the level of delay differentiation by adjusting parameters. Complexity analysis and extensive simulation results are presented and illustrate that MLDDRR is a high-performance packet scheduler and suitable for being deployed in future high-speed networks to provide relative delay differentiated service.

Predictive Path Switching Control for Improving the Quality of Service in Real-Time Applications

A congestion avoidance strategy based on the concept of predictive path switching control (PPSC) is proposed for improving the quality-of-service (QoS) in real-time applications, and in particular in Voice over Internet Protocol (VoIP) applications deployed over the public Internet. The proposed PPSC strategy requires the dynamic prediction of traffic congestion levels over all available network paths. This predictive information is then used as an input for a control strategy to select the best available path at each pre-determined time. A study using emulated network paths explores the impact of overall path loss rate and traffic delay signal frequency content on the proposed PPSC strategy. The study reveals that PPSC provides the best QoS improvement for real-time applications if the average over-all loss rate of the available paths is between 5% and 15%, and if the traffic delay signal contains mostly low frequencies. Linear and nonlinear dynamic predictors are developed and used along with actual network data collected from PlanetLab for demonstrating the effectiveness of the PPSC strategy. The results show that PPSC is better than no path switching, with no one dynamic predictor providing the best performance for all case studies. A voting-based control strategy is proposed to overcome this problem. The results demonstrate that the voting-based control results in universally better performance for all cases studied. VoIP packets encoded with Speex, a publicly available encoder, demonstrate that any PPSC strategy is far more effective than no path switching. The proposed voting-based PPSC is moderately more effective than PPSC based on a simple predictor, both resulting in voice quality mostly over 3.0 in MOS, if the available network paths have overall loss rate in the range of 5% and 15%. Though encouraging, the PPSC strategy raises a number of implementation issues, which must still be addressed. In particular, scaling of the PPSC to a large number of network paths will require probing packets that generate significant overhead traffic. These and other issues require further research.

Bandwidth aggregation for real-time applications in heterogeneous wireless networks

A variety of wireless interfaces are available for today's mobile user to access Internet content. When coverage areas of these different technologies overlap, a terminal equipped with multiple interfaces can use them simultaneously to improve the performance of its applications. In this paper, we motivate the advantages that can be had through simultaneous use of multiple interfaces and present a network layer architecture that enables diverse multiaccess services. In particular, we explore in depth one such service provided by the architecture: Bandwidth Aggregation (BAG) for real-time applications. An important aspect of the architecture when providing BAG services for real-time applications is the scheduling algorithm that partitions the traffic onto different interfaces such that the QoS requirements of the application are met. We propose one such algorithm Earliest Delivery Path First (EDPF), that ensures packets meet their playback deadlines by scheduling packets based on the estimated delivery time of the packets. We show through analysis that EDPF performs close to an idealized Aggregated Single Link (ASL) discipline, where the multiple interfaces are replaced by a single interface with same aggregated bandwidth. A prototype implementation and extensive simulations carried using video and delay traces show the performance improvement BAG with EDPF scheduling offers over using just the Highest Bandwidth Interface (HBI) and other scheduling approaches based on weighted round robin.

An Efficient Network-Switch Scheduling for Real-Time Applications

Bursts consist of a varying number of asynchronous transfer mode cells corresponding to a datagram. Here, we generalized weighted fair queueing to a burst-based algorithm with preemption. The new algorithm enhances the performance of the switch service for real-time applications, and it preserves the quality of service guarantees. We study this algorithm theoretically and via simulations.

Providing Absolute Differentiated Services for Real-Time Applications in Static-Priority Scheduling Networks

In this paper, we propose and analyze a methodology for providing absolute differentiated services for real-time applications. We develop a method that can be used to derive delay bounds without specific information on flow population. With this new method, we are able to successfully employ a utilization-based admission control approach for flow admission. This approach does not require explicit delay computation at admission time and, hence, is scalable to large systems. We assume the underlying network to use static-priority schedulers. We design and analyze several priority assignment algorithms and investigate their ability to achieve higher utilization bounds. Traditionally, schedulers in differentiated services networks assign priorities on a class-by-class basis, with the same priority for each class on each router. In this paper, we show that relaxing this requirement, that is, allowing different routers to assign different priorities to classes, achieves significantly higher utilization bounds.

End-to-end network delay model for heavy-tailed environments

Adequate quality of Internet Protocol (IP) services demand low transmission delays. However, packets traveling in a network are subject to a variety of delays that degrade severely the quality of service in real-time applications. This paper presents a general packet jitter-assessment methodology for a multi-node path in the presence of heavy-tailed traffic. Using the extreme-value theory, it is shown that delay performance is governed by a proposed networking-processing factor |T|lambda dependent on the traffic characteristics, the processing time along the path segments and the number of nodes in a route. |T|lambda allows the establishment of design constraints and the definition of a feasibility space for a routing algorithm in order to guarantee a quality of service (QoS). Copyright © 2003 AEI.

Efficient adaptive connection admission control algorithms for real-time ATM LANs

This study aims to provide adaptive communication services for real-time applications. In particular, how to admit adaptive real-time connections is addressed. Various search techniques in connection with admission control are investigated, and their tradeoffs under different performance criteria are assessed. The implementation and application of this new connection model in the NetEx system is also discussed.