Assured Performance Research Articles

Analysis of Standards Establishment for the Testing of Electrical Appliances

As science and technology continue to develop, power equipment has become an indispensable part of industrial production and daily life. Whether it is the precise automation machinery utilized on production lines or the convenient electrical appliances found in households, their functionality relies heavily on electrical technology. Nonetheless, without stringent safety and performance assurances, these devices could potentially endanger lives and property. Thus, this paper explores the development strategy for establishing a standardized system within the electrical testing service industry, aiming to ensure safety and reliability.

Cloud Service Selection System Approach based on QoS Model: A Systematic Review

The Internet of Things (IoT) has received a lot of interest from researchers recently. IoT is seen as a component of the Internet of Things, which will include billions of intelligent, talkative "things" in the coming decades. IoT is a diverse, multi-layer, wide-area network composed of a number of network links. The detection of services and on-demand supply are difficult in such networks, which are comprised of a variety of resource-limited devices. The growth of service computing-related fields will be aided by the development of new IoT services. Therefore, Cloud service composition provides significant services by integrating the single services. Because of the fast spread of cloud services and their different Quality of Service (QoS), identifying necessary tasks and putting together a service model that includes specific performance assurances has become a major technological problem that has caused widespread concern. Various strategies are used in the composition of services i.e., Clustering, Fuzzy, Deep Learning, Particle Swarm Optimization, Cuckoo Search Algorithm and so on. Researchers have made significant efforts in this field, and computational intelligence approaches are thought to be useful in tackling such challenges. Even though, no systematic research on this topic has been done with specific attention to computational intelligence. Therefore, this publication provides a thorough overview of QoS-aware web service composition, with QoS models and approaches to finding future aspects.

Time-aware Traffic Shaper using Time-based Packet Scheduling on Intel I210

By 2015, the Institute of Electrical and Electronics Engineers (IEEE) time-sensitive networking (TSN) task group has released several TSN standards. Amongst them is 802.1Qbv, also known as a time-aware shaper, aiming to provide performance assurances of latency and delivery variation to enable applications in a TSN network. While there are several products and evaluation kits that employ 802.1Qbv in the market now, it is still not widely adopted yet due to the maturity of the standard. Hardware-enabled 802.1Qbv use hardware queues and timers to achieve accurate transmission of packets in the switch and bridge. This research aims to investigate the feasibility of using an existing end-station Ethernet controller, Intel I210, and its launch time control feature (commonly known as time-based packet scheduling) to shape traffic compatible to 802.1Qbv-enabled network bridges. A software solution is developed by implementing a software configurable gate-control list and employing open-source Linux RFC patches for per-packet transmit time specification. By configuring the kernel and mapping kernel-layer traffic classes to the hardware queues, packets can be transmitted out at precise times while attaching 802.1Q VLAN tags, required by bridges to identify packets. Through analysis, it is found that this solution will require an additional 30 μs transmit offset to be used effectively. That is 55% more time is needed to transmit a packet in a back-to-back connection and 17.6% on a 3-switch network to improve period peak jitter performance to just 8.9 μs compared to 1 ms on solutions that send packets out periodically using software sleep functions.

Required extra capacity: A comparative estimation of overprovisioning needed for a classless IP backbone

The benefit of Class-of-Service (CoS) is an important topic in the “Network Neutrality” debate. As part of the debate, it has been suggested that over-provisioning is a viable strategy to meet performance targets of future applications, and that there is no need for to worry about provisioning differentiated services in an IP backbone for a small fraction of users needing better-than-best-effort service. In this paper, we quantify the extra capacity requirement for an over-provisioned classless (i.e., best-effort) network compared to a CoS network providing the same delay or loss performance for premium traffic. We first develop a link model that quantifies the required extra capacity (REC). To illustrate key parameters involved in analytically quantifying REC, we start with simple traffic distributions. Then, for more bursty traffic distributions (e.g., long-range dependent), we find the REC using ns-2 simulations of CoS and classless links. We, then, use these link models to quantify the REC for network topologies (obtained from Rocketfuel) under various scenarios including situations with “closed loop” traffic generated by many TCP sources that adapt to the available capacity. We also study the REC under link and node failures. We show that REC can still be significant even when the proportion of premium traffic requiring performance assurances is small, a situation often considered benign for the over-provisioning alternative. We also show that the impact of CoS on best-effort (BE) traffic is relatively small while still providing the desired performance for premium traffic.

Hierarchical Tree Alternative Path (HTAP) algorithm for congestion control in wireless sensor networks

Recent advances in wireless sensor networks (WSNs) have lead to applications with increased traffic demands. Research is evolving from applications where performance is not considered as a crucial factor, to applications where performance is a critical factor. There are many cases in the fields of automation, health monitoring, and disaster response that demand wireless sensor networks where performance assurances are vital, especially for parameters like power, delay, and reliability. Due to the nature of these networks the higher amount of traffic is observed when the monitored event takes place. Exactly at this instance, there is a higher probability of congestion appearance in the network. Congestion in WSNs is tackled by the employment of two methods: either by reducing the load (“traffic control”), or by increasing the resources (“resource control”). In this paper we present the Hierarchical Tree Alternative Path (HTAP) algorithm, a “resource control” algorithm that attempts, through simple steps and minor computations, to mitigate congestion in wireless sensor networks by creating dynamic alternative paths to the sink. HTAP is evaluated in several scenarios in comparison with another “resource control” algorithm (TARA), as well as with a “traffic control” algorithm (SenTCP), and also the case where no congestion control exists in the network (“no CC”). Results show that HTAP is a simple and efficient algorithm capable of dealing successfully with congestion in WSNs, while preserving the performance characteristics of the network.

Performance control in wireless sensor networks: the ginseng project - [Global communications news letter

Research on wireless sensor networks (WSNs) has mainly been focused on protocols and architectures for applications in which network performance assurances are not considered essential, such as agriculture and environmental monitoring. However, for many important areas, such as plant automation and health monitoring, performance assurances are crucial, especially for metrics such as delay and reliability.

Providing QOS support at the distributed wireless MAC layer: a comprehensive study

Holding the promise of making ubiquitous mobile access to IP-based applications and services a reality, wireless local area networks have been deployed in an unlimited way over the last few years. Due to their robust characteristics, distributed MAC protocols are the most widely used mechanisms to arbitrate access to the wireless channel. However, their ability to achieve high medium usage efficiency while providing services with meaningful performance assurances is being challenged by a wide range of existing and emerging applications that have lately migrated from other telecommunication networks to wireless environments. This article aims to provide a comprehensive study of the limitations and merits of mechanisms that have been proposed toward embedding QoS support to distributed wireless MAC protocols. A hybrid scheme that incorporates signaling and information sharing is proposed, and extensive simulation experiments are run to assess the efficiency of the access schemes in maximizing utilization of the wireless bandwidth while providing QoS support for heterogeneous applications.

Building resilient low-diameter peer-to-peer topologies

As more applications rely on underlying peer-to-peer topologies, the need for efficient and resilient infrastructure has become more pressing. A number of important classes of topologies have emerged over the last several years, all with various strengths and weaknesses. For example, the popular structured peer-to-peer topologies based on distributed hash tables (DHTs) offer applications assured performance, but are not resilient to attacks and major disruptions that are likely in the overlay. In contrast, unstructured topologies where nodes create random connections among themselves on-the-fly, are resilient to attacks but can not offer performance assurances because they often create overlays with large diameters, making some nodes practically unreachable. We propose Phenix, a peer-to-peer algorithm for building resilient low-diameter peer-to-peer topologies that can resist different types of organized and targeted malicious behavior. Phenix leverages the strengths of these existing approaches without inheriting their weaknesses and is capable of building topologies of nodes that follow a power-law while being fully distributed requiring no central server, thus, eliminating the possibility of a single point of failure in the system. We present the design and evaluation of the algorithm and show through extensive analysis, simulation, and experimental results obtained from an implementation on the PlanetLab testbed that Phenix is robust to network dynamics such as bootstrapping mechanisms, joins/leaves, node failure and large-scale network attacks, while maintaining low overhead when implemented in an experimental network.

An adaptive medium access control protocol using m-ary tree algorithms for quality-of-service support in single-cell ad hoc networks

Concurrent with the rapid expansion of wireless networks is an increasing interest in providing Quality-of-Service (QoS) support to them. As a consequence, a number of medium access control protocols has been proposed which aims at providing service differentiation at the distributed wireless medium access layer. However, most of them provide only average performance assurances. We argue that average performance guarantees will be inadequate for a wide range of emerging multimedia applications and “per-flow” service assurances must be provided instead. Based on m-ary tree algorithms, we propose an adaptive and distributed medium access algorithm for single-cell ad hoc networks to provide “per-flow” service assurances to flows whose QoS requirement can be expressed as a delay requirement. Both analytical and simulation experiments are conducted to assess the performance of the proposed scheme.

Pricing network resources for adaptive applications

The Differentiated Services framework (DiffServ) has been proposed to provide multiple Quality of Service (QoS) classes over IP networks. A network supporting multiple classes of service also requires a differentiated pricing structure. In this work, we propose a pricing algorithm in a DiffServ environment based on the cost of providing different levels of services, and on long-term average user resource demand of a service class. We integrate the proposed service-dependent pricing scheme with a dynamic pricing and service negotiation environment by considering a dynamic and congestion-sensitive pricing component. Pricing network services dynamically based on the level of service, usage, and congestion allows a more competitive price to be offered, allows the network to be used more efficiently, and provides a natural and equitable incentive for applications to adapt their service requests according to network conditions. We also develop the demand behavior of adaptive users based on a physically reasonable user utility function. Simulation results show that a congestion-sensitive pricing policy coupled with user rate adaptation is able to control congestion and allows a service class to meet its performance assurances under large or bursty offered loads, even without explicit admission control. Users are able to maintain a stable expenditure, and allowing users to migrate between service classes in response to price increases further stabilizes the individual service prices. When admission control is enforced, congestion-sensitive pricing still provides an advantage in terms of a much lower connection blocking rate at high loads.

Multimedia-friendly server and communication design

We report on a set of projects to: design, implement, and evaluate software frameworks for providing performance assurances in emerging Internet services and real-time applications with a focus on multimedia; and design and evaluate video-on-demand (VOD) servers as an application. First we describe the Adaptware project, which investigates adaptive software for server platforms. A complementary project addresses reliable transmission of QoS-sensitive data over packet switched networks. Together, these two prongs compose an end-to-end approach to achieving flexible QoS guarantees for future Internet applications. We discuss VOD servers as a potential application of this two-pronged approach.