Multidimensional Multilevel Coding for Satellite Broadcasting with Highly Flexible QoS

Defending against fake VIP in scant-transparency information systems with QoS differentiation

Multistage decoding of multilevel block multilevel phase-shift keying (M-PSK) modulation codes for the additive white Gaussian noise (AWGN) channel is investigated. Several types of multistage decoding, including a suboptimum soft-decision decoding scheme, are devised and analyzed. Upper bounds on the probability of an incorrect decoding of a code are derived for the proposed multistage decoding schemes. Error probabilities of some specific multilevel block 8-PSK modulation codes are evaluated and simulated. The computation and simulation results for these codes show that with multistage decoding, significant coding gains can be achieved with large reduction in decoding complexity. In one example, it is shown that the difference in performance between the proposed suboptimum multistage soft-decision decoding and the single-stage optimum decoding is small, only a fraction of a dB loss in SNR at the block error probability of 10/sup -6/. >

To provide Quality of Service (QoS) and data rate differentiation, we investigate in this paper a 2 dimensional optical code division multiple access (OCDMA) technique. A 2D multi-weight coding scheme with parallel mapping technique is developed. The system enhancement is assessed thanks to the use of Forward Error Correction (FEC) based on Low Density Parity Check (LDPC) codes. In order to have an efficient correction power, we develop an adaptation of the LDPC decoding algorithm to the specific multiple access interference distribution in a multimedia OCDMA network. The proposed network permits a high number of users to communicate with high data rates adapted to a multimedia transmission (voice, data and video) with corresponding QoS (10-3, 10-6, 10-9).

<div>Originally, networks were engineered to provide only one type of service, i.e. either voice or data, so only one level of resiliency was requested. This trend has changed, and today’s approach in service provisioning is quite different. A Service Level Agreement (SLA) stipulated between users and service providers (or network operators) regulates a series of specific requirements, e.g., connection set-up times and connection availability that has to be met in order to avoid monetary fines. In recent years this has caused a paradigm shift on how to provision these services. From a “one-solution-fits-all” scenario, we witness now a more diversified set of approaches where trade-offs among different network parameters (e.g., level of protection vs. cost and/or level of protection vs. blocking probability) play an important role.</div><div>This chapter aims at presenting a series of network resilient methods that are specifically tailored for a dynamic provisioning with such differentiated requirements. Both optical backbone and access networks are considered. In the chapter a number of provisioning scenarios - each one focusing on a specific Quality of Service (QoS) parameter - are considered. First the effect of delay tolerance, defined as the amount of time a connection request can wait before being set up, on blocking probability is investigated when Shared Path Protection is required. Then the problem of how to assign “just-enough” resources to meet each connection availability requirement is described, and a possible solution via a Shared Path Protection Scheme with Differentiated Reliability is presented. Finally a possible trade off between deployment cost and level of reliability performance in Passive Optical Networks (PONs) is investigated. The presented results highlight the importance of carefully considering each connection’s QoS parameters while devising a resilient provisioning strategy. By doing so the benefits in terms of cost saving and blocking probability improvement becomes relevant, allowing network operators and service providers to maintain satisfied customers at reasonable capital and operational expenditure levels</div>

Multidimensional TCM schemes can be used to improve the performance of the asymmetrical digital subscriber line (ADSL). The operating principle of how M-D (multidimensional) TCM works in an ADSL channel is analysed and criteria for evaluating and choosing effective multidimensional TCM schemes are described. The results of a simulation for evaluating the performance is presented.

The software is created and constructed to address particular issues in the applied field. In this context, there is a need to be aware of the crucial characteristics to assess the quality of software. But not all software requires checking all the quality-of-service parameters, resulting in effort loss and time consumption. Therefore, it is required to develop software quality characteristics recommendation model to address and resolve the issue. The proposed work involved in this paper can be subdivided into three main parts (1) a review of popular software quality models and their comparison to create a complete set of predictable, and (2) the design of an ML-based recommendation model for recommending the software quality model and software quality characteristics (3) performance analysis. The proposed recommendation system utilizes the different software quality of service attributes as well as the software attributes where these models are suitably applied to satisfy the demands. Profiling of applications and their essential requirements have been performed Based on the different quality of service parameters and the requirements of applications. These profiles are learned by machine learning algorithms for distinguishing the application-based requirement and recommending the essential attributes. The implementation of the proposed technique has been done using Python technology. The simulation aims to demonstrate how to minimize the cost of software testing and improve time and accuracy by utilizing the appropriate quality matrix. Finally, a conclusion has been drawn and the future extension of the proposed model has been reported.

On the multidimensional gas-kinetic BGK scheme

The development, registration, discovery, and invocation of quality Web services are vital for the successful implementation of applications using Web services. Considerable research focuses on quality for Web services. Unfortunately, current research on Quality of Service (QoS) for Web services is concentrated on service users and the implementation stage. This research highlights the importance of incorporating QoS at the design and development stages; the authors propose the introduction of QoS at the same time as functional requirements. However, Web Service Description Language (WSDL) describes the functional elements of a Web service, and QoS is significant for this description. Therefore, the authors propose an extension to the WSDL through a generic QoS metamodel, incorporating QoS specifications into the functionalities. This paper begins by defining the required QoS specifications for the development of quality Web services and explores the potential of the Unified Modeling Language as a technique and notation to specify QoS. To properly integrate QoS in the design, the authors propose extensions to the existing UML QoS profile. The paper concludes with the evaluation of the proposed framework and summarises its advantages.

With the increasing number of Web services, the Semantic Web research community is moving toward enhancing procedures so that clients may effectively discover appropriate Web services that maximally satisfy not only functional but also non-functional requirements. Using purely syntactic approaches to discover Web services has limited efficiency. Therefore, semantic matchmaking registries can play an important role in providing better results. However, most of the semantic registries make decisions based on only functional requirements. Due to the proliferation of Web services that have similar functionality, there is a need to further filter Web services according to Quality of Service (QoS) specifications. This work introduces a rich QoS ontology inspired from the World Wide Web Consortium that defines relationships among QoS attributes. The QoS attributes defined here are mainly used to define network related characteristics. However, the work can be extended by defining QoS ontologies for other domains. Additionally, we extend the test collection OWLS-TC according to the QoS ontology. The extension is intended to integrate quantified values for QoS attributes into Web service descriptions. A matchmaking algorithm based on similarity measurements is presented. Moreover, deterministic and adaptive parameter control techniques are introduced to guide the requester, when needed, to adjust QoS specifications so better similarity can be achieved. Parameter control algorithms integrate Pellet, an OWL reasoner, to reason about dependencies among QoS concepts in the QoS ontology.

We describe a framework for providing quality-of-service (QoS) guarantees within the endsystem for networked multimedia applications. There are four components in this framework namely—QoS specification, QoS mapping, QoS enforcement, and protocol implementation. QoS specifications are at a high level, and use a small number of parameters to allow applications greater ease in specifying their requirements. Based on the QoS specifications, QoS mapping operations derive resource requirements for each end-to-end session of the application. Important resources considered are the cpu and the network connection. The third component of the framework is QoS enforcement. Enforcement is mainly concerned with providing real-time processing guarantees for protocol code during data transfer. We have implemented a real-time upcall (rtu) facility which is an enhancement to the well known upcall mechanism for structuring protocols, rtus are scheduled using a policy called rate monotonie with delayed pre-emption (rmdp) that takes advantage of the iterative nature of protocol processing to reduce context switching overhead and increase scheduling efficiency. The last component of our framework is an application level protocol implementation model. Protocol code is structured as rtus with attributes that are derived from high level specifications by the QoS mapping operations. We describe techniques to reduce the cost of data movement and context switching in such implementations. The rtu mechanism currently runs in the Netbsd os on Sparc and Pentium based platforms. Initial measurements show that it is an effective means to implement protocols with QoS support.

The rapid development of the Internet of Things (IoT) concept has promoted the presence of routing protocol for low power and lossy network (RPL). Unlike traditional applications, many applications envisioned for IoT networks may have different and sometimes conflicting requirements. In this context, the underlying routing protocol requires to provide quality of service (QoS) for multipurpose IoT and is inevitable. However, the routing approach in RPL is not efficient because default objective functions (OFs) rely on a single metric, which can result in a tradeoff in routing performance, particularly for multipurpose IoT that enchant different QoS requirements in the same network. Although RPL specification allows the use of multiple metrics for parent selection, however, no specific guideline is defined for metric combinations. Besides, many studies have revealed that RPL encounters severe problems in large scale networks as it was mainly designed for low data traffic network. To address these problems, in this paper, we primarily focus on QoS differentiation by exploiting the multi-topology routing feature of the RPL standard. For this, we propose different OFs, which ensures the QoS differentiation at the network level by splitting the physical network virtually into multiple RPL Instances. Each Instance can incorporate different traffic by associating with differing OFs, and routed it through the corresponding virtual network topology. We also present a new parent selection framework based on a multi-attribute decision-making approach that addresses the single routing metric problem in RPL. The extensive simulation results verify that our multi-topology routing approach can support the QoS provisioning and is suitable for large scale networks as compared with standard RPL.

Edge computing is a new computing paradigm after cloud computing. Edge service scheduling and composition (ESC) has been well recognized as a convenient and flexible way of services sharing and integrating in industrial application fields. The ESC aims at selecting a set of existing edge service candidates with different Quality of Service (QoS) attributes (e.g., price), then compositing them to accomplish a complex task to meet users' QoS requirements, where each edge service may have multiple functionally equivalent, but different QoS metrics. A grand research challenge of the ESC based on QoS is to select proper service candidates to maximize QoS of the composited edge service and meanwhile meet the global QoS requirements. In this article, we focus on this challenge and propose a hierarchical solution for ESC. Specifically, we classify service candidates into specified grades based on their QoS attributes, and use hierarchical model to address service selection problem. Furthermore, in order to expand the flexibility of our approach, we design a near-optimal solution by decomposing the global end-to-end QoS constraints into local QoS constraints and adopting local service selecting and updating strategy based on the hierarchical model. The results of simulation-based experiments are conducted to show our approach is more efficient and valid compared to other existing approaches.

The Border Gateway Protocol (BGP) is the dominant inter-domain routing protocol in IP-based networks today. However, the requirements of emerging applications have exposed limitations in the current BGP protocol. In particular, future military IP networks, exemplified by the Global Information Grid (GIG), will carry a diverse mix of applications with widely different Quality of Service (QoS) requirements. At the same time, the GIG includes a diverse set of component networks, such as tactical ad-hoc networks, with highly dynamic QoS characteristics. In this paper we investigate the problem of enhancing BGP to discover routing paths with QoS characteristics that match application requirements. We explore the requirements posed on multi-domain QoS routing protocols that provide multiple classes of service with multi-dimensional QoS requirements and present how these requirements map to BGP. We discuss enhancements to BGP that allow nodes to discover multiple paths with associated QoS attributes. In particular, we discuss a dominant path selection algorithm that allows nodes to discover the minimum set of paths needed to make QoS routing decisions. We present details of the proposed BGP changes and identify the modifications needed at each stage of the BGP path selection process. We implemented the proposed enhancements in the NS-2 simulator. Preliminary simulation results indicate the potential performance benefits of the introduced QoS enhancements to inter-domain routing.

In two-tier femtocell networks, the femtocell users (FUs) can be admitted to the femto base stations (FBSs) provided that the interference to the primary users (PUs) is no higher than the defined thresholds. Moreover, several FBSs may require different quality of service (QoS) with different payments. This paper proposes a method to obtain from maximally achievable revenue from FBSs to the required QoS. It also proposes an efficient QoS aware admission algorithm which is compared with other schemes, such as minimum signal-to-interference-plus-noise ratio (SINR) removal algorithm (MSRA) and random SU removal algorithm (RSRA). Presented QoS aware admission algorithm can achieve a much higher revenue with required QoS. In addition, the proposed algorithm is evaluated by the simulation experiments.

Different distributed component-based applications (e.g., distributed multimedia, library information retrieval, secure stock trading applications), running in heterogeneous execution environments, need different quality of service (QoS). The semantics of QoS requirements and their provisions are application-specific, and they vary among different application domains. Furthermore, QoS provisions vary per applications in heterogeneous execution environments due to the varying distributed resource availability. Making these applications QoS-aware during the development phase, and ensuring their QoS guarantees during the execution phase is complex and hard