UMTS Services and Applications

To facilitate the Quality of Service (QoS) interoperability, a multi-plane end-to-end (E2E) QoS architecture reference model has been developed. This modelprovides a network-functional-plane-based QoS architecture and defines different interfaces for composing a coherent data transfer and management. In this model, QoS functions are categorized into Data Plane, Control Plane, and Management Plane. However, a lack of sufficient network resource hinders the support for such sophisticated network architecture. A major mitigation approach is to implement an optical/Radio Frequency (RF) hybrid system. This paper proposes a resource management scheme for an optical/RF hybrid system and looks into the realization of multi-planes model in this hybrid system that supports an acceptable QoS level.

Real-time multimedia traffic requires some minimum delivery guarantees to be effectively transmitted over packet-switched networks. This is even more necessary when interactive sessions (e.g., voice-over-IP applications) are involved. Effective and timely packet delivery is sometimes achieved by overdimensioning network capacity. However, this is not the most practical and economic solution. Instead, providing a specific service to different traffic types may achieve better results without wasting network resources. Quality of service (QoS) be implemented at different layers of the protocol stack, but tight control at the link layer is essential when the physical medium is shared among a number of devices. Wireless LANs are a typical example of that. The IEEE 802.11e amendment enhances the original version of the WiFi standard with new QoS functionalities. It maintains backward compatibility with legacy hardware, and this may cause the priority scheme to be ineffective in those deployments where non-QoS enabled hardware is present. In this paper, we analyze some widespread commercial 802.11 products to check the effectiveness of the QoS mechanisms. We show that all hardware under examination fails in providing effective QoS guarantees when legacy stations are present.

DIVINE: Data offloading in vehicular networks with QoS provisioning

Quality of service maintenance is one of the key tasks in mixed service UMTS networks. In this paper, an algorithm for capacity dimensioning is proposed to assure the quality of different services provided in the network. The algorithm allows to determine the highest allowable cell capacity under the various quality of service requirements and cell throughput conditions.

Quality of Service (QoS) provisioning is one of the main requirements in the 3GPP IP Multimedia Subsystem (IMS) and it has been addressed in different works since the beginning of the IMS standardization process. As a result of the fixed and mobile networks evolution, the parameters standardized in IMS have changed constantly until the specification of the Policy and Charging Control (PCC) architecture that integrates IMS QoS and charging functionalities. However, current IMS QoS specifications still have some limitations to handle service flexibility that is required to provide Internet services over IMS. In this work, we propose an enhanced IMS QoS architecture to support efficient QoS providing for flexible services with dynamic requirements. This proposal is compared against different approaches to evaluate their behavior under network saturation conditions. Simulations results show that the architecture we propose achieves efficiency and flexibility, maintaining the number of blocked and active sessions, and increasing the number of high priority sessions activated in a saturated network.

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

Wireless Local Area Networks (WLAN)s are today common for access to Internet; well-known and used is IEEE 802.11 standardized technology. Some drawbacks of the standardized distributed medium access scheme, Distributed Coordination Function (DCF) has resulted in considerations made to extend the DCF from single-hop communications to multi-hop. Multihopping has the potential to reduce energy consumption and increase throughput and coverage. The drawback is lack of Quality-of-Service (QoS) support, which already with single-hop communication was bad, but extending a communication between two peers to multi-hop significantly reduces the possibility to offer reliable transmissions. The contention-based medium access performed at each hop with the DCF results in large uncertainties as to when a packet arrives to its end-destination. There are two general approaches for extending the DCF with QoS functionality: 1. Allocate resources for a flow and 2. Assign a flow higher priority than other flows. My hypothesis is that for strict QoS guarantees, a reservation-based approach is the better one. This has been my motivation to design a new medium access protocol; based on the DCF, periodic time slots for QoS-demanding real-time applications are reserved. The Distributed Allocation of time slots for Real-time traffic (DARE) is unique as it totally distributed sets up an end-to-end reservation before the transmission of data begins, repairs broken reservations, support many periods and time slot sizes and distribute piggy-backed information even to a two-hop radius from a receiver. This thesis describes the DARE protocol and also presents results from comparisons of DARE, DCF and the IEEE 802.11 E standardized priority-based QoS medium access protocol Enhanced Distributed Channel Access (EDCA). Using simulations, this thesis shows that DARE offers constant end-to-end packet delay for a flow, very low average packet delay in the whole system and constant throughput. EDCA and DCF depend strongly on the total network load; average packet delay for a real-time flow increases rapidly with the surrounding load. DARE outperforms both DCF and EDCA when many flows are present, even in networks with frequent topology changes where reservations must be repaired. Thus, the reservation-based DARE protocol is the most suitable approach for extending DCF with QoS.

We consider the design of optimum biorthogonal, as opposed to orthonormal, discrete multitone (DMT) systems supporting a service whose quality of service (QoS) requirements are quantified by bit rate and symbol error rate specifications. Our goal is to minimize the transmitted power given the QoS specifications subject to the knowledge of the channel and colored interference at the receiver input of the DMT system. We find an optimum bit loading scheme that distributes the bit rate transmitted across the various subchannels, and an optimum transceiver. Earlier papers, [2] and [4] showed the following: (i) Relaxing the orthonormality constraint yields no performance improvement. (ii) The optimum transceiver is unaffected by changing service characteristics, and depends only on the channel and interference conditions. (iii) The QoS requirements, only affect bitloading. These conclusions form a separation principle that has important implications to wireline applications like DSL. These papers, [2] and [4], however worked with an approximation that only works if each subchannel supports a very high data rate. In this paper we show that even if one relaxes this high bit rate assumption, (i-iii) still hold.

Wireless mobile radio systems have to serve users with different quality of service (QoS) requirements. Scheduling algorithms like weighted proportional fair (WPF) have been proposed considering channel gains to improve the system capacity in terms of sector throughput as well as user priorities to fulfill QoS requirements. These scheduling algorithms allow assigning different priority factors to users and services so that different QoS requirements can be fulfilled. This paper provides an analysis of the influence of users with different priorities on the sector and user throughput. It is shown analytically and by system level simulations that the average user throughput can be adjusted by choosing a specific priority factor. Furthermore, it is shown that the sector throughput decreases if WPF scheduling for users with different priorities and full buffer model are considered compared to a scenario with users having equal priority. If QoS requirements for realistic traffic models, e.g. FTP, have to be fulfilled, for each high priority user low priority users have to be removed from the system in order not to exceed an acceptable number of unsatisfied users. It is shown that the decrease in sector throughput with a realistic traffic model and QoS requirements is higher than for the full buffer model.

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).

The goal of 5G wireless networks is to support a diverse set of requirements spanning low-latency, high connectivity, and high bit-rates. Support for the multitude of deployment scenarios is enabled by 5G Quality of Service (QoS) flows. In 5G, an inbound service from outside the cellular network can be separated into multiple QoS flows and scheduled onto multiple data bearers; each 5G data bearer meets specific QoS requirements. These requirements include extended networks, as enabled by UE-to-Network Relays. Typical examples are the networks formed by Device to Device (D2D) User Equipment (UEs) and Internet of Things (IoT) devices. Traditional latency-driven assignment methodologies typically assign a fixed Latency / Sub-Carrier Spacing (SCS) to each multicast flow, as directed by the QoS requirements. A drawback to traditional approaches is they do not account for the impact of multi-path / delay spread, as such they are unable to efficiently utilize the allocated radio spectrum in high delay spread radio environments; low latency flows are more sensitive to high delay spread. In this research work we derive an optimal QoS to 5G data bearer mapping for an extended network, subject to the constraints imposed by UEs and the UE-to-Network Relay. Compared to legacy multicast methodologies, our methodology can achieve an equivalent or higher throughput while minimizing deviation from the original latency requirements.

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.

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.

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.