End-to-end QoS provisioning in mobile heterogeneous networks

The remarkable advances in information technologies bring a heterogeneous environment for mobile users and service providers. This heterogeneity exists in wireless access technologies, networks, user terminals, applications, service providers, and so on. The ability to provide seamless and adaptive quality of service in such a heterogeneous environment is key to the success of next-generation wireless communications systems. There has been a considerable amount of QoS research recently. However, the main part of this research has been in the context of individual architectural components, and much less progress has been made in addressing the issue of an overall QoS architecture for the mobile Internet. This article first summarizes the state-of-the-art QoS techniques and standardization activities, then examines in detail important challenges in building a ubiquitous QoS framework over the heterogeneous environment, and finally proposes a QoS framework integrating a three-plane network infrastructure and a unified terminal cross-layer adaptation platform to provide seamless support for future applications.     

Predictive mobility support for QoS provisioning in mobile wirelessenvironments

With the proliferation of wireless network technologies, mobile users are expected to demand the same quality of service (QoS) available to fixed users. This paper presents a predictive and adaptive scheme to support timed-QoS guarantees in pico- and micro-cellular environments. The proposed scheme integrates the mobility model into the service model to achieve efficient network resource utilization and avoid severe network congestion. The mobility model uses a probabilistic approach to determine the most likely cluster to be visited by the mobile unit. The admission control is invoked when a new call arrives or an existing call performs a handoff to verify the feasibility of supporting the call. The performance of the proposed schemes is compared to the shadow cluster scheme. The performance of the proposed scheme under different traffic patterns is also presented     

A self-adaptive service provisioning framework for 3G+/4G mobile applications

In light of the increasing acceptance of the notion of next generation networks (NGN), which results from the convergence of the fixed and mobile telecommunications, Internet, and entertainment sectors, there is a need for the realization of next-generation service delivery platforms to allow seamless and adaptive provisioning of multimedia information and communication services to mobile users. This means that in such an NGN environment different end systems, access networks, and service platforms have to be integrated. For this highly heterogeneous communications and services environment, we propose a self-adaptive service provisioning middleware framework (ASPF), which, by interoperating with existing wireless and wireline service delivery platforms, aims to enable seamless omnipresent service provisioning to mobile users anywhere, anytime, and in any context. The ASPF is intended to "liberate" applications from space and time limitations, networks, platforms, and device dependences, minimize time-to-market constraints, and eliminate major hurdles that hinder the rapid deployment of new mobile services and applications. Key to this goal is interworking/integration with current SDPs, such as IN/CAMEL, OSA/Parlay, and the emerging IMS.     

Flexible resource allocation strategies for class-based QoS provisioning in mobile networks

Flexible resource-allocation (FRA) strategies have been proposed in the literature to mitigate the high blocking rate caused in high-speed mobile communication networks when resource aggregation is used to increase the data rate. In this paper, new FRA strategies that cope with scenarios with multiple service types and multiple priorities are proposed. These are called the FRA strategy with differentiated priorities and quality of service (FRAQoS) and the FRA strategy with prioritized levels (FRASPL). The main distinguishing feature of these strategies is their capacity to prioritize some service types over others. FRAQoS prioritizes the quality of service (QoS) of particular service types over others by introducing the concepts of prioritized call degradation and compensation. However, FRAQoS provides a limited ability to prioritize particular service types over the rest because any incoming call, irrespective of its service type and priority, may trigger resource reallocations to service it. The FRASPL overcomes this limitation by introducing a call-admission mechanism that, when necessary, rejects calls originated by low-priority service types. This enhances the protection to high-priority service types. By prioritizing some services over the others, FRASPL can trade off capacity against QoS. FRAQoS represents particular limiting cases of FRASPL. A mathematical model is developed to investigate the performance of FRAQoS and FRASPL. Then, they are compared with other FRA strategies in a scenario with multiple differentiated service types. Results show that the proposed strategies effectively prioritize service types, providing them with better QoS. This makes FRAQoS and FRASPL specially suitable for class-based QoS provisioning in mobile networks.     

5G NSA网络端到端差异化QoS策略研究

通过将不同的业务、用户映射到不同的QCI类型承载,并对不同的QCI类型承载配置不同的QoS参数,可以实现基于业务和用户的网络差异化服务。首先对NSA网络进行整体介绍,明确NSA网络无线承载类型,并逐一介绍相关的QoS参数。之后从业务差异化和用户差异化2个维度,制定相应的QoS策略,同时基于不同的策略,对无线网、传输网和核心网参数进行统一梳理,实现5G NSA网络端到端差异化QoS参数的合理化、标准化。     

Call admission control for QoS provisioning in 4G wireless networks: issues and approaches

This article presents a survey on the issues and the approaches related to designing call admission control schemes for fourth-generation wireless systems. We review the state of the art of CAC algorithms used in the traditional wireless networks. The major challenges in designing the CAC schemes for 4G wireless networks are identified. These challenges are mainly due to heterogeneous wireless access environments, provisioning of quality of service to multiple types of applications with different requirements, provisioning for adaptive bandwidth allocation, consideration of both call-level and packet-level performance measures, and consideration of QoS at both the air interface and the wired Internet. To this end, architecture of a two-tier CAC scheme for a differentiated services cellular wireless network is presented. The proposed CAC architecture is based on the call-level and packet-level QoS considerations at both the wireless and wired parts of the network. A performance analysis model for an example CAC scheme based on this architecture is outlined, and typical numerical results are presented.     

End to end QoS provisioning multimedia wireless/mobile networksusing an adaptive framework

This article presents a framework for multimedia networking in a wireless and mobile environment. We consider both multimedia application needs as well as networking requirements, and try to bridge these paradigms using an adaptive framework. Central to this framework is the concept of representing a multimedia connection in terms of multiple substreams each with their own specified QoS requirement and making network elements (switching and access points), services, and protocols (signaling, control, routing) aware of the QoS requirements of such substreams. As resource availability in the wireless and mobile network fluctuates, the network selects and schedules substreams in order to present the information content with an acceptable quality at a receiver (or each receiver in case of multicast connections). This is done while achieving a reasonable utilization efficiency of network resources and sharing them in a fair manner     

QoS guarantee and provisioning for realtime digital video over mobile ad hoc cdma networks with cross-layer design

In this article we investigate the trade-offs and the constraints for multimedia over mobile ad hoc CDMA networks, and propose a cross-layer distributed power control and scheduling protocol to resolve those trade-offs and constraints in order to provide high-quality video over wireless ad hoc CDMA networks. In particular, a distributed power control and scheduling protocol is proposed to control the incurred delay of video streaming over multihop wireless ad hoc networks, as well as the multiple access interference (MAI). We also investigate the impacts of Doppler spread and noisy channel estimates upon the end-to-end video quality, and provide a relatively robust system which employs a combination of power control and coding/interleaving to combat the effects of Doppler spread by exploiting the increased time diversity when the Doppler spread becomes large. Thus, more robust end-to-end video quality can be achieved over a wide range of channel conditions     

QoS provisioning for multimedia wireless networks

As we move towards IP-based multimedia wireless networks with voice, video and data convergence, quality of service (QoS) provisioning will become an increasingly challenging task. One implication is that greater emphasis on managing the call admission and overall network resources will be needed. This paper presents a conservative and adaptive quality of service (CAQoS) framework for provisioning the QoS for both real-time and non-real-time traffic in a multimedia wireless network. Unlike most conventional schemes, which gradually scale down the bandwidth of ongoing connections to accommodate new connection/hand-off requests, CAQoS introduces an early scaling-down of bandwidth for new connections based on a designated provisioning model. The performance of a CAQoS system is evaluated through simulations of a realistic wireless environment. Simulation results show that CAQoS meets our design goals and outperforms conventional schemes.     

QoS provisioning for large-scale multi-ap WLANs

Large-scale deployment of IEEE 802.11 wireless LANs (WLANs) with a high density of access points (APs) has become commonplace due mainly to its potential for numerous benefits, such as ubiquitous service coverage, seamless handover, and improved link quality. However, the increased AP density can induce significant channel contention among neighboring cells, thus causing severe performance degradation and throughput imbalance between cells. There have been a plethora of research efforts to improve the WLAN performance, but most of them focused only on single WLAN environments without accounting for inter-cell contention. The de facto QoS-provisioning mechanism for WLANs, i.e., the Enhanced Distributed Channel Access (EDCA), is no exception to this. The EDCA focuses only on inter-flow priority distinction and has not considered the effect of inter-cell contention which significantly restricts its efficiency. This paper presents an enhanced QoS provisioning framework that takes into account inter-cell level differentiation as well as inter-flow level priority, which may be viewed as extension of QoS provisioning from a single-WLAN domain to a multi-WLAN domain. We also propose an architecture for managing multi-AP systems in which a central controller regulates the wireless channel occupancy of APs by adaptively configuring the cell-level QoS parameters. Our extensive simulation results show that the proposed inter-AP cooperative QoS scheme overcomes the limit of legacy 802.11e and provides a high level of fairness in large-scale densely-deployed WLANs.     

端到端的QoS服务保障分析

随着行业竞争的日益激烈,用户感知很大程度上影响了一个业务的发展。因此,用户体验在电信行业越来越重要,也受到各方的关注。随着网络演进,QoS服务将为OTT提供一定的带宽保障,从而带来新的合作模式和更好的用户体验。分析了WCDMA/LTE/PCC网络架构下的端到端QoS带宽保障机制及在业务开展中的相关问题。     

End-to-end QoS framework for heterogeneous wired-cum-wireless networks

With information access becoming more and more ubiquitous, there is a need for providing QoS support for communication that spans wired and wireless networks. For the wired side, RSVP/SBM has been widely accepted as a flow reservation scheme in IEEE 802 style LANs. Thus, it would be desirable to investigate the integration of RSVP and a flow reservation scheme in wireless LANs, as an end-to-end solution for QoS guarantee in wired-cum-wireless networks. For this purpose, we propose WRESV, a lightweight RSVP-like flow reservation and admission control scheme for IEEE 802.11 wireless LANs. Using WRESV, wired/wireless integration can be easily implemented by cross-layer interaction at the Access Point. Main components of the integration are RSVP-WRESV parameter mapping and the initiation of new reservation messages, depending on where senders/receivers are located. In addition, to support smooth roaming of mobile users among different basic service sets (BSS), we devise an efficient handoff scheme that considers both the flow rate demand and network resource availability for continuous QoS support. Furthermore, various optimizations for supporting multicast session and QoS re-negotiation are proposed for better performance improvement. Extensive simulation results show that the proposed scheme is promising in enriching the QoS support of multimedia applications in heterogeneous wired-cum-wireless networks. Ming Li received his B.S. and M.S. in Engineering from Shanghai Jiao Tong University, China, in 1995 and 1998, respectively. He is currently a Ph.D. candidate in department of Computer Science, University of Texas at Dallas, where he received M.S. degree in Computer Science in Dec. 2001. His research interest includes QoSschemes for mobile ad-hoc networks and multimedia over wireless networks. Hua Zhu received the Ph.D. degree in Electrical Engineering from the University of Texas at Dallas, Texas. Since 2005, he has been working for San Diego Research Center, Inc., San Diego, CA, as a Research Engineer. His research interests include all layers of wireless communication systems. His particular interest is in L2/3 air interface design, performance analysis, and optimization for ad hoc and sensor networks. Imrich Chlamtac is the President of CREATE-NET and the Bruno Kessler Professor at the University of Trento, Italy. He has held various honorary and chaired professorships in USA and Europe including the Distinguished Chair in Telecommunications Professorship at the University of Texas at Dallas, Sackler Professroship at Tel Aviv University and has been on faculty at Technion, and UMass. Dr. Imrich Chlamtac has made significant contribution to various networking technologies as scientist, educator and entrepreneur. Dr. Chlamtac is the recipient of multiple awards and recognitions including Fellow of the IEEE, Fellow of the ACM, Fulbright Scholar, the ACM Award for Outstanding Contributions to Research on Mobility and the IEEE Award for Outstanding Technical Contributions to Wireless Personal Communications. Dr. Chlamtac published over three hundred and fifty refereed journal, book, and conference articles and is the co-author of four books. Dr. Chlamtac has widely contributed to the scientific community as founder and Chair of ACM Sigmobile, founder and steering committee chair of some of the lead conferences in networking including Mobicom, OptiComm, Mobiquitous, Broadnets, Securecomm. Dr. Chlamtac also serves as the founding Editor in Chief of the ACM/URSI/Springer Wireless Networks (WINET), the ACM/Springer Journal on Special Topics in Mobile Networks and Applications (MONET). B. Prahbakaran is with the faculty of Computer Science Department, University of Texas at Dallas. He has been working in the area of multimedia systems: animation & multimedia databases, authoring & presentation, resource management, and scalable web-based multimedia presentation servers. Dr. Prabhakaran received the prestigious National Science Foundation (NSF) CAREER Award in 2003 for his proposal on Animation Databases. He has published several research papers in various refereed conferences and journals in this area. He has served as guest-editor (special issue on Multimedia Authoring and Presentation) for ACM Multimedia Systems journal. He is also serving on the editorial board of Multimedia Tools and Applications journal, Kluwer Academic Publishers. He has also served as program committee member on several multimedia conferences and workshops. B. Prabhakaran has served as a visiting research faculty with the Department of Computer Science, University of Maryland, College Park. He also served as a faculty in the Department of Computer Science, National University of Singapore as well as in the Indian Institute of Technology, Madras, India.     

基于Intserv和Diffserv的端到端QoS研究

本文首先介绍了集成服务模型(Intserv)和区分服务模型(Diffserv)的原理及特点，以及MPLS技术同这两种模型的结合方法。并针对集成服务模型和区分服务模型各自的优缺点，提出了对两者相结合的端到端QoS。最后对QoS的现状进行了分析，展望了其今后的发展趋势。     

Joint resource allocation with QoS provisioning in K-tier heterogeneous cellular networks

In this paper, the joint resource allocation （RA） problem with quality of service （QoS） provisioning in downlink heterogeneous cellular networks （HCN） is studied. To fully exploit the network capacity, the HCN is modeled as a K-tier cellular network where each tier＇s base stations （BSs） have different properties. However, deploying numbers of low power nodes （LPNs） which share the same frequency band with macrocell generates severe inter-cell interference. Enhancement of system capacity is restricted for inter-cell interference. Therefore, a feasible RA scheme has to be developed to fully exploit the resource efficiency. Under the constraint of inter-cell interference, we formulate the RA problem as a mixed integer programming problem. To solve the optimization problem we develop a two-stage solution. An integer subchannel assignment algorithm and Lagrangian-based power allocation algorithm are designed. In addition, the biasing factor is also considered and the caused influence on system capacity is evaluated. Simulation results show that the proposed algorithms achieve a good tradeoff between network capacity and interference. Moreover, the average network efficiency is highly improved and the outage probability is also decreased.     

QoS provisioning in GEO satellite with onboard processing using predictor algorithms

Recently, IP satellite networks have attracted considerable interest as a technology to deliver high-bandwidth IP-based multimedia services to nationwide areas. In particular, IP satellite networks seem to be one of the most promising technologies for connecting users in rural areas, where a wired high-speed network (e.g., xDSL) is not foreseen to be used. However, one of the main problems arising here is to guarantee specific quality of service constraints in order to have good performance for each traffic class. Among various QoS approaches used in the Internet, recently the DiffServ technique has become the most promising solution, mainly for its scalability with respect to the IntServ approach. Moreover, in satellite communication systems, DiffServ computational capabilities are placed at the edge points, reducing the implementation complexity of the satellite onboard equipment. This article deals with the problem of QoS provisioning for packet traffic by considering some resource allocation schemes, including bandwidth allocation techniques and priority-driven onboard switching algorithms. As to the first aim, the proposed technique takes advantage of proper statistical traffic modeling to predict future bandwidth requests. This approach takes into consideration DiffServ-based traffic management to guarantee QoS priority among different users. Moreover, the satellite onboard switching problem has been addressed by considering a suitable implementation of the DiffServ policy based on a cellular neural network.     

Multiple QoS provisioning with pre-emptive priority schedulers in multi-resource OFDMA networks

Wireless Networks - In this paper, we present an analytical framework for the performance evaluation of a pre-emptive priority scheduler in multi-resource networks, like those using Orthogonal...     

移动WiMAX网络端到端QoS解决方案的研究

本文根据移动WiMAX的组网特点和业务流分类,深入分析了无线承载和IP传输承载的QoS机制,给出了一种无线承载和IP传输承载的QoS对应的映射方案,从而解决移动WiMAX系统中端到端的QoS问题.     

QoS abstraction layer in 4G access networks

Emerging access networks will use heterogeneous wireless technologies such as 802.11, 802.16 or UMTS, to offer users the best access to the Internet. Layer 2 access networks will consist of wireless bridges (access points) that isolate, concatenated, or in mesh provide access to mobile nodes. The transport of real time traffic over these networks may demand new QoS signalling, used to reserve resources. Besides the reservation, the new signalling needs to address the dynamics of the wireless links, the mobility of the terminals, and the multicast traffic. In this paper a new protocol is proposed aimed at solving this problem—the QoS Abstraction Layer (QoSAL). Existing only at the control plane, the QoSAL is located above the layer 2 and hides from layer 3 the details of each technology with respect to the QoS and to the network topology. The QoSAL has been designed, simulated, and tested. The results obtained demonstrate its usefulness in 4G networks.