Location-Based Service Provisioning for Next Generation Wireless Networks

We study how the wireless network infrastructure can support location-based services (LBSs). We assume that each mobile is equipped with self-geolocation capability. The wireless network can provide geolocation information of mobiles to an application services provider (ASP) so that the ASP can customize services based on the geolocation of the users. The main challenge in wireless networking is to keep track of the geolocation of mobile users such that the application service can maintain a certain quality of service (QoS). In general, the quality of service depends on how often mobiles update their geolocation. Because geolocation updates require battery power, radio resources, and signaling in the wired network, optimization of the geolocation update frequency is critical. In this paper, we present geolocation update schemes in which we can minimize the update frequency while satisfying the QoS of application service. For case study, we consider location-based traffic report service (LBS-TR) and location-based navigation service (LBS-NS). In LBS-TR, each mobile user about to enter a heavily jammed highway is informed in a timely manner so that the user can avoid traffic congestion. In LBS-NS, a mobile user is given navigation instructions custom-tailored to the geolocation of the user. The granularity of navigation instructions changes as the user moves from highway to local street and from local street to building complex.     

Quality of Service Modelling of Virtualized Wireless Networks: A Network Calculus Approach

Wireless network virtualization is an emerging technology that logically divides a wireless network element, such as a base station (BS), into multiple slices with each slice serving as a standalone virtual BS. In such a way, one physical mobile wireless network can be partitioned into multiple virtual networks each operating as an independent wireless network. Wireless virtual networks, as composed of these virtual BSs, need to provide quality of service (QoS) to mobile end user services. Key QoS parameters include buffer queue length, network delay and effective bandwidth, in particular their upper bound forms. This paper presents a QoS model for such a wireless virtual network addressing these parameters. This QoS model considers resources of both physical nodes and virtual nodes and provides a realistic modelling of the delay and bandwidth behaviours of wireless virtual networks. Network calculus (NC), which usually provides finer insight into a system, is utilized to fulfil the modelling task. The numerical results have shown the effectiveness of the proposed model. The model is useful for both off-line network planning and online network admission control.     

基于QoS的3G网络系统设计与研究

为了有效地解决无线通信网络在宽带业务不断增加时产生的拥塞问题,提出了将区分服务模型应用于第三代移动通信网络以满足不同业务对QoS的需求。详细分析了区分服务模型的关键技术以及区分服务模型的系统结构,将区分服务模型和第三代移动通信分组域核心网系统结合起来,设计了支持QoS的第三代移动分组域核心网络。实验表明提出的模型较好地解决了第三代移动网络分组域核心网的QoS问题,提高了对不同业务的服务质量。     

A Novel Optimal Channel Partitioning Algorithm for Integrated Wireless and Mobile Networks

How to efficiently support multi-class services is a very important issue in integrated wireless and mobile networks because each type of services has distinct characteristics and quality of service (QoS) requirements. This paper presents an efficient algorithm for near optimal channel allocation when different types of services are to be provided in the next generation integrated wireless and mobile networks. We specifically propose a preemptive priority scheme for an integrated wireless and mobile network by first dividing channels into three independent groups and classifying traffic into four different types. The proposed system is modeled by a multi-dimension Markov chain model. Then such a model is used to obtain a set of relations that correlate performances with various system parameters. A novel recursive algorithm is developed to determine the minimal number of channels in each channel group that would be necessary to satisfy the QoS requirements. We also investigate the impact of load ratio for different types of traffic on channel assignment. Finally, we discuss some limitations of our approach and indicate possible future work. We believe that the partitioning scheme proposed in this paper can become a starting point for analysis of future integrated wireless and mobile networks.     

基于动态描述逻辑的服务组合及质量模型

 本文提出一个基于动态描述逻辑的Web服务自动组合框架.在该框架中,Web服务自动组合被划分为逻辑层和实现层两部分,于是服务的自动组合问题在逻辑上归结为一个动作规划问题,在实现上归结为一个根据动作选择具体服务的服务选择问题.基于该框架,本文给出了一个支持非线性QoS聚合和显式数据流声明的QoS模型.得益于合理的服务组合框架和QoS模型,本文提出的服务选择方法可以将复杂服务分解为较小的服务,然后分别用递归的剪枝算法求解.实验显示该方法是有效的,不但可适应候选Web服务数量较大的情况,且相对于现有方法能更好地处理服务组合中的复杂结构.     

A survey of quality of service in IEEE 802.11 networks

Developed as a simple and cost-effective wireless technology for best effort services, IEEE 802.11 has gained popularity at an unprecedented rate. However, due to the lack of built-in quality of service support, IEEE 802.11 experiences serious challenges in meeting the demands of multimedia services and applications. This article surveys 802.11 QoS schemes, including service differentiation in the MAC layer, admission control and bandwidth reservation in MAC and higher layers, and link adaptation in the physical layer, designed to meet these challenges by providing the necessary enhancements for the required QoS. Furthermore, the article addresses issues that arise when end-to-end QoS has to be guaranteed in today's pervasive heterogeneous wired-cum-wireless networks. Among these challenges, protocol interoperability, multihop scheduling, full mobility support, and seamless vertical handoff among multiple mobile/wireless interfaces are specifically addressed.     

Performance evaluation of the RQMA-CDMA scheme for multimedia traffic with QoS guarantees

The rapid growth of cellular mobile technology in recent years, coupled with the explosive growth of the Internet, has significantly increased the demand for wireless data services. Traffic on mobile devices is expected to be a mix of real-time traffic such as video, voice, and data, with users requiring diverse quality of service (QoS) guarantees for different types of traffic (video, voice and data). One of the primary challenges of providing QoS is how to prioritize and allocate network resources among contending applications. In order to achieve these goals, a scheduling scheme that can provide equitable and effective packet routing is required. This paper proposes a scheduling scheme called remote queuing multiple access-code division multiple access (RQMA-CDMA), whose purpose is to equitably assign bandwidth resources with QoS guarantees to different mobile devices. RQMA-CDMA is a rate scheduling scheme that can be used to assign bandwidth resources in conjunction with GPS (generalized processor sharing). Additionally, we analyze an admission control that is based on signal to interference plus noise ratio (SINR) for multimedia traffic. Finally, the performance of RQMA-CDMA is evaluated and compared to schemes based on CDMA-GPS according to dropped packets, delay, and throughput.     

The Service Utility Model in Service Management

1IntroductionWith the increasing competing in telecom,telecomoperators are under the pressure of providing more highperformance services based on the li mited network re-source. Adaptive QoS service is such a solution, whichcan increase the network efficiency and produce moreprofit ulti mately.Service QoScontrol andserviceinven-tory management are key techniques for adaptive QoSservices. Many issues in these aspects ,such as charac-terization of QoS, mapping QoS to resource ,efficiencyand …     

Priority-determined multiclass handoff scheme with guaranteed mobile QoS in wireless multimedia networks

The provision of multiclass services is gaining wide acceptance and will be more ubiquitous in future wireless and mobile systems. The crucial issue is to provide the guaranteed mobile quality of service (QoS) for arriving multiclass calls. In multimedia cellular networks, we should not only minimize the dropping rate of handoff calls, but also control the blocking rate of new calls at an acceptable level. This paper proposes a novel multiclass call-admission-control mechanism that is based on a dynamic reservation pool for handoff requests. In this paper, we propose the concept of servicing multiclass connections based on priority determination through the combined analysis of mobile movement information and the desired QoS requirements of multimedia traffic. A practical framework is provided to determine the occurrence time of handoff-request reservations. In our simulation experiments, three kinds of timers are introduced for controlling the progress of discrete events. Our simulation results show that the individual QoS criteria of multiclass traffic such as the handoff call-dropping probability can be achieved within a targeted objective and the new-call-blocking probability is constrained to be below a given level. The proposed scheme is applicable to channel allocation of multiclass calls over high-speed wireless multimedia networks.     

Next Generation Wireless Mobile System Efficient, Fair, Class Based Packet Scheduling Algorithm

Efficient utilization of network resources is a key goal for emerging broadband wireless access systems (BWAS). This is a complex goal to achieve due to the heterogeneous service nature and diverse quality of service (QoS) requirements of various applications that BWAS support. Packet scheduling is an important activity that affects BWAS QoS outcomes. This paper proposes a novel packet scheduling mechanism that improves QoS in mobile wireless networks which exploit IP as a transport technology for data transfer between BWAS base stations and mobile users at the radio transmission layer. In order to improve BWAS QoS the new packet algorithm makes changes at both the IP and the radio layers. The new packet scheduling algorithm exploits handoff priority scheduling principles and takes into account buffer occupancy and channel conditions. The packet scheduling mechanism also incorporates the concept of fairness. Performance results were obtained by computer simulation and compared to the well known algorithms. Results show that by exploiting the new packet scheduling algorithm, the transport system is able to provide a low handoff packet drop rate, low packet forwarding rate, low packet delay and ensure fairness amongst the users of different services.     

Service configuration and traffic distribution in composite radio environments

This paper adopts the assumption that cellular, broadband fixed wireless access (BFWA), wireless local area networks (WLAN), and digital video broadcasting (DVB) systems can be co-operating components of a composite-radio infrastructure. It is believed that through the composite radio concept, operators will be enabled to offer efficient, in terms of cost and QoS, wireless access to broadband IP-based services. The exploitation of this infrastructure calls for the application of computational intelligence (CI) technologies for the development of appropriate, sophisticated service and network resource management functionality. In this context, this paper identifies and addresses the important problem of service configuration and distribution in a composite radio environment (SCD-CRE). The problem's objective is to determine the best way to accommodate a demand volume, with which the composite radio infrastructure is faced. The pro finds the QoS levels that can be offered, and the networks that can support the demand at the selected QoS levels. The paper includes a first approach to the definition, mathematical formulation, and solution of a version of the SCD-CRE problem. Results indicating some of the capabilities of the SCD-CRE are also presented. Further application fields for CI technologies are indicated, in the area of the necessary reconfiguration of the managed, radio and fixed, network segments.     

Proportional degradation services in wireless/mobile adaptive multimedia networks

Adaptive multimedia services are very attractive since resources in wireless/mobile networks are relatively scarce and widely variable, and more importantly the resource fluctuation caused by mobility and channel fading can be mitigated using adaptive services. Therefore, there are extensive research activities on Quality of Service (QoS), call admission control, as well as bandwidth degradation and adaptation for adaptive multimedia services in wireless/mobile networks in recent years. However, fairness of bandwidth degradation has largely been ignored in previous work and remains an important issue in adaptive multimedia service provisioning. In this paper, we propose and study proportional degradation service provisioning in wireless/mobile networks that offer multiple classes of adaptive multimedia services. The proposed proportional degradation fairness model guarantees the proportional bandwidth degradation among different classes of services. Two proportional degradation scenarios are studied in this paper. In the first scenario, we study the proportional degradation provisioning with two QoS parameters for adaptive multimedia: the degradation ratio (DR) and the degradation degree (DD). In the second scenario, we study the proportional degradation provisioning with a new QoS parameter for adaptive multimedia: the degradation area (DA). For each scenario, based on the QoS parameters, proportional degradation adaptation algorithms are proposed to approximate the proportional degradation model, to fairly adapt calls' degradations, to utilize the system resource efficiently, as well as to optimize QoS parameters. Performance studies show that in the first scenario, proportional DR has been achieved very well, whereas proportional DD has not been well achieved. In other words, DR outperforms DD in terms of proportional degradation. In the second scenario, proportional DA has been well achieved. Furthermore, bandwidth resources have been efficiently utilized and DA has been minimized. Copyright © 2004 John Wiley & Sons, Ltd.     

Piecewise Network Awareness Service for Wireless/Mobile Pervasive Computing

This paper presents a piecewise framework for network awareness service (NAS) for wireless/mobile pervasive computing. We investigate how piecewise consideration of wired and wireless elements of the framework architecture benefits service advertisement and discovery and network-awareness techniques. We also discuss scalability of the NAS framework with respect to platform computing capabilities. The framework is suitable for a wide range of computing devices, from powerful ones with multi-tasking operating systems (OS) to small ones with lightweight OS. Case studies applying the NAS framework to sensor monitoring in home networks and data streaming in pervasive multimedia computing are presented. The analytical results on the performance of the NAS framework in these case studies show that it has significant advantages over traditional network-awareness frameworks in terms of reducing wireless bandwidth consumption and saving battery energy of mobile devices.     

Vertical Handover Over Intermediate Switching Framework: Assuring Service Quality for Mobile Users

Ensuring quality of service (QoS) for the mobile users during vertical handover between IEEE 802.11 wireless local area networks (WLAN) and data network provided by Ultramodern Telecommunication Systems (UMTS) is one of the key requirements for seamless mobility and transfer of existing connections from one network to another. QoS fulfillment is a complex problem and requires participation of both the mobile users as well as the connection networks. The QoS assurance criteria for existing connections can be affected by fluctuations of data rates when a user moves from the high speed WLAN network to the low speed UMTS network, even in the presence of another WLAN network in its vicinity. This can happen if the alternate WLAN network is highly loaded. Therefore handover from a high speed network to a low speed network should be avoided, whenever possible. This paper proposes a QoS based handover procedure that prioritizes the existing connection over the new connections so that rate fluctuations due to handover can be avoided if there exist another WLAN network in the range of the mobile user. Whenever the possibility of handover is detected, a pre-handover bandwidth reservation technique is used to reserve bandwidth at the alternate WLAN networks to avoid QoS degradation. The proposed scheme is implemented in Qualnet network simulator and the performance is analyzed and compared with traditional handover techniques.     

Radio Network Aggregation for 5G Mobile Terminals in Heterogeneous Wireless and Mobile Networks

This paper provides a novel design concept for advanced mobile multi interface terminals with radio network aggregation capability and enhanced quality of service (QoS) provisioning for multimedia services (voice, video and data) in heterogeneous wireless and mobile networks. A new module is established which provides the best QoS and lowest cost for any given multimedia service by using simultaneously all available wireless and mobile access networks for a given traffic flow. This novel adaptive QoS module with adaptive QoS routing algorithm is called advanced QoS routing algorithm (AQoSRA), which is defined independently from any existing and future radio access technology. The performance of our proposal is evaluated using simulations and analysis with multi-interface mobile stations with AQoSRA within, carrying multimedia traffic in heterogeneous mobile and wireless environment with coexistence of multiple Radio Access Technologies, such as 3G, 4G as well as future 5G radio access networks. The analysis of the proposed framework for radio networks aggregation in advanced mobile terminals has shown overall better performances regarding the achievable throughput and multimedia access probability in heterogeneous wireless and mobile environment.     

无线传感器网络多业务仿真平台的实现方案

在无线传感器网络中,由于传感器节点的能源十分有限,节能是设计的首要因素。然而,无线传感器网络的多业务在现实生活应用中对QoS(服务质量)都有不同的需求,这就使得WSN网络的QoS研究成为了专家学者们的主要研究方向。在WSN网络拓扑结构和业务类型的研究基础上,使用网络模拟器(Network Simulator Version 2,NS2)来搭建基于多业务共存的星型以及对等结构两种WSN网络仿真平台,建立多种业务流量模型,实现以无线传感器网络协议、流量模型、拓扑为基础的功能模块化设计;并对无线传感器网络关键性能进行了仿真模拟,实现延时、吞吐量、能耗等关键性能的分析。     

移动P2P流媒体中基于有效容量的邻居节点选择机制

For Peer-to-Peer (P2P) streaming services in mobile networks, the selection of appropriate neighbour peers from candidate peers with demanding data is an important approach to improve Quality-of-Service (QoS). This paper proposes a novel Effective Capacity Peer Se-lection (ECPS) scheme based on effective capacity. In the ECPS scheme, the neighbour peer selection problem was modeled using the Multiple Attribute Decision Making (MADM) theory, which considered multiple factors of candidate peers, including Signal to Interference and Noise Ratio (SINR), residen-cy time, power level, security, moving speed, and effective capacity. This model could increase the suitability of ECPS for wireless mobile environments. Then, the Technique for Order Preference by Similarity to Ideal Solu-tion (TOPSIS) was used to solve the MADM problem and identify the preferred neighbour peers. Simulation results show that the ECPS scheme can improve the network throughput, reduce packet delay by about 82%, and al-most double the packet delivery ratio of the mobile P2P streaming service.     

Service Discovery in Ad Hoc Networks: Performance Evaluation and QoS Enhancement

With the increasing popularity of wireless portable devices, such as laptops, PDAs and mobile phones, it is getting more and more important for mobile users to discover their required resources (e.g. printers and fax machines) without any need of configurations. To this end, automatic service discovery is an important feature of mobile Ad Hoc networks (Manets). In this paper a service discovery protocol for Manets based on the IETF Service Location Protocol has been implemented in the NS-2 simulator. Its performance is studied under different mobility patterns, network sizes and number of service agents. A lightweight quality of service (QoS) aware service discovery protocol is also proposed to support QoS applications. Zhong Fan is currently a Principal Researcher with Toshiba Research Europe in Bristol, UK. He received the B.S. and M.S. degrees in Electronic Engineering from Tsinghua University, China and the Ph.D. degree in Telecommunication Networks from Durham University, UK. His research interests are protocol design and performance analysis of wireless networks.     

A location‐based service advertisement algorithm for pervasive service discovery in wireless mobile networks

The practical success of pervasive services running in mobile wireless networks relies largely on its flexibility in providing adaptive and cost‐effective services. Service discovery is an essential mechanism to achieve this goal. As an enhancement to our previous work for service discovery, that is, model‐based service discovery (MBSD), this paper proposes a location‐based service advertisement (SA) algorithm named as MBSD‐sa. MBSD‐sa advocates the importance of service location to the service availability and integrates the service location information together with the service semantic information into service information for advertisement. MBSD‐sa utilizes prediction to estimate the service location so as to reduce the number of SA messages (SAMs). Two complementary types of SA mechanisms (Types 1 and 2) are employed by MBSD‐sa to strike the balance between the SAM overhead and the accuracy of service information. The performance of MBSD‐sa is analyzed both numerically and using simulations. Copyright © 2008 John Wiley & Sons, Ltd.     

宽带无线IP系统中基于区分服务的QoS实现策略

讨论了在宽带无线IP系统中实现QoS的问题。提出了一个基于区分服务(DiffServ)的QoS框架,并针对无线链路上的高误码率、窄带宽、性能变化剧烈、用户移动性等特点,对DiffServ进行了加强,并提供了一种针对业务类型的用户接入控制机制。仿真结果显示了该QoS框架的性能。