LTE系统中用户平面承载的研究与实现

LTE系统取消了QoS协商机制,采用网络端承载控制模式.用户平面引入EPS承载进行IP分组包的传输.研究并设计出满足LTE系统QoS机制的EPS承载,针对未来数据业务具有高速、突发性的特征,基于EPS承载传输IP分组包的应用,真正实现了用户的"永远在线",提高了业务的数据速率.     

Class-based quality of service over air interfaces in 4G mobilenetworks

We present a framework for quality of service provisioning over the air interfaces in future wireless networks, including 3G enhancement and 4G mobile networks. The framework is based on the paradigm of service classes, wherein each class can exhibit a characteristic behavior in terms of resource allocation over the air interface. Using this QoS framework, future wireless network operators can define their own sets of service classes, choose the preferred way of implementing the QoS behavior of these classes, and offer class-based pricing schemes. The user application can choose the service class that best suits its expectations in terms of QoS and cost of access. A class-based bandwidth scheduling scheme is described as a mechanism to implement this QoS framework over CDMA air interfaces. This scheme incorporates the paradigm of service classes, in conjunction with fair resource allocation and air interface congestion resilience, while allocating air interface bandwidth to mobile users     

Quality of Service Drivers in LTE and LTE-A Networks

In the last years, cellular operators have experienced a rapid growth of mobile broadband subscribers and traffic volume per subscriber. At the same time, operators are moving from a single to a multi-service offering by adding new services such as multimedia telephony and mobile-TV. In this challenging scenario, the Quality of Service (QoS) concept provides network and service operators with a set of tools to enable service and subscriber differentiation. This paper presents an overview of the QoS drivers in Long-Term Evolution (LTE) and LTE-Advanced (LTE-A) networks, focusing on their QoS policy control capabilities. Proposals of policy control and management for increasing the QoS in LTE and LTE-A networks are described. This paper also includes a detailed list and analysis of the inputs to the Policy and Charging Rules Function (PCRF) that can be used for policy decision as well as a set of use cases involving the Policy and Charging Control architecture: (1) the analysis of a potential cooperation between the PCRF and a Deep Packet Inspector, and (2) the analysis of a potential interaction between the PCRF and the radio scheduler to provide a consistent end-to-end QoS.     

LTE核心网中基于PCC的QoS控制和能力开放技术研究

在LTE核心网中,通过引入PCC机制,来实现应用层业务数据流QoS需求到核心网承载层QoS分组过滤器之间的一致性映射和匹配问题。文章在详细介绍和分析LTE核心网中承载层QoS机制和PCC总体架构的基础上,研究如何将二者结合起来实现基于PCC和网络能力开放平台的QoS控制,从而提升运营商掌控网络提供业务的能力并改善用户的业务体验。     

EPS系统中业务流模板研究

为了更好地保证端到端的QoS机制,为用户提供差异化服务体验,EPS系统支持通过EPS承载对分组数据进行传送。通过对业务流模板(TFT)的研究,了解UE中上行分组过滤器(UL_PF)与EPS承载的关系,研究上行IP分组包与分组过滤器(PF)的匹配过程,给出一种PF与IP分组包之间的匹配实现方案,最终实现IP数组在EPS承载上传输。     

EPS系统中业务流模块研究

为了更好保证端到端的QoS机制,为用户提供差异化服务体验,EPS系统支持通过EPS承载对分组数据进行传送。本文通过对业务流模块(TFT)的研究,了解UE中上行分组过滤器(UL_PF)与EPS承载的关系,研究上行IP分组包与分组过滤器(PF)的匹配过程,给出一种PF与IP分组包之间的匹配实现方案,最终实现IP数组在EPS承载上传输。     

LTE/SAE系统中EPS承载的研究与设计

为了更好地保证端到端的QoS机制,为用户提供差异化服务,LTE/SAE系统采用了EPS承载进行IP分组包的传输。通过对默认承载、专用承载、聚合资源调度、EPS承载架构等概念进行介绍,设计了满足LTE/SAE系统QoS机制的EPS承载。本方案对EPS承载的具体设计中在保证有效传输IP分组包的基础上缩短了会话建立时延,保证了QoS参数的有效映射。针对未来数据业务具有高速、突发性的特征,这种基于EPS承载传输IP分组包的应用,真正实现了用户的＂永远在线＂,提高了业务的数据速率。     

IP网络QoS问题和对策

服务质量(QoS)技术是IP网络技术能否成为未来统一承载网络技术的关键。根据拥塞持续时间,网络QoS风险可以分为微秒级、毫秒级、秒级、分钟级,和更长时间级别等5个等级。调度机制、缓存和队列、呼叫接纳控制、流量工程等技术均是解决一类QoS风险的有效手段。IP网络运营商需要在分析网络中主要风险的基础上制定整体QoS解决方案,在呼损、时延、抖动、丢包4项指标中取得均衡。     

Network-based mobility management in the evolved 3GPP core network

A key aspect of the 3GPP system architecture evolution is the specification of an evolved packet core that supports multiple access networks. The EPC enables operators to deploy and operate one common packet core network for 3GPP radio accesses (E-UTRAN, UTRAN, and GERAN), as well as other wireless and wireline access networks (e.g., eHRPD, WLAN, WIMAX, and DSL/Cable), providing the operator with a common set of services and capabilities across the networks. A key requirement of the EPC is to provide seamless mobility at the IP layer as the user moves within and between accesses. This article provides an overview of the EPC specifications that use a network-based mobility mechanism based on Proxy Mobile IPv6 to enable mobility between access networks. An important facet of providing seamless mobility for a user?s sessions across technologies is to ensure that quality of service is maintained as the user moves between accesses. An overview of the ?off-path? QoS model to supplement PMIPv6 is also provided.     

一种新的对称CDMA系统中非对称业务下的呼叫允许控制策略

未来无线多媒体网络将以分组技术为基础,支持多种业务的传输,业务的QoS保证将受到一定的挑战.各运营商也将针对自己所服务的对象特点,定义各类业务的QoS等级,来提供具有不同QoS要求的业务.因此,呼叫允许控制(Call Admission Control,CAC)策略将要以分组业务为主要对象,即既要在充分利用系统资源的基础上保证各业务的QoS要求,又要适应各运营商之间的不同需求.因此本文提出一种新的对称CDMA系统中非对称业务下基于动态QoS保证的CAC策略.各运营商可根据自己的要求定义各业务的QoS等级.由于业务的不同特性,使得网络中上行链路和下行链路的业务呈现不对称性,为避免资源的浪费,将根据网络中的资源占有情况动态的地分配上行和下行链路中的资源.仿真结果表明,该策略可以自适应地保证各业务的QoS要求,提高了业务间的公平性和系统资源的利用率.     

LTE/SAE系统中EPS承载的研究与设计

对默认承载、专用承载和聚合资源调度进行了详细介绍,并研究了ESM子层对EPS承载的控制,设计出了满足LTE/SAE系统QoS机制的EPS承载。     

An access-aware pricing strategy for the evolved packet system

The evolved packet system (EPS) integrates third generation partnership project (3GPP) and non-3GPP wireless access networks to provide mobile users with ubiquitous access to a diverse set of multimedia services. As we know, 3GPP and non-3GPP access networks differ significantly with respect to bandwidth capacity, coverage range, and service cost. It is crucial to enable efficient load balancing between 3GPP and non-3GPP access networks to improve resource utilization, and still maximize revenue generation. From an economic point of view, pricing plays an important role in achieving load balancing in the EPS. This paper proposes an access-aware pricing strategy for the EPS to achieve load balancing between 3GPP and non-3GPP access networks and to maximize revenue generation for network operators. In addition, this paper develops an analytical model for the system using the proposed access-aware pricing strategy. With the analytical model, this paper also proposes an iterative method for determining the optimal pricing that maximizes revenue generation in the EPS. The analytical model is verified by simulation.     

Real-time call admission control for packet-switched networking by cellular neural networks

In this paper, novel call admission control (CAC) algorithms are developed based on cellular neural networks. These algorithms can achieve high network utilization by performing CAC in real-time, which is imperative in supporting quality of service (QoS) communication over packet-switched networks. The proposed solutions are of basic significance in access technology where a subscriber population (connected to the Internet via an access module) needs to receive services. In this case, QoS can only be preserved by admitting those user configurations which will not overload the access module. The paper treats CAC as a set separation problem where the separation surface is approximated based on a training set. This casts CAC as an image processing task in which a complex admission pattern is to be recognized from a couple of initial points belonging to the training set. Since CNNs can implement any propagation models to explore complex patterns, CAC can then be carried out by a CNN. The major challenge is to find the proper template matrix which yields high network utilization. On the other hand, the proposed method is also capable of handling three-dimensional separation surfaces, as in a typical access scenario there are three traffic classes (e.g., two type of Internet access and one voice over asymmetric digital subscriber line.     

Cross‐layer and cognitive QoS management system for next‐generation networking

Owing to limited wireless network resources, network applications must provide an adaptive quality‐guaranteed service to satisfy user requirements. Different applications are associated with different quality of service (QoS) concerns, as well as different QoS control parameters. This work presents an adaptive QoS algorithm by discussing the QoS specifications of three wireless access technologies, i.e. 3G, WiMAX and WiFi. Based on cross‐layer and cognition concepts, these environmental parameters are integrated with the sensing of spectral and received signal strength from a cognitive radio paradigm. An adaptive QoS algorithm is then proposed to select the optimal access network for services. Simulation results indicate that the proposed adaptive QoS algorithm outperforms available ones in real‐time applications. Compared with traditional algorithms, the proposed algorithm reduces not only the average delay time and jitter for VoIP services to 0.16 s and 0.09 ms, respectively, but also the packet loss ratio for high‐definition video streaming by 3.4%. Copyright © 2011 John Wiley & Sons, Ltd.     

IP承载网Qos保证解决方案

服务质量(Qos)技术是IP网络技术能否成为未来统一承载网络技术的关键.本文通过分析IP承载网多业务的特点,提出了一套IP承载网Qos解决方案.该方案将DiffServ、RSVP-TE、MPLS VPN三者按需组合,对IP承载网上承载的各种业务提供了很好的服务质量保证.     

LTE系统中PDN连接过程的建立与实现

作为全IP化的LTE系统,接入分组数据网成为数据传输的重要手段.PDN连接过程是LTE通信系统接入分组数据网的一个重要过程,其目的是在UE和分组数据网络问建立一个默认承载.笔者通过对LTE终端协议栈结构的介绍,筛选出PDN连接过程涉及到的模块,提出了一种终端PDN连接过程的设计和实现的方法.使用TTCN测试工具对终端PDN连接过程的开发软件进行了测试与仿真,结果显示此过程完全符合LTE标准,验证了设计的正确性和可行性.     

Policy and charging control in the evolved packet system

Policy and charging control provides operators with advanced tools for service-aware QoS and charging control. PCC for the evolved packet system, defined as part of the 3GPP Release 8 specifications, has evolved significantly from previous releases to support multiple-access technologies, roaming, and mobility. Within the PCC framework, a number of protocols have been specified to implement these functions. This article describes key PCC concepts and explains additional amendments to support PCC in the EPS.     

MSTP的应用与发展

多业务传送平台(MSTP)和数据设备的关系是联合组网、长期并存的关系,运营商的运维体制必须改革,不能仍将传输设备和数据设备截然分开进行建设;互连互通涉及到业务层、封装层、数据处理层、SDH承载层、SDH线路侧,运营商应重点关注;MSTP的进一步发展是加载自动交换光网络(ASON)控制平面,但要注意在支持数据业务的情况下,传送平面和控制平面在带宽调整方面的协调性;MSTP将来可能有两种转向:逐步退出传送网络的核心层或演化成为事实上的以分组交换为核心的承载网设备.     

Estimation of the efficiency of bandwidth request piggybacking to data packets in the wireless network controlled by the IEEE 802.16 protocol

A data transmission process of the centralized wireless network controlled by IEEE 802.16 protocol, in which a set of subscriber stations utilizes the common channel to transmit data to the base station, is discussed. The developed analytical model makes it possible to investigate the efficiency of upstream traffic transmission, including channel reservation using the random multiple access algorithm and packet sending with allowance for bandwidth request piggybacking onto data. The analytical estimates of packet registration and service durations are presented.     

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.