EPS系统的QoS机制

为了适应未来10年移动通信技术的发展，给用户不断增强的数据业务需求提供更好支持，3GPP组织启动了长期演进计划（LTE）与系统框架演进（SAE）研究项目。针对未来数据业务具有高速、突发性的特征，演进的分组系统（EPS）对服务质量（QoS）机制进行了诸多改进与增强，通过引入默认承载、聚合资源调度等概念，真正实现了用户的“永远在线”，提高了业务的数据速率，进而最终提升了用户体验。同时，针对未来UTRAN与E-UTRAN网络之间的互操作场景，设计了EPS的QoS等级标识（QCI）参数与通用移动通信系统（UMTS）QoS参数之间的合理映射。     

UMTS及EPC网络QoS机制的研究

随着社会的发展,用户对业务质量的需求也日益提高,为此3GPP组织加强了对QoS的研究,在UMTS阶段引入了端到端QoS机制,并在LTE阶段对QoS机制进行了扩展和增强,目前QoS的研究是3GPP研究的一个热点。本文对3GPP移动通信网QoS演进进行了介绍,分析了UMTS和EPC网络的QoS实现机制,并对两种QoS实现机制进行了分析。     

基于QoS的端到端差异化管控策略研究

在目前热点区域资源受限的情况下,本文基于eNode B侧和PCC侧的主要QoS管控能力开展网络差异化管控策略研究,形成无线侧最大聚合比特速率限速管控策略、基于用户的PCC管控策略以及基于业务的PCC管控策略,并在现场环境下完成验证。差异化管控策略能够在容量不足的区域有效保障特定用户/业务感知不受影响或优于普通用户/业务,妥善解决高流量和高负荷带来的整体用户感知问题,且能实现资源投入和经济效益的平衡。     

中国电信FDD 4G VoLTE语音感知MOS质量问题分析和优化提升的研究

随着终端、基站、EPC、IMS网元的大量端到端性能及配合问题解决,VoLTE业务在接通率、掉话率指标均已经基本达到了CDMA网络的水平,接入性能和保持性能方面的感知得到了较大改善。VoLTE作为LTE网络实现语音通话的最终方案,其通话质量、用户感知成为主要关注方向。本文主要介绍了衡水电信网优团队针对VoLTE语音通话在无线层问题导致的丢弃包、时延问题进行分析、定位的基本思路、优化方法。希望能够为网优工程师在VoLTE优化工作中提供帮助和支撑。     

质量竞争力指数管理模型在包钢的应用

通过对质量竞争力指数研究,对国家、地区、行业层次质量竞争力的测评以及基础信息的维护,引导各地区和各行业采取积极有效措施提高质量竞争力,加速整体实力的提高。     

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。     

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。     

基于QCI优先级的分组调度算法

长期演进(LTE)系统对用户同时获得的多种业务配置了服务质量(QoS)等级标识(QCI)优先级参数,从而优化了移动通信系统QoS评价体系。为此,结合M-LWDF算法,提出一种基于QCI优先级的分组调度算法。将QCI参数引入资源分配和分组调度判决机制,在用户与申请的多项业务间建立优先级关联性,实现多用户之间、单用户的多类型业务之间的联合优化调度。仿真结果表明,该算法能有效提高系统平均吞吐量,降低平均时延。     

Improved MLWDF scheduler for LTE downlink transmission

In long-term evolution (LTE) downlink transmission, modified least weighted delay first (MLWDF) scheduler is a quality of service (QoS) aware scheduling scheme for real-time (RT) services. Nevertheless, MLWDF performs below optimal among the trade-off between strict delay and loss restraints of RT and non-RT traffic flows, respectively. This is further worsened with the implementation of hybrid automatic retransmission request (HARQ). As these restraints grow unabated with increasing number of user demands, the performance of MLWDF further reduces. In order to ameliorate this situation, there is a need to directly incorporate the variations in user demands and HARQ implementation as parameters to the MLWDF scheduler. In this work, an improvement to the MLWDF scheduler is proposed. The improvement entails adding two novel parameters that characterise user demand and HARQ implementation. The scheduler was tested using varying three classes of service in QoS class identifiers (QCIs) table standardised by Third Generation Partnership Project for LTE network to characterise different services. It was also tested on the basis of packet prioritisation. The proposed scheduler was simulated with LTE-SIM simulator and compared with the MLWDF and proportional fairness schedulers. In terms of delay, throughput and packet loss ratio; the proposed scheduler increased overall system performance.     

Fractional Order ［Proportional Integral］ Controllers Parameters Algorithm Based on the Vector Method

A new calculation method of fractional order [proportional integral ]( FO [PI ]) controller parameters is proposed. And the systematic design schemes of fractional order [proportional integral ]( FO[PI]) controllers based on vector method are discussed in detail. The FO[PI]controller parameters algorithm based on the vector method can be programmed in MATLAB. According to MATLAB programs of the FO[PI]controller parameters algorithm,the FO[PI] controllers are designed following the different phase margins,different gain crossover frequency and different plants,respectively. From the simulation results,the calculated parameters based on MATLAB program is unique and the designed FO[PI] controllers work efficiently.