未来移动通信系统中的无线资源管理

文章结合当前正在研究的后3代(B3G)、第4代(4G)移动通信系统的发展和处于运营及推广阶段的第3代移动通信系统,分析了未来移动通信系统中无线资源管理系统的关键技术,探讨了多体制标准下的无线通信网络和多种业务情况下的无线资源管理的研究方向。     

试论5G移动通信发展趋势与若干关键技术

近几年来,移动通信事业迅速发展,第四代移动通信系统已经问世,随后业界人士提出了建立第5代移动通信系统,即5G的构想,并制定一系列计划。与4G相比,5G的频谱更高,实现了信息快速传输。现就5G移动通信的概念进行阐述,并分析其未来发展趋势,最后从无线传输技术及网络技术角度,总结5G移动通信的关键技术。     

基于MPLS技术的3G无线接入网络

介绍了第三代移动通信系统(3G)的无线接入网络的体系结构以及所采用的传输网技术。在此基础之上,重点分析了基于MPLS技术的3G无线接入网络方案,并对基于不同传输网方案的3GRAN中的实时业务时延性能进行了仿真比较。分析和仿真结果表明,基于MPLS技术的3C无线接入网络不仅可以提供多种类型业务的区分服务,而且也改善了实时业务的时延性能。     

极化码混合自动请求重传技术综述

极化码在有限码长下具有优异的性能,被3GPP采纳为5G控制信道编码方案。Beyond 5G(B5G)及6G对通信系统的可靠性和频谱效率有着更高的要求,需要解决逼近信道容量极限,提高系统性能的问题。为应对这一挑战,需要以极化码为基础,研究面向数据信道的极化编码传输技术。面对B5G及6G对通信系统的更高要求,总结了极化编码的链路自适应技术框架,介绍了几种典型的极化编码混合自动请求重传(Polar-Coded HARQ)技术方案。从性能、吞吐率、灵活性和复杂度等角度,对各种方案的优势与不足进行了综合对比。相较于传统HARQ方案,这些基于极化编码的新型HARQ方案能够显著提高无线传输性能,满足6G移动通信系统需求。归纳总结了极化编码HARQ的关键技术及未来研究方向,旨在为进一步研究提供有益的参考。     

5G eMBB场景中SR保护技术应用研究

针对传统第四代移动通信(4G)承载网络只能满足2G、3G和4G无线业务回传承载,而无法满足5G无线回传对承载网络在带宽、时延、切片和可靠性等方面提出的更高需求,更不能满足5G各种业务场景中极高要求的实时保护倒换需求,以及增强型移动宽带(eMBB)场景中业务保护和快速收敛需求,文章提出一种分段路由(SR)隧道技术在5 G...     

未来移动通信系统中的无线资源管理

文章结合当前正在研究的后3代（B3G），第4代（4G）移动通信系统的发展和处于运营及推广阶段的第3代移动通信系统，分析了未来移动通信系统中无线资源管理系统的关键技术，探讨了多体制标准下的无线通信网络和多种业务情况下的无线资源管理的研究方向。     

面向5G的大规模MIMO技术综述

未来第5代移动通信系统(5G)中无线数据业务量的爆发性增长推动着研究人员发展新的颠覆性技术.作为5G的关键候选技术之一,大规模多入多出(MIMO)在基站使用远超激活终端数的天线,能增加一个数量级的频谱效率并大幅降低发射功率.首先介绍了大规模MIMO的系统模型和理论性能,其次分析和归纳了在信道测量与建模、信道信息获取、传输方法的研究成果,然后简述了实验和测试进展,最后讨论了未来研究方向.     

变电站内5G终端通信信道建模与分析

以巡检机器人为代表的终端设备在变电站中应用广泛,第五代移动通信(5G)技术发展迅速,未来5G可移动终端在变电站的应用将会越来越多。通信系统的性能与无线信道息息相关,因此研究变电站中可移动终端的5G通信信道特性至关重要。文章针对变电站三维(3D)散射环境下5G可移动终端的通信信道的特性问题,基于多输入多输出技术,提出采用几何分析法建立3D信道模型,并推导出了信道的时间自相关函数、空间互相关函数。基于5G频段,仿真并分析了无线信道的自相关和互相关特性;研究了不同大小的莱斯因子对无线信道特性的影响。上述仿真结果表明了5G终端在变电站的可用性,拓宽了变电站场景下可移动终端运用5G通信技术的研究。     

OFDM(正交频分复用)技术抗干扰性能分析

本文概述了正交频分复用(OFDM)的系统工作原理,优点和不足。较之第三代移动通信系统,OFDM采用了多种新技术,使其具有更高的频谱利用率和优质的抗干扰能力,OFDM增加系统容量,可承载更多信道,能更好地满足多媒体通信要求,将实时性、声音和画面清晰度要求高的多媒体业务通过宽频信道高品质地传送出去。可以提供比目前无线数据技术质量更高(速率高、时延小)的服务和更好的性能价格比,能为4G无线网提供更好的方案。在此基础上分析了OFDM的抗干扰性能,对在无线传输中普遍存在的几种干扰进行分析并着重用调幅和调频两种方式分析了传输信道上的高斯噪声对信号的干扰来说明OFDM特有的优点,最后并推导出结论,说明了OFDM技术优越的抗干扰性能。随着通信的加速发展,OFDM将有更广阔的前景。     

LTE上行块状导频的信道估计研究

继第三代（3G）移动通信之后,长期演进（LTE）作为3G的演进,将是未来通信领域的主流技术。信道估计性能一定程度上决定了通信系统的可靠性,LTE系统上行采用基于块状导频的信道估计。通过MATLAB仿真分析了不同信道估计方法、不同插值方法及不同导频间隔对估计性能的影响,仿真结果可用于指导实际工程应用中信道估计参数的选择。     

A survey of 5G technologies: regulatory,standardization and industrial perspectives

In recent years, there have been significant developments in the research on 5th Generation (5G) networks. Several enabling technologies are being explored for the 5G mobile system era. The aim is to evolve a cellular network that is intrinsically flexible and remarkably pushes forward the limits of legacy mobile systems across all dimensions of performance metrics. All the stakeholders, such as regulatory bodies, standardization authorities, industrial fora, mobile operators and vendors, must work in unison to bring 5G to fruition. In this paper, we aggregate the 5G-related information coming from the various stakeholders, in order to i) have a comprehensive overview of 5G and ii) to provide a survey of the envisioned 5G technologies; their development thus far from the perspective of those stakeholders will open up new frontiers of services and applications for next-generation wireless networks.     

Web browsing optimization over 2.5G and 3G: end‐to‐end mechanisms vs. usage of performance enhancing proxies

2.5 Generation (2.5G) and Third Generation (3G) cellular wireless networks allow mobile Internet access with bearers specifically designed for data communications. However, Internet protocols under‐utilize wireless wide area network (WWAN) link resources, mainly due to large round trip times (RTTs) and request‐‐reply protocol patterns. Web browsing is a popular service that suffers significant performance degradation over 2.5G and 3G. In this paper, we review and compare the two main approaches for improving web browsing performance over wireless links: (i) using adequate end‐to‐end parameters and mechanisms and (ii) interposing a performance enhancing proxy (PEP) between the wireless and wired parts. We conclude that PEPs are currently the only feasible way for significantly optimizing web browsing behavior over 2.5G and 3G. In addition, we evaluate the two main current commercial PEPs over live general packet radio service (GPRS) and universal mobile telecommunications system (UMTS) networks. The results show that PEPs can lead to near‐ideal web browsing performance in certain scenarios. Copyright © 2006 John Wiley & Sons, Ltd.     

3GPP中URLLC标准研究进展

为了应对未来移动流量与设备连接数量的爆炸式增长,第五代通信系统(5G)将通信服务从人与人之间通信渗透到物联网及各种垂直行业领域,3 GPP从NR第一个版本开始就开展了针对低时延高可靠通信的标准研究工作。首先概述了URLLC在3GPP中研究的标准化进程;然后列举了URLLC用例与需求,基于多样化的需求指标,详细介绍了使能URLLC业务的物理层关键技术与其在3GPP各个阶段的研究进展;最后,总结全文并对未来URLLC技术的发展做出展望。     

Introduction to the 3GPP-defined NTN standard: A comprehensive view on the 3GPP work on NTN

With the recent publication of a set of technical specifications in 3rd Generation Partnership Project (3GPP) related to non-terrestrial network (NTN) enhancements, a global standard for satellite systems is newly defined aiming to support any orbit, any frequency band, and any device. It opens the door for the seamless integration of satellite network component in 5G system and beyond, delivering the promise of a ubiquitous mobile system that can support new use cases. The emergence of hybrid terrestrial-satellite systems is the result of a joint effort between stakeholders of both mobile and satellite industries and is paving the way to new business opportunities. This paper attempts to provide a comprehensive view on this 3GPP NTN standard and what are the next steps.     

SEAI: Secrecy and Efficiency Aware Inter-gNB Handover Authentication and Key Agreement Protocol in 5G Communication Network

Recently, the Third Generation Partnership Project (3GPP) has initiated the research in the Fifth Generation (5G) network to fulfill the security characteristics of IoT-based services. 3GPP has proposed the 5G handover key structure and framework in a recently published technical report. In this paper, we evaluate the handover authentication mechanisms reported in the literature and identify the security vulnerabilities such as violation of global base-station attack, failure of key forward/backward secrecy, de-synchronization attack, and huge network congestion. Also, these protocols suffer from high bandwidth consumption that doesn’t suitable for energy-efficient mobile devices in the 5G communication network. To overcome these issues, we introduce Secrecy and Efficiency Aware Inter-gNB (SEAI) handover Authentication and Key Agreement (AKA) protocol. The formal security proof of the protocol is carried out by Random Oracle Model (ROM) to achieve the session key secrecy, confidentiality, and integrity. For the protocol correctness and achieve the mutual authentication, simulation is performed using the AVISPA tool. Also, the informal security evaluation represents that the protocol defeats all the possible attacks and achieves the necessary security properties.Moreover, the performance evaluation of the earlier 5G handover schemes and proposed SEAI handover AKA protocol is carried out in terms of communication, transmission, computation overhead, handover delay, and energy consumption. From the evaluations, it is observed that the SEAI handover AKA protocol obtains significant results and strengthens the security of the 5G network during handover scenarios.

     

利用差分进化算法优化设计的多泵浦Te基光纤拉曼放大器

为适应下一代6G网络对光纤传输系统大容量、高速率和低延时的要求,以Te基光 纤为传输介质,利用差分进化算法设计了一款具有两级放大结构的(Raman-fiber amplifier,RFA) ,实现了对C+L波段内各信道的平坦光放大。差分进化算法具有结构简单、性能优越和鲁棒 性强的特点,能够有效解决拉曼耦合微分方程中的大空间、非线性和组合优化等问题。通过 Matlab仿真,该Te基光纤拉曼放大器(T-RFA)在100 nm带宽范围内 的平均增益为37.7 dB,增 益平坦度为0.9 dB。同时,分析了两级放大结构下该T-RFA的噪声增 益对系统的影响,为6G网络的拉曼光纤放大器的设计与优化提供了参考。     

第三代移动通信系统的网络安全

对3G移动通信系统的网络安全问题进行了探讨,对于中国在不远的将来将要开展的3G系统及工程的建设具有特别重要的意义。     

Dissecting the performance of YouTube video streaming in mobile networks

Video streaming applications constitute a significant portion of the Internet traffic today, with mobile accounting for more than half of the online video views. The high share of video in the current Internet traffic mix has prompted many studies that examine video streaming through measurements. However, streaming performance depends on many different factors at different layers of the TCP/IP stack. For example, browser selection at the application layer or the choice of protocol in transport layer can have significant impact on the video performance. Furthermore, video performance heavily depends on the underlying network conditions (eg, network and link layers). For mobile networks, the conditions vary significantly, since each operator has a different deployment strategy and configuration. In this paper, we focus on YouTube and carry out a comprehensive study investigating the influence of different factors on streaming performance. Leveraging the Measuring Mobile Broadband Networks in Europe (MONROE) test bed that enables experimentation with 13 different network configurations in four countries, we collect more than 1800 measurement samples in operational mobile networks. With this campaign, our goal is to quantify the impact of parameters from different layers on YouTube's streaming quality of experience (QoE). More specifically, we analyze the role of the browser (eg, Firefox and Chrome), the impact of transport protocol (eg, TCP or QUIC), the influence of network bandwidth, and signal coverage on streaming QoE. Our analysis reveals that all these parameters need to be taken into account jointly for network management practices, in order to ensure a high end‐user experience.     

An efficient resource allocation to improve QoS of 5G slicing networks using general processor sharing‐based scheduling algorithm

Fifth generation (5G) slicing is an emerging technology for software‐defined networking/network function virtualization–enabled mobile networks. Improving the utilization and throughput to meet the quality of service (QoS) requirements of 5G slicing is very important for the operators of mobile networks. With growing data traffic from different applications of numerous smart mobile devices having several QoS requirements, we expect networks to face problems of congestion and overload that prevent the effective functioning of a radio access network (RAN). This paper proposes a more effective packet‐based scheduling scheme for data traffic by 5G slicing with two operation modes for improving the resource utilization of 5G cloud RAN and providing an efficient isolation of the 5G slices. These two operation modes are referred to as static sharing resource (SSR) scheme and dynamic sharing resources (DSR) scheme. The SSR scheme is a modified version of an existing method. The goal of this approach is to reallocate the shared available resources of 5G network fairly and maximize the utilization of bandwidth while protecting a 5G slice from overwhelming other 5G slices. Throughput and delays of the system model are also discussed to show its performance limits. On the basis of the simulation outcomes, we observed that the proposed DSR scheme outperforms the SSR scheme in terms of provided delay and throughput. In addition, the token bucket parameters together with the assigned capacity weight for each slice can be selected and configured based on the required QoS. Finally, a good estimate for the maximum delay bounds of the slices is provided by the derived theoretical delay bound.