智能管道的内涵与特征

在网络带宽能力持续增强、用户个性化需求不断提高的背景下,如何提升网络智能化水平,进而提升管道价值成为当前运营商亟需解决的关键问题。本文在分析运营商网络发展趋势和已有标准的基础上,提出了旨在按需匹配网络资源的智能管道发展思路,探讨了智能管道的内涵特征和整体架构,分析了智能管道涉及的关键技术,并对智能管道所能支撑的典型业务进行了解析。     

异构无线网络中支持端到端重配置的资源管理技术

可重配置的异构网络是无线领域研究的一个热点问题。通过有效的资源管理,重配置技术可以实现对异构环境的灵活适应和对异构无线资源的有效利用。作为一种适变能力很强的技术,重配置可以使异构无线系统从目前的隔离状态走向互通与协同,真正实现网络融合。本文描述了异构网络重配置技术的产生背景和基本概念,对重配置研究中的一系列资源管理关键技术,包括动态网络规划与管理、联合无线资源管理和先进频谱管理,进行了系统的总结。     

Low-Latency Short-Packet Transmission over a Large Spatial Scale

Short-packet transmission has attracted considerable attention due to its potential to achieve ultralow latency in automated driving, telesurgery, the Industrial Internet of Things (IIoT), and other applications emerging in the coming era of the Six-Generation (6G) wireless networks. In 6G systems, a paradigm-shifting infrastructure is anticipated to provide seamless coverage by integrating low-Earth orbit (LEO) satellite networks, which enable long-distance wireless relaying. However, how to efficiently transmit short packets over a sizeable spatial scale remains open. In this paper, we are interested in low-latency short-packet transmissions between two distant nodes, in which neither propagation delay, nor propagation loss can be ignored. Decode-and-forward (DF) relays can be deployed to regenerate packets reliably during their delivery over a long distance, thereby reducing the signal-to-noise ratio (SNR) loss. However, they also cause decoding delay in each hop, the sum of which may become large and cannot be ignored given the stringent latency constraints. This paper presents an optimal relay deployment to minimize the error probability while meeting both the latency and transmission power constraints. Based on an asymptotic analysis, a theoretical performance bound for distant short-packet transmission is also characterized by the optimal distance–latency–reliability tradeoff, which is expected to provide insights into designing integrated LEO satellite communications in 6G.     

Real-Time Traffic Scheduling and Routing in Packet-Switched Networks Using a Least-Laxity-First Strategy

In this paper, we address the problem of transmission scheduling and buffer management at a switch in a high-speed packet-switched network. Future computer networks are expected to carry bursty real-time multimedia traffic with specific time-delay requirements. We propose a technique to schedule competing packets at a switch in a packet-switched network with two objectives—(i) maximizing the number of packets that would reach their destination before their deadline has been reached (ii) minimizing the number of packets dropped in transit in the network. The method is broadly based on the popular least-laxity heuristic in real-time process scheduling and is combined with buffer management at the switch.     

移动通信网中的端端保密通信

移动通信网络应用范围的不断扩展和新型业务的涌现需要有更多的特殊安全协议来保障其安全性.Yi Mu和Vijay Varadharajan提出了两种分别应用于同一服务区和不同服务区的端端保密通信协议 .本文首先分析了其不足之处,然后设计了同时适用于同一归属局和不同归属局移动用户之间进行保密通信的安全协议(分别称为域内和域间保密通信协议),最后,分析了上述协议的各项性能.与原有协议相比,本文所提出的协议不仅在安全性和其他性能上有较大改进,而且更具普遍性和统一性.     

基于OPNET的网络仿真技术研究及其应用

网络仿真技术是一种反映和预测网络性能的科学手段。仿真软件提供了真实网络和仿真器交互的方法,在不同条件下对网络进行模拟,并分析设计方案的可行性和健壮性。介绍了OPNET仿真软件的主要特性、建模机制及仿真步骤,重点论述了OPNET的网络域、节点域、进程域的建模过程和建模方法,并结合一个包交换网络的实例进行了仿真,通过对比链路平均利用率、网络吞吐量和端对端延迟在不同包产生速率时的变化,阐述了OPNET在具体网络规划和设计中的应用。     

大颗粒专线业务端到端造价评估

随着专线业务带宽的不断提升,大颗粒专线业务端到端造价评估变得愈发重要。以大颗粒专线业务端到端承载方式和经济评价理论为依据,提出了一种造价评估模型,并辅以案例分析。该模型全面考虑了主设备、管道、光缆和机房等成本,可以准确评估大颗粒专线业务的年均总成本费用,并对运营商定价进行指导。     

异构无线网络的端到端重配置技术研究

E2R（端到端重配置）技术利用SDR（软件无线电）提供的重配置能力,结合先进的资源管理机制和灵活的空中接口实现技术,实现对异构环境的灵活适应和对异构无线资源的有效利用。本文论述了E2R技术的产生背景和基本概念,对重配置研究中的关键技术（体系结构、资源管理和空中接口实现）进行了系统总结,最后就重配置未来研究的重点提出了一些看法。     

Enabling End-to-End QoS over Hybrid Wired-Wireless Networks

Providing end-to-end parameterized QoS is desirable for many network applications and has received a lot of attention in recent years. However, it remains a challenge, especially over hybrid networks involving both wired networks and wireless access segments (such as IEEE 802.11 Wireless Local Area Networks (WLANs)). The difficulty in achieving such QoS arises mainly because wireless segments often constitute “gaps" in terms of resource guarantee, due to the lack of efficient resource scheduling and management ability over shared wireless media, as well as the lack of an appropriate QoS signaling interface to seamlessly embed these wireless segments into an end-to-end QoS signaling system. In this paper, we consider the scenario where an IEEE 802.11 wireless node wishes to make an end-to-end resource reservation to a remote wired Internet node and vice versa. We propose Wireless Subnet Bandwidth Manager (Wireless SBM), an extension of SBM protocol to WLANs, to provide seamless end-to-end resource reservations. Wireless SBM utilizes the enhanced resource management ability provided by Hybrid Coordination Function (introduced in the upcoming IEEE 802.11e standard) to provide parameterized resource reservation and admission control.     

IP分组的AAL3/4适配及性能分析

本文提出一种用AAL3/4适配IP分组,支持MPLS(多协议标签交换)的方法.给出单个分组经过基于信元的交换网络的端到端时延分析方法—"等价长度"法以及相应的结果,进行了仿真验证;并对此条件下接收端所需缓存容量进行了估计.研究表明,在实现VC合并时,采用AAL3/4适配能够获得较小的分组端到端时延,简化中间结点的操作并减小结点所需缓存容量.与其它方式(AAL5)相比,这是一种更好的适配方式.