世界短波广播频率规划前景及对策建议

本文以短波（ＨＦ）广播频率规划问题的产生和对１９８４、１９８７两届世界短波频率规划大会的回顾为主线，一方面较全面地分析比较了ＩＴＵ原国际频登会（ＩＦＲＢ）以１９９１年冬季ＨＦ季度表（Ｄ－９１）为例试编的“ＨＦＢＣ规划练习”结果，侧重给出了中国和美国、前苏联等国的试算结果比较，说明了“改进的ＨＦＢＣ规划系统”指配频率方法失败的原因；另一方面介绍了美、欧等发达国家近几年在ＨＦ广播规划问题上的研究动态；     

短波组网及其相关技术

讨论了一种短波（ＨＦ）组网策略,包括物拓扑结构、自适应选频、自动链路建立、短波数传以及网络控制管理等相关技术。     

一种新的短波数传调制体制

本文提出一种利用短波信道传输数据时能够抗衰落抗多径的新方案——多频相位组合编码结合跳频（ＭＦＰＣＣ／ＦＨ），讨论了ＭＦＰＣＣ／ＦＨ编码原理和性能，介绍了ＭＦＰＣＣ／ＦＨ调制解调器的实现方法。     

双向HFC网络的规划思路

以海门市有线电视ＨＦＣ网络规划为例,介绍了ＨＦＣ网络结构,提出了双向ＨＦＣ网络规划的基本思路。     

H／TJF—441型短波自适应发信机操作指南

本文主要介绍了Ｈ／ＴＪＦ－４４１型短波自适应发信机操作过程，并对常用菜单作了解释，最后介绍了使用中的注意事项。     

HFC网络上行噪声控制系统

分析ＨＦＣ接入网上行通道的噪声问题，并介绍一种用于上行通道噪声控制的系统，该系统能实时监控ＨＦＣ网络的运行信噪比，并对入侵噪声进行及时定位和处理，较好地提高了ＨＦＣ网络的通信质量。     

短波数字通信系统

短波数字通信系统近年来，我国ＶＨＦ／ＵＨＦ常规通信、８００ＭＨｚ集群通信以及９００ＭＨｚ移动电话发展迅速，人们对短波通信有所淡忘。但短波通信是具有成本低、通信距离远等特点，加上近年来自适应技术和数字化技术的发展，使短波通信又从低谷走向另一个高峰。目前...     

HFC网络中的宽带接入技术

文中介绍了ＨＦＣ网络的结构和频谱分配，同时对ＨＦＣ网络中的接入协议作了深入分析。     

HFC网络基本群数字业务

本文根据有线电视ＨＦＣ网络现状和频率划分特点，讨论了ＨＦＣ网络上开展数字通信的可能性和可行性，并着重介绍了ＨＦＣ网络基本群数字业务，阐述了ＲＦ数字调制解调方法及数字端和数字终端的工作原理和特点。     

HFC网络基本群数字业务

本文根据有线电视ＨＦＣ网络现状和频率划分特点，讨论了ＨＦＣ网络上开展数字通信的可能性和可行性，并着重介绍了ＨＦＣ网络基本群数字业务，阐述了ＲＦ数字调制解调方法及数字端和数字终端的工作原理和特点。     

Research on Multi-Layer Distributed HF Radio Network Structure

High frequency（HF）transmission is an important communication techniques.However,conven-tional point-to-point transmission can be easily destroyed,which limits its utilization in practice.HF networking communication has the capability against demolishment.The network structure is one of the key factors for HF networking communication.In this paper,a novel analysis method of the network connectedness based on the eigenvalue is derived,and a multi-layer distributed HF radio network structure is proposed.Both the theore-tical analysis and the computer simulation results verify that the application of the proposed network structure in the HF radio communication can improve the anti-demolishment ability of the HF network efficiently.     

短波网络的拓扑性能分析

对短波网络的拓扑结构方面作了定性和定量的分析,给出了能够符合短波通信组网要求的网络结构。     

The DARPA packet radio network protocols

In this paper we describe the current state of the DARPA packet radio network. Fully automated algorithms and protocols to organize, control, maintain, and move traffic through the packet radio network have been designed, implemented, and tested. By means of protocols, networks of about 50 packet radios with some degree of nodal mobility can be organized and maintained under a fully distributed mode of control. We have described the algorithms and illustrated how the PRNET provides highly reliable network transport and datagram service, by dynamically determining optimal routes, effectively controlling congestion, and fairly allocating the channel in the face of changing link conditions, mobility, and varying traffic loads.     

基于SIP协议的短波接入系统

传统电信网需要研究将包括短波通信系统在内的现有各种通信系统融合到统一的核心分组网中的方法,以实现向下一代网络(NGN)的演进。论文从系统需求分析出发,提出了一种基于SIP协议的短波接入系统实现方法,给出了系统体系结构和参考设计,可以为下一代网络融合短波通信系统标准的制定提供参考。     

短波自组织网关键技术探讨

分析了短波自组织网还需进一步研究的主要关键技术,包括网络协议体系结构、信道接入技术、路由技术与传输控制技术等。短波自组织网的网络技术不能套用传统Ad Hoc网络技术,针对短波信道所特有的不稳定性、速率低以及易受干扰等问题,需要对传统的网络技术进行重新设计,满足短波自组织网的组网需求。将短波自组织网的网络技术与Ad Hoc网络技术进行了对比分析。     

A design concept for reliable mobile radio networks with frequency hopping signaling

The design of a packet radio network must reflect the operational requirements and environmental constraints to which it is subject. In this paper, we outline those features that distinguish the High Frequency (HF) Intra Task Force (ITF) Network from other packet radio networks, and we present a design concept for this network that encompasses organizational structure, waveform design, and channel access. Network survivability is achieved through the use of distributed network control and frequency hopping spread-spectrum signaling. We demonstrate how the execution of the fully distributed Linked Cluster Algorithm can enable a network to reconfigure itself when it is affected by connectivity changes such as those resulting from jamming. Additional resistance against jamming is provided by frequency hopping, which leads naturally to the use of code division mutiple access (CDMA) techniques that permit the simultaneous successful transmission by several users. Distributed algorithms that exploit CDMA properties have been developed to schedule contention-free transmissions for much of the channel access in this network. Contention-based channel access protocols can also be implemented in conjunction with the Linked Cluster network structure. The design concept presented in this paper provides a high degree of survivability and flexibility, to accommodate changing environmental conditions and user demands.     

基于模糊小波神经网络的短波频率预测

短波信道由于受电离层的非线性变化影响而不能及时选到最佳频率,严重制约了短波通信系统的效能发挥。为了提高短波频率预测及选频的准确性,在总结前人关于短波频率预测经验的基础上,结合人工智能技术在非线性时间序列预测方面取得的成就,提出了一种短波通信频率的预测方法,该方法结合相空间重构技术和模糊小波神经网络技术,并在数据预处理阶段采用奇异值分解对历史数据进行降噪处理,实验结果表明,该方法比其他预测方法的精度有很大的提高。     

Issues in packet radio network design

There are many design choices that must be made in the development of a packet radio network. There is usually no single correct choice, and the decisions are dependent on the environment that the network must work in, the requirements for performance and other functionalities, and the cost and other limitations, in addition, as new hardware and software technologies become available, the parameters governing the decisions change and often result in different selections. This paper outlines a number of design issues and choices available. The intent is to provide an overview of the design decisions that must be made so as to provide a context for the decisions made in a number of existing and developing packet radio networks. It is hoped that this will allow future designs to take advantage of both the wealth of experience available as well as new technologies. Three areas of design decisions are identified. The first area deals with the physical aspects of the network and concentrates on the radio connectivity and channel sharing. The second area deals with the automated management of the network and concentrates on issues such as link management and routing. The third area deals with the interface of the network to the users and some practical aspects of operating and maintaining a network.     

Automated optimization of service coverage and base station antenna configuration in UMTS networks

Deployment and maintenance of UMTS networks involve optimizing a number of network configuration parameters in order to meet various service and performance requirements. In this article we address automated optimization of service coverage and radio base station antenna configuration. We consider three key configuration parameters: transmit power of the common pilot channel (CPICH), antenna tilt, and antenna azimuth. CPICH power greatly influences coverage. From a resource management point of view, satisfying the coverage requirement using minimum CPICH power offers several performance advantages. In particular, less CPICH power leads to less interference and higher system capacity. Optimal CPICH power, in its turn, is highly dependent on how the other two parameters, tilt and azimuth, are configured at radio base station antennas. Optimizing antenna tilt and azimuth network-wise, with the objective of minimizing the CPICH power consumption, is a challenging task. The solution approach in this article adopts automated optimization. Our optimization engine is a simulated annealing algorithm. Staring from an initial configuration, the algorithm searches effectively in the solution space of possible configurations in order to find improvements. The algorithm is computationally efficient; thus, we can optimize large networks without using excessive computing resources. We present a case study for a UMTS planning scenario in Lisbon. For this network, automated optimization saves up to 70 percent of the CPICH power used in the reference network configuration. In addition, the optimized network configuration offers significant performance improvement in terms of fewer overloaded cells and lower downlink load factor     

Intent-based networks for 6G: Insights and challenges

Intent-Based Networks (IBNs), which are originally proposed to introduce Artificial Intelligence (AI) into the sixth-generation (6G) wireless networks, can effectively solve the challenges of traditional networks in terms of efficiency, flexibility, and security. IBNs are mainly used to transform users’ business intent into network configuration, operation, and maintenance strategies, which are prominent for designing the AI-enabled 6G networks. In particular, in order to meet the massive, intelligent service demands and overcome the time-varying radio propagation, IBNs can continuously learn and adapt to the time-varying network environment based on the massive collected network data in real-time. From the aspects of both the core network and radio access network, this article comprehensively surveys the architectures and key techniques of IBNs for 6G. In particular, the demonstration platforms of IBNs, such as the Apstra Operating System, Forward Networks Verification Platform, and One Convergence Service Interaction Platform, are presented. Moreover, the industrial development of IBNs is elaborated, including the emerging new products and startups to solve the problems of open data platforms, automated network operations, and preemptive network fault diagnosis. Finally, several open issues and challenges are identified as well to spur future researches.