战术认知无线电网络架构设计

认知无线电技术具有智能电磁频谱感知、干扰避免和动态频谱接入的能力,因此利用认知无线电技术可以提升战术网络的性能.由于战术作战的复杂性,需要建立适用于战术任务的认知无线电架构.首先分析了战术通信的特点和认知无线电技术在战术网络中的运用,以及目前国外战术认知无线网络的建设情况.结合战术通信网络移动性高、电磁对抗复杂的特点,利用对抗环境下的战术网络结构和模型,提出了分层的战术认知无线电网络结构以及面向作战任务的网络管理方法,形成拓扑结构分层次、管理运行分阶段的网络架构.该网络架构均衡考虑了网络的灵活性和稳定性,适用于动态变化的战术网络,为认知无线电在战术通信中的技术应用和网络设计提供了参考.     

战术通信网络的识别方法

战术通信对抗系统中识别通信目标及其所属的通信网络,可以实现网络目标的活动监控并有效利用干扰资源对其实施干扰。提出利用辐射源的方位信息和信号时间特征进行通信网络或专向识别,可以提高信号分析处理速度,增强设备的单站能力。     

Efficient attack strategy for legitimate energy-powered eavesdropping in tactical cognitive radio networks

Wireless Networks - The cognitive radio network (CRN) is not only considered a useful medium for users, but it is also an environment vulnerable to proactive attackers. This paper studies an attack...     

典型战术Ad Hoc电台一维组网连通性仿真与分析

针对单兵便携式战术Ad Hoc电台在一维场景下网络的连通性,分别研究随机均匀分布网络的链路连通概率和全连通概率,并通过蒙特卡罗方法和网络仿真平台,对网络部署和业务运行情况进行了仿真模拟。分析和实验结果表明,典型战术Ad Hoc电台一维组网时,全网连通概率在l/τ附近取得最小值;大规模Ad Hoc网络中,网络全连通概率与节点通信范围之间存在0~1突变现象;与实现全连通相比,实现网络高概率连通所需节点数要少得多。     

Delay-sensitive and multimedia communication in cognitive radio sensor networks

Multimedia and delay-sensitive data applications in cognitive radio sensor networks (CRSN) require efficient real-time communication and dynamic spectrum access (DSA) capabilities. This requirement poses emerging problems to be addressed in inherently resource-constrained sensor networks, and needs investigation of CRSN challenges with real-time communication requirements. In this paper, the main design challenges and principles for multimedia and delay-sensitive data transport in CRSN are introduced. The existing transport protocols and algorithms devised for cognitive radio ad hoc networks and wireless sensor networks (WSN) are explored from the perspective of CRSN paradigm. Specifically, the challenges for real-time transport in CRSN are investigated in different spectrum environments of smart grid, e.g., 500 kV substation, main power room and underground network transformer vaults. Open research issues for the realization of energy-efficient and real-time transport in CRSN are also presented. Overall, the performance evaluations provide valuable insights about real-time transport in CRSN and guide design decisions and trade-offs for CRSN applications in smart electric power grid.     

Automated design algorithms for tactical wireless networks

To guide users who attempt to deploy wireless networks in military applications, there is an evolving need for developing systematic methodologies to analyze/predict the performance of mobile ad hoc networks (MANETs). In addition, the advance in cognitive networking research provides opportunities for exploiting unused spectrum to optimize throughput of MANETs. However, with the increasing number of parameters/constraints, there is even a more demanding need to develop automated methodologies to design/tune such networks.In this work, we study the concepts and challenges for automatic design/re-configuration of cognitive MANETs, in addition to proposing design automation algorithms. The paper is divided into two parts. In the first part, we describe the design objectives, imposed constraints, and involved parameters in MANET design. We discuss how cognitive techniques can be employed to exploit the unused spectrum in military architectures. We then discuss the challenges that face the design/re-configuration of a cognitive network and their implications at different network layers. We also describe possible implementation options for designing MANETs that employ cognitive features at all layers. In the second part of this work, we propose design automation algorithms for optimally setting parameters to achieve a desired objective and satisfy certain constraints. Despite providing the optimal configuration, the simple approach of testing all possible combinations of parameter settings has significant time complexity (the COMB approach). Thus, we propose a novel heuristic (Sequential Parameter Optimization or SEPO) for searching through the possible parameter settings and selecting the best design options. SEPO is efficient in terms of both convergence speed and parameter tuning. We also discuss the foundation for using supervised learning to speed up the design (search) process. By evaluating realistic design of military-like scenarios that require optimizing a diverse set of metrics, we show that SEPO generates comparable results to the optimal, straightforward (slow-converging) COMB approach that is based on exhaustive search.     

Secure communication in cognitive radio networks with untrusted AF relays

In this paper, two underlay based cognitive cooperative radio networks, each with one secondary source (SS), one secondary destination (SD), N untrusted secondary amplify and forward relays (USAFRs), one primary transmitter, and one primary receiver (PU‐RX), are considered for evaluating the secrecy performance. The SS sends the information to the SD in two time slots via multiple USAFRs in the absence of direct link between SS and SD. In the first time slot, SS and SD transmit the message and jamming signal to multiple USAFRs, respectively. In the second slot, a selected USAFR amplifies and forwards the combined received signals to the SD. The transmit powers of the secondary nodes are chosen so as to maintain the overall interference at PU‐RX below a specified limit. The transmit power of a selected USAFR is derived using the harvested energy from the RF signals of SS and SD. Two network scenarios of eavesdropping by USAFRs are studied: in one case, all USAFRs eavesdrop; while in the second case, only the selected USAFR eavesdrops the message during forwarding of the signal and power is allocated to secondary nodes on the basis of outage threshold of primary network. We investigate the secrecy outage probability (SOP) in both of the networks under several physical parameters. Analytical framework for evaluating SOP for both the cases are given while SOP in single integration form is given for the second case. MATLAB simulation results are presented for both the cases.     

Energy efficiency in cognitive radio assisted D2D communication networks

Telecommunication Systems - The next generation networks intend to have features like device to device (D2D) connectivity, energy efficiency and spectral efficiency. This paper presents problem...     

New coalition formation game for spectrum sharing in cognitive radio networks

In cognitive radio networks, Secondary Users (SUs) can access the spectrum simultaneously with the Primary Users (PUs) in underlay mode. In this case, interference caused to the licensed users has to be effectively controlled. The SUs have to make spectrum access decisions in order to enhance their quality of service, but without causing harmful interference to the coexisting PUs. In this paper, we propose a cooperative spectrum decision, which enables the SUs to share the spectrum with the PUs more efficiently. Our approach is based on a new coalitional game in which the coalition value is a function of the SUs' spectral efficiencies, the inter‐SUs interference, and the interference caused to the PUs. By applying new Enter and Leave rules, we obtain a stable coalition structure. Simulation results show that the SUs' spectral efficiencies are considerably increased and that the interference caused to the coexisting PU is reduced by about 7.5% as compared to an opportunistic spectrum access scheme. Moreover, the proposed coalitional game results in a more balanced spectrum sharing in the network. Copyright © 2014 John Wiley & Sons, Ltd.     

Transoceanic radio communication

The paper defines the state of the art of today which is the result of developments during the war. Transatlantic radio communication is at present maintained by five first class stations, two in America and three in Europe. These stations operate at wave lengths between 12,500 and 17,000 meters. The range of wave lengths suited for such traffic is rather limited, the desirable wave length being included between the limits of 10,000 to 20,000 meters. New developments indicate three methods for increasing the radio traffic without interference between the different messages. These methods are increase of the transmitting speed, closer spacing of wave lengths and directive reception. If these technical possibilities are intelligently used, the author predicts that radio communication will be equal to all demands that will be placed upon it. The second part of the paper describes the radio transmitting system for the development of which the author is responsible. This system is represented by the naval radio station, New Brunswick, N. J. and comprises new means for generating modulating, and radiating the continuous wave energy. The generator is the high-frequency alternator with which the author's name has become associated. The modulating system is the "magnetic amplifier" which is described in a paper by the author before the Institute of Radio Engineers. The "multiple antenna" system of radiation is described in this paper for the first time. The general theory and figures for the increased radiation efficiency are given. The author also predicts that the multiple antenna will make possible directive radiation on a large scale.     

A novel reliable and secure communication scheme for cognitive radio networks using concatenated kernel codes

Cognitive radio networks have emerged as a possible solution for the spectrum scarcity problem. Cognitive radio networks involve heterogeneous entities as part of it for facilitating spectrum sharing. Ensuring reliability and security in such scenario is inevitable for the licensed users (primary users) as well as for the unlicensed users (secondary users). To address the challenges of reliable and secure communication for the secondary users, in this paper, a novel reliable and secure communication framework is proposed. A class of group codes called concatenated kernel codes is used to achieve reliability and techniques of fundamental cutset and fundamental circuit to achieve security in terms of authentication of sender. It is shown that the proposed communication framework provides reliability mitigating the continuous interference of primary users and security by defending against the cryptanalytic attacks such as replay attack, related key attack, and man‐in‐the‐middle attacks. The theoretical basis of the proposed framework is validated, and its performance is evaluated through simulations.     

战术无线电台半实物仿真系统设计与实现

战术无线电台是军队重要的通信装备,采用S3C6410微处理器为核心的嵌入式硬件平台,提出一种战术无线电台半实物仿真训练系统的设计方案,该系统可以实现模拟战场通信环境、设置通信预案、控制仿真训练进程和评估训练效果等功能,为部队提供了近似实战的训练环境,节省了训练经费,军事和经济效益显著。     

战术通信子网建模及仿真研究

针对战术通信网中信息传递的层级关系特征,采用多频分层技术对该网络进行仿真建模。通过引入营连级通信场景,给出子网成员节点和簇首节点的仿真模型及实现描述,并提出了一种简单有效的路由表数据结构,在模型节点域中进行加载。实验结果证明:该仿真建模方法具有一定可行性,用其搭建仿真网络可有效客观地反映通信子网的各项性能指标。     

适于ad hoc网络安全通信的新签密算法

首先提出了一个基于身份的新签密算法,并对其安全性和效率进行了分析及证明;结果表明,该算法在随机预言机模型下是可证明安全的,而且与已有基于身份的签密算法相比,其计算量和传输代价小,特别适合用于ad hoc网络的密钥管理、安全路由等通信安全协议.最后,以ad hoc网络分布式门限密钥管理中各服务节点所拥有的系统密钥份额的更新为例,说明了将新签密算法用于ad hoc网络安全协议的方法及其意义.     

Partitioning QoS management for secure tactical wireless ad hoc networks

Addressing quality of service in military wireless ad hoc communication networks involves unique challenges due to imposed tactical requirements and,conditions, such as heterogeneous traffic with stringent-real-time and survivability requirements, mobile wireless nodes in hostile environments, and limited spectrum availability. Encryption adds another layer of complexity because of the partitioning of the network into plain text (unencrypted) and cipher text (encrypted) parts that, by definition, cannot communicate QoS information to one another. A typical communication shelter is composed of unencrypted LANs connected to a packet-encrypted backbone network. This article presents a partitioned QoS approach, focusing on QoS management at the unencrypted LAN that complements QoS management done at the encrypted backbone. Some of the unencrypted LAN QoS techniques being considered for the Warfighter Information Network-Tactical (the future Army tactical backbone network) are outlined.     

战术TDMA网络分析与研究

数据链作为新军事变革中军事信息装备的重要组成部分,其应用水平在很大意义上决定着信息化战争的水平。TDMA协议是目前战术数据链采用的主流组网协议之一。以战术TDMA网络为背景,主要从技术特点和体系结构方面介绍了LINK-16,LINK-22和EPLRS三种TDMA网络,另外,也对当前存在的其他一些战术TDMA网络做了简单概括。     

Evaluating the performability of tactical communications networks

Tactical communications networks are multihop wireless networks in which switches and endpoints are mobile nodes. In a tactical environment, system performance degrades when switching nodes and/or communication links fail to operate. Fast algorithms for performance analysis are desirable for optimizing the network in a timely fashion. Further, tactical networks commonly use preemptive priorities to achieve low blocking probabilities for high-priority calls when the loss of equipment in the battlefield is not trivial. This paper discusses three measures and analytical algorithms for the performability evaluation of a two-tier tactical communications network where preemptive priority service discipline is employed and traffic is divided into multiple classes to provide multiple grades of service. Each class of traffic has its distinct characteristics, such as average call-arrival rate, average call-holding time, and service priority. The three performability measures are devised to evaluate the impact of nodes/links failures on system performance. Experiments show that the preemption does provide robust service for higher priority traffic. The techniques for performability evaluation presented in this paper may also be useful in other rapidly deployable networks, where mobility, communication efficiency, and computational complexity for adapting the network to unpredictable environments are of significant concern.     

Scheduling algorithms for multihop radio networks

Algorithms for transmission scheduling in multihop broadcast radio networks are presented. Both link scheduling and broadcast scheduling are considered. In each instance, scheduling algorithms are given that improve upon existing algorithms both theoretically and experimentally. It is shown that tree networks can be scheduled optimally and that arbitrary networks can be scheduled so that the schedule is bounded by a length that is proportional to a function of the network thickness times the optimum. Previous algorithms could guarantee only that the schedules were bounded by a length no worse than the maximum node degree times optimum. Since the thickness is typically several orders of magnitude less than the maximum node degree, the algorithms presented represent a considerable theoretical improvement. Experimentally, a realistic model of a radio network is given and the performance of the new algorithms is studied. These results show that, for both types of scheduling, the new algorithms (experimentally) perform consistently better than earlier methods     

基于SDN的战术通信网络架构研究

战术通信网络具有高动态、弱连接、低带宽和多链路备份等特性,软件定义网络（software defined network,SDN）技术通过传统网络控制设备软硬件解耦,将核心控制功能软件化,通过集中控制策略获取全局视图,从而实现资源的灵活调度与信道资源的高效利用,推动战术通信网络朝着更加智能化的弹性适变网络发展。首先介绍了SDN的发展现状及优势,分析了传统架构战术通信网络的若干问题,并对SDN技术在外军战术通信领域的应用情况进行了分析,提出了SDN在军事通信领域应用的可行性思路,对应用场景进行了构想,最后对SDN在军事通信领域的应用可行性进行了总结。