Circular ring UWB antenna with reconfigurable notch band at WLAN/sub 6 GHz 5G mobile communication

Microsystem Technologies - A compact UWB circular ring-shaped monopole antenna with a reconfigurable band-notched characteristic is introduced. The antenna design has a low profile of...     

Suboptimal network coding subgraph algorithms for 5G minimum-cost multicast networks

To reduce the transmission cost in 5G multicast networks that have separate control and data planes, we focus on the minimum-power-cost network-coding subgraph problem for the coexistence of two multicasts in wireless networks. We propose two suboptimal algorithms as extensions of the Steiner tree multicast. The critical 1-cut path eliminating (C1CPE) algorithm attempts to find the minimum-cost solution for the coexistence of two multicast trees with the same throughput by reusing the links in the topology, and keeps the solution decodable by a coloring process. For the special case in which the two multicast trees share the same source and destinations, we propose the extended selective closest terminal first (E-SCTF) algorithm out of the C1CPE algorithm. Theoretically the complexity of the E-SCTF algorithm is lower than that of the C1CPE algorithm. Simulation results show that both algorithms have superior performance in terms of power cost and that the advantage is more evident in networks with ultra-densification.     

A hybrid scheme for multicast authentication over lossy networks

For multicast communication, authentication is a challenging problem, since it requires that a large number of recipients must verify the data originator. Many of multicast applications are running over IP networks, in which several packet losses could occur. Therefore, multicast authentication protocols must resist packet loss. Other requirements of multicast authentication protocols are: to perform authentication in real-time and to have low communication and computation overheads. In the present paper, a hybrid scheme for authenticating real-time data applications, in which low delay at the sender is acceptable, is proposed. In order to provide authentication, the proposed scheme uses both public key signature and hash functions. It is based on the idea of dividing the stream into blocks of m packets. Then a chain of hashes is used to link each packet to the one preceding it. In order to resist packet loss, the hash of each packet is appended to another place in the stream. Finally, the first packet is signed. The proposed scheme resists packet loss and is joinable at any point. The proposed scheme is compared to other multicast authentication protocols. The comparison shows that the proposed scheme has the following advantages: first, it has low computation and communication overheads. Second, it has reasonable buffer requirements. Third, the proposed scheme has a low delay at the sender side and no delay at the receiver side, assuming no loss occurs. Finally, its latency equals to zero, assuming no loss occurs.     

Performance evaluation of multicast communication in packet-switched networks

In this paper we describe the theoretical background and practical application of QNA-MC (queueing network analyser supporting multicast), a tool for the analytical evaluation of multicast protocols. QNA-MC is based on the QNA method, which (approximately) analyses open networks of GI|G|m queues. In contrast to standard QNA, QNA-MC allows for the specification and evaluation of multicast routes. As in real multicast communication, packets leaving a particular node can be copied and deterministically routed to several other nodes. In order to analyse such queueing networks, QNA-MC converts the multicast routes to a suitable input for standard QNA. From the results delivered by QNA, QNA-MC then derives several performance measures for multicast streams in the network. A validation of QNA-MC, via a comparison to simulation results, shows that QNA-MC yields very good results. Finally, we give a detailed application example by evaluating different multicast routing algorithms for a realistic video conferencing scenario in the European MBONE.     

Performance analysis of multicast algorithms for mobile satellite communication networks

With the rise of mobile computing and an increasing need for ubiquitous high-speed data connections, Internet-in-the-sky solutions are becoming increasingly viable. To reduce the network overhead of one-to-many transmissions, the multicast protocol has been devised. The implementation of multicast in these low earth orbit (LEO) constellations is a critical component to achieving an omnipresent network environment. This paper examines the system performance associated with two terrestrial-based multicast mobility solutions, distance vector multicast routing protocol (DVMRP) with mobile IP and on demand multicast routing protocol (ODMRP). These protocols are implemented and simulated in a satellite LEO constellation. Results from the simulation trials show the ODMRP protocol provided greater than 99% reliability in packet deliverability, at the cost of more than 8 bits of overhead for every 1 bit of data for multicast groups with multiple sources. In contrast, DVMRP proved robust and scalable, with data-to-overhead ratios increasing logarithmically with membership levels. DVMRP also had less than 70 ms of average end-to-end delay, providing stable transmissions at high loading and membership levels.     

An enhanced framework for providing multimedia broadcast/multicast service over heterogeneous networks

Multimedia broadcast multicast service （MBMS） with inherently low requirement for network resources has been proposed as a candidate solution for using such resources in a more efficient manner. On the other hand, the Next Generation Mobile Network （NGMN） combines multiple radio access technologies （RATs） to optimize overall network performance. Handover performance is becoming a vital indicator of the quality experience of mobile user equipment （UE）. In contrast to the conventional vertical handover issue, the problem we are facing is how to seamlessly transmit broadcast/multicast sessions among heterogeneous networks. In this paper, we propose a new network entity, media independent broadcast multicast service center （MIBM-SC）, to provide seamless handover for broadcast/multicast sessions over heterogeneous networks, by extensions and enhancements of MBMS and media independent information service （MIIS） architectures. Additionally, a network selection scheme and a cell transmission mode selection scheme are proposed for selecting the best target network and best transmission mode. Both schemes are based on a load-aware network capacity estimation algorithm. Simulation results show that the pro- posed approach has the capability to provide MBMS over heterogeneous networks, with improved handover performance in terms of packet loss rate, throughput, handover delay, cell load, bandwidth usage, and the peak signal-to-noise ratio （PSNR）.     

6LoWPAN网络组播通信方案的研究与设计

随着无线传感器网络(WSN)对新应用的需求不断增加,基于IEEE 802.15.4实现IPv6通信的低速无线个人局域网标准6LoWPAN是将WSN接入Internet实现全IP通信的理想解决方案.在此提出了一种基于6LoWPAN网络的组播通信方案,通过自组建M AC地址的方式,对现有的6LoWPAN网络增加了对组播通信...     

5G/B5G毫米波网络TCP传输性能分析

5G/B5G移动通信系统的高带宽、高可靠性和低延迟的通信需求需要更多新技术的支持.毫米波由于其丰富的频谱资源和极高的带宽容量而成为5G/B5G移动通信系统的研究热点之一.不同于以往由有线网络主导的互联网架构,如今的移动互联网已经成为无线接入网和高速核心网的融合.但是目前对毫米波端到端通信传输性能的研究工作还相对较少,而且多采用仿真实验.本文利用真实网络设备,通过开展真实网络环境下的实验,对毫米波链路基本传输性能和5G/B5G毫米波网络端到端通信系统中TCP传输性能进行测量分析,研究5G/B5G毫米波网络传输过程中的链路瓶颈,为设计毫米波端到端网络传输协议,提高网络传输吞吐率奠定基础.     

毫米波5G网络中一种D2D通信的资源分配方案

在5G系统中,毫米波（mmWave）与终端直通技术（device-to-device,D2D）有利于提升系统容量和频谱利用率。针对73 GHz下underlay蜂窝网络中的D2D资源分配进行了研究。为了降低彼此间的干扰,首先提出对基站和D2D用户接收机进行区域限制;其次利用线性相关的方法选出可复用的蜂窝用户;最后在满足蜂窝通信和D2D通信服务质量（QoS）的要求下提出一种基于干扰控制的资源分配,以提升系统的吞吐量。仿真结果表明所提算法的性能优于参考算法。该算法能够有效提升系统吞吐量和频谱效率。     

A parametric quality model to evaluate the performance of tele-operated driving services over 5G networks

Multimedia Tools and Applications - We have developed a parametric model to quantify the Key Quality Indicators which affect video-based Tele-operated Driving (ToD) over a mobile network, as well...     

TTPM – An efficient deadlock-free algorithm for multicast communication in 2D torus networks

A torus network has become increasingly important to multicomputer design because of its many features including scalability, low bandwidth and fixed degree of nodes. A multicast communication is a significant operation in multicomputer systems and can be used to support several other collective communication operations. This paper presents an efficient algorithm, TTPM, to find a deadlock-free multicast wormhole routing in two-dimensional torus parallel machines. The introduced algorithm is designed such that messages can be sent to any number of destinations within two start-up communication phases; hence the name Torus Two Phase Multicast (TTPM) algorithm. An efficient routing function is developed and used as a basis for the introduced algorithm. Also, TTPM allows some intermediate nodes that are not in the destination set to perform multicast functions. This feature allows flexibility in multicast path selection and therefore improves the performance. Performance results of a simulation study on torus networks are discussed to compare TTPM algorithm with a previous algorithm.     

下一代光接入网络上安全的多虚拟专网构建机制

简要介绍了下一代光接入网络上构建安全的虚拟专网存在的挑战以及网络编码的特性, 重点研究基于网络编码构建安全多虚拟专网的机制。依据提出的机制, 多个安全的虚拟专网可以在无源光网络的下一代光接入网络的主要实现形式上独立构建。最后分析了提出的虚拟专网机制, 提高了下行数据传输吞吐量。     

Planar dual-band 27/39 GHz millimeter-wave MIMO antenna for 5G applications

Microsystem Technologies - This research work presents another design of a multi-input multi-output (MIMO) antenna with dual wide operating bands at the millimeter-wave (MMW) region proposed for 5G...     

移动Ad Hoc网络中基于多树的视频组播协议的研究

在移动AdHoc网络中进行视频传输,组播技术起着非常重要的作用.设计移动AdHoc网络视频组播协议的一个重要目标就是保证传输的不间断性,降低接收到的无用视频帧的比例.对移动AdHoc网络中基于多树的视频组播协议进行了研究,介绍了视频编码技术,给出了多树视频组播路由协议的设计要求和衡量协议性能的度量指标,详细分析和比较了已有的几个多树视频组播协议,指出了它们的优缺点,并探讨了下一步的研究方向.     

Delay and energy efficiency analysis of multicast cooperative ARQ over wireless networks

This paper investigates the performance of multicast cooperative ARQ (MCARQ) in wireless networks for reducing the system’s waiting time and the sum energy, where the delay and energy analytical model are proposed under equivalent service time and ideal Nyquist pulse. The packet transmission process is modulated by a three-state Markov chain, then the steady-state distribution of the MCARQ is obtained by solving the Markov chain. Further, the queue waiting time and energy efficiency of the multicast ARQ (MARQ) and MCARQ are obtained respectively. Theoretical analysis and simulation results demonstrate that the MCARQ protocol has a better performance than the MARQ in delay and energy efficiency. The presented model has potentially applications in practical systems, e.g. Multi-user MIMO communications.     

Optimal D2D power for secure D2D communication with random eavesdropper in 5G-IoT networks

In the rapidly evolving landscape of fifth generation Internet of Things (5G-IoT) networks, Device-to-Device (D2D) communication has emerged as a promising paradigm to enhance secrecy transmission rate (STR) and connectivity. However, the security of D2D communications in the presence of eavesdroppers remains a critical challenge. This article investigates the problem of optimizing D2D transmit power to achieve secure D2D communication while considering the presence of random eavesdroppers in 5G-IoT networks. We propose a novel secrecy-based power control approach (SRMWPCA) approach to model the random distribution of eavesdroppers in the network, taking into account their varying distances from D2D pairs and deliberately increasing interference at the eavesdropper's link. By leveraging tools from stochastic geometry, we derive an analytical expression for the secrecy transmission probability (STP), which quantifies the probability of eavesdroppers successfully decoding the D2D transmission. In this analysis, we have incorporated practical considerations such as channel fading, path loss, and interference from other devices. To enhance the security of D2D communication, we formulate an optimization problem to determine the optimal transmit power levels for D2D pairs, subject to constraints on the secrecy transmission probability and interference to the cellular network. We propose an efficient algorithm to find the power allocation that maximizes the secrecy outage performance while meeting these constraints. Simulation results demonstrate the effectiveness of the proposed approach in achieving secure D2D communication in 5G-IoT networks with random eavesdroppers. The performance of the proposed SRMWPCA approach improved by 23.25% and 20.9% compared with standard approaches in terms of the secrecy rate and throughput of the users from malicious attacks.     

A comparative performance analysis of reliable group rekey transport protocols for secure multicast

In this paper, we present a new scalable and reliable key distribution protocol for group key management schemes that use logical key hierarchies (LKH) for scalable group rekeying. Our protocol called WKA-BKR is based upon two ideas—weighted key assignment and batched key retransmission—both of which exploit the special properties of LKH and the group rekey transport payload to reduce the bandwidth overhead of the reliable key delivery protocol. Using both analytic modeling and simulation, we compare the performance of WKA-BKR with that of other rekey transport protocols, including a recently proposed protocol based on proactive FEC. Our results show that for most network loss scenarios, the bandwidth used by WKA-BKR is lower than that of the other protocols.     

A hybrid method for performance analysis of G/G/m queueing networks

Open queueing networks are useful for the performance analysis of numerous real systems. Since exact results exist only for a limited class of networks, decomposition methods have been extensively used for approximate analysis of general networks. This procedure is based on several approximation steps. Successive approximations made in this approach can lead to a considerable error in the output. In particular, there are no general accurate formulas for computing the mean waiting time and the inter-departure variance in general multiple-server queues. This causes the results from decomposition methods when applied to G/G/m queueing networks to be very approximative and to significantly deviate from actual performance values. We suggest substituting some approximate formulae by low-cost simulation estimates in order to obtain more accurate results when benefiting from the speed of an analytical method. Numerical experiments are presented to show that the proposed approach provides improved performance.