A new generation of mobile communications has been evolving for every 10 years, keeping in mind the enormous data traffic, huge capacity requirements, excellent quality of service with minimal latency; there is a shift in paradigm toward the upcoming 5G technology which is expected to be rolled out by 2020 that promises to meet the requirements stated above. 5G is envisaged to be a merged framework of wide range of applications ranging from device-to-device communications, smart grid to Internet of Things and many more. In this survey paper, a brief discussion on the major pillars of 5G which are millimeter wave technology, massive MIMO, ultra-dense network, beamforming and full-duplex transmission are presented. This survey paper also focuses on the role of optics in 5G technology, sometimes commonly referred to as microwave photonics, an interdisciplinary research platform. Due to huge bandwidth and enormous capacity upgrade, optical fibers are considered to be ideal backhaul and fronthaul media rather than copper cables in order to support small cells and next-generation networks. These advantages of optical fiber technology enable integrated optical and wireless access technologies for 5G wireless communications an interdisciplinary area of research.
相似文献These days, 5G wireless communication are being created for different modern IoT (Internet of Things) applications around the world, arising with the IoT. All things considered, it is feasible to send energy efficient innovation in a manner that advances the drawn out sustainability of networks. Next-generation heterogeneous wireless communication is composed of different base stations. In this network, sustainable spectrum allocation is required to maximize the bandwidth utilization along with a reduction in power consumption. This paper proposes an algorithm for allocating an optimized spectrum to clusters in a multi-cluster environment for sustainable 5G environment using particle swarm optimization (PSO). The proposed strategy is applicable for 3G, 4G, and 5G mobile networks. Mobile devices enter and leave the cluster randomly and stay within the cluster for an uncertain amount of time. During that period the user demands may vary. Consequently, various bandwidth allocations are required. For such cases, static allocation might result in inefficient utilization of bandwidth, wastage of power, and degrade user satisfaction. The proposed algorithm will optimize the spectrum allocated to a cluster from time to time to solve this problem and produce an optimized solution within a given deadline. PSO based proposed scalable spectrum allocation method is applicable for the different frequency range for each cluster, hence scalable from 3G telecommunication to 5G-mobile edge technology. The convergence of the strategy is analyzed. From simulation analysis, it is observed that the proposed strategy reduces power consumption by approximately 8%, 11%, and 6% in 3G, 4G, and 5G communications respectively than the existing scheme.
相似文献By 2020 world will testimony new archaic Multi-antenna technologies like beamforming along with massive multiple-input multiple-output in 5G system. The cellular networks with 5th Generation (5G) are introduced with the determined aim of supporting a very heterogeneous service mixture, everyone with its individual detailed requirements. It largely leverages a very huge count of independently controllable antennas at the BS, and thereby attains greater enhancement regarding the energy and spectral efficiency. This paper elucidate about the Hybrid Beamforming techniques, 3D beamforming techniques, Interference mitigation between small and macro cell beamforming proficiency and secure data transmission pre-owned in beamforming technologies dispense a comprehensive analysis of all aspect of Beamforming technologies used in 5G systems.
相似文献Implementation of different telecommunication systems based on wireless optical technologies requires careful awareness of the link conditions in order to predict the performance of each system and its expectations. Wireless optical communication channels, like telecommunication channels, have a fading phenomenon, which is called optical turbulence. A particular class of adaptive networks has the ability to move nodes and can move and converge to moving or static targets. The applications of these networks include dynamic and regional observation and pursuit of underwater military objects. The best type of communication technologies proposed for such networks is Visible Light Communication, or VLC, through which sensors, like the fish schools, with the optical communication between each other, move toward the targets. Investigating the impact of channel conditions and optical noise on these networks are other innovations of this research. In this paper, we model the behavior of a fish school in underwater VLC conditions using a mobile diffusion network. Our simulation results show the effects of water properties on the convergence of the mobile network nodes to a certain target. It is shown that as the water temperature, salinity level and the distance between the nodes increase, the convergence error rises and the nodes become departed from the target position.
相似文献
VoIP has become a revolutionary technology in the field of communication as it provides long distant calls at a very low cost and has many other advantages. But it depends upon a reliable Internet connection with high bandwidth availability. To meet this requirement researchers have proposed the employment of VoIP over 5G network (Vo5G) which is expected to upgrade mobile broadband services in future. In this paper, we recommend integration of Vo5G with high altitude aeronautical platforms (HAAPs) which are used to decrease the distance of transmitted signals from the satellites. HAAPs are also used to extend the coverage and capacity of wireless communication. We propose an architecture in which voice services will be provided through a 5G network which is integrated with HAAP, i.e., Vo5G integrated with HAAP. A dependability model is developed using the key components of Vo5G and HAAP to analyze the dependability attributes of the proposed architecture. To analyze the dependability model we use a semi-Markov process (SMP), a generalized version of continuous time Markov chain (CTMC), which takes into account the non-Markovian behaviour of the time spent in different states of the system. The steady-state as well as the transient results for availability and reliability are obtained through the SMP model. The steady-state results are obtained analytically, whereas the transient results are obtained through simulation. A comparison is also presented between Vo5G integrated with HAAP and Vo5G without HAAP to show that the former performs better. Numerical results are presented graphically, and the proposed dependability model is also validated through discrete-event simulation.
相似文献Two promising technologies cosidered for the Beyond 5G networks are the terahertz and nano-technologies. Besides other possible application areas they hold the commitment to numerous new nano-scale solutions in the biomedical field. Nano-technology, as the name implies, examines the construction and design of nano-sized materials. These two interconnected emerging technologies have the potential to find application in quite many areas, one of the most importan being healthcare. This overview paper discusses the specifics of these technologies, their most important characteristics and introduces some of the trends for their application in the healthcare sector. In the first section terahertz frequency radio waves and their specific properties depending on the surrounding environment are discussed, followed by an introduction to nano-scale communications. Terahertz waves mandate the use of nano-scale antennas, which in turn brings us to the concept of nano-scale nodes. Nano-scale nodes are units that can perform the most basic functions of nano-machines and inter-nano-machine communications, which allow distributed nano-machines to perform more complex functions. Beyond 5G the development of these nano-communications is expected to lead to the emergence of new complex network systems. In the second part of this paper the paradigms of the Internet of Nano Things, molecular commnications and the Internet of Bio-Nano Things are discussed followed by details on their integration in healthcare related applications. The main goal of the article is to provide an introduction to these intriguing issues discussing advanced nano-technology enablers for Beyond 5G networks such as terahertz and molecular communications, nano-communications between nano-machines and the Internet of Bio-Nano-Things in light of health related applications.
相似文献As power consumption results in greenhouse gas emissions and energy costs for operators, analyzing power consumption in wireless networks and portable devices is of crutial importance. Due to environmental effects resulted from energy generation and exploitation as well as the cost of surging energy, energy-aware wireless systems attract unprecedented attention. Cognitive Radio (CR) is one of the optimal solutions that allows for energy savings on both the networks and devices. Thus, cognitive radio contributes to increase spectral and energy efficiency as well as reduction in power consumption. In addition, energy consumption of the CR technologies as intelligent technology should be considered to realize the green networks objective. In this article, we look into energy efficiency of the cognitive wireless network paradigms. Moreover, energy efficiency analysis and modelling in these systems are specifically focused on achieving green communications objectives. However, CRs by altering all elements of wireless data communications are considered in this paper, and the energy-efficient operation and energy efficiency enabler perspectives of CRs are also analyzed.
相似文献Cognitive radio (CR) is currently one of the most promising information transmission technologies to deal with the problem of spectrum scarcity and spectrum underutilization in wireless communications. CR networks aim to enhance spectrum efficiency to meet the ever-increasing demands of end users. The principle is to provide the opportunity for unlicensed users (secondary users, SUs) to temporarily and dynamically access the unused or sparsely used bandwidth while ensuring that it never interferes or degrades the performance of the incumbent license holders, commonly called primary users (PUs). This raises several challenges to be addressed in CR networks and performance of secondary users is one of the critical issues tackled in this paper. That is, we propose to devise CR networks as a retrial queueing system where PUs have preemptive priority over SUs. To calculate performance measures of the devised model under quite general assumptions about the model parameters, analytical methods are known to require hard calculations and the obtained results are generally not exploitable. For this reason, simulation modeling becomes the last resort to assess the dependability indicators. To this extend, we build the simulation model of the queueing system using Timed Stochastic Colored Petri Nets. Various useful results will be hence drawn while varying network conditions. Both exponential and Erlang distributions are considered for modeling service time of SUs. The obtained results with restrictive assumptions fit the analytical outcomes experienced for quite similar queuing models, which demonstrate the effectiveness of the proposed STCPN simulation model.
相似文献Many varieties of technologies have been introduced for mobile communication and data traffic plays a major role in each generation of communication systems. 5G is termed as Next Generation Wireless Mobile Networks that has higher bandwidth, maximum spectral efficiency, super-speed connection, minimum energy consumption, when compared to 4G wireless networks. Next Generation of Mobile communication will use mmWave frequency bands for 5G systems. Millimeter wave transmission is one of the greatest technology in 5G mobile communication systems having higher bandwidth. It is also considered to be having high user demands and have a mobile growth in coming years. It is a promising technology having a non-shortage bandwidth and traffic demands. The major drawback in this system is Phase noise, In-phase and Quadrature timing mismatch, PAPR, local oscillator noise and blockage effects. The phase noise occurs due to the imperfections in local oscillators. In this paper, we discuss the Phase noise issues in millimeter wave systems. This review will act as guide for researchers to compare the various emerging phase noise problems and mitigation techniques for future 5G wireless networks.
相似文献Full-duplex cognitive radio (CR) is a promising technology for upcoming 5G wireless communication systems. This paper presents a robust fast Fourier transform (FFT) based multiband spectrum sensing using two-dimensional averaging algorithms in orthogonal frequency division multiplexing systems in full-duplex CR networks with residual self interference under Rayleigh flat fading scenario. In the proposed algorithm, we have used modified Daniell windowing technique both in time and frequency dimensions to smoothen the FFT spectrum under full-duplex scenario. The analytical expressions for the performance metrics are derived for the aforementioned algorithm. The simulated and analytical results, obtained for the proposed algorithm using modified Daniell windowing technique are found in good agreement. Finally, the comparison studies between the proposed scheme using modified Daniel windowing technique and the conventional rectangular windowing scheme clearly depict that the proposed scheme gives optimal performance even at low SNR using fewer filter lengths in time and frequency dimensions as the modified Daniell windowing algorithm is less influenced due to spectral leakage.
相似文献Nowadays, information and communication technology grows rapidly. The microelectronics and communication mediums also enhance their reachability of coverage and connectivity. 5G enhances the capacity of the network in terms of lowest communication latency, highest speed, enhanced throughput, minimum E2E delay, and minimizing the packet loss. In this paper, we discuss the working principle and key features of 5G communication technology along with the limitations of existing technologies. Further, we provide the taxonomy of the 5G network. Moreover, we provide a comparison of 5G and 4G LTE in terms of data privacy and security aspects. Further, we propose a four-layer architecture for ehealthcare system, which uses 5G NR (New Radio) architecture incorporating the control plane and user plane. We perform the simulation over the frequency range1 and frequency range2 and calculated the throughput and latency for distinct values of OFDM numerologies. Further, we provide a comparative analysis for 4G and 5G and deduce that 5G facilitates 10 times lower latency than 4G, and 5G can accommodate a much higher number of devices than 4G. In this work, we discuss providing better healthcare facilities electronically using 5G NR. Moreover, the data sharing and diagnosing the disease become faster and easier by using 5G NR.
相似文献- the market demand of new services;
- the politically stimulated liberalization of the telecommunication market and
- the technical possibilities of new telecommunication technologies.
Due to the enhancement in both spectral efficiency and energy efficiency, cognitive radio (CR) being combined with relay cooperation technique is deemed as a promising way to realize green-broadband communication in the fifth generation (5G) networks. In this paper, for such CR-relay networks operating in underlay mode, when multiple secondary cognitive users (SUs) share a common cognitive relay in decode-and-forward manner to complete their physical transmissions, system power consumption is investigated. For the scenarios where the co-channel interference to primary users and the peak transmit power of SUs and cognitive relay are constrained, the problem of power allocation in CR-relay network is formulated to minimizing sum-system-consumption. Then, based on the principle that power-consumption minimization is equivalent to energy-efficiency maximization, a novel power allocation scheme is proposed. Further numerical simulation is used to verify the optimality of the proposed power allocation scheme.
相似文献The last decade has witnessed an excessive demand for mobile traffic. Though, fifth generation (5G) networks are in the initial phase of deployment and have wide capabilities and noble features to meet the data thrust up to some extent, it’s time to think beyond 5G systems. It is being expected that next generation wireless system (6G) will entirely be automated and intelligent, and will be ubiquitous and ultra-high reliable towards connectivity to large number of devices. This paper aims towards discussing stringent requirements while focusing on key expected technologies that may shape the 6G networks. Various applications of 6G communications are then briefly outlined. At the end, paper also discusses the potential challenges for achieving the goal. These discussions will definitely open up the horizon for future research directions.
相似文献Fifth generation (5G) cellular networks promise to support multi-radio access technologies (multi-RATs) with low and high frequencies aiming at delivering good coverage, several gigabits data rate, and ultra-reliable services. In this context, user-association and resource allocation appear to be a huge challenge due to the variety of specifications and varied propagation environments. In this treatise, the focus is on the technical and administrative difficulties of the adoption of user association (UA) mechanism and spectrum sharing approach (SSA) in millimeter wave (mmWave) systems, for example, the technical design considerations and their underlying options, as well as their impact on users and network performance. In addition, details on the importance of the rules and regulations of SSA are presented. This study also identified a few possible design solutions and potential promising technologies in both UA and SSA. In the context of UA, several mechanisms are identified, such as backhaul-, caching-, and hybrid multi-criteria-aware UA to achieve seamless connectivity and to enhance the network utility. In the context of SSA, this study pinpoints varied subjects that need to be explored, such as joint efficient rules and regulations enactment, assessment of fairness and independence in multi-independent mobile network operators (multi-IMNOs) that support SSA, as well as the implementation of hybrid-SSA via Virtualized Cloud Radio Access Network. Finally, attention is drawn to several key conclusions to enable readers and interested researchers to learn about the most controversial points of mmWave 5G cellular networks.
相似文献