Small Cells Research Papers - Academia.edu (original) (raw)

Physical layer protection, which protects data confidentiality using information-theoretic methods, has recently attracted a lot of research attention. Using the inherent randomness of the transmission channel to ensure protection in the physical layer is the core concept behind physical layer security. In 5G wireless communication, new challenges have arisen in terms of physical layer security. This paper introduces the most recent survey on various 5G technologies, including millimeter-Wave, massive multi-input multiple outputs, microcells, beamforming, full-duplex technology, etc. The mentioned technologies have been used to solve this technology, such as attenuation, millimeter-Wave penetration, antenna array architecture, security, coverage, scalability, etc. Besides, the author has used descriptions of the techniques/algorithms, goals, problems, and meaningful outcomes, and the results obtained related to this approach were demonstrated.

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- Computer Science, Beamforming, Small Cells, G

Optical wireless communication (OWC) is an excellent complementary solution to its radio frequency (RF) counterpart. OWC technologies have been demonstrated to be able to support high traffic generated by massive connectivity of the Internet of Things (IoT) and upcoming 5th generation (5G) wireless communication systems. As the characteristics of OWC and RF are complementary, a combined application is regarded
as a promising approach to support 5G and beyond communication systems. Hybrid RF/optical and optical/optical wireless systems offer an excellent solution for recovering the limitations of individual systems as well as for providing positive features of each of the technologies. An RF/optical wireless hybrid system consists both RF and optical-based wireless technologies, whereas an optical/optical wireless hybrid system consists two or more types of OWC technologies. The co-deployment of wireless systems can improve system performance in terms of throughput, reliability, and energy efficiency of individual networks. This
study surveys the state of the art and key research directions regarding optical wireless hybrid networks, being the first extensive survey dedicated to this topic. We provide a technology overview of existing literature on optical wireless hybrid networks, such as RF/optical and optical/optical systems. We consider the RF-based macrocell, small cell, wireless fidelity, and Bluetooth, as well as optical-based visible light communication, light fidelity, optical camera communication, and free-space optical communication technologies for different combinations of hybrid systems. Moreover, we consider underwater acoustic communication for hybrid acoustic/optical systems. The opportunities brought by hybrid systems are presented in detail. We outline important challenges that need to be addressed for successful deployment of optical wireless hybrid network systems for 5G and IoT paradigms.

- by Moh. Khalid Hasan and +2
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- Optical wireless Communications, RF communication, Small Cells, 5G Mobile Communications

Keywords: 5G, C-RAN, CoMP, SDR, LTE, Small Cells, USRP. Supervisor: Dr. Cicek Cavdar (cavdar@kth.se) Coordinated MultiPoint leverages coordination between different nodes in the network to jointly processing signals, increasing the... more

- by Subhi R M Zeebaree and +3
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- Beamforming, 5G, Small Cells, Massive Mimo

—The surge of the Internet traffic with exabytes of data flowing over operators' mobile networks has created the need to rethink the paradigms behind the design of the mobile network architecture. The inadequacy of the 4G UMTS Long term Evolution (LTE) and even of its advanced version LTE-A is evident, considering that the traffic will be extremely heterogeneous in the near future and ranging from 4K resolution TV to machine-type communications. To keep up with these changes, academia, industries and EU institutions have now engaged in the quest for new 5G technology. In this paper we present the innovative system design, concepts and visions developed by the 5G PPP H2020 project SESAME (Small cEllS coordinAtion for Multi-tenancy and Edge services). The innovation of SESAME is manifold: i) combine the key 5G small cells with cloud technology, ii) promote and develop the concept of Small Cells-as-a-Service (SCaaS), iii) bring computing and storage power at the mobile network edge through the development of non-x86 ARM technology enabled micro-servers, and iv) address a large number of scenarios and use cases applying mobile edge computing.

- by Vassilios Vassilakis
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- Small Cells, 5G Mobile Communications

Based upon the context of Mobile Edge Computing (MEC) actual research and within the innovative scope of the SESAME EU-funded research project, we propose and assess a framework for security analysis applied in virtualised Small Cell Networks, with the aim of further extending MEC in the broader 5G environment. More specifically, by applying the fundamental concepts of the SESAME original architecture that aims at providing enhanced multi-tenant MEC services though Small Cells coordination and virtualization, we focus on a realistic 5G-oriented scenario enabling the provision of large multi-tenant enterprise services by using MEC. Then we evaluate several security issues by using a formal methodology, known as Secure Tropos.

- by Vassilios Vassilakis
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- Network Security, Small Cells, Mobile Edge Computing

Research on next-generation 5G wireless networks is currently attracting a lot of attention in both academia and industry. While 5G development and standardization activities are still at their early stage, it is widely acknowledged that 5G systems are going to extensively rely on dense small cell deployments, which would exploit infrastructure and network functions virtualization (NFV), and push the network intelligence towards network edges by embracing the concept of mobile edge computing (MEC). As security will be a fundamental enabling factor of small cell as a service (SCaaS) in 5G networks, we present the most prominent threats and vulnerabilities against a broad range of targets. As far as the related work is concerned, to the best of our knowledge, this paper is the rst to investigate security challenges at the intersection of SCaaS, NFV, and MEC. It is also the rst paper that proposes a set of criteria to facilitate a clear and eective taxonomy of security challenges of main elements of 5G networks. Our analysis can serve as a staring point towards the development of appropriate 5G security solutions. These will have crucial eect on legal and regulatory frameworks as well as on decisions of businesses, governments, and end-users. Keywords: Security, small cell as a service, network functions virtual-ization, mobile edge computing, 5G.

- by Reza Vaez-Ghaemi
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- Wireless Backhaul, Carrier Ethernet, Ethernet, Small Cells

In this paper, we study the problem of joint inband backhauling and interference mitigation in 5G heterogeneous networks (HetNets) in which a massive multiple-input multipleoutput (MIMO) macro cell base station equipped with a large number of antennas, overlaid with self-backhauled small cells is assumed. This problem is cast as a network utility maximization subject to wireless backhaul constraints. Due to the non-tractability of the problem, we first resort to random matrix theory to get a closed-form expression of the achievable rate and transmit power in the asymptotic regime, i.e., as the number of antennas and users grows large. Subsequently, leveraging the framework of stochastic optimization, the problem is decoupled into dynamic scheduling of macro cell users and backhaul provisioning of small cells as a function of interference and backhaul links. Via simulations, we evaluate the performance gains of our proposed framework under different network architectures and low/high...

- by Sumudu Samarakoon
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- Mathematics, Computer Science, Convex Optimization, Non-convex optimization
- by Mozhgan Mahloo and +1
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- Telecommunications, Microwave, Fiber, Costing
- by AMiR HOSEiN
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- Wireless Communications, Open Access, Power Consumption, Green Communications

Small cell networks (SCNs) have emerged as promising technologies to meet the data traffic demands for the future wireless communications. However, the benefits of SCNs are limited to their hard handovers between base stations (BSs). In addition, the interference is another challenging issue. To solve this problem, this study employs a cooperative transmission mechanism focusing on correlated Rician/Gamma fading channels with zero-forcing receivers. The analytical expressions for the achievable sum rate, symbol error rate and outage probability are derived, which are applicable to arbitrary Rician factors, correlation coefficients, the number of antennas, and remain tight across entire signal-to-noise ratios (SNRs). Asymptotic analyses at the high and low SNR regimes are carried out in order to further reveal the insights of the model parameters on the system performance. Monte-Carlo simulation results validate the correctness of their derivations. Numerical results indicate that the theoretical expressions provide sufficiently accurate approximation to simulated results.

- by Li Xingwang
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- Small Cells

The recent explosive growth of mobile data traffic, the continuously growing demand for higher data rates, and the steadily increasing pressure for higher mobility have led to the fifth-generation mobile networks. To this end, network-coding (NC)-enabled mobile small cells are considered as a promising 5G technology to cover the urban landscape by being set up on-demand at any place, and at any time on any device. In particular, this emerging paradigm has the potential to provide significant benefits to mobile networks as it can decrease packet transmission in wireless multicast, provide network capacity improvement , and achieve robustness to packet losses with low energy consumption. However, despite these significant advantages, NC-enabled mobile small cells are vulnerable to various types of attacks due to the inherent vulnerabilities of NC. Therefore, in this paper, we provide a categorization of potential security attacks in NC-enabled mobile small cells. Particularly, our focus is on the identification and categorization of the main potential security attacks on a scenario architecture of the ongoing EU funded H2020-MSCA project "SECRET" being focused on secure network coding-enabled mobile small cells.

- by Reza Parsamehr
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- Network Security, Network coding, Small Cells, 5G Mobile Communications

Full-duplex (FD) communication is an emerging technology that can potentially double the throughput of cellular networks. Preliminary studies in single-cell or small FD network deployments have revealed promising rate gains using self-interference cancellation (SIC) techniques and receive processing. Nevertheless, the system-level performance gains of FD small cells in ultra-dense networks (UDNs) have not been fully investigated yet. In this paper, we evaluate the performance of resource allocation in ultra-dense FD small-cell networks using spatial stochastic models for the network layout and 3GPP channel models. More specifically, we consider various UDN scenarios and assess the performance of different low-complexity user-scheduling schemes and power allocation between uplink and downlink. We also provide useful insights into the effect of the SIC capability on the network throughput.

- by George Alexandropoulos
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- Dense Ad Hoc Networks, Stochastic Geometry, Small Cells

LTE-A addresses the challenges of coverage block holes and increase in user density with new features, such as small cell and femto cell. Small cell can be an inexpensive substitute to macro cell in coverage depleted areas. In contrast, heterogeneous network using femto cells with its ubiquitous coverage, can deliver high-speed data. Resource scheduling algorithm has an important role in determining the overall system performance. Several schedulers are available whose performance ranges from maximizing UE throughput to achieving the best fairness. UE mobility significantly affects the performance of different network topologies and various scheduling algorithms. In this paper, we have evaluated and compared various LTE downlink performance parameters between small cell network and heterogeneous network to conclude which type of network deployment is best suited for mobile users and dense urban environment under different scheduling schemes.

- by Mikko Säily
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- Heterogeneous Networks, LTE, Mobility, Small Cells

Network planning is facing new and critical challenges due to ad-hoc deployment, unbalanced and drastically varying traffic demands, as well as limited backhaul and hardware resources in emerging small cell architectures. We discuss the application of graph theory to address the challenges. A clique based software-defined on-line network management approach is proposed that captures traffic imbalance and fluctuation of small cells and optimally plans frequencies, infrastructures, and network structure at any instant. Its applications to three important small cell scenarios of cloud radio, point-to-point microwave backhaul, and inter-operator spectrum sharing are demonstrated. Comparison studies show that in each of the scenarios, this new approach is able to significantly outperform conventional static off-line network planning schemes in terms of throughput and satisfaction levels of small cells with regards to allocated bandwidths. Specifically, the throughput can be improved by 155% for the cloud radio scenario and by 110.95% for the microwave backhaul scenario. The satisfaction can be improved by 40% for inter-operator spectrum sharing.

"Mobile operators are facing an exponential traffic growth due to the proliferation of portable devices that require a high-capacity connectivity. This, in turn, leads to a tremendous increase of the energy consumption of wireless access networks. A promising solution to this problem is the concept of heterogeneous networks, which is based on the dense deployment of low-cost and low power base stations, in addition to the traditional macro cells. However, in such a scenario the energy consumed by the backhaul, which aggregates the traffic from each base station towards the metro/core segment, becomes significant and may limit the advantages of heterogeneous network deployments. This paper aims at assessing the impact of backhaul on the energy consumption of wireless access networks, taking into consideration different data traffic requirements (i.e., from todays to 2020 traffic levels). Three backhaul architectures combining different technologies (i.e., copper, fiber, and microwave) are
considered. Results show that backhaul can amount to up to 50% of the power consumption of a wireless access network. On the other hand, hybrid backhaul architectures that combines fiber
and microwave performs relatively well in scenarios where the
wireless network is characterized by a high small-base-stations
penetration rate."

- by Sibel Tombaz and +3
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- Wireless networks, Energy efficiency, Wireless Backhaul, Power Consumption
- by Abdullah Bin Shams
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- Mobility/Mobilities, Heterogeneous Networks, IEEE, Small Cells

A presentation from a workshop at EuMW 2016 which reviews the current uses of microwave and millimetre wave radio systems in mobile backhaul networks. The presentation goes on to review new use cases associated with 5G ultra-dense... more

- by Andy Sutton
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- Mobile Ad Hoc Networks, Wireless Communications, Mobile Technology, Microwave

Small cells and heterogeneous networks offer an exciting opportunity for mobile network operators to significantly increase network capacity and enhance in-building coverage while also extending geographical coverage to rural not-spots. Mobile network planners have a wide range of cell site design options available to them; from large tower and roof-top mounted macro-cells through to micro-cells, pico-cells and femto-cells, what are these and how will they all fit together? This presentation reviews the state of the art in cellular radio network design and explains the role of small cells and the concepts of heterogeneous networks, including options for inter-working between WiFi and cellular technologies.

The application of Radio-over-Fiber (RoF) technology in cellular systems has attracted considerable attention in recent time. Consequently, the indoor personal communication systems (PCS) using the RoF architecture needs reinvestigation in performance domain. In this paper, we investigate such a system, which uses tiny cells (pico-cells) with limited number of users. We develop a corresponding traffic model for state dependent fresh call requests (Engset distribution) from limited user population. The model, in addition, considers frequent handoffs of users, which is not necessarily a memoryless random process. The model has a provision of channel reservation for handoff calls thereby prioritize the handoff process. The proposed model is computationally efficient and simple to implement. Further, it is effective to determine the optimum level of reservation in system design.

- by Jaafar M. H. Elmirghani and +1
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- Stochastic Process, Wireless Communications, Traffic Engineering, Performance Analysis
- by vinod kumar
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- Broadcasting, MIMO, Precoding, Random Matrix Theory
- by F. Farias
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- Wireless networks, Energy efficiency, Wireless Backhaul, Power Consumption
- by Salam Akoum
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- Scheduling, Cognitive radio, OFDM, Cooperation
- by Walid Saad
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- Reinforcement Learning, Self Organizing Networks, Small Cells, Dynamic-TDD

Small cells have been proposed as a vehicle for wireless networks to keep up with surging demand. Small cells come with a significant challenge of providing backhaul to transport data to (from) a gateway node in the core network. Fiber based backhaul offers the high rates needed to meet this requirement, but is costly and time-consuming to deploy, when not readily available. Wireless backhaul is an attractive option for small cells as it provides a less expensive and easy-to-deploy alternative to fiber. However, there are multitude of bands and features (e.g. LOS/NLOS, spatial multiplexing etc.) associated with wireless backhaul that need to be used intelligently for small cells. Candidate bands include: sub-6 GHz band that is useful in non-line-of-sight (NLOS) scenarios, microwave band (6-42 GHz) that is useful in point-to-point line-of-sight (LOS) scenarios, and millimeter wave bands (e.g. 60, 70 and 80 GHz) that are recently being commercially used in LOS scenarios. In many deployment topologies, it is advantageous to use aggregator nodes, located at the roof tops of tall buildings near small cells. These nodes can provide high data rate to multiple small cells in NLOS paths, sustain the same data rate to gateway nodes using LOS paths and take advantage of all available bands. This work performs the joint cost optimal aggregator node placement, power allocation, channel scheduling and routing to optimize the wireless backhaul network. We formulate mixed integer nonlinear programs (MINLP) to capture the different interference and multiplexing patterns at sub-6 GHz and microwave band. We solve the MINLP through linear relaxation and branch-and-bound algorithm and apply our algorithm in an example wireless backhaul network of downtown Manhattan.

- by Muhammad Nazmul Islam and +1
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- Microwave, Millimeter Waves, Wireless Backhaul, Multihop Networks

The growth demand in wireless communication and its application leads to a great effort should be into researcher's consideration to meet the future requirement of wireless network architecture. It's expected that the traffic will reaches multiple of hundreds than this in nowadays and to increase the capacity of the network with high and efficient energy efficiency. This can be reached by the use of small cell configuration like micro and pico cells, and use massive MIMO (Massive Multiple-input Multiple-output) with lowcost components which are prone to hardware impairments. This configuration leads to high energy efficiency for large number of base stations and user density. This article focuses in simulating an area covered by random deployment of small cells to serve hundreds of users in the simulation area. The results show that the (Energy efficiency) decreases as the SINR values increases, which is why it is important to specify a target SINR; otherwise the energy efficiency maximizing operation point might be very spectrally inefficient, and the efficient energy can be greatly improved by increasing the base station density, meaning that small cells are a promising solution for maximal energy efficiency deployment.

- by Saif H. Alrubaee
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- Small Cells, Massive Mimo

- by sanaa mohsin
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- Computer Science, Beamforming, Small Cells, G
- by Andrea Zanella
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- Computer Science, Handover, LTE, Trajectory
- by Martti Moisio
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- Computer Science, Handover, Mobility, Self Organization
- by Rahim Tafazolli
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- LTE, MIMO, CDMA, HetNet
- by Muhammad Shakir
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- Sociology, Statistics, Heterogeneous Networks, Next Generation Networks
- by Nikolaos Bompetsis
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- Network Security, Small Cells, Mobile Edge Computing

This paper evaluates the impact of multi-5G small cell systems on the energy efficiency (EE) in a Fifth Generation (5G) of cellular networks. Both the proposed model and the analysis of the EE in this study take into account (i) the path losses, fading, and shadowing that affect the received signal at the user equipment (UE) within the same cell, and (ii) the interference effects of adjacent cells. In addition, the concepts of new technologies such as large MIMO in millimeter range communication have also been considered. The simulation results show that the interference from adjacent cells can degrade the EE of a multi-cell cellular network. With the high interference the number of bits that will be transferred per joule of energy is 1.29 Mb/J with a 0.25 GHz bandwidth and 16 transmit antennas. While, with a 1 GHz bandwidth the transfer rate increases to 5.17 Mb/J. Whereas, with 64 transmit antennas the EE improved to 5.17 Mb/J with a 0.25 GHz BW and 20.70 Mb/J with a 1 GHz BW. These results provide insight into the impact of the number of antennas in millimeter range communication and the interference from adjacent cells on achieving real gains in the EE of multi-5G small cells cellular network.

5G+ systems expect enhancement in data rate and coverage area under limited power constraint. Such requirements can be fulfilled by the densification of small cells (SCs). However, a major challenge is the management of fronthaul links connected with an ultra dense network of SCs. A cost effective and scalable idea of using network flying platforms (NFPs) is employed here, where the NFPs are used as fronthaul hubs that connect the SCs to the core network. The association problem of NFPs and SCs is formulated considering a number of practical constraints such as backhaul data rate limit, maximum supported links and bandwidth by NFPs and quality of service requirement of the system. The network centric case of the system is considered that aims to maximize the number of associated SCs without any biasing, i.e., no preference for high priority SCs. Then, two new efficient greedy algorithms are designed to solve the presented association problem. Numerical results show a favorable performance of our proposed methods in comparison to exhaustive search.

- by Syed Awais Wahab Shah
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- Unmanned Aerial Vehicles, Drones, Small Cells, 5G Mobile Communications