Upcoming 5G Networks Research Articles

MIoT Slice for 5G Systems: Design and Performance Evaluation.

Network slicing is a key feature of the upcoming 5G networks allowing the design and deployment of customized communication systems to integrate services provided by vertical industries. In this context, massive Internet of Things (mIoT) is regarded as a compelling use case, both for its relevance from business perspective, and for the technical challenges it poses to network design. With their envisaged massive deployment of devices requiring sporadic connectivity and small data transmission, yet Quality of Service (QoS) constrained, mIoT services will need an ad-hoc end-to-end (E2E) slice, i.e., both access and core network with enhanced Control and User planes (CP/UP). After revising the key requirements of mIoT and identifying major shortcomings of previous generation networks, this paper presents and evaluates an E2E mIoT network slicing solution, featuring a new connectivity model overcoming the load limitations of legacy systems. Unique in its kind, this paper addresses mIoT requirements from an end-to-end perspective highlighting and solving, unlike most prior related work, the connectivity challenges posed to the core network. Results demonstrate that the proposed solution, reducing CP signaling and optimizing UP resource utilization, is a suitable candidate for next generation network standards to efficiently handle massive device deployment.

Mobile Network Operator and Mobile User Cooperation for Customized D2D Data Services

The explosive growth of smart devices has led to the evolution of multimedia data (mainly video) services in mobile networks. It attracted many mobile network operators (MNO) to deploy novel network architectures and develop effective economic policies. Mobile data offloading through smart devices (SDs) by exploring device-to-device (D2D) communications can significantly reduce network congestion and enhance quality of service at a lower cost, which is the key requirement of upcoming 5G networks. This reasonable cost solution is useful for attracting mobile users to participate in the offloading process by paying them proper incentives. It is beneficial for MNOs as well as mobile users. Moreover, D2D communications promise to be one of the prominent services for 5G networks. In this paper, we present a combinatorial optimal reverse auction (CORA) mechanism, which efficiently selects and utilizes available high-end SDs on the basis of available resources for offloading purposes. It also decides the optimal pricing policy for the selected SDs. The efficiency of CORA has been realized in terms of bandwidth and storage demand. Subsequently, we implement caching in SDs, eNodeB (eNB), and evolved packet core (EPC) with the help of our novel video dissemination cache update algorithm to solve the latency or delay issues in the offloading process. Due to high popularity, we specifically focus on video data. Simulation results show that the proposed SD caching scenario curtails the delay up to 75% and the combined cache (CC) scenario slashes the delay varying from 15 to 57%. We also scruitinize the video downloading time performance of various cache scenarios (i.e., CC, EPC cache, eNB cache, and SD cache scenarios).

An Interference Contribution Rate Based Small Cells On/Off Switching Algorithm for 5G Dense Heterogeneous Networks

Dense heterogeneous network serves as one of the most promising technologies for the upcoming 5G network. However, with a larger number of densely deployed small cells, the problem of co-channel interference and power consumption of 5G small cell base stations (also known as S-gNBs) becomes more severe. In order to improve the power efficiency and alleviate the co-channel interference, S-gNBs in the network need to be dynamically switched on or off via appropriate criteria or strategies. This paper proposes an interference contribution rate (ICR) based small cell on/off switching algorithm. With the incorporation of network adjacency matrix (NAM), the proposed algorithm circumvents the complicated computation of the ICRs of the S-gNBs in the network and hence yields less computational complexity. In addition, the proposed algorithm identifies the S-gNBs that need to be switched on or off based on the NAM and the serving signal strength measurements of user equipment’s and therefore involves less signaling information in the procedure of switching on/off decision. Simulation results verify that the proposed algorithm effectively diminishes the co-channel interference among the small cells, ameliorates the network power efficiency and total data rate, and meanwhile maintains a lower traffic loss in the network.

Software Defined Radio Implementation of a Digital Self-interference Cancellation Method for Inband Full-Duplex Radio Using Mobile Processors

New means to improve spectral efficiency and flexibility in radio spectrum use are in high demand due to congestion of the available spectral resources. Systems deploying inband full-duplex transmission aim at providing higher spectral efficiency by concurrent transmission and reception at the same frequency. Potentially doubling system throughput, full-duplex communications is considered as an enabler technology for the upcoming 5G networks. However, system performance is degraded due to the strong self-interference (SI) caused by overlapping of high power transmit signal with the received signal of interest. Furthermore, due to commonly existing radio frequency imperfections, advanced techniques capable of mitigating nonlinear SI are required. This article presents a real-time software-defined implementation of a digital SI canceller for full-duplex transceivers, potentially applicable even in mobile-scale devices. Recently, software-defined radio has gained a lot of interest due to its higher flexibility, scalability, and shorter time-to-market cycles compared to traditional fixed-function hardware designs. Moreover, as the performance enhancements achieved by increasing the clock frequency is reaching its limits, the current trend is towards multi-core processors. Since contemporary mobile phones already contain powerful massively parallel GPUs and CPUs, feasibility of a real-time implementation on mobile processors is studied. The reported results show that by adopting the presented solution, it is possible to achieve sufficient SI cancellation under time varying coupling channel conditions. Additionally, the possibility of carrying out such advanced processing in a real-time fashion on the selected platforms is investigated, and the implementation is evaluated in terms of execution time, power, and energy consumption.

Joint power allocation and relay selection strategy for 5G network: a step towards green communication

Green communication has emerged as the most important concept for the next generation networks. Along with improved data rate and capacity, the upcoming 5G networks aim at improving energy efficiency without compromising on the user experience. In this paper, we have used amplify and forward relays in the heterogeneous network topology consisting of low power and high power nodes. A three layered system model for power optimization is discussed using a relay selection strategy for power optimization with the aim to improve energy efficiency of the network. Further, we have used Hidden Markov Model for training and maintaining of base station, relay and SCA with the aim of probabilistic power allocation to client nodes in order to solve the power optimization problem. We have also used adaptive modulation schemes for lowering the power consumption of the network to meet our goal of green communication for the next generation network.

An Overview of Sustainable Green 5G Networks

The stringent requirements of a 1000x increase in data traffic and 1 ms round-trip latency have made limiting the potentially tremendous ensuing energy consumption one of the most challenging problems for the design of the upcoming 5G networks. To enable sustainable 5G networks, new technologies have been proposed to improve the system energy efficiency, and alternative energy sources are introduced to reduce our dependence on traditional fossil fuels. In particular, various 5G techniques target the reduction of the energy consumption without sacrificing the quality of service. Meanwhile, energy harvesting technologies, which enable communication transceivers to harvest energy from various renewable resources and ambient radio frequency signals for communication, have drawn significant interest from both academia and industry. In this article, we provide an overview of the latest research on both green 5G techniques and energy harvesting for communication. In addition, some technical challenges and potential research topics for realizing sustainable green 5G networks are also identified.

Cooperative localization in 5G networks: A survey

In upcoming 5G networks, key prospects such as increased bandwidth, smaller cells, higher mobile terminal (MT) densities, multiple radio access technologies, and the capability of device-to-device communication are beneficial for localization. Meanwhile, technologies suggested in 5G, such as massive multiple-in multiple-out, would also benefit from the accurate locations of MTs. Therefore, an opportunity to develop and integrate mobile localization technology in 5G networks has presented itself at this early stage. This paper reviews recent literature relating to localization in 5G networks, and emphasizes the prospect for implementing cooperative localization, which exploits the location information from additional measurements between MTs. To evaluate the accuracy of cooperative localization, a performance evaluation approach is also suggested.

Studying Applicability Feasibility of OFDM in Upcoming 5G Network

Orthogonal frequency-division multiplexing (OFDM) is one of unbeatable multiplexing technique till date. However with increasing version of next generation mobile standards like 5G, the applicability of OFDM is quite questionable. The prime reason behind this is in order to offer higher data rates and extensive networking services in 5G, OFDM will be required to overcome some inherent problems of spectral leakage, power consumption, less supportability of increased channel capacity. The reason community still believes that there is positive scope of OFDM to be applicable in 5G network provided it undergoes certain changes. This paper reviews some of the complimentary waveforms that have been theoretically proven to be adding edge to OFDM system. The paper reviews different waveforms as well as multiple access techniques to be used in designing 5G technology and assess their effectiveness in viewpoint of research applicability and effectiveness towards leveraging 5G.

Load balancing in 5G Networks

The expected huge increase of mobile devices and user data demand by 2020 will stress the current mobile network in an unprecedented way. The future mobile networks must meet several strong requirements regarding the data rate, latency, quality of service and experience, mobility, spectrum and energy efficiency. Therefore, efforts for more efficient mobile network solutions have been recently initiated. To this direction, load balancing has attracted much attention as a promising solution for higher resource utilization, improved system performance and decreased operational cost. It is an effective method for balancing the traffic and alleviating the congestion among heterogeneous networks in the upcoming 5G networks. In this paper, we focus on an offloading scenario for load balancing among LTE and Wi-Fi networks. Additionally, network graphs methodology and its abstracted parameters are investigated in order to better manage wireless resource allocation among multiple connections. The COHERENT architectural framework, which consists of two main control components, makes use of such abstracted network graphs for controlling or managing various tasks such as traffic steering, load balancing, spectrum sharing and RAN sharing. As a result, the COHERENT project eventually develops a unified programmable control framework used to efficiently coordinate the underlying heterogeneous mobile networks as a whole.

State-of-the-art on Virtualization and Software Defined Networking for Efficient Resource Allocation on Multi-tenant 5G Networks

Global data traffic explosion is expected to set stringent requirements for next generation networks in the next decades. Besides, very low latencies will have to be guaranteed for enabling new delay critical services. However, current Software Defined Networking (SDN) solutions have limitations in terms of separating both data and control planes among tenants/operators, and the capability to adapt to new or changing requirements. Moreover, some virtualization schemes do not ensure isolation of resources and do not guarantee bandwidth across the entities. While some others fail to provide flexibility to the slices to customize the resource allocation across the users. Therefore, novel SDN and virtualization techniques should be implemented to realize the upcoming 5G network that will facilitate at least efficient resource allocation and multi-tenancy among the plethora of different requirements.

Fundamental Tradeoffs on Energy-Aware D2D Communication Underlaying Cellular Networks: A Dynamic Graph Approach

With the ever-increasing energy consumption in transmissions of explosive growing mobile data, energy-efficient solutions are needed to be integrated into the future mobile networks. The upcoming 5G networks support device-to-device (D2D) communication underlaying the cellular networks, which enables proximity cellular users to communicate directly with high data rate and low transmit power. In this paper, targeting the energy-aware D2D communications underlaying cellular system, we investigate the fundamental problems of what is the potential gains of D2D communications for energy saving, which are the fundamental reasons to decrease the energy consumption, and how about the tradeoffs between energy consumption and other network factors of available bandwidth, buffer size and service delay in large scale D2D communication networks. To answer the above challenging problems, we utilize a dynamic graph approach to model the system with human mobility for a realistic D2D communication scenario. Specifically, by formulating a mixed integer linear programming problem that minimizes the energy consumption for data transmission from the cellular base stations to the receivers through any possible ways of transmissions, we obtain the theoretical performance lower bound of system energy consumption, which shows that cellular D2D communications decrease the energy consumption about 65% averagely under the realistic scenario. Furthermore, the obtained fundamental tradeoffs reveal that energy consumption for large bandwidth can be kept at a low level with increase of the buffer size and service delay.

Power Optimization in 5G Networks: A Step Towards GrEEn Communication

In the present scenario, an energy efficiency has become a matter of prime importance for wireless networks. To meet the demands of an increased capacity, an improved data rate, and a better quality of the service of the next-generation networks, there is a need to adopt energy-efficient architectures. Along with these requirements, it is also our social responsibility to reduce the carbon footprint by reducing the power consumption in a wireless network. Hence, a green communication is an urgent need. In this paper, we have surveyed various techniques for the power optimization of the upcoming 5G networks. The primary focus is on the use of relays and small cells to improve the energy efficiency of the network. We have discussed the various scenarios of relaying for the next-generation networks. Along with this, the importance of simultaneous wireless power and information transfer, massive multiple input multiple output, and millimeter waves has been analyzed for 5G networks.

Network coded software defined networking: enabling 5G transmission and storage networks

Software defined networking has garnered large attention due to its potential to virtualize services in the Internet, introducing flexibility in the buffering, scheduling, processing, and routing of data in network routers. SDN breaks the deadlock that has kept Internet network protocols stagnant for decades, while applications and physical links have evolved. This article advocates for the use of SDN to bring about 5G network services by incorporating network coding (NC) functionalities. The latter constitutes a major leap forward compared to the state-ofthe- art store and forward Internet paradigm. The inherent flexibility of both SDN and NC provides fertile ground to envision more efficient, robust, and secure networking designs, which may also incorporate content caching and storage, all of which are key challenges of the upcoming 5G networks. This article not only proposes the fundamentals of this intersection, but also supports it with key use cases and a thorough performance evaluation on an implementation that integrated the Kodo library (NC) into OpenFlow (SDN). Our results on singlehop, multihop, and multi-path scenarios show that gains of 3x to 11x are attainable over standard TCP and multi-path TCP.

Toward D2D-enhanced heterogeneous networks

In this paper, we examine upcoming 5G networks where the support of D2D communication is expected to be a key asset for operators and users alike. First, we argue the need to functionally integrate D2D and infrastructure-to-device (I2D) modes. Next, we address practical issues such as integrated resource scheduling of D2D communication within heterogeneous networks, proposing an extension of the proportional fairness algorithm that we call multi-modal proportional fairness (MMPF). We evaluate the impact of D2D in a two-tier scenario combining macroand micro-coverage, finding that although I2D retains a clear edge for general-purpose downloading, D2D is an appealing solution for localized transfers as well as for viral content.