The recent adoption of virtualized technologies in Next Generation Radio Access Network (NG-RAN) has driven a significant impact on energy consumption by subsequently decreasing the number of active base stations. The base station (gNodeB) of 5G is segregated into cost-efficient Central Units (CU) hosted on virtual platforms and cheaper & smaller Distributed Units (DU) present at the cell sites. Multiple CUs are pooled together in a single powerful central cloud, known as CU pool. The logical connection between DU and CU can be dynamically adjusted and can potentially affect the energy consumption of the CU pool. The deployment of NG-RAN imposes strict latency requirements on the fronthaul link that connects DUs to CU. To relax these strict latency requirements, various alternate architectures such as Flexible RAN Functional Splits have been proposed by 3GPP. In this paper, we first evaluate the energy consumption of DU and CU for various functional split options using OpenAirInterface (OAI), a real-time open source software radio solution. We find that lower layer splits have high energy consumption at CU as compared to higher layer split options. We also observe the variation in energy consumption due to traffic heterogeneity. Motivated by the above study, we formulate an optimization model, Apt-RAN , that optimizes the energy consumption of the CU pool and the number of handovers, considering different functional splits. To address the computational complexity of solving the optimization model, a lightweight polynomial time heuristic algorithm is proposed. Simulation results demonstrate that our proposed model outperforms existing state-of-art schemes.

Apt-RAN: A Flexible Split-Based 5G RAN to Minimize Energy Consumption and Handovers

An expansion of services and unprecedented traffic growth is anticipated in future networks, aligned with the adoption of the long-awaited Fifth Generation (5G) of mobile communications To support this demand, without exposing mobile operators to the pressure of CAPEX and OPEX, 5G uses new frequency bands, and adopts promising trends, including: densification, softwarization, and autonomous management While the first technology is proposed to handle the traffic growth requirements, the softwarization and autonomous management are expected to play, in synergy, to ensure the desired trade-off between reducing the CAPEX and OPEX, while guaranteeing the quality of service (QoS) Softwarization is expected to transform the network design, from one size fits all, to more demand oriented adaptive resource allocation In this work, we focus on this point, by discussing how these technologies act in synergy towards enabling RAN sharing Particularly, we focus on how they fit into the issue of energy efficient Multi-Operator Resource Allocation (MO-RA) After a survey and classification of schemes leveraging this synergy for distinct resource allocation (RA) objectives, we present a detailed survey and qualitative classification of RA schemes with respect to energy efficiency This work presents an innovative survey, since it concentrates on multiple operators, and the enabling of Mobile Virtual Network Operators (MVNOs), which will come into play with the complete virtualization of mobile networks Based on the deep literature analysis of the different operations that can bring energy savings to MO-RA, we conclude the work with listing open challenges and future research directions

On Energy Efficient Resource Allocation in Shared RANs: Survey and Qualitative Analysis

Excitation of electromagnetic waves in rotating media

A virtualized radio access network (V-RAN) is considered one of the key research points in the development of 5G and the interception of machine learning algorithms in the Telecom industry. Recent technological advancements in Network Function Virtualization (NFV) and Software Defined Radio (SDR) are the main blocks towards V-RAN that have enabled the virtualization of dual-site processing instead of all BBU processing as in the traditional RAN. As a result, several types of research discussed the trade-off between power and bandwidth consumption in V-RAN. Processing at remote locations instead of BBU reduces mid-haul bandwidth at the expense of power consumption and vice versa. As a result, the integration of NFV and SDR in V-RAN facilitates dynamic power consumption and processing whenever relaxation is needed. This paper studies several functional splits proposed by ETSI in the NFV of the dual-site network. In addition, network performance is analyzed in terms of data rate, power consumption, and energy efficiency (EE) optimization. Furthermore, the combined optimization of power consumption and mid-haul bandwidth are investigated, and optimal operating parameters are recommended for similar network operators. Thus, regulators/operators can adjust their networks with these parameters to achieve the best performance. Additionally, the UEs switching scheme is introduced to sleep some RRHs in low-density traffic to lessen power consumption.

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Optimum Functional Splits for Optimizing Energy Consumption in V-RAN

Network Functions Virtualization (NFV) has recently gained much popularity in the research scene for the flexibility and programmability that it will bring with the software implementation of network functions on commercial off-the-shelf (COTS) hardware. To substantiate its roll out, a number of issues (e.g., COTS’ inherent performance and energy efficiency, virtualization overhead, etc.) must be addressed, in a scalable and sustainable manner. Numerous works in the scientific literature manifest the strong correlation of network key performance indicators (KPIs) with the burstiness of the traffic. This paper proposes a novel model-based analytics approach for profiling virtualized network function (VNF) workloads, towards real-time estimation of network KPIs (specifically, power and latency), based on an MX/G/1/SET queueing model that captures both the workload burstiness and system setup times (caused by interrupt coalescing and power management actions). Experimental results show good estimation accuracies for both VNF workload profiling and network KPI estimation, with respect to the input traffic and actual measurements, respectively. This demonstrates that the proposed approach can be a powerful tool for scalable and sustainable network/service management and orchestration.

A Model-Based Approach Towards Real-Time Analytics in NFV Infrastructures

In cloud radio access networks (C-RAN), more accurate prediction of the number of virtual machines (VMs) one server can support would improve network capacity and energy efficiency (EE). In this paper, the problem of allocating an optimal number of VMs to the cloud server is introduced. Monte Carlo-based evolutionary algorithm [particle swarm optimization (PSO), quantum PSO, or genetic algorithm] are used to find the suboptimal number of VMs that optimizes the EE of C-RAN. To enable such evaluation, a power model is proposed to evaluate the power consumption of each unit within a virtualized server. This evaluation occurs under the circumstances of increased number of hosted VMs, and processed resource blocks (RBs) at each VM. Moreover, power allocation methods are proposed to transmit the power from base band unit pool to the remote radio heads (RRHs), and from RRHs to the users (UEs). This allocation is based on the combination of one or more of RRH distance, RRH channel gain, UE distance, UE channel gain, and UE path loss. The EE problem was constrained to crucial quality of service indicators, including minimum UE data rate, number of allocated RBs, and latency imposed due to virtualization.

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Maximizing the Energy Efficiency of Virtualized C-RAN via Optimizing the Number of Virtual Machines

https://iopscience.iop.org/article/10.1088/1757-899X/518/4/042007/pdf

Fractal Sierpinski Square Patch Antenna for GPS Applications

In this paper, comparative study of three dispersion compensation fiber models, namely, pre, post and symmetrical involving ideal dispersion compensation fiber Bragg grating for three different modulation schemes in 40 Gb/s single channel optical fiber transmission system are performance evaluated. Three modulation schemes, different namely, duo-binary coding, modified duo-binary and carrier suppressed return to zero are simulated and analyzed in terms of Q-factor and bit error rate for each set up by range of CW laser power. The simulation of optical system based on optisystem-10.The result report that the symmetrical with ideal FBG at duo-binary coding depicts good performance for increasing the input power from-5 dBm to 10 dBm. It is clear that best Q value obtained is 28.24 dB for BER of 5.9 ×10-176 at input power of 5 dBm using symmetrical compensation cascaded with ideal FBG for duo-binary modulation scheme.

Performance evaluation of high data rate optical communication system utilizing fbg compensated dispersion schemes under different modulation techniques

Biological tissue interaction with Electromagnetic fields became one of the interesting studies in the last years. Wide variety wireless electronic devices are emerged in day to day life each providing a wireless connection for a certain service such as Global Positioning System, broadcasting systems, mobile communication systems, and networking. In this research article, Fractal Sierpinski Square Patch Antenna is proposed and simulated to operate over L1 frequency range of 1.575 GHz for GPS applications using CST studio Suite where the proposed antenna has been investigated on Carpet shaped substrate made of Arlon 250 AD lossy. The dielectric constant equals to 2.5 and thickness of 1.6 mm. Thickness of patch is 0.6 mm. Also, the electromagnetic fields absorption on the human fingers is investigated where SAR levels are calculated for 0th, 1st, 2nd and 3rd iteration of the Fractal Sierpinski Square Patch Antenna. The results reported that the SAR limit of human finger tissue is enhanced with increasing the number of iteration.

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Radiation effect of fractal sierpinski square patch antenna

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Riyadh Khlf Ahmed

Papers

Maximizing the Energy Efficiency of Virtualized C-RAN via Optimizing the Number of Virtual Machines

Fractal Sierpinski Square Patch Antenna for GPS Applications

Performance evaluation of high data rate optical communication system utilizing fbg compensated dispersion schemes under different modulation techniques

Radiation effect of fractal sierpinski square patch antenna

SAR Level Reduction Based on Fractal Sausage Minkowski Square Patch Antenna