5G Wireless Technology: Spectrum Sharing and Heterogeneous Networks

Abstract

This paper addresses the critical challenge of 5G network cell planning, emphasizing the essential role of estimating the number of cells or base stations required for a given area and user bandwidth. The proposed model explores four scenarios with varying network parameters to determine the optimal base station deployment. The increasing demand for 5G networks necessitates a focus on small cells or femtocells, offering advantages such as consistent coverage, power adjustment, energy efficiency, and higher data rates. However, deploying excessive femtocells may lead to unnecessary handovers, requiring optimization strategies. The study introduces an analytical model for heterogeneous cellular networks, integrating fourth and fifth-generation systems. The model, represented by a two dimensional Markov Chain, employs a novel decomposition approach for analyzing system performance measures. Validation is conducted through simulation and simultaneous equation systems. The proliferation of mobile devices and data traffic necessitates dense 5G network deployments, with small cells gaining traction due to their versatile coverage, power adaptability, energy efficiency, and higher data rates. However, an excessive deployment of small cells can lead to frequent handovers, prompting the need for enhanced handover strategies and coexistence with other technologies in the 5G landscape. The paper concludes by highlighting the impending need for practical implementation testing of 5G systems, emphasizing the significant role of small cell deployments. It discusses an initiative focusing on testing small cell-enabled operator business models in real-world scenarios, anticipating the pivotal role of small cells in future 5G systems.

Introduction

I. INTRODUCTION

The advent of 5th generation (5G) mobile communication systems heralds a transformative era in wireless technology, poised to reshape the landscape of connectivity as we know it. With diverse applications ranging from low-sensor data transmission to high-quality video content delivery, 5G introduces a spectrum of requirements encompassing stringent low latency, minimal energy consumption, and heightened reliability. These technological aspirations are envisioned to be achieved at costs either equivalent to or lower than current technologies. The imminent World Radio communication Conference (WRC'15) stands as a pivotal juncture, steering the course toward the establishment of the next communication standard[1]. A pivotal facet of 5G's innovation lies in its proposed novel spectrum sharing mechanisms, exemplified by the concept of co-primary spectrum sharing. In this paradigm, any operator gains the privilege to leverage shared spectrum allocated specifically for 5G cellular systems. This novel approach becomes feasible within the domain of small cells, where base station coverage mirrors today's WiFi access points, and the frequency band is exclusively designated for small cell utilization. Meanwhile, the discourse surrounding the segregation of access network operation and content provision persists, despite operator reservations. Nevertheless, the rise of streaming services like Netflix and YouTube, coupled with distinct pricing models, has effectively precipitated a de facto separation.

Within the intricate realm of Radio Network Planning (RNP), an indispensable role unfolds in shaping cell design for optimal wireless cellular network development. Operators grapple with the multifaceted task of devising a network that proves both economically viable and capable of accommodating dynamic variables such as environmental factors, fluctuating user numbers, base station configurations, path loss, and frequency schemes[2]. A strategic solution to the challenges of 5G cell planning involves adopting a multi-layer architecture featuring macrocells, various small cells, relays, and D2D networks. This approach aims to meet the demands for spectral and energy efficiency, catering to users with diverse throughput requirements and Quality of Service (QoS). Contrary to a wholesale replacement, 5G networks operate synergistically with their 3G and 4G predecessors, integrating them as components within macrocells. The access part of 5G, employing micro, pico, and femtocells, operates across GHz bands, extending up to 60 GHz, with channel widths reaching 1 GHz and theoretical access rates soaring up to 10 Gbps under ideal conditions.

These short-range cells, akin to public Wi-Fi nodes, epitomize the foundational characteristic of 5G systems—heterogeneous networks characterized by distributed base stations with varying densities, strategically designed to augment capacity and coverage.

II. ADVANCING 5G INNOVATION: STRATEGIC GOALS AND TEST NETWORK OVERVIEW

In the pursuit of advancing 5G technologies, a comprehensive test network has been established with strategic goals aimed at fostering research and development (R&D) in a realistic 5G environment. Beyond serving as a testing ground for cutting-edge technologies, the network endeavors to incubate new ideas, innovations, algorithms, and applications. Positioned as a living lab, it facilitates robust testing of applications, services, algorithms, and system functionalities, offering a dynamic platform for continuous improvement. The overarching goals include the evolution of the test network into a full-scale 5G network, integrating 5G devices, higher frequency bands, cognitive management functionalities, and system testing tools for innovative solutions[3-4]. Open for collaboration, the network extends invitations to third parties to develop and test cloud-based services, fostering a collaborative ecosystem. Moreover, the initiative contributes to regional competence building in 5G development and standardization, while concurrently assessing new operator business models.

The test network, orchestrated by VTT Technical Research Centre of Finland and the University of Oulu in collaboration with partners, is strategically located. Comprising a restricted network on VTT's premises and a public network at the University of Oulu, it provides a dual environment for technology functionality testing and large-scale deployment verification. The open network, featuring a macro base station and 50-100 small cell base stations, aims to evolve into an open test environment for collaborative innovation[10]. Expanding its reach across different city segments, the test network emerges as a versatile platform for the development and testing of groundbreaking applications, solidifying its role in daily business scenarios within the city of Oulu and beyond.

III. UNRAVELING THE DYNAMICS: RADIO CHANNEL MODELING IN 5G NETWORK PLANNING

In the intricate realm of cellular network planning, the concept of radio channel modeling stands as a paramount task, pivotal in ensuring the efficacy of communication systems. Diverse geographical topologies globally necessitate the development and exploration of various models, steering away from a one-size-fits-all approach[5-6]. An illustrative strategy involves employing highly accurate 3D environmental data maps with ray-tracing principles, specifically tailored for dense urban areas, while steering clear of complex estimations in rural and suburban landscapes.

Fundamentally, the radio link budget, akin to previous mobile systems, hinges on estimating path loss, factoring in a myriad of gains and losses. The coverage area estimation, a critical facet, is intricately linked to the capacity offered in terms of data transfer rate. Higher data transfer rates correspond to reduced coverage, with peak bit rates near the base station and diminished rates at the periphery of the cell's coverage area. The 5G network, characterized by its ability to manipulate power through NOMA (Non-Orthogonal Multiple Access), aims to achieve significantly higher throughput compared to 4G, boasting maximum data rates of up to 20 Gbps and an average transfer rate exceeding 100 Mbps[7-8]. This paper delves into the initial planning phase of 5G radio networks, striving to provide a preliminary assessment of coverage and capacity within the planning area, underpinning the nuanced dynamics of 5G network planning.

The approximate data transfer rate in 5G NR can be calculated :

After calculating the throughput of one cell, which contains a certain number of users, the throughput for one user in that cell is calculated according to Eq.

Conclusion

In summary, this paper extensively explores the intricate challenges associated with planning 5G network cells, underscoring the crucial importance of estimating optimal base station deployment for a specified area and user bandwidth. The research introduces a sophisticated analytical model tailored for heterogeneous cellular networks, seamlessly integrating both fourth and fifth-generation systems, with a specific emphasis on the potential of small cells or femtocells. The model\\\'s versatility is demonstrated through an examination of various scenarios, considering factors such as consistent coverage, power adjustment, energy efficiency, and enhanced data rates. The paper strongly advocates for the practical implementation testing of 5G systems, particularly highlighting the pivotal role of small cell deployments in addressing the surging demands of mobile devices and data traffic. Moreover, the introduction sheds light on the transformative phase ushered in by 5G technology and its diverse applications, necessitating a paradigm shift in wireless connectivity. The overarching objectives of the test network encompass evolving into a full-scale 5G network and contributing to regional competence building in 5G development and standardization. In our future for research work, our focus will be exploring diverse models that incorporate distinct path loss calculations tailored to urban, suburban, or rural settings. Furthermore, we aim to refine the existing cell number calculation methodology to better accommodate variations in geographical terrain configurations.

References

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Copyright

Copyright © 2024 Vibhav Kr. Sachan, Abhinav Trivedi, Yashi Srivastava, Shubham Shukla. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.