3D Spatial Reuse of Multi-Millimeter-Wave Spectra by Ultra-Dense In-Building Small Cells for Spectral and Energy Efficiencies of Future 6G Mobile Networks

2021

IEEE Access

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In this paper, we present a framework to give a comprehensive review of how to improve the spectrum utilization of millimeter-wave (mmWave) systems using indoor small cells in multi-operator network scenarios. More specifically, the framework concerns with the improvement of the utilization of the 28 GHz mmWave spectrum allocated to an arbitrary number of mobile network operators (MNOs) in a country using numerous spectrum allocation techniques, namely Static and Equal Spectrum Allocation (SESA), Flexible and Unequal Spectrum Allocation (FUSA), and Countrywide Full Spectrum Allocation (CFSA). A number of spectrum utilization improvement mechanisms such as spectrum trading, spectrum sharing, and spectrum reusing are then exploited into SESA, FUSA, and CFSA techniques in four majorinterconnected domains, including time, frequency, power, and space. Using the Equal Likelihood Criterion and the properties of left-justified Pascal's triangle, the average capacity, spectral efficiency (SE), and energy efficiency (EE) performance metrics for each spectrum allocation technique in each domain are derived. Extensive system-level numerical and simulation results and analyses are carried out to evaluate the performance of each technique in each domain for example scenario of a country with four MNOs. Overall, it is shown that, in the power-domain, CFSA outperforms SESA and FUSA (when operating either at the interweave or at the underlay spectrum access technique), whereas, in the time-domain and frequency-domain, SESA and FUSA outperform CFSA, in terms of the average capacity, SE, and EE. Finally, we show that CFSA in the power-domain outperforms SESA and FUSA operating in any domain to achieve the prospective SE and EE requirements for the sixth generation (6G) mobile networks.

Section: ) Td and Fd Spectrum Sharingmentioning

confidence: 99%

Millimeter-Wave Spectrum Utilization Improvement in Multi-Operator Networks: A Framework Using the Equal Likelihood Criterion

2021

IEEE Access

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“…Mobile Information Systems PL(dB) � 68 + 21.7 log 10 (d), where d is in the meter. Like the 28 GHz band, adopting [42], a minimum distance between co-channel small cells for the path loss of 60 GHz mmWave spectrum as given above in the intrafloor level and interfloor level, respectively, for any MNO o can be expressed as follows: is implies that the minimum distance in the intrafloor level decreases with an increase in frequency. Moreover, due to the higher frequency band, α f (Δ e,60 ) ≥ α f (Δ e,28 ).…”

Section: Impact Of Frequency Bands On Spectrum Exploitationmentioning

confidence: 99%

“…Data, primarily, in the form of numerous simulation assumptions and parameters reported previously by the standardization bodies, including 3 rd Generation Partnership Project (3GPP) [31,32] and International -Telecommunication Union-Radiocommunication Sector (ITU-R) [33], included and detailed within the article in Table 3, were used to carry out the performance evaluation of this study. Other prior studies than these above [31][32][33] were cited at relevant places within the text as references [34,[36][37][38][39]42]. No data other than these were used to evaluate the performance studies.…”

Section: Data Availabilitymentioning

confidence: 99%

Spectrum Allocation and Reuse in 5G New Radio on Licensed and Unlicensed Millimeter-Wave Bands in Indoor Environments

Mobile Information Systems

2021

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In this paper, by exploiting the frequency-domain, we propose a countrywide millimeter-wave (mmWave) spectrum allocation and reuse technique to allocate and reuse spatially the countrywide 28 GHz licensed spectrum and 60 GHz unlicensed spectrum to small cells (SCs) on each floor of a building of each Fifth-Generation (5G) New Radio (NR) Mobile Network Operator (MNO) of an arbitrary country. We develop an interference management scheme, model user statistics per SC, and interferer statistics per apartment and formulate the amount of the 28 GHz and 60 GHz spectra per MNO. We derive average capacity, spectral efficiency (SE), energy efficiency (EE), and cost efficiency (CE) when employing the proposed technique, as well as the traditional static licensed spectrum allocation technique. We discuss the implementation of the proposed technique and evaluate the performance under two scenarios, namely, SCs operate only in the 28 GHz in scenario 1, and both 28 GHz and 60 GHz in scenario 2. Extensive results and analyses are carried out for four MNOs, i.e., MNOs 1, 2, 3, and 4, in scenario 1. However, in scenario 2, in addition to MNOs 1, 2, 3, and 4, an incumbent Wireless Gigabit (WiGig) operator is considered. It is shown that the proposed technique with no co-channel interference can improve average capacity, SE, EE, and CE of MNO 1 by 3 times, 1.65 times, 75%, and 60%, respectively, in scenario 1, whereas 6.12 times, 5.104 times, 85.8%, and 83.15%, respectively, in scenario 2. Moreover, with an increase in reuse factors, SE increases linearly and EE increases negative exponentially. Further, we show that the proposed technique can satisfy SE and EE requirements for sixth-generation (6G) mobile systems. Finally, we discuss offered benefits and point out key issues of the proposed technique for further studies.

“…Hence, by varying the spectrum reuse factor (RF) both vertically within the same building and horizontally between adjacent buildings, the required capacity can be obtained. Following [28], a minimum distance between cochannel small cells for the 28 GHz mmWave spectrum in the intrafloor level and interfloor level, respectively, for MNO o can be given by, [27].…”

Section: Spectrummentioning

confidence: 99%

“…Data, primarily, in the form of numerous simulation assumptions and parameters reported previously by the standardization bodies, including 3rd Generation Partnership Project (3GPP) [26,27] and International-Telecommunication Union-Radiocommunication Sector (ITU-R) [28], included and detailed within the article in Table 3, were used to carry out the performance evaluation of this study. Other prior studies than these above [26][27][28] were cited at relevant places within the text as references [29,31,[35][36][37][38][39]. No data other than these were used to evaluate the performance studies.…”

Section: Data Availabilitymentioning

confidence: 99%

Power‐Domain Based Dynamic Millimeter‐Wave Spectrum Access Techniques for In‐Building Small Cells in Multioperator Cognitive Radio Networks toward 6G

Wireless Communications and Mobile Computing

2021

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Power-domain based dynamic spectrum access (PDSA) techniques are proposed for sharing 28 GHz spectrum of any Mobile Network Operator (MNO) with in-building small cells (SCs) of the other countrywide. By controlling the transmission power of SCs, PDSA techniques explore the traditional interweave access by operating an SC at the maximum transmission power and the underlay access by allowing to operate an SC at a lowered transmission power separately, as well as jointly. Average capacity, spectral efficiency, energy efficiency, cost efficiency, and throughput per SC user equipment (UE) are derived for an arbitrary number of MNOs in a country. By varying the spectrum reuse factor for the millimeter-wave spectrum in each building of SCs, extensive numerical and simulation results and analyses for an illustrative scenario of a country consisting of four MNOs are carried out for the interweave and underlay techniques when applying separately, as well as the hybrid interweave-underlay technique and the static licensed spectrum allocation (SLSA) technique. It is shown that, due to gaining more shared spectra, the hybrid interweave-underlay technique provides the best, whereas the SLSA provides the worst, performances of all techniques in terms of the average capacity, spectral efficiency, energy efficiency, cost efficiency, and throughput per UE of an SC. Moreover, we show that the hybrid interweave-underlay technique, the interweave technique, and the underlay technique, respectively, can satisfy the expected requirements of spectral and energy efficiencies for Sixth-Generation (6G) networks by reusing each MNO’s 28 GHz spectrum to SCs of about 33.33%, 50%, and 50% less number of buildings than that required by the SLSA for a spectrum reuse factor of six per building of small cells.