Licensed Countrywide Full-Spectrum Allocation: A New Paradigm for Millimeter-Wave Mobile Systems in 5G/6G Era

Abstract

The traditional static allocation of a portion of the licensed spectrum specified for a country to a mobile network operator (MNO) is no longer sufficient to address the required spectrum demand, as well as efficient to utilize the allocated spectrum. To overcome these constraints, i.e. to increase the spectrum availability and utilization, in this paper, we present a new paradigm for the spectrum allocation called licensed countrywide full-spectrum allocation (LCFSA) to allocate the licensed countrywide full 28 GHz millimeter-wave (mmWave) spectrum to each MNO of a country to operate its small cells per building subject to avoiding co-channel interference (CCI). Since most data is generated indoors, the countrywide full mmWave spectrum allocated to an MNO is considered reusing further to its in-building small cells. CCI avoidance in both the time-domain and frequency-domain is presented along with deducing the conditions for optimality. We derive average capacity, spectral efficiency (SE), energy efficiency (EE), and cost efficiency (CE) for LCFSA, and perform extensive numerical and simulation results and analyses for a country consisting of four MNOs. It is shown that LCFSA with both the time-domain and frequencydomain CCI avoidance schemes provide similar performance improvement in average capacity, SE, EE, and CE by about 296%, 164%, 75%, and 60% respectively for no interfering user equipments (UEs), whereas by about 59.2%, 6.1%, 37.2%, and 0.45% respectively for all interfering UEs with the frequencydomain CCI scheme. Moreover, it is found that the improvement in the above metrics does not change with the spectrum reuse factor (RF) and the number of buildings of small cells per macrocell L, and the impact of interfering UEs can be compensated by adjusting RF. Finally, we show that LCFSA can satisfy the SE and EE requirements for sixth-generation (6G) systems by adjusting either RF or L, or both.

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

“…The licensed spectrum in a country can be allocated primarily to its MNOs in a number of ways, namely, Static and Equal Spectrum Allocation (SESA) [5], Flexible and Unequal Spectrum Allocation (FUSA) [6], and Countrywide Full Spectrum Allocation (CFSA) [5], [7]. An equal amount of spectrum in SESA, whereas an unequal amount of spectrum in FUSA, is allocated to each MNO in a country.…”

“…Besides, for CFSA, the authors have presented the idea of CFSA to overcome the constraints of SESA in [15]. The authors have detailed and evaluated the idea of CFSA in [7] for the allocation of the 28 GHz spectrum to all MNOs in a numerous fractional frequency reuse techniques have been addressed in [26][27][28]. Further, analytical models to reuse spectrum to indoor small cells have been presented in [29] for the microwave spectrum and in [30] for the mmWave spectrum.…”

“…Further, analytical models to reuse spectrum to indoor small cells have been presented in [29] for the microwave spectrum and in [30] for the mmWave spectrum. Furthermore, the authors in [7], [16] have presented reusing the 28 GHz mmWave spectrum to indoor small cells.…”

“…Particularly, in TD, the authors have exploited TD almost blank subframe (ABS) based enhanced intercell interference coordination (eICIC) technique to avoid CCI between satellite users and small cell users in multistory buildings in [31] for satellite-mobile networks and in [32] for ultra-dense mobile networks. Moreover, the TD CCI avoidance scheme has been presented in [33] to derive the optimal amount of time for each MNO to operate at the countrywide full mmWave spectrum. Further, in FD, the authors in [13] have proposed a technique by exploiting the FD to define the amount of the mmWave spectrum to be allocated to an MNO corresponding to its number of subscribers at any spectrum license renewal term.…”

“…The framework presented in this paper gives a general review of our findings, mostly in [4][5][6][7], [11][12][13][14][15][16], [29][30][31][32][33][34][35][36], and [40][44][52], relating to improving spectrum utilization of the 28 GHz mmWave systems using indoor small cells in multi-operator network scenarios for 5G and beyond mobile systems. In doing so, we use the Equal Likelihood Criterion and the properties of left-justified Pascal's triangle to derive closed-form solutions with a view to summarizing those findings in a unified manner for each spectrum allocation technique in each domain of the framework in terms of the system-level average capacity, SE, and EE performance metrics.…”