Study on the Idle Mode Capability with LoS and NLoS Transmissions

Abstract

In this paper, we study the impact of the base station (BS) idle mode capability (IMC) on the network performance in dense small cell networks (SCNs). Different from existing works, we consider a sophisticated path loss model incorporating both line-of-sight (LoS) and non-line-of-sight (NLoS) transmissions. Analytical results are obtained for the coverage probability and the area spectral efficiency (ASE) performance for SCNs with IMCs at the BSs. The upper bound, the lower bound and the approximate expression of the activated BS density are also derived. The performance impact of the IMC is shown to be significant. As the BS density surpasses the UE density, thus creating a surplus of BSs, the coverage probability will continuously increase toward one. For the practical regime of the BS density, the results derived from our analysis are distinctively different from existing results, and thus shed new light on the deployment and the operation of future dense SCNs.Comment: final IEEE version: http://ieeexplore.ieee.org/document/7842302/. arXiv admin note: substantial text overlap with arXiv:1609.07710, arXiv:1611.0186

Performance Impact of Idle Mode Capability on Dense Small Cell Networks

“…The former case is able to generate a larger p cov (λ, γ) than the latter one, sinceλ ≤ λ and exp (−x) is a decreasing function with respect to x in (14) and (16). The intuition is that the aggregate interference power of the former case with the BS IMC is less than that of the latter case without, since…”

“…• The impact of I agg on the coverage probability is measured by (14) and (16). Since only the active BSs emit effective interference into the considered SCN, the expressions of (14) and (16) are thus based onλ, not on λ.…”

“…• For p cov (λ, γ) with the BS IMC,λ is plugged into (14) and (16), while for p cov (λ, γ) with all BSs being active, λ was used in (14) and (16) [10]. The former case is able to generate a larger p cov (λ, γ) than the latter one, sinceλ ≤ λ and exp (−x) is a decreasing function with respect to x in (14) and (16).…”

Toward Ultradense Small Cell Networks: A Brief History on the Theoretical Analysis of Dense Wireless Networks

“…The reality is that some cells will be empty, with no UE, in the latter case! In this section, and assuming that the BS density is much larger than the UE density in a true UDN, we show how the UDN system model was revisited to account for a finite UE density for the first time by the authors in [66], and how this led to a significantly different understanding of UDNs. Moreover, we also present and discuss the resulting more realistic capacity scaling law, when taking this consideration into account, which is far from a linearly increasing one.…”

“…Considering the advantages of having a surplus of small cell BSs equipped with an IMC to save energy and reduce interference, and building on [66] [67], in this article, we show the more realistic capacity scaling law for UDNs, presented in [69] [69], under the following practical and relevant system assumptions: i) a general multi-piece path loss model, ii) a non-zero small cell BS-to-UE antenna height difference, iii) a finite UE density, and iv) a surplus of small cell BSs equipped with an IMC. In essence, this model incorporates all the modelling factors previously discussed in this article.…”