Page 10 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 6 – Wireless communication systems in beyond 5G era

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 6

mmWave massive analog relay MIMO

Pages 43–55
Kei Sakaguchi, Takumi Yoneda, Masashi Iwabuchi, Tomoki Murakami

Millimeter-Wave (mmWave) communications are a key technology to realize ultra-high data rate and
ultra-low latency wireless communications. Compared with conventional communication systems in
the microwave band such as 4G/LTE, mmWave communications employ a higher frequency band
which allows a wider bandwidth and is suitable for large capacity communications. It is expected to be
applied to various use cases such as mmWave cellular networks and vehicular networks. However, due
to the strong diffraction loss and the path loss in the mmWave band, it is difficult or even impossible to
achieve high channel capacity for User Equipment (UE) located in Non-Line-Of-Sight (NLOS)
environments. To solve the problem, the deployment of relay nodes has been considered. In this paper,
we consider the use of massive analog Relay Stations (RSs) to relay the transmission signals. By
relaying the signals by a large number of RSs, an artificial Multiple-Input Multiple-Output (MIMO)
propagation environment can be formed, which enables mmWave MIMO communications to the NLOS
environment. We describe a theoretical study of a massive relay MIMO system and extend it to include
multi-hop relays. Simulations are conducted, and the numerical results show that the proposed system
achieves high data rates even in a grid-like urban environment.
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Multi-tier multi-tenant network slicing: A multi-domain games

approach

Pages 57–82
Sunday Oladayo Oladejo, Stephen Obono Ekwe, Lateef Adesola Akinyemi

The 5G slice networks will play a critical role in meeting the stringent quality‑of‑service requirements
of different use cases, reducing the Capital Expenditure (CapEX) and Operational Expenditure (OpEX)
of mobile network operators. Owing to the flexibility and ability of 5G slice networks to meet the needs
of different verticals, it attracts new network players and entities to the mobile network ecosystem, and
therefore it creates new business models and structures. Motivated by this development, this paper
addresses the dynamic resource allocation in a multi‑slice multi‑tier multi‑domain network with
different network players. The dynamic resource allocation problem is formulated as a maximum utility
optimisation problem from a multiplayer multi‑domain perspective. Furthermore, a 3‑level hierarchical
business model comprising Infrastructure Providers (InPs), Mobile Virtual Network Operators
(MVNOs), Service Providers (SPs), and slice users are investigated. We propose two schemes: a
multi‑tier multi‑domain slice user matching game scheme and a distributed backtracking multiplayer
multi‑domain game scheme in solving the transformed maximum utility optimisation problem. We
compare the multi‑tier multi‑tenant multi‑domain game scheme with a Genetic Algorithm (GA)
Intelligent Latency‑Aware Resource (GI‑LARE) allocation scheme, and a static slicing resource
allocation scheme via Monte Carlo simulation. Our findings reveal that the proposed scheme
significantly outperforms these other schemes.
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