Page 162 - ITU Journal, Future and evolving technologies - Volume 1 (2020), Issue 1, Inaugural issue

ITU Journal on Future and Evolving Technologies, Volume 1 (2020), Issue 1

architecture as enablers for network slicing. 3GPP 3 rd Generation Partnership Project
BS Base Station
Infrastructure sharing in this broader sense has been a C-RAN Cloud Radio Access Network
very prolific research topic over the last three decades. DCS Digital Cellular System
Samdanis et al. in [125] provide a compelling analysis of EDGE Enhanced Data rates for GSM Evolution
the path from infrastructure sharing to multi-tenancy. GERAN GSM EDGE RAN
However, to the best of our knowledge, our survey is GSM Global System for Mobile communications
1
the first comprehensive study on how the infrastructure IaaS Infrastructure as a Service
sharing topic in mobile networks has evolved over time, InP Infrastructure Provider
i.e., with the advent of the different mobile network gen- IoT Internet of Things
erations, and which research branches have spurred from IP Integer Programming
Joint Venture
JV
this topic. Reviewing this evolution is particularly im- MLFG Multi-Leader-Follower Game
portant now that networking slicing is being introduced mmWave millimiter Wave
in 5G (from release 16 onwards) and operators are look- MNO Mobile Network Operator
ing for models for sharing infrastructure costs and to MVNO Mobile Virtual Network Operator
invest more in new services and applications, collaborat- NaaS Network as a Service
ing with different players of vertical industrial sectors. NFV Network Functions Virtualization
Moreover, it is becoming clear to the telecommunica- NSP Network Service Provider
tions industry sector that some form of infrastructure OTT Over The Top
sharing will be the common basis on which networks PRB Physical Resource Block
will be deployed in different countries and services will QoS Quality of Service
evolve and diversify, going beyond 5G and preparing the RAN Radio Access Network
RRH
Remote Radio Head
ground for the next generation. SaaS Software as a Service
This survey is organized in the following fashion. Due SDN Software-Defined Networking
Signal-to-Interference-plus-Noise Ratio
SINR
to the change in the nature of problems studied over SLA Service Level Agreement
time, we first make a broad chronological classification SP Service Provider
of the literature into early works and recent and up-to- UMTS Universal Mobile Telecommunications System
date works. For the latter, we further identify several VNO Virtual Network Operator
research branches/categories. The overall picture of our VO Virtual Operator
classification is depicted in Fig. 1. An overview of the W-CDMA Wideband Code Division Multiple Access
early works on the topic is provided in Section 2. Fur- WNV Wireless Network Virtualization
ther, in Section 3, we focus on the more recent and up- xG x th mobile network Generation
to-date works. Then in Section 4 we make a critical
discussion of the research area related to infrastructure Table 1 – Definitions of acronyms and abbreviations
sharing and provide an outlook of future research direc- • state regulatory standpoints and provide guidelines
tions. Finally, conclusions are drawn in Section 5. for the latter and
For readers’ ease, in Table 1 we provide the definitions
of the acronyms and abbreviations used in the paper. • conceive new paradigms for the mobile market.

2. EARLY WORKS In [118], which dates back to 1994, Ramsdale states that
national roaming is part of the specifications of the Dig-
3
[16,49,55,70,115,118,142] are among the earliest articles ital Cellular System at 1800 MHz (DCS 1800), unlike
on infrastructure sharing (combined at times also with the Global System for Mobile Communications at 900
spectrum sharing). With the exception of [70] , these MHz (GSM 900), which supported international roam-
2
articles have tended to: ing only. National roaming was introduced in the DCS
1800 to improve coverage due to smaller cell sizes at
• address technical issues of different sharing alterna- 1800 MHz (as opposed to 900 MHz).
tives,
Instead, the work in [55] shows the positive impact of
• assess the financial profitability through techno- infrastructure sharing in financial terms for the Univer-
economic approaches, sal Mobile Telecommunications Systems (UMTS), espe-
cially for lowly populated areas in which network de-
1 This survey is based on the PhD thesis of Lorela Cano [24].
2 The study in [70] is an early work on the problem of schedul- ployment is dictated by coverage instead of capacity.
ing users of multiple operators arising from the case when a 3G,
facility-based MNO hosts several Mobile Virtual Network Oper- 3 National roaming is an infrastructure sharing alternative that
ators (MVNOs): the authors propose a non-pre-emptive priority allows users of an operator which does not provide coverage in
queuing model for circuit-switched traffic applied through an ad- certain areas of a country to be served by the network of another
mission control scheme. operator of that country covering such areas.

142 © International Telecommunication Union, 2020