5G Mobile Networks: Requirements, Enabling Technologies, and Research Activities 49
called IMT‐2020. Currently, the 5G related activities within ITU are happening in two of its
three main sectors: ITU Radiocommunication sector (ITU‐R), which focuses on wireless
and radio system aspects, and ITU Telecommunication standardization sector (ITU‐T),
which focuses on wireline and network architecture aspects.
2.4.1.1 ITU‐R
In 2012, ITU‐R, having the leading role of Working Party (WP) 5D, initiated work to
develop the next generation IMT for the year 2020 and beyond, or IMT‐2020. As initial
results from the work, in September 2015, ITU‐R released a recommendation ITU‐R
M.2083‐0 [7], which defines the framework and overall objectives, including the description of key usage scenarios, key capabilities, technology trends, spectrum implications,
and timelines for the development of IMT‐2020. By June 2017, several deliverables are
expected to be completed at the ITU‐R WP 5D 27th meeting, including reports on the
technical performance requirements, evaluation criteria and evaluation methods, specification submission requirements, and a circular letter.
From the spectrum regulation perspective, ITU‐R published a report in July 2015,
which provides information on the study of technical feasibility of IMT in the bands
above 6 GHz. As already discussed, the WRC‐15 hosted by ITU‐R has come up with
several agenda items for investigating additional spectrum above 24 GHz, which will be
finalized in the WRC‐19.
2.4.1.2 ITU‐T
In May 2015, ITU‐T started working on IMT‐2020 by establishing a new Focus Group
(FG IMT‐2020) within the ITU‐T Study Group 13, to identify the network standardization requirements for the 5G development of IMT for 2020 and beyond. The main objectives of FG IMT‐2020 are to identify the needs for standardization of the “wireline
elements” of 5G networks, to be a launching point for ITU‐T’s contribution to IMT‐2020
standardization, and to align deliverables with those of ITU‐R. As the initial results from
the first phase, FG IMT‐2020 has completed a report on gap analysis in December 2015
[32]. The report identifies 85 gaps, such as high‐level network architecture, network softwarization, etc. In 2016, FG IMT‐2020 was restructured into four working groups (WG),
including Architecture and Framework WG, Network Softwarization WG, Information
Centric Networking WG, and End‐to‐End Network Management WG. Also, in 2016,
several proofs of concepts were demonstrated, such as end‐to‐end network slicing.
2.4.2 3GPP Activities
Overall, the 5G research activities within the 3GPP can be divided into three phases:
Pre‐5G phase, 5G phase I, and 5G phase II, happening at both 3GPP RAN and Service
and System Aspect (SA) Technical Specification Groups (TSG). The outputs of these
phases will appear in technical specifications Release 14, Release 15, and Release 16,
respectively. The status of ongoing 5G related activities in 3GPP is summarized below.
2.4.2.1 Pre‐5G Phase
The Pre‐5G phase is also known as the study phase, which started in early 2015. At that
time, the 3GPP Services WG within TSG SA (SA1) initiated a Study Item (SI) on New
Services and Markets Technology Enablers (SMARTER), with the objectives of developing
called IMT‐2020. Currently, the 5G related activities within ITU are happening in two of its
three main sectors: ITU Radiocommunication sector (ITU‐R), which focuses on wireless
and radio system aspects, and ITU Telecommunication standardization sector (ITU‐T),
which focuses on wireline and network architecture aspects.
2.4.1.1 ITU‐R
In 2012, ITU‐R, having the leading role of Working Party (WP) 5D, initiated work to
develop the next generation IMT for the year 2020 and beyond, or IMT‐2020. As initial
results from the work, in September 2015, ITU‐R released a recommendation ITU‐R
M.2083‐0 [7], which defines the framework and overall objectives, including the description of key usage scenarios, key capabilities, technology trends, spectrum implications,
and timelines for the development of IMT‐2020. By June 2017, several deliverables are
expected to be completed at the ITU‐R WP 5D 27th meeting, including reports on the
technical performance requirements, evaluation criteria and evaluation methods, specification submission requirements, and a circular letter.
From the spectrum regulation perspective, ITU‐R published a report in July 2015,
which provides information on the study of technical feasibility of IMT in the bands
above 6 GHz. As already discussed, the WRC‐15 hosted by ITU‐R has come up with
several agenda items for investigating additional spectrum above 24 GHz, which will be
finalized in the WRC‐19.
2.4.1.2 ITU‐T
In May 2015, ITU‐T started working on IMT‐2020 by establishing a new Focus Group
(FG IMT‐2020) within the ITU‐T Study Group 13, to identify the network standardization requirements for the 5G development of IMT for 2020 and beyond. The main objectives of FG IMT‐2020 are to identify the needs for standardization of the “wireline
elements” of 5G networks, to be a launching point for ITU‐T’s contribution to IMT‐2020
standardization, and to align deliverables with those of ITU‐R. As the initial results from
the first phase, FG IMT‐2020 has completed a report on gap analysis in December 2015
[32]. The report identifies 85 gaps, such as high‐level network architecture, network softwarization, etc. In 2016, FG IMT‐2020 was restructured into four working groups (WG),
including Architecture and Framework WG, Network Softwarization WG, Information
Centric Networking WG, and End‐to‐End Network Management WG. Also, in 2016,
several proofs of concepts were demonstrated, such as end‐to‐end network slicing.
2.4.2 3GPP Activities
Overall, the 5G research activities within the 3GPP can be divided into three phases:
Pre‐5G phase, 5G phase I, and 5G phase II, happening at both 3GPP RAN and Service
and System Aspect (SA) Technical Specification Groups (TSG). The outputs of these
phases will appear in technical specifications Release 14, Release 15, and Release 16,
respectively. The status of ongoing 5G related activities in 3GPP is summarized below.
2.4.2.1 Pre‐5G Phase
The Pre‐5G phase is also known as the study phase, which started in early 2015. At that
time, the 3GPP Services WG within TSG SA (SA1) initiated a Study Item (SI) on New
Services and Markets Technology Enablers (SMARTER), with the objectives of developing