nclude system- level and link-level simulations, analytical, and inspection by reviewing the functionalities and supported configurations of the candidates. The process defined by ITU-R for standardi- zation of IMT-2020 systems is illustrated in Fig. 17. According to the IMT-2020 process, Ixxviii Introduction and Background 31bis Technical performance Report technology trends M.2320 requirements IMT-2020 proposals Report IMT feasibility above 6 GHz Evaluation methodology External evaluation Requirements, evaluation criteria, and Recommendation vision of IMT beyond 2020 Consensus building submission templates Outcome and Modifications of resolutions 56/57 Circular letter and addendum decision Modifications of resolutions IMT-2020 specifications 56/57 Figure 17 Detailed timeline and process for IMT-2020 in ITU-R [1]. the deadline for submission of candidates is 3Q 2019, followed by independent evaluations by external groups, which ultimately results in IMT-2020 specifications in 3Q 2020 [1]. 5 3GPP 5G Standardization Activities 3GPP2 initiated the study of 5G NR in September 2015 by inviting all 3GPP membership to share their 5G visions during a 2-day workshop. A preliminary study on 5G candidate technologies was conducted as part of 3GPP Rel-14 that was concluded in March 2017 [15]. The 3GPP services and requirements working group has contributed to the study phase for 5G service requirements, known as SMARTER [21]. In late 2015, the 3GPP system architecture working group approved a technical report on the study of architecture for next-generation systems [13] which laid out 3GPP vision for the design of 5G architecture, support of new RAT(s), the evolved LTE, as well as interworking with non-3GPP access networks. The latter study investigated high-level architectural requirements and defined a common terminology for the next-generation networks. At the same time, based on the out- come of the RAN feasibility studies, 3GPP began to develop 5G specifications in two phases. 3GPP Rel-15 is associated with the first p