Even before the introduction of 5G in Release 15, “5G phase 1,” aspects of further improvements already were in development, as not all features could be completed in time for Rel-15.
This article discusses the ideas and enhancements currently being worked on for 3GPP Release-16. These enhancements cover not only 5G-NR, but also LTE, which is being advanced in parallel. We focus on the selected Rel-16 work items (WI) known as features and study items (SI), and split those into two chapters.
The first part elaborates on the 3GPP Rel-16 Work Items currently under 3GPP consideration to be included in this release:
- eNB(s) Architecture Evolution for E-UTRAN and NG-RAN
- LTE-NR & NR-NR Dual Connectivity and NR Carrier Aggregation enhancements
- Rel-16 Enhancements for NB-IoT Security Assurance Specification for 5G
- LAN support in 5G
- Integration of Satellite Access in 5G
- 5G positioning services
- NR intra-band Carrier Aggregation
- Dual Connectivity (EN-DC)
- Enhancements on MIMO for NR
- NR mobility enhancements
- Energy efficiency for 5G
The second part of the article focuses on the selected Study Items that 3GPP has chosen for Rel-16, including:
- Study on NR beyond 52.6 GHz
- Study on self-organizing networks (SON) for 5G
- Study on NR V2X
- Study on Cellular IoT support and evolution for the 5G System
- Feasibility Study on 6 GHz for LTE and NR in Licensed and Unlicensed Operations
- Study on NR-based Access to Unlicensed Spectrum
- Study on Non-orthogonal Multiple Access for NR
As can be seen, a lot of items currently being discussed by 3GPP for Release 16 that would enhance the existing LTE and 5G RATs towards achieving the goals of IMT-2020. 3GPP Release-16, or “5G phase 2,” is slated for completion by December 2019, and should be fully compliant with IMT-2020 requirements. It will be interesting to see the outcome of these WIs and how they influence their respective RATs.
We can see that some of the items target improvements to the current 5G system (like the use of even higher frequencies, SON, and IoT improvements), while others expand the 5G system scope (like NOMA, unlicensed spectrum, V2X). Let us also not forget that the enhanced LTE (i.e., this from 3GPP Rel-15 and 16) also is a part of SRIT (set of radio interface technologies), which will be submitted by 3GPP to ITU-R as a 5G technology, and thus should be discussed together with NR when speaking about current and future releases in 3GPP.
References http://www.3gpp.org/DynaReport/FeatureListFrameSet.htm  https://portal.3gpp.org/ngppapp/CreateTdoc.aspx?mode=view&contributionUid=RP-180339  http://www.3gpp.org/release-16