Summary Report from RAN#89e (Electronic meeting, 14 - 18 September 2020)

Summary

This is a summary of 3GPP TSG RAN#89e. Because of the COVID-19 virus, the meeting was held as an electronic meeting.

General

RAN Meeting Plan

The latest RAN meeting plan assumes the worst case of electronic meetings throughout 2021 because of COVID-19. The RAN plenary dates remain unchanged. RAN1 will have only one meeting in Q1, in line with the other WGs. Several "inactive periods" have been introduced when no email discussions and no teleconference sessions are allowed. Submission deadlines have been defined for all WGs.

Rel-16

Rel-16 Planning (aka 5G Phase 2)

Stage 1: frozen December 2018 without exceptions

Stage 2: frozen June 2019 with exceptions; all remaining Stage 2 work was completed by March 2020

RAN1: frozen December 2019

RAN2 and RAN3: frozen June 2020 with 12 exceptions; by September 2020 there are 2 exceptions left (see below)

Stage 3: frozen June 2020 with exceptions in CT and SA; by September 2020 some work is still unfinished in SA3/SA5 (see below)

ASN.1 and open APIs: frozen June 2020; note that the June 2020 version of RRC specifications is not implementable (see below)

RAN4: freezing target December 2020

Rel-16 Exceptions (Core part)

An exception means that WGs can continue working on a topic for 3 more months, on specific topics as indicated. Of the 12 exceptions granted at RAN#88e (June/July), most work was completed, but 2 topics required an additional exception:

-     RP-202071 LTE/NR spectrum sharing in band 48/n48 frequency range

-     RP-202099 NR-based access to unlicensed spectrum

In addition, in SA and CT the following work is not yet complete:

Rel-16 Closed Work Items and Study Items (excluding spectrum-related and conformance testing)

The following Rel-16 work was completed and the corresponding SIs and WIs closed:

NR

-     WI core: Enhancements on MIMO for NR

-     WI core: NR positioning support

-     WI core: Multi-RAT Dual-Connectivity and Carrier Aggregation enhancements (LTE, NR)

-     WI core: Integrated access and backhaul for NR

-     WI core: RF requirements for NR frequency range 1 (FR1)

-     WI core: NR RF requirement enhancements for frequency range 2 (FR2)

-     WI perf.: NR RF requirement enhancements for frequency range 2 (FR2)

-     WI core: RRM requirement for CSI-RS based L3 measurement in NR

-     WI core: NR RRM enhancement

LTE

-     WI perf.: LTE-based 5G terrestrial broadcast

Rel-16 Work Item Summaries (descriptions of features in the release after the work has actually finished)

-     RP-201718 Cross Link Interference (CLI) handling and Remote Interference Management (RIM) for NR

-     RP-201757 Integrated Access and Backhaul for NR (NR_IAB)

-     RP-201840 NR-based Access to Unlicensed Spectrum

-     RP-201884 NR RRM enhancement

-     RP-201905 29 dBm UE Power Class for LTE Band 41 and NR Band n41

-     RP-201942 RRM requirement for CSI-RS Based L3 measurement

-     RP-201984 NR RF Requirement Enhancements for FR2

-     RP-201987 NR positioning support

-     RP-202039 Multi-RAT Dual-Connectivity and Carrier Aggregation enhancements (LTE, NR)

NR: 5G-ACIA simulation (LSin: RP-201279, RP-201434; Endorsed WF: RP-202069; LSout: RP-202097)

5G-ACIA had requested RAN at RAN#88e for simulation work related to IIoT and URLLC. The simulation work will be done offline (no need for work in RAN1). The outcome will directly go to RAN, and RAN will decide at RAN#91 on a response LS to 5G-ACIA.

NR: RRC June 2020 versions not backwards compatible and not implementable (Approved RAN2 corrective CRs: RP-201932)

Rel-16 RRC (both 36.331 and 38.331) June 2020 version is not implementable. It has wrong ASN.1, which is not backwards compatible with Rel-15. This problem was corrected in this meeting by RAN2's CRs.

NR: NR-U and 6GHz (Approved company CRs: RP-202117, RP-202113, RP-201914/15/16/17/18; Granted exception:
RP-202099; LSout: RP-202115; Approved WIs: RP-202114, RP-202116)

A combined way forward was found with regard to all 6GHz-related aspects on the table, with the intention to make both supporters of licensed 6GHz and supporters of unlicensed 6GHz happy:

(1) Company CRs on NR-U 6GHz were approved with value ranges for all parts with disagreement on exact value (e.g. REFSENS).

(2) WI on 6GHz licensed work indicates that work will start once regulations are available. WI on 6GHz NR unlicensed operation has the same indication that work will be on hold until regulations are available. Both WIs were approved.

(3) Exception sheet for remaining NR-U 6GHz work was compiled. Exception was granted.

(4) Outgoing response LS sent to RCC, which had asked 3GPP to prepare for regulation. It states that "work item will be on hold until regulatory requirements are available for this band, work will commence as soon as regulatory requirements are available".

NR: FR2 Fallback (Postponed company CRs: RP-201872/73/74/75; Not agreed WF: RP-201538)

Although this issue, which had been carried forward from the previous meeting, seemed close to resolution, at the very last moment there was no agreement on the final wording, so that it requires another comeback at the next RAN plenary meeting.

NR: UE features - Applicability to licensed/unlicensed operation (Disc.: RP-201525)

It was decided to discuss applicability to licensed operation of features developed for unlicensed operation on a feature by feature basis. All features not specifically targeting unlicensed operation are assumed to be applicable to unlicensed operation. For features (including Rel-15) that are applicable to both licensed and unlicensed operation, it may be discussed case by case based on company input if differentiation between licensed and unlicensed is justified. For Rel-15 features, additional capability signalling will be introduced from Rel-16 onward.

Rel-17

Rel-17 Planning (3-6 month delay unavoidable due to COVID-19, but formal decision not taken until December 2020)

Stage 1: frozen December 2019 with exceptions (all remaining Stage 1 work was completed by June 2020)

RAN "Feature Packaging" ("Content definition") achieved December 2019; definition of "inter-TSG coordination areas" started

Stage 2: freezing target December 2020 (but see comment above)

RAN1: freezing target June 2021 (but see comment above)

RAN2 and RAN3: freezing target September 2021 (but see comment above)

Stage 3: freezing target September 2021 (but see comment above)

ASN.1 and open APIs: freezing target December 2021 (but see comment above)

RAN4: freezing target March 2022 (but see comment above)

Rel-17 Timeline (Endorsed WF: RP-202111)

The Rel-17 timeline was not yet formally changed, and will be addressed in December 2020. However, it is clear that a further delay of 3-6 months compared to the decision made at RAN#87e (March) is unavoidable. In December, he RAN leadership will present a detailed plan and analysis for achieving a timeline with an additional (max.) 6 months delay. Tightening of scope of existing work may be addressed in December and follow-up WIs need a very well-defined, tight scope. The Studies on XR and NB-IoT/MTC over NTN will have a slow start in Q4.

NR: MBMS scope (LSout: RP-202086)

SA2 asked feedback on removing broadcast from MBMS scope. RAN decided to keep broadcast in the scope.

NR: Secondary DRX (Disc.: RP-201595, RP-201657)

The proposal was to add enhancements of secondary DRX in the Rel-17 WI of UE power saving enhancements, but nothing was agreed this time and it may be rediscussed in RAN#90.

NR: Enhancement of Private Network Support for NG-RAN (Approved WI: RP-202051)

This WI was approved without NB-IoT, but it will be revisited based on the result in SA2.

NR: Work package for RAN4 (non-spectrum)

As scheduled, a work package of eight Work Items and a Study Item was approved for RAN4. For details, see the list of approved WIs/SIs below. It is possible that additional work will be approved for RAN4. Topics under discussion (but not yet approved) include Smart Repeaters, Base Station Electromagnetic Compatibility (EMC), Over the Air (OTA) and Air-To-Ground (ATG).

Approved Work Items and Study Items (excluding spectrum-related and conformance testing)

-     RP-202051 WI: Enhancement of Private Network Support for NG-RAN
Keywords: Support (1) SNPN along with subscription / credentials owned by an entity separate from the SNPN; (2) UE onboarding and provisioning for NPN; (3) IMS voice and emergency services for SNPN

-     RP-202044 WI: Introduction of DL 1024QAM for NR FR1
Keywords: Specify (1) high order modulation for PDSCH; (2) corresponding RRC signalling and UE capabilities; (3) corresponding UE and BS RF core requirements

-     RP-202000 WI: Further enhancement on NR demodulation performance
Keywords: UE demodulation and CSI reporting requirements: MMSE-IRC receiver for suppressing inter-cell interference; MMSE-IRC receiver for suppressing intra-cell inter-user interference; BS demodulation requirements: PUSCH demodulation requirements for FR1 256QAM

-     RP-202106 WI: Enhancement for NR high speed train scenario
Keywords: Core: Specify UE RRM core requirements for CA scenario with same target speed (up to 500km/h) and carrier frequency (up to 3.6 GHz) as Rel-16 NR HST; if needed, discuss signalling impact; Perf.: Specify UE demod requirements for above CA scenario and RRM test cases related to enhanced core requirements; Study and specify if needed UE demod requirements and for transmission scheme 2 (PDSCHs transmitted from 2 or more adjacent TRPs scheduled by multi-DCI)

-     RP-202118 WI: NR support for high speed train scenario in FR2
Keywords: Core: NR SA single carrier scenario in FR2; Focus on train roof-mounted high-power devices; Target frequency up to 30GHz; Candidate frequency bands n261, n257 and n258; Target deployment scenario is multi-RRHs share same cell-ID; Study channel model; Investigate max Doppler frequency; Specify UE RF core requirements for power class 4 if identified; Study/specify UE RRM core requirements; Perf.: Specify (1) RRM performance requirements of measurement accuracy if identified; (2) RRM test cases related to new core requirements; (3) UE and BS demodulation requirements

-     RP-202088 WI: RF requirements enhancement for NR frequency range 1 (FR1) in Rel-17
Keywords: Core: (1) Enable UL MIMO configuration for SUL band configurations; (2) Specify UE requirements to enable Tx switching between different cases across carriers based on SUL and NR inter-band uplink CA for UE supporting maximum two concurrent transmissions; (3) HPUE for TDD intra-band contiguous UL CA; Perf.: Add required changes to release independence TS 38.307; Specify RRM performance requirements if needed

-     RP-202107 WI: NR RF Enhancements for FR2
Keywords: Inter-band DL CA enhancements; Inter-band UL CA; Study and, if feasible, introduce UE specific and NW configured gap for general self-calibration and monitoring purposes

-     RP-202053 WI: NR RRM further enhancement
Keywords: Core: (1) SRS antenna port switching; (2) HO with PSCell; (3) PUCCH SCell activation/deactivation; Perf.: Specify RRM performance requirements and test cases related to new core requirements

-     RP-202119 WI: NR measurement gap enhancements
Keywords: Core: (1) Pre-configured MG pattern(s) (fast MG configuration); (2) Multiple concurrent and independent MG patterns; (3) Network Controlled Small Gap (NCSG) specification; Perf.: Specify necessary UE RRM performance requirements for specified enhancements if needed

-     RP-202103 SI: Study on Efficient utilization of licensed spectrum not aligned with existing NR channel bandwidths
Keywords: (1) Identify operator licensed channel bandwidths in FR1 that do not align with existing NR channel bandwidths (>5MHz); (2) Evaluate potential use of larger channel bandwidths than operator licensed bandwidth, including impacts on regulatory emission requirements/UE output power implications and UE ACS/blocking impacts depending on guard band and SCS; (3) Study use of overlapping UE channel bandwidths to cover operator's license spectrum for UL and DL, and if new gNB channel bandwidths are needed; (4) Identify operator licensed bandwidths not compatible with use of techniques like overlapping UE channel bandwidths; (5) Study complexity and efficiency of adding new channel bandwidths vs. using other including testing aspects; (6) Avoid introduction of new channel BWs on UE side