A study item, "Study on NR-based Access to Unlicensed Spectrum", was approved at 3GPP TSG RAN #77 [2] and revised in 3GPP TSG RAN #80 [30]. This study is to determine a single global solution for NR-based access to unlicensed spectrum, to be compatible with the NR concepts. The objectives of the study include:

• Study NR-based operation in unlicensed spectrum (RAN1, RAN2, RAN4) including
  • Physical channels inheriting the choices of duplex mode, waveform, carrier bandwidth, subcarrier spacing, frame structure, and physical layer design made as part of the NR study and avoiding unnecessary divergence with decisions made in the NR WI
    • Consider unlicensed bands below 7GHz
    • Consider similar forward compatibility principles made in the NR WI
  • Initial access, channel access. Scheduling/HARQ, and mobility including connected/inactive/idle mode operation and radio-link monitoring/failure
  • Coexistence methods within NR-based and between NR-based operation in unlicensed and LTE-based LAA and with other incumbent RATs in accordance with regulatory requirements in e.g., 5GHz , 6GHz bands
    • Coexistence methods already defined for 5GHz band in LTE-based LAA context should be assumed as the baseline for 5GHz operation. Enhancements in 5GHz over these methods should not be precluded. NR-based operation in unlicensed spectrum should not impact deployed Wi-Fi services (data, video and voice services) more than an additional Wi-Fi network on the same carrier

The above study will address the following architectural scenarios (RAN2):

• An NR-based LAA cell(s) connects with an LTE or NR anchor cell operating in licensed spectrum
• The study assumes the techniques for linking between Pcell (LTE or NR licensed CC) and Scell (NR unlicensed CCs) according to the NR WI
• An NR-based cell operating standalone in unlicensed spectrum, connected to a 5G-CN network, e.g., for private network deployments;
• Study how to ensure from a RAN level that connection and security management can be integrated with the E-UTRAN, NG RAN and 5G CN architecture, including service continuity requirements for users moving between cells of licensed and unlicensed frequency bands, liaising with SA2 as required

The results and findings of the study are documented in this technical report.

The present document contains the results and findings from the study item, "Study on NR-based Access to Unlicensed Spectrum" [2]. The purpose of this TR is to document the identified NR enhancements and corresponding evaluations for a single global solution framework for NR based access to unlicensed spectrum. This document addresses evaluation methodology and possible scenarios for NR based unlicensed deployments. This technical report documents the existing regulatory requirements for unlicensed spectrum deployment in the 5GHz bands, [and other bands] This document identifies and captures coexistence evaluations of physical layer options and enhancements to NR and, if necessary, NR RAN protocols to meet the requirements and targets for unlicensed spectrum deployments. This document contains an assessment of the feasibility of base station and terminal operation of 5GHz band (based on regulatory limits) in conjunction with relevant licensed frequency bands. This document is a 'living' document, i.e. it is permanently updated and presented to TSG-RAN meetings.