R1-2508639
discussion
Requirements for 6GR Frame Structure Design
From AT&T
Summary
This AT&T contribution presents a total of 4 proposals and 1 observation on the 6GR frame structure design. It covers subcarrier spacing, duplex types, and maximum channel bandwidth specifications across various frequency ranges.
Position
AT&T proposes that the 6GR design allows at most one subcarrier spacing per band, codifying the Study on 6G Radio objective to avoid multiple numerologies for the same band, though it does not preclude overlapping bands with different SCS definitions. For duplex types, AT&T requires support for FD-FDD, semi-static TDD, and HD-FDD on the UE side, while marking gNB semi-static SBFD and dynamic TDD as items for further study; it argues that UE support and certification for a large number of semi-static TDD configurations is more critical than dynamic TDD support. On channel bandwidth, AT&T sets specific maximum values per frequency range, including 400MHz around 7GHz and above, with further study on expanding to 800MHz for certain ranges. The company is open to studying 30kHz SCS for FDD in the 1-2.5GHz range and 60kHz SCS for FR3 to reduce latency.
Key proposals
- Proposal 1 (Sec: Subcarrier Spacings for 6GR): The 6GR design allows for at most one sub-carrier spacing per band
- Proposal 3 (Sec: Duplex Types): 6GR supports at least FD-FDD, Semi-static TDD, and HD-FDD on UE side; gNB semi-static SBFD and Dynamic TDD are marked FFS.
- Proposal 4 (Sec: Maximum Channel Bandwidth Options): Specifies maximum channel bandwidths: 100MHz (FDD) / 200MHz (TDD) for 0.410–6.425 GHz; 400MHz for 6.425–7.125 GHz and beyond up to Y; 800MHz for 24.25–52.6 GHz, with several FFS items on bandwidth restrictions and frequency boundaries.
- Proposal 2 (Sec: Subcarrier Spacings for 6GR): For sub 6GHz, at least 15kHz SCS for FDD and 30kHz SCS for TDD are supported; for around 7GHz, 30kHz is supported; for around 15GHz, 30, 60, 120 kHz are for study; for 24.25-52.6 GHz, 120kHz SCS is supported.
- Observation 1 (Sec: Duplex Types): More important than the support of dynamic TDD is that UEs support and are tested and certified for a large number of semi-static TDD configurations that are relevant in current or future deployments by mobile network operators