1. WF on UL Beam Management
3GPP TSG RAN WG1 #88
R1-170xxxx
Athens, Greece, 13 – 17 Feb 2017
Agenda Item:
WF on UL Beam Management
Huawei, HiSilicon, Intel, MediaTek, [NTT DOCOMO], [Qualcomm], […]

2. Background
Working assumption in RAN1 Ad Hoc meeting for NR in January 2017
NR supports at least one NW-controlled mechanism for beam management for UL transmission(s)
Details are FFS, including at least the following study:
Signal(s) for the mechanism(s) if necessary
E.g., SRS, PRACH preamble, UL DMRS
Additional contents can also be included, e.g., beam reporting
Method(s) and content for TRP to indicate selected UE Tx beam and configure UE sweeping
Impact of beam correspondence Status
E.g., When to use the mechanism(s)
E.g., Procedures such as U-1, U-2, U-3, and beam correspondence based procedure
UE capability reporting
E.g., capability of analog beamforming
Consider the cases when UL and DL are from the same TRP and from different TRPs
Conditions when the mechanism is particularly useful

3. Proposal Confirm the WA of
NR supports at least one NW-controlled mechanism for beam management for UL transmission(s)
Support the following for UL beam management
At least for but not limited to the scenarios where beam correspondence does not hold
U-1/U-2/U-3 procedures for UL beam management
Exact definitions can be found in the agreements of RAN1#86bis
Based on at least SRS and/or RACH
UE determines Tx beam(s) based on beam-related configuration from gNB
FFS: gNB Rx beam(s), beam pair link(s)
NR considers
The following UE beam sweeping types with possible down-selection
Sweeping type 1: UE keeps same Tx beam across symbols within one slot
Sweeping type 2: UE changes Tx beams across symbols within one slot
Sweeping type 3: UE changes Tx beams across K (K≥1) repetitions and the duration of each repetition can be smaller than one symbol
Note: the symbol duration is obtained based on a reference numerology
UE beam switching latency for SRS configuration
FFS: UE information on DL/UL beam correlation provided to NW for reducing UL beam management overhead