RACH configuration ZTE, Sanechips R1-171xxxx 3GPP TSG RAN WG1 Meeting RAN1 #90bis Prague, CZ, 9th – 13th, October 2017 Agenda item: 7.1.2.1 R1-171xxxx RACH configuration ZTE, Sanechips

AGENDA for RACH configuration during this week Numerology that the RACH resource configuration is based on. Then we can discuss the RACH resource configuration period and resource density within one RACH resource configuration period Then focus on the mapping within a RACH block (RACH block will be discussed in combination with the numerology for the RACH resouces configuration) Other key issues (depending on progress of above)

RACH resource configuration period RACH resource configuration period, P (ms) RACH slot A RACH slot is based on Msg1 numerology N RACH slots within one RACH configuration period. N equals P/R, R = Msg1 num / 15kHz N = P for Msg1 num = 15kHz, N = 8P for Msg1 num = 120kHz Define D as the density of the RACH slots within a RACH configuration period. D = 1 -> One RACH slot is configured within one RACH configuration period D = n -> n RACH slots are configured within one RACH configuration period P can be: fixed, e.g 5ms Follow the SS burst set periodicity other?

Discussion on RACH configuration Question rasied during online session: What numerology to base the RACH configuration on Alt1: Signaled, Working assumption Alt2: Based on Msg1: 14 symbol RACH blocks Alt3: Based on SS block, (SS block numerology >= Msg1 num). 14 symbol RACH blocks Alt4: For short sequences, below 6GHz. Use SCS [15 30] kHz For short sequences, above 6GHz. Use SCS [60 120] kHz

RACH blocks based on signaled RACH block 2 DL 12 UL UL/DL data based on 30kHz RACH blocks configuration based on MSG1 SCS = 15kHz Configured with 30kHz Will be a 14 symbol RACH block 1 DL 6 UL 1 DL 6 UL 14 symbols RACH block

RACH blocks based on signaled RACH block 2 DL 12 UL UL/DL data based on 15kHz RACH blocks configuration based on MSG1 SCS = 30kHz Configured with 15kHz Will be a 28 symbol RACH block 4 DL 24 UL 28 symbols