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

2. 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)

3. 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?

4. 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

5. 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

6. 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