F1 Setup
The
purpose of the F1 Setup procedure is to exchange application level data needed
for the gNB-DU and the gNB-CU to correctly interoperate on the F1 interface.
This procedure shall be the first F1AP procedure triggered after a TNL
association has become operational. The procedure uses non-UE associated
signalling, it is cell related procedure.
This
procedure erases any existing application level configuration data in the two
nodes and replaces it by the one received. This procedure also re-initialises
the F1AP UE-related contexts (if any) and erases all related signalling
connections in the two nodes like a Reset procedure would do.
Successful Operation
The gNB-DU initiates the procedure by
sending a F1 SETUP REQUEST message including the appropriate data to the gNB-CU. The gNB-CU responds
with a F1 SETUP RESPONSE message including the appropriate
data.
If the F1 SETUP REQUEST message contains
the gNB-DU Name IE the gNB-CU may use
this IE as a human readable name of the gNB-DU.
For NG-RAN, the gNB-DU shall include the gNB-DU System Information IE and the TAI Slice Support List IE.
The gNB-CU may include the Cells to be Activated List IE in the F1
SETUP RESPONSE message. The Cells to be
Activated List IE includes a list of cells that the gNB-CU requests the
gNB-DU to activate. The gNB-DU shall activate the cells included in the Cells to be Activated List IE and
reconfigure the physical cell identity for cells for which the NR PCI IE is included.
For NG-RAN, the gNB-CU shall include the gNB-CU System Information IE in the F1
SETUP RESPONSE message.
The exchanged data shall be stored in
respective node and used as long as there is an operational TNL association.
When this procedure is finished, the F1 interface is operational and other F1
messages may be exchanged.
For NG-RAN, the gNB-DU may include the RAN Area Code IE in the F1 SETUP REQUEST message. The gNB-CU may use it according to TS 38.300 [6].
F1 SETUP REQUEST IEs.
This message is sent by the gNB-DU to
transfer information for a TNL association.
Direction: gNB-DU ® gNB-CU
IE/Group Name |
Presence |
Range |
IE type and reference |
Semantics description |
Criticality |
Assigned Criticality |
Message Type |
M |
|
9.3.1.1 |
|
YES |
reject |
Transaction ID |
M |
|
9.3.1.23 |
|
YES |
reject |
gNB-DU ID |
M |
|
9.3.1.9 |
|
YES |
reject |
gNB-DU Name |
O |
|
PrintableString(SIZE(1..150,…)) |
|
YES |
ignore |
gNB-DU Served Cells List |
|
1 |
|
List of cells configured in the gNB-DU |
YES |
reject |
>gNB-DU Served
Cells Item |
|
1.. <maxCellingNBDU> |
|
|
EACH |
reject |
>>Served Cell Information |
M |
|
9.3.1.10 |
Information about the cells configured in the gNB-DU |
- |
- |
>>gNB-DU System Information |
O |
|
9.3.1.18 |
RRC container with system information owned by gNB-DU |
- |
- |
Range bound |
Explanation |
maxCellingNBDU |
Maximum no. cells that can be served
by a gNB-DU. Value is 512. |
9.3.1.1 Message Type
The Message
Type IE uniquely identifies the message being sent. It is mandatory for all
messages.
IE/Group Name |
Presence |
Range |
IE type and reference |
Semantics description |
Message Type |
|
|
|
|
>Procedure Code |
M |
|
INTEGER (0..255) |
|
>Type of Message |
M |
|
CHOICE (Initiating Message, Successful Outcome,
Unsuccessful Outcome, …) |
|
Procedure Code: every message has its procedure code, so that, that can be identified their class and message type by other nodes.
Type of Message: The Type can be Initiating Message, Successful Outcome, Unsuccessful Outcome. it is selected by sending node.
9.3.1.23 Transaction ID
The Transaction
ID IE uniquely identifies a
procedure among all ongoing parallel procedures of the same type initiated by
the same protocol peer. Messages belonging to the same procedure shall use the
same Transaction ID. The Transaction ID is determined by the initiating peer of
a procedure.
IE/Group Name |
Presence |
Range |
IE type and reference |
Semantics description |
Transaction ID |
M |
|
INTEGER (0..255, …) |
|
9.3.1.9 gNB-DU ID
The gNB-DU ID uniquely identifies the
gNB-DU at least within a gNB-CU.
IE/Group Name |
Presence |
Range |
IE type and
reference |
Semantics
description |
gNB-DU ID |
M |
|
INTEGER (0 ..
236-1) |
The gNB-DU ID
is independently configured from cell identifiers, i.e. no connection between
gNB-DU ID and cell identifiers. |
9.3.1.10 Served Cell Information
This IE contains cell configuration
information of a cell in the gNB-DU.
IE/Group Name |
Presence |
Range |
IE type and reference |
Semantics description |
Criticality |
Assigned Criticality |
NR CGI |
M |
|
9.3.1.12 |
|
- |
- |
NR PCI |
M |
|
INTEGER
(0..1007) |
Physical Cell
ID |
|
|
5GS TAC |
M |
|
9.3.1.29 |
5GS Tracking
Area Code |
YES |
reject |
Configured EPS
TAC |
O |
|
9.3.1.29a |
|
– |
|
Served PLMNs |
|
1..<maxnoofBPLMNs> |
|
Broadcast PLMNs |
– |
– |
>PLMN Identity |
M |
|
9.3.1.14 |
|
- |
- |
>TAI Slice Support List |
O |
|
Slice Support List 9.3.1.37 |
Supported S-NSSAIs per TA. |
YES |
ignore |
CHOICE NR-Mode-Info |
M |
|
|
|
– |
– |
>FDD |
|
|
|
|
|
|
>>FDD Info |
|
1 |
|
|
- |
- |
>>>UL
FreqInfo |
M |
|
NR Frequency Info 9.3.1.17 |
|
– |
– |
>>>DL
FreqInfo |
M |
|
NR Frequency Info 9.3.1.17 |
|
– |
– |
>>>UL
Transmission Bandwidth |
M |
|
NR Transmission Bandwidth 9.3.1.15 |
|
– |
– |
>>>DL
Transmission Bandwidth |
M |
|
NR Transmission Bandwidth 9.3.1.15 |
|
– |
– |
>TDD |
|
|
|
|
- |
- |
>>TDD Info |
|
1 |
|
|
- |
- |
>>> NR FreqInfo |
M |
|
NR Frequency Info 9.3.1.17 |
|
– |
– |
>>> Transmission Bandwidth |
M |
|
NR Transmission Bandwidth 9.3.1.15 |
|
– |
– |
Measurement Timing Configuration |
M |
|
OCTET STRING |
Contains the MeasurementTimingConfiguration inter-node message defined in TS
38.331 [8]. |
– |
– |
RANAC |
O |
|
9.3.1.57 |
RAN Area Code |
YES |
ignore |
Range bound |
Explanation |
maxnoofBPLMNs |
Maximum no.
of Broadcast PLMN Ids. Value is 6. |
9.3.1.18 gNB-DU System Information
This IE
contains the system information generated by the gNB-DU. here we have two mandatory parameters, you could further reach to 38.331 for details.
IE/Group Name |
Presence |
Range |
IE type and reference |
Semantics description |
MIB message |
M |
|
OCTET STRING |
MIB message, as defined in TS 38.331
[8].
|
SIB1 message |
M |
|
OCTET STRING |
SIB1 message, as defined in TS 38.331
[8].
|