User's Manual

Ver.
CHAPTER 4. Message Flow
2600-00FKQFGA2
1.0
Step Description
1) The UE performs the random access procedure (TS 36.321, 5.1) with the Indoor Pico
Cell.
2)~4) The UE initializes the RRC Connection Establishment procedure (TS 36.331, 5.3.3).
The UE includes the NAS ATTACH REQUEST message in the RRC
RRCConnectionSetupComplete message and transmits it to the Indoor Pico Cell.
5) The Indoor Pico Cell induces the MME from the RRC factors. The Indoor Pico Cell
includes the ATTCH REQUEST message in the INITIAL UE message, which is an S1-
MME Control message, and transmits it to the MME.
6) If there is no UE context for the UE in the network, integrity is not protected for the
ATTACH REQUEST message, or the integrity check fails, authentication and NAS
security setup are always performed.
The UE performs the EPS authentication and key agreement (AKA) procedure (TS
33.401, 6.1.1) with the MME. The MME sets up an NAS security association with the
UE using the NAS security mode command (SMC) procedure (TS 33.401, 7.2.4.4).
7)~8) The MME selects the P-GW and S-GW. The MME transmits the Create Session
Request message to the S-GW The S-GW adds a record to the EPS bearer table.
From this step to step 20, the S-GW keeps the downlink packet received from the P-
GW until the Modify Bearer Request message is received. The S-GW returns the
Create Session Request message to the MME.
9)
The MME includes the ATTACH REQUEST message in the INITIAL CONTEXT SETUP
REQUEST message, which is an S1-MME Control message, and transmits it to the
Indoor Pico Cell. This S1 message also includes the AS security context information for
the UE. This information starts the AS SMC procedure at the RRC level.
10)~12) If the UE Radio Capability IE value is not contained in the INITIAL CONTEXT SETUP
REQUEST message, the Indoor Pico Cell starts the procedure for obtaining the UE
Radio Capability value from the UE and then transmits the execution result to the MME.
13)~14) The Indoor Pico Cell transmits the SecurityModeCommand message to the UE, and the
UE responds with the SecurityModeComplete message. In the Indoor Pico Cell, the
encoding downlink must start after transmitting the SecurityModeCommand and the
decoding uplink must start after receiving the SecurityModeComplete.
In the UE, the uplink encryption must be started after the SecurityModeComplete
message has been transmitted, and the downlink decryption must be started after the
SecurityModeCommand message has been received (TS 33.401, 7.2.4.5).
15)~16) The Indoor Pico Cell includes the ATTACH ACCEPT message in the
RRCConnectionReconfiguration message and transmits it to the UE. The UE transmits
the RRCConnectionReconfigurationComplete message to the Indoor Pico Cell. After
receiving the A
TTACH ACCEPT message, the UE can transmit uplink packets to both of
the S-GW and P-GW via the Indoor Pico Cell.
17) The Indoor Pico Cell transmits the INITIAL CONTEXT SETUP RESPONSE message to
the MME.
18)~19) The UE transmits the ULInformationTransfer message containing the ATTACH COMPLETE to
the Indoor Pico Cell. The Indoor Pico Cell transmits the UPLINK NAS TRANSPORT
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