10.6 UE requested PDN disconnect
36.523-13GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 1: Protocol conformance specificationRelease 17TSUser Equipment (UE) conformance specification
10.6.1 UE requested PDN disconnect procedure accepted by the network
10.6.1.1 Test Purpose (TP)
(1)
with { UE is in BEARER CONTEXT ACTIVE STATE state }
ensure that {
when { UE is triggered to disconnect from a PDN }
then { UE sends a PDN DISCONNECT REQUEST message including the default EPS bearer identity associated with this PDN }
}
(2)
with { UE is in PROCEDURE TRANSACTION PENDING state }
ensure that {
when { UE receives a DEACTIVATE EPS BEARER CONTEXT REQUEST message with any valid ESM cause }
then { UE deactivates the default EPS bearer context for this PDN connection between the UE and the SS }
}
10.6.1.2 Conformance requirements
References: The conformance requirements covered in the present TC are specified in: TS 24.301, clauses 6.5.2.2, and 6.5.2.4.
[TS 24.301, clause 6.5.2.2]
In order to request PDN disconnection from a PDN, the UE shall send a PDN DISCONNECT REQUEST message to the MME, start the timer T3492 and enter the state PROCEDURE TRANSACTION PENDING (see example in figure 6.5.2.2.1). The PDN DISCONNECT REQUEST message shall include the EPS bearer identity of the default bearer associated with the PDN to disconnect from as the linked EPS bearer identity in the PDN DISCONNECT REQUEST message.
[TS 24.301, clause 6.5.2.3]
…
Upon receipt of the DEACTIVATE EPS BEARER CONTEXT REQUEST message, the UE shall stop the timer T3492 and enter the state PROCEDURE TRANSACTION INACTIVE. The behaviour of the UE is described in subclause 6.4.4.
…
[TS 24.301, clause 6.4.4.2]
If a NAS signalling connection exists when the MME initiates the EPS bearer context deactivation procedure, the MME shall initiate the EPS bearer context deactivation procedure by sending a DEACTIVATE EPS BEARER CONTEXT REQUEST message to the UE, start the timer T3495, and enter the state BEARER CONTEXT INACTIVE PENDING (see example in figure 6.4.4.2.1). The DEACTIVATE EPS BEARER CONTEXT REQUEST message contains an ESM cause typically indicating one of the following:
#8: operator determined barring;
#36: regular deactivation;
#38: network failure; or
#112: APN restriction value incompatible with active EPS bearer context.
The procedure transaction identity (PTI) shall also be included if the deactivation is triggered by a UE initiated bearer resource modification procedure or UE requested PDN disconnect procedure.
…
10.6.1.3 Test description
10.6.1.3.1 Pre-test conditions
System Simulator:
– Cell A is configured according to Table 6.3.2.2-1 in [18].
UE:
None.
Preamble:
– The UE is in state Registered, Idle mode (state 2) according to [18] on Cell A.
– Two default EPS bearer context are activated and present on UE side (a first PDN obtained during the attach procedure and an additional PDN).
10.6.1.3.2 Test procedure sequence
Table 10.6.1.3.2-1: Main behaviour
|
St |
Procedure |
Message Sequence |
TP |
Verdict |
|
|
U – S |
Message |
||||
|
1 |
Cause the UE to request disconnection from the additional PDN (see Note 1) |
– |
– |
– |
– |
|
1A |
The UE transmits a SERVICE REQUEST |
–> |
SERVICE REQUEST |
– |
– |
|
1B |
The SS establishes SRB2 and DRBs associated with two default EPS bearer context (a first PDN obtained during the attach procedure and an additional PDN). |
– |
– |
– |
– |
|
2 |
Check: Does the UE transmit a PDN DISCONNECT REQUEST message as specified (to disconnect from the additional PDN)? |
–> |
PDN DISCONNECT REQUEST |
1 |
P |
|
3 |
The SS transmits a DEACTIVATE EPS BEARER CONTEXT REQUEST message included in an RRCConnectionReconfiguration message. |
<– |
DEACTIVATE EPS BEARER CONTEXT REQUEST |
– |
– |
|
4 |
The UE transmits a DEACTIVATE EPS BEARER CONTEXT ACCEPT message. |
–> |
DEACTIVATE EPS BEARER CONTEXT ACCEPT |
2 |
P |
|
5 |
Void |
– |
– |
– |
– |
|
5A |
The SS releases the RRC connection. |
– |
– |
– |
– |
|
Note 1: The request to disconnect from a PDN may be performed by MMI or AT command. |
|||||
10.6.1.3.3 Specific message contents
Table 10.6.1.3.3-1: Message PDN DISCONNECT REQUEST (step 2, Table 10.6.1.3.2-1)
|
Derivation Path: TS 36.508 Table 4.7.3-22 |
|||
|
Information Element |
Value/remark |
Comment |
Condition |
|
EPS bearer identity |
‘0000’ |
"no EPS bearer identity assigned" |
|
|
Procedure transaction identity |
PTI-1 |
UE assigns a particular PTI not yet used between 1 and 254 |
|
|
Linked EPS bearer identity |
6 |
||
Table 10.6.1.3.3-1a: Message RRCConnectionReconfiguration (step 3, Table 10.6.1.3.2-1)
|
Derivation path: 36.508 table 4.6.1-8 using condition DRB-REL(2) |
Table 10.6.1.3.3-2: Message DEACTIVATE EPS BEARER CONTEXT REQUEST (step 3, Table 10.6.1.3.2-1)
|
Derivation Path: TS 36.508 Table 4.7.3-12 |
|||
|
Information Element |
Value/remark |
Comment |
Condition |
|
EPS bearer identity |
6 |
SS re-uses the EPS Bearer Id defined by UE for this present PDN disconnection procedure. |
|
|
Procedure transaction identity |
PTI-1 |
SS re-uses the particular PTI defined by UE for this present PDN disconnection procedure. |
UE-INITIATED |
|
ESM cause |
#36 |
regular deactivation |
|
Table 10.6.1.3.3-3: Message DEACTIVATE EPS BEARER CONTEXT ACCEPT (step 4, Table 10.6.1.3.2-1)
|
Derivation Path: TS 36.508 Table 4.7.3-11 |
|||
|
Information Element |
Value/remark |
Comment |
Condition |
|
EPS bearer identity |
6 |
The same value as the value set in DEACTIVATE EPS BEARER CONTEXT REQUEST message. |
|
|
Procedure transaction identity |
0 |
No procedure transaction identity assigned |
|