23 CIoT optimization for E-UTRA

36.523-13GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Part 1: Protocol conformance specificationRelease 17TSUser Equipment (UE) conformance specification

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

23.1 CIoT Optimization / Control Plane

23.1.1 CIoT / Control Plane MO and MT IP and non-IP Data Transfer / Serving PLMN Rate Control / APN Rate Control

23.1.1.1 Test Purpose (TP)

(1)

with { the UE in RRC-IDLE after attaching with Control Plane CIoT EPS optimisation for EPS services }

ensure that {

when { UE has user data to send via the control plane }

then { the UE initiates a Service request procedure for EPS services with Control Plane CIoT EPS optimization by sending a CONTROL PLANE SERVICE REQUEST message (rules for ciphering of the initial NAS message apply )

when { UE has already a PDN established }

then { the UE incorporates ESM DATA TRANSPORT message carrying the user data in the CONTROL PLANE SERVICE REQUEST message (rules for ciphering of the initial NAS message apply) }

}

(2)

with { the UE in RRC-IDLE after attaching with Control Plane CIoT EPS optimisation for EPS services }

ensure that {

when { UE, while in RRC-CONNECTED, has user data to send via the control plane }

then { the UE sends one or more ESM DATA TRANSPORT message(s) including the user data to be sent in the User data container IE }

}

(3)

with { the UE in RRC-IDLE after attaching with Control Plane CIoT EPS optimisation for EPS services }

ensure that {

when { UE performs Control Plane data transfer whenever this is needed }

then { the UE obeys the local serving PLMN rate control, and, if supported the APN Rate Control and the maximum length of user data container that can be sent in the ESM DATA TRANSPORT message (set by the MTU parameter) through EPS bearer context modification }

}

(4)

with { the UE in RRC-IDLE after attaching with Control Plane CIoT EPS optimisation for EPS services }

ensure that {

when { the Network has user data to send via the control plane, and, has executed a Paging for EPS services procedure }

then { the UE successfully completes RRC connection establishment together with Service request procedure for EPS services with Control Plane CIoT EPS optimization }

when { UE has a PDN established }

then { is able to receive user data sent via ESM DATA TRANSPORT message }

}

23.1.1.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331 and TS 24.301, unless otherwise stated these are Rel-13 requirements.

[TS 36.331, clause 5.3.3]

1> set the content of RRCConnectionSetupComplete message as follow

…

2> if the UE supports CIoT EPS optimisation(s):

3> include attachWithoutPDN-Connectivity if received from upper layers;

3> include up-CIoT-EPS-Optimisation if received from upper layers;

3> except for NB-IoT, include cp-CIoT-EPS-Optimisation if received from upper layers;

[TS 24.301, clause 4.2]

A UE using EPS services with control plane CIoT EPS optimization can initiate transport of user data via the control plane. For this purpose a UE in EMM-IDLE mode can initiate the service request procedure and transmit the ESM DATA TRANSPORT message in an information element in the CONTROL PLANE SERVICE REQUEST message.

[TS 24.301, clause 5.3.15]

If the UE indicates support of one or more CIoT EPS optimizations and the network supports one or more CIoT EPS optimizations and decides to accept the attach or tracking area update request, the network indicates the supported CIoT EPS optimizations to the UE per TAI list when accepting the UE request. Network indication of support is interpreted by the UE as the acceptance to use the respective feature. After completion of the attach or tracking area updating procedure, the UE and the network can then use the accepted CIoT EPS optimizations for the transfer of user data (IP, non-IP and SMS).

Broadcast system information may provide information about support of CIoT EPS optimizations (see 3GPP TS 36.331 [22]). At reception of new broadcast system information, the lower layers deliver it to the EMM layer in the UE. The information provided by lower layers is per PLMN and used by the UE to determine whether certain CIoT EPS optimizations are supported in the cell.

The UE shall not attempt to use CIoT EPS optimizations which are indicated as not supported.

In WB-S1 mode, when the UE requests the lower layer to establish a RRC connection and the UE requests the use of EMM-REGISTERED without PDN connection, control plane CIoT EPS optimization or user plane CIoT EPS optimization, the UE shall pass an indication of the requested CIoT EPS optimizations to the lower layers.

[TS 24.301, clause 5.5.1]

If the UE supports NB-S1 mode or Non-IP PDN type, then the UE shall support the extended protocol configuration options IE.

If the UE supports the extended protocol configuration options IE, then the UE shall set the ePCO bit to "extended protocol configuration options supported" in the UE network capability IE of the ATTACH REQUEST message.

If the UE supports CIoT EPS optimizations, it shall indicate in the UE network capability IE of the ATTACH REQUEST message whether it supports EMM-REGISTERED without PDN connection.

If EMM-REGISTERED without PDN connection is not supported by the UE or the MME, or if the UE wants to request PDN connection with the attach procedure, the UE shall send the ATTACH REQUEST message together with a PDN CONNECTIVITY REQUEST message contained in the ESM message container IE.

[TS 24.301, clause 5.6.1.2.1]

The UE shall send a CONTROL PLANE SERVICE REQUEST message, start T3417 and enter the state EMM-SERVICE-REQUEST-INITIATED.

For case a in subclause 5.6.1.1, the Control plane service type of the CONTROL PLANE SERVICE REQUEST message shall indicate "mobile terminating request". The UE may include the ESM DATA TRANSPORT message. The UE shall not include any ESM message other than ESM DATA TRANSPORT message.

For case b in subclause 5.6.1.1,

For cases b and m in subclause 5.6.1.1,

– if the UE has pending IP or non-IP user data that is to be sent via the user plane radio bearers, the UE shall set the Control plane service type of the CONTROL PLANE SERVICE REQUEST message to "mobile originating request" and the "active" flag in the Control plane service type IE to 1. The UE shall not include any ESM message container or NAS message container IE in the CONTROL PLANE SERVICE REQUEST message.

[TS 24.301, clause 5.6.2.2.1.1]

Upon reception of a paging indication, if control plane CIoT EPS optimization is used by the UE, the UE shall stop the timer T3346, if running, and shall additionally:

– initiate a service request procedure as specified in subclause 5.6.1.2.2 if the UE is in the EMM-IDLE mode without suspend indication; or

– proceed the behaviour as specified in subclause 5.3.1.3 if the UE is in the EMM-IDLE mode with suspend indication.

NOTE 2: If the UE is in the EMM-IDLE mode without suspend indication and has an uplink user data to be sent to the network using control plane CIoT EPS optimization when receiving the paging indication, the UE can piggyback the uplink user data during the service request procedure initiated to respond to the paging, as specified in subclause 5.6.1.2.2.

[TS 24.301, clause 6.2A]

The UE and the MME may support robust header compression (ROHC) framework (see IETF RFC 4495 [37]) for IP header compression if control plane CIoT EPS optimization is supported for PDN connections of IP PDN type. If IP header compression for control plane CIoT EPS optimization is supported, the ROHC profiles defined in 3GPP TS 36.323 [38] may be supported. The ROHC configuration is negotiated and established during the UE requested PDN connectivity procedure as specified in subclause 6.5.1. Both the UE and the MME indicate whether IP header compression for control plane CIoT EPS optimization is supported during attach and tracking area updating procedures (see subclauses 5.5.1 and 5.5.3). The ROHC configuration can be re-negotiated by using the UE requested bearer resource modification procedure or the EPS bearer context modification procedure as specified in subclauses 6.4.3 and 6.5.4.

[TS 24.301, clause 6.3.8]

Serving PLMN rate control is applicable for PDN connections established for control plane CIoT EPS optimization only.

[TS 24.301, clause 6.3.9]

APN rate control controls the maximum number of uplink user data messages sent by the UE in a time interval for the APN in accordance with 3GPP TS 23.401 [10]. The UE shall limit the rate at which it generates uplink user data messages to comply with the APN rate control policy. The NAS shall provide the indicated rates to upper layers for enforcement. The indicated rate in a NAS procedure applies to the APN the NAS procedure corresponds to, and the indicated rate is valid until a new value is indicated or the last PDN connection using this APN is released.

If an indication of additional exception reports is provided with the APN rate control parameters, the UE is allowed to send uplink exception reports even if the limit for the APN rate control has been reached.

NOTE: The HPLMN can discard or delay user data that exceeds the limit provided for APN rate control.

[TS 24.301, clause 6.5.1.2]

When the PDN CONNECTIVITY REQUEST message is sent together with an ATTACH REQUEST message, the UE shall not start timer T3482 and shall not include the APN.

NOTE 1: If the UE needs to provide protocol configuration options which require ciphering or provide an APN, or both, during the attach procedure, the ESM information transfer flag is included in the PDN CONNECTIVITY REQUEST. The MME then at a later stage in the PDN connectivity procedure initiates the ESM information request procedure in which the UE can provide the MME with protocol configuration options or APN or both.

In the PDN type IE the UE shall either indicate the IP version capability of the IP stack associated with the UE or non IP as specified in subclause 6.2.2.

If the PDN type value of the PDN type IE is set to IPv4 or IPv6 or IPv4v6 and the UE indicates "Control plane CIoT EPS optimization supported" in the UE network capability IE of the ATTACH REQUEST message, the UE may include the Header compression configuration IE in the PDN CONNECTIVITY REQUEST message.

[TS 24.301, clause 6.6.4.2]

Upon receipt of a request to transfer user data via the control plane, if the UE is in EMM-CONNECTED mode, the UE initiates the procedure by sending the ESM DATA TRANSPORT message including the user data to be sent in the User data container IE. The length of the value part of the User data container IE should not exceed the link MTU size for the respective type of user data (IPv4, IPv6 or Non-IP).

NOTE: The recommended maximum size for link MTU is 1358 octets to prevent fragmentation in the backbone network (see 3GPP TS 23.060 [74]). Depending on the network configuration, setting link MTU size to a value larger than 1358 octets could lead to inefficient core network implementation due to fragmentation.

If the UE is in EMM-IDLE mode, the UE initiates the procedure by sending the ESM DATA TRANSPORT message included in a CONTROL PLANE SERVICE REQUEST message.

23.1.1.3 Test description

23.1.1.3.1 Pre-test conditions

System Simulator:

– Cell 1, default system information combination.

UE:

None.

Preamble:

– UE is in State 3A-CP, Control Plane CIoT connection request, UE Test Mode Activated (Test Loop G) according to TS 36.508 [18].

23.1.1.3.2 Test procedure sequence

Table 23.1.1.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
0	NOTE: Settings in ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST, in preamble, to check PLMN rate control: – PLMN Rate control set to max of 10 messages per 6 minutes; – APN control not provided; – MTU parameters not provided.
1	The SS transmits a CLOSE UE TEST LOOP message to close the UE test loop mode for user data transfer (12 transmission; 60 sec delay).	<–	RRC: DLInformationTransfer TC: CLOSE UE TEST LOOP	–	–
2	The UE transmits a CLOSE UE TEST LOOP COMPLETE message to confirm that loopback is activated.	–>	RRC: ULInformationTransfer TC: CLOSE UE TEST LOOP COMPLETE	–	–
3	SS transmits an ESM DATA TRANSPORT message containing downlink user data of 3 octets.	<–	RRC: ULInformationTransfer ESM DATA TRANSPORT	–	–
4	The SS transmits an RRCConnectionRelease message.	<–	RRC: RRCConnectionRelease	–	–
5	Wait for the time set in the CLOSE UE TEST LOOP to expire.	–	–	–	–
6	SS starts timer 6 min PLMN Rate control	–	–	–	–
7	Check: Does the UE transmit an RRCConnectionRequest message?	–>	RRC: RRCConnectionRequest	–	–
8	SS transmits an RRCConnectionSetup-message.	<–	RRC: RRCConnectionSetup	–	–
9	Check: does the UE transmits an RRCConnectionSetupComplete message to confirm the successful completion of the connection establishment and to initiate the session management procedure by including the CONTROL PLANE SERVICE REQUEST message and an ESM DATA TRANSPORT message containing the same user data sent by the SS in step 3?	–>	RRC: RRCConnectionSetupComplete NAS: CONTROL PLANE SERVICE REQUEST NAS: ESM DATA TRANSPORT	1	P
10	The SS transmits a SERVICE ACCEPT message.	<–	RRC: DLInformationTransfer NAS: SERVICE ACCEPT
11	Check: Does the UE send an ESM DATA TRANSPORT message containing the same user data sent by the SS in step 3?	–>	RRC: ULInformationTransfer TC: ESM DATA TRANSPORT	2	P
–	EXCEPTION: Step 12 is repeated 8 times. Note: The number of messages is set so that together with the message sent in step 11 it respects the PLMN data rate set in the latest ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST.	–	–	–	–
12	Check: Does the UE send an ESM DATA TRANSPORT message containing the same user data sent by the SS in step 3?	–>	RRC: ULInformationTransfer TC: ESM DATA TRANSPORT	2,3,4	P
13	Wait until 6 min timer Expires	–	–	–	–
14	SS starts timer 6 min PLMN Rate control	–	–	–	–
–	EXCEPTION: Step 15 is repeated 2 times. Note: The number of messages is set so that it respects the PLMN data rate set in the latest ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST.	–	–	–	–
15	Check: Does the UE send an ESM DATA TRANSPORT message containing the same user data sent by the SS in step 3?	–>	RRC: ULInformationTransfer TC: ESM DATA TRANSPORT	2, 3	P
16	SS stops timer 6 min PLMN Rate control	–	–	–	–
–	EXCEPTION: Steps 17a1 to 17a8 describe behaviour that depends on UE capabilities; the "lower case letter" identifies a step sequence that take place depending on whether the UE supports APN control.	–	–	–	–
17a1	IF pc_APN_RateControl THEN The SS sends a MODIFY EPS BEARER CONTEXT REQUEST message of to modify APN, MTU and PLMN rate controls. NOTE: Settings in MODIFY EPS BEARER CONTEXT REQUEST to check APN rate control – APN control set for max 1 message per minute; – MTU parameters are not provided – PLMN Rate control not provided (ie previous value still applies).	<–	RRC: DLInformationTransfer NAS: MODIFY EPS BEARER CONTEXT REQUEST	–	–
17a2	Check: Does the UE transmit a MODIFY EPS BEARER CONTEXT ACCEPT message?	–>	RRC: ULInformationTransfer NAS: MODIFY EPS BEARER CONTEXT ACCEPT	4	P
17a3	The SS transmits a CLOSE UE TEST LOOP message to close the UE test loop mode for user data transfer (2 transmission; 0 sec delay).	<–	RRC: DLInformationTransfer TC: CLOSE UE TEST LOOP	–	–
17a4	The UE transmits a CLOSE UE TEST LOOP COMPLETE message to confirm that loopback is activated.	–>	RRC: ULInformationTransfer TC: CLOSE UE TEST LOOP COMPLETE	–	–
17a5	SS transmits an ESM DATA TRANSPORT message containing of downlink user data.	<–	RRC: DLInformationTransfer ESM DATA TRANSPORT	–	–
–	EXCEPTION: Steps 17a6-17a8 are repeated twice. Note: The number of repetitions is set so that it respects the APN rate controls set in step 17a1. Max of one message every minute.	–	–	–	–
17a6	SS starts timer 1 min APN Rate control	–	–	–	–
17a7	Check: Does the UE send an ESM DATA TRANSPORT message respecting the APN set in step 17a1: Max size of message 256 Octets?	–>	RRC: ULInformationTransfer TC: ESM DATA TRANSPORT	2,3,4	P
17a8	Wait until timer 1 min APN Rate control expires.	–	–	–	–
–	EXCEPTION: Steps 18a1-18a6 describe behaviour that depends on UE capabilities; the "lower case letter" identifies a step sequence that take place depending on whether the UE supports MTU parameters.	–	–	–	–
18a1	IF pc_NonIP_Link_MTU_Parameter OR pc_IPv4_Link_MTU_Parameter THEN The SS sends a MODIFY EPS BEARER CONTEXT REQUEST message to modify APN, MTU and PLMN rate controls. NOTE: Settings in MODIFY EPS BEARER CONTEXT REQUEST to check MTU parameters – APN control set to unrestricted; – MTU parameters container size limits set to max 128 Octet; . – PLMN Rate control not provided.	<–	RRC: DLInformationTransfer NAS: MODIFY EPS BEARER CONTEXT REQUEST	–	–
18a2	Check: Does the UE transmit a MODIFY EPS BEARER CONTEXT ACCEPT message?	–>	RRC: ULInformationTransfer NAS: MODIFY EPS BEARER CONTEXT ACCEPT	3	P
18a3	The SS transmits a CLOSE UE TEST LOOP message to close the UE test loop mode for user data transfer (1 transmission; 0 sec delay).	<–	RRC: DLInformationTransfer TC: CLOSE UE TEST LOOP	–	–
18a4	The UE transmits a CLOSE UE TEST LOOP COMPLETE message to confirm that loopback is activated.	–>	RRC: ULInformationTransfer TC: CLOSE UE TEST LOOP COMPLETE	–	–
18a5	SS transmits an ESM DATA TRANSPORT message containing 240 Octets of downlink user data.	<–	RRC: DLInformationTransfer ESM DATA TRANSPORT	4	P
–	EXCEPTION: Step 18a6 is repeated until the sum of the Octets of uplink user data sent in each ESM DATA TRANSPORT message =>240 Octets (the complete downlink user data provided in step 18a5 is looped back). Note: The number of messages is set so that it respects the APN, MTU and PLMN rate controls set in step 17a1.	–	–	–	–
18a6	Check: Does the UE send an ESM DATA TRANSPORT message respecting each containing user data container of max of 128 Octets (the MTU set in step 18a1)?	–>	RRC: ULInformationTransfer TC: ESM DATA TRANSPORT	2,3,4	P
19	The SS transmits DEACTIVATE TEST MODE message to deactivate the test mode G.	<–	RRC: DLInformationTransfer TC: DEACTIVATE TEST MODE	–	–
20	The UE transmits an DEACTIVATE TEST MODE COMPLETE message.	–>	RRC: ULInformationTransfer TC: DEACTIVATE TEST MODE COMPLETE	–	–
21	The SS transmits an RRCConnectionRelease message.	<–	RRC: RRCConnectionRelease	–	–

23.1.1.3.3 Specific message contents

Table 23.1.1.3.3-1: Message CLOSE UE TEST LOOP (step 1, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7A-3
Information Element	Value/Remark	Comment	Condition
UE test loop mode	‘00000110’B	UE test loop mode G setup
Operation mode and repetitions
M0	0	data is returned in uplink at the EMM entity
R6..R0	‘0001100’B	12 The received DL message in uplink shall be looped back 12 times.
Uplink data delay	‘00111100’B	T_delay_modeG timer=60 sec 0..255 seconds (binary coded, T7 is most significant bit and T0 least significant bit)

Table 23.1.1.3.3-2: Message ESM DATA TRANSPORT (steps 3 and 11, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	‘11110000 11110000 11110000’B	3 Octets of user data – The value is arbitrary chosen
Release assistance indication	Not present

Table 23.1.1.3.3-3: Message ESM DATA TRANSPORT (steps 12, 15, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	‘11110000 11110000 11110000’B	3 Octets of user data – The value is arbitrary chosen
Release assistance indication	Not present Or Present with DDX=’00’B	The messages sent in step 120 and the first message sent in step 15.
	Not present Or Present (with DDX=’00’B Or DDX=’01’B)	The second message sent in step 15.

Table 23.1.1.3.3-4: Message MODIFY EPS BEARER CONTEXT REQUEST (step 17a1, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], Table 4.7.3-18.
Information Element	Value/Remark	Comment	Condition
EPS bearer identity	The same value as the value set in the latest ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message sent prior to this message
Protocol configuration options	Not present
Extended Protocol configuration options
Container ID n+X+3	‘0016’H	APN rate control support parameters	pc_APN_RateControl
Length of container ID n+X+3 contents	4
Container ID n+X+3 contents		The container identifier contents field contains parameters for APN rate control functionality
Octet 1 AER+Uplink time unit	‘0001’B	– Additional exception reports at maximum rate reached are not allowed – minute (interval)
Octets 2-4	0000001’O	– Max 1 message per minute

Table 23.1.1.3.3-5: Message CLOSE UE TEST LOOP (step 17a3, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7A-3
Information Element	Value/Remark	Comment	Condition
UE test loop mode	‘00000110’B	UE test loop mode G setup
Operation mode and repetitions
M0	0	data is returned in uplink at the EMM entity
R6..R0	‘0000010’B	2 The received DL message in uplink shall be looped back 2 times
Uplink data delay	‘00000000’B	T_delay_modeG timer=0 sec 0..255 seconds (binary coded, T7 is most significant bit and T0 least significant bit)

Table 23.1.1.3.3-6: Message ESM DATA TRANSPORT (step 17a5, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	10 Octets, not all zeroes	Randomly chosen
Release assistance indication	Not present

Table 23.1.1.3.3-7: Message ESM DATA TRANSPORT (step 17a7, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	The same as the one provided in the relevant DL ESM DATA TRANSPORT message.
Release assistance indication	Not present Or Present with DDX=’00’BNot checked	The messages before the last.
	Not present Or Present (with DDX=’00’B Or DDX=’01’B)	The last message

Table 23.1.1.3.3-8: Message MODIFY EPS BEARER CONTEXT REQUEST (step 18a1, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], Table 4.7.3-18
Information Element	Value/Remark	Comment	Condition
EPS bearer identity	The same value as the value set in the latest ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message sent prior to this message
Protocol configuration options	Not present
Extended Protocol configuration options
Container ID n+X+1	‘0010’H	IPv4 Link MTU	pc_IPv4_Link_MTU_Parameter
Length of container ID n+X+1 contents	2
Container ID n+X+1 contents	‘00000000 10000000’B	– 128 octets maximum length of user data container that can be sent in the ESM DATA TRANSPORT message
Container ID n+X+2	‘0015’H	Non-IP Link MTU	pc_NonIP_Link_MTU_Parameter
Length of container ID n+X+2 contents	2
Container ID n+X+2 contents	‘00000000 10000000’B	– 128 octets maximum length of user data container that can be sent in the ESM DATA TRANSPORT message
Container ID n+X+3	‘0016’H	APN rate control support parameters	pc_APN_RateControl
Length of container ID n+X+3 contents	4
Container ID n+X+3 contents		The container identifier contents field contains parameters for APN rate control functionality
Octet 1 AER+Uplink time unit	‘0000’B	– Additional exception reports at maximum rate reached are not allowed – unrestricted (interval)
Octets 2-4	‘11111111 11111111 11111111’B	– unrestricted Maximum uplink rate (octet 2 to octet 4) is a binary coded representation of the maximum number of messages the UE is restricted to send per time unit. The time unit is indicated in the uplink time unit. If the uplink time unit is set to "unrestricted", the maximum uplink data volume the UE can send is not restricted.

Table 23.1.1.3.3-9: Message CLOSE UE TEST LOOP (steps 18a3, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7A-3
Information Element	Value/Remark	Comment	Condition
UE test loop mode	‘00000110’B	UE test loop mode G setup
Operation mode and repetitions
M0	0	CP data loopback mode
R6..R0	‘0000001’B	1 The received DL message in uplink shall be looped back 1 time (once)
Uplink data delay	‘00000000’B	T_delay_modeG timer=0 sec 0..255 seconds (binary coded, T7 is most significant bit and T0 least significant bit)

Table 23.1.1.3.3-10: Message ESM DATA TRANSPORT (step 18a5, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	240 Octets, not all zeroes	240 Octets of user data – The number of Octets is chosen in relation to the MTU parameters set in the TC and shall be obeyed; the value of each octet is not of importance
Release assistance indication	Not checked

Table 23.1.1.3.3-11: Message ESM DATA TRANSPORT (step 18a6, Table 23.1.1.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	Max 128 Octets of data	– The number of Octets is chosen in relation to the MTU parameters set in the TC and shall be obeyed; the value of each octet is not checked.
Release assistance indication	Not present Or Present with DDX=’00’BNot checked	The messages before the last.
	Not present Or Present (with DDX=’00’B Or DDX=’01’B)	The last message

23.1.2 CIoT Optimization / Control Plane / MT and MO SMS Data Transfer

23.1.2.1 Test Purpose (TP)

(1)

with { UE with CIoT Optimization and with SMS data configured }

ensure that {

when { when a MO SMS is triggered }

then { performs RRC connection establishment by transmitting RRCConnectionRequest, and RRCConnectionSetupComplete message including CONTROL PLANE SERVICE REQUEST message, with data service type="mobile originating request" }

}

(2)

with { UE with CIoT Optimization, with SMS data configured and in RRC Connected state }

ensure that {

when { when the network transmits SMS data in a DOWNLINK NAS TRANSPORT message }

then { the UE receives the SMS data }

}

(3)

with { UE with CIoT Optimization, with SMS data configured and in RRC Connected state }

ensure that {

when { MO SMS is triggered the UE }

then { UE transmits an UPLINK NAS TRANSPORT message containing the SMS data}

}

23.1.2.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 24.301, clauses 5.3.15. [TS 24.301 5.3.15]

CIoT EPS optimizations provide improved support of small data and SMS transfer. A UE supporting CIoT EPS optimizations can indicate the CIoT network behaviour the UE can support and prefer to use during attach or tracking area updating procedure (see 3GPP TS 23.401 [10]). The UE may indicate the support for control plane CIoT EPS optimization, user plane CIoT EPS optimization, EMM-REGISTERED without PDN connection, S1-U data transfer and header compression (see subclause 9.9.3.34). The UE may also request to use SMS transfer without combined attach procedure during the attach procedure. Furthermore, the UE may, separately from the indication of support, indicate preference for control plane CIoT EPS optimization or user plane CIoT EPS optimization (see subclause 9.9.3.0B). The indication of preference is also considered as the request to use.

The UE can be in NB-S1 mode or WB-S1 mode when requesting the use of CIoT EPS optimizations during an attach or tracking area updating procedure. A UE in NB-S1 mode always indicates support for control plane CIoT EPS optimization. A UE in NB-S1 mode can also request SMS transfer without combined procedure by using the normal attach or tracking area updating procedure (see subclause 5.5.1 and 5.5.3).

In NB-S1 mode, the UE, when requesting the use of CIoT EPS optimization, does not:

– request an attach for emergency bearer services procedure;

– request an attach procedure for initiating a PDN connection for emergency bearer services with attach type not set to "EPS emergency attach"; or

– indicate voice domain preference and UE’s usage setting.

The network does not indicate to the UE support of emergency bearer services when the UE is in NB-S1 mode (see subclause 5.5.1.2.4 and 5.5.3.2.4).

The control plane CIoT EPS optimization enables support of efficient transport of user data (IP, non-IP) or SMS messages over control plane via the MME without triggering data radio bearer establishment. The support of control plane CIoT EPS optimization is mandatory for the network in NB-S1 mode and optional in WB-S1 mode. Optional header compression of IP data can be applied to IP PDN type PDN connections that are configured to support header compression.

The user plane CIoT EPS optimization enables support for change from EMM-IDLE mode to EMM-CONNECTED mode without the need for using the service request procedure (see subclause 5.3.1.3).

If the UE indicates support of EMM-REGISTERED without PDN connection in the attach request, the UE may include an ESM DUMMY MESSAGE instead of a PDN CONNECTIVITY REQUEST message as part of the attach procedure. If the EMM-REGISTERED without PDN connection is supported by the network, the UE and the network can at any time release all the PDN connections and the UE still remains EPS attached.

NOTE: For both the UE and the network, the term "EMM-REGISTERED without PDN connection" is equivalent to the term "EPS attach without PDN connectivity" as specified in 3GPP TS 23.401 [10].

In NB-S1 mode, if the UE indicates "SMS only" during a normal attach or tracking area updating procedure, the MME supporting CIoT EPS optimisations provides SMS so that the UE is not required to perform a combined attach or tracking area updating procedure.

If the UE supports user plane CIoT EPS optimization, it shall also support S1-U data transfer.

If the UE and the network support both the control plane CIoT EPS optimization and S1-U data transfer, then when receiving the UE’s request for a PDN connection, the MME decides whether the PDN connection should be SCEF PDN connection or SGi PDN connection as specified in 3GPP TS 23.401 [10]:

– if SCEF PDN connection is to be established for non-IP data type, the MME shall include Control plane only indication for the requested PDN connection;

– if SGi PDN connection is to be established and existing SGi PDN connections for this UE were established with Control plane only indication, the MME shall include Control plane only indication for the newly requested SGi PDN connection;

– if SGi PDN connection is to be established and existing SGi PDN connections for this UE were established without Control plane only indication, the MME shall not include Control plane only indication for the newly requested SGi PDN connection; and

– if SGi PDN connection is to be established and no SGi PDN connection for this UE exists, the MME determine whether to include Control plane only indication for the requested SGi PDN connection based on local policies, the UE’s preferred CIoT network behaviour and the supported CIoT network behaviour.

If the network supports user plane CIoT EPS optimization, it shall also support S1-U data transfer.

The UE shall not attempt to use CIoT EPS optimizations which are indicated as not supported.

In NB-S1 mode, when the UE requests the lower layer to establish a RRC connection and the UE requests the use of EMM-REGISTERED without PDN connection or user plane CIoT EPS optimization, the UE shall pass an indication of the requested CIoT EPS optimizations to the lower layers. If the UE requests the use of S1-U data transfer without user plane CIoT optimization, then the UE shall also pass an indication of user plane CIoT EPS optimization to lower layers.

23.1.2.3 Test description

23.1.2.3.1 Pre-test conditions

System Simulator:

– Cell 1.

– System information combination 1 as defined in TS 36.508 [18] clause 4.4.3.1 is used in Cell 1;

UE:

px_SMSTransport_CP_CIoT is true.

Preamble:

– The UE shall be in Loopback Activation state 3A-CP using the UE TEST LOOP MODE H

23.1.2.3.2 Test procedure sequence

Table 23.1.2.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	The SS transmits a CLOSE UE TEST LOOP message to close the UE test loop mode for SMS transfer (2 transmissions; 60 sec delay).	<–	RRC: DLInformationTransfer TC: CLOSE UE TEST LOOP	–	–
2	The UE transmits a CLOSE UE TEST LOOP COMPLETE message to confirm that loopback is activated.	–>	RRC: ULInformationTransfer TC: CLOSE UE TEST LOOP COMPLETE	–	–
3	SS transmits a DOWNLINK NAS TRANSPORT message containing downlink user data (SMS).	<–	RRC: DL InformationTransfer NAS: DOWNLINK NAS TRANSPORT	–	–
3A	The UE transmits a CP-ACK encapsulated in an UPLINK NAS TRANSPORT message.	–>	NAS: UPLINK NAS TRANSPORT	–	–
3B	The UE transmits a CP-DATA containing an RP-ACK RPDU encapsulated in an UPLINK NAS TRANSPORT message.	–>	NAS: UPLINK NAS TRANSPORT	–	–
3C	The SS transmits a CP-ACK encapsulated in a DOWNLINK NAS TRANSPORT message to the UE.	<–	NAS: DOWNLINK NAS TRANSPORT	–	–
4	The SS transmits an RRCConnectionRelease	<–	RRC: RRCConnectionRelease	–	–
5	Wait for the time set in the CLOSE UE TEST LOOP step 1 to expire.	–	–	–	–
6	Check: Does the UE transmit an RRCConnectionRequest message?	–>	RRC: RRCConnectionRequest	1	P
7	SS transmits an RRCConnectionSetup message.	<–	RRC: RRCConnectionSetup	–	–
8	Check: Does the UE transmit an RRCConnectionSetupComplete message and a CONTROL PLANE SERVICE REQUEST message, data service type="mobile originating request", integrity protected and partially ciphered and including the SMS in the NAS message container IE?	–>	RRC: RRCConnectionSetupComplete NAS: CONTROL PLANE SERVICE REQUEST	2	P
8A	The SS transmits a SERVICE ACCEPT message.	<–	RRC: DLInformationTransfer NAS: SERVICE ACCEPT
8B	The SS transmits a CP-ACK encapsulated in a DOWNLINK NAS TRANSPORT message.	<–	NAS: DOWNLINK NAS TRANSPORT	–	–
8C	The SS transmits a CP-DATA containing an RP-ACK RPDU encapsulated in a DOWNLINK NAS TRANSPORT message	<–	NAS: DOWNLINK NAS TRANSPORT	–	–
8D	The UE transmits a CP-ACK encapsulated in an UPLINK NAS TRANSPORT message.	–>	NAS: UPLINK NAS TRANSPORT	–	–
9	Check: Does the UE send an UPLINK NAS TRANSPORT message containing SMS, matching the SMS sent in step 3?	–>	RRC: ULInformationTransfer NAS: UPLINK NAS TRANSPORT	1,3	P
9A	The SS transmits a CP-ACK encapsulated in a DOWNLINK NAS TRANSPORT message.	<–	NAS: DOWNLINK NAS TRANSPORT	–	–
9B	The SS transmits a CP-DATA containing an RP-ACK RPDU encapsulated in a DOWNLINK NAS TRANSPORT message	<–	NAS: DOWNLINK NAS TRANSPORT	–	–
9C	The UE transmits a CP-ACK encapsulated in an UPLINK NAS TRANSPORT message.	–>	NAS: UPLINK NAS TRANSPORT	–	–
10	The SS transmits DEACTIVATE TEST MODE message to deactivate the test mode H.	<–	RRC: DLInformationTransfer TC: DEACTIVATE TEST MODE	–	–
11	The UE transmits an DEACTIVATE TEST MODE COMPLETE message.	–>	RRC: ULInformationTransfer TC: DEACTIVATE TEST MODE COMPLETE	–	–
12	The SS transmits an RRCConnectionRelease message.	<–	RRCConnectionRelease	–	–

23.1.2.3.3 Specific message contents

Table 23.1.2.3.3-1: SystemInformationBlockType2 (preamble and all steps Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.4.3.3-1
Information Element	Value/remark	Comment	Condition
SystemInformationBlockType2 ::= SEQUENCE {
cIoT-EPS-OptimisationInfo-r13 SEQUENCE (SIZE (1.. maxPLMN-r11)) OF SEQUENCE {
up-CIoT-EPS-Optimisation-r13	false
}

Table 23.1.2.3.3-2: Message CLOSE UE TEST LOOP (step 1, Table 23.1.2.3.2-1)

Derivation path: TS 36.508 [18], table 4.7A-3
Information Element	Value/Remark	Comment	Condition
UE test loop mode	‘00000111’B	UE test loop mode H setup (SMS)
Operation mode and repetitions
M0	‘0’B	data is returned in uplink at the SMC SAP
R6..R0	‘0000010’B	2 The received DL message in uplink shall be looped back 2 times
Uplink data delay	‘00111100’B	T_delay_modeG timer=60 sec 0..255 seconds (binary coded, T7 is most significant bit and T0 least significant bit)

Table 23.1.2.3.3-3: Message DOWNLINK NAS TRANSPORT (step 3, Table 23.1.2.3.2-1)

Derivation path: TS 36.508 [18], Table 4.7.2-12A
Information Element	Value/Remark	Comment	Condition
NAS message container	An arbitrary value	Short message protocol message (i.e. CP-DATA) as defined in subclause 7.2 in 3GPP TS 24.011 [54] carrying a TPDU. (Note 1)
NOTE 1: TP-User-Data (SMS user data) in a downlink TPDU (SMS-DELIVER) as defined in subclause 5.1 in TS 36.509 [25].

Table 23.1.2.3.3-4: Message UPLINK NAS TRANSPORT (step 9, Table 23.1.2.3.2-1)

Derivation path: TS 36.508 [18], Table 8.2.30
Information Element	Value/Remark	Comment	Condition
NAS message container	The same TP-User-Data (Note 1) sent in DOWNLINK NAS TRANSPORT Table 23.1.2.3.2-1
NOTE 1: TP-User-Data (SMS user data) in an uplink TPDU (SMS-SUBMIT) as defined in subclause 5.1 in TS 36.509 [25].

Table 23.1.2.3.3-5: Message DOWNLINK NAS TRANSPORT (step 3, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-12A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-DATA

Table 23.1.2.3.3-6: Message CP-DATA (step 3, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 6.6A.1-2
Information Element	Value/remark	Comment	Condition
CP-User data	RP-DATA

Table 23.1.2.3.3-7: Message UPLINK NAS TRANSPORT (step 3A, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-27A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-ACK

Table 23.1.2.3.3-8: Message UPLINK NAS TRANSPORT (step 3B, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-27A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-DATA

Table 23.1.2.3.3-9: Message CP-DATA (step 3B, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 6.6A.1-2
Information Element	Value/remark	Comment	Condition
CP-User data	RP-ACK

Table 23.1.2.3.3-10: Message DOWNLINK NAS TRANSPORT (step 3C, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-12A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-ACK

Table 23.1.2.3.3-11: Message UPLINK NAS TRANSPORT (steps 8, 9, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-27A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-DATA

Table 23.1.2.3.3-12: Message CP-DATA (steps 8, 9, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 6.6A.1-2
Information Element	Value/remark	Comment	Condition
CP-User data	RP-DATA

Table 23.1.2.3.3-13: Message DOWNLINK NAS TRANSPORT (steps 8B, 9A, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-12A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-ACK

Table 23.1.2.3.3-14: Message DOWNLINK NAS TRANSPORT (steps 8C, 9B, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-12A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-DATA

Table 23.1.2.3.3-15: Message CP-DATA (steps 8C, 9B, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 6.6A.1-2
Information Element	Value/remark	Comment	Condition
CP-User data	RP-ACK

Table 23.1.2.3.3-16: Message UPLINK NAS TRANSPORT (steps 8D, 9C, Table 23.1.2.3.2-1)

Derivation Path: 36.508 clause 4.7.2-27A
Information Element	Value/remark	Comment	Condition
NAS message container	CP-ACK

23.1.3 CIoT Optimization / Control Plane / EDT

23.1.3.1 Test Purpose (TP)

(1)

with { UE with CIoT Optimization with EDT supported in IDLE }

ensure that {

when { when EDT data is triggered }

then { transmits an RRCEarlyDataRequest message, including CONTROL PLANE SERVICE REQUEST message, with data service type="mobile originating request" and ESM DATA TRANSPORT including the data}

}

(2)

with { UE with CIoT Optimization with EDT supported and EDT initiated by transmitting an RRCEarlyDataRequest message}

ensure that {

when { when the network transmits RRCConnectionSetup message}

then { the UE transmits an RRCConnectionSetupComplete with the a zero length dedicatedInfoNAS IE}

}

23.1.3.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clauses 5.3.3.1b, 5.3.3.2, 5.3.3.3b, 5.3.3.3c, 5.3.3.4 and 5.3.3.4b. TS 24.301, clauses 5.6.1.2.2].

[TS 36.331 5.3.3.1b]

A BL UE, UE in CE or NB-IoT UE can initiate EDT when all of the following conditions are fulfilled:

1> for CP-EDT, the upper layers request establishment of an RRC connection, the UE supports CP-EDT, and SystemInformationBlockType2 (SystemInformationBlockType2-NB in NB-IoT) includes cp-EDT; or

1> for UP-EDT, the upper layers request resumption of an RRC connection, the UE supports UP-EDT, SystemInformationBlockType2 (SystemInformationBlockType2-NB in NB-IoT) includes up-EDT, and the UE has a stored value of the nextHopChainingCount provided in the RRCConnectionRelease message with suspend indication during the preceding suspend procedure;

1> the establishment or resumption request is for mobile originating calls and the establishment cause is mo-Data or mo-ExceptionData or delayTolerantAccess;

1> the establishment or resumption request is suitable for EDT as specified in TS 36.300 [9], clause 7.3b.1;

1> SystemInformationBlockType2 (SystemInformationBlockType2-NB in NB-IoT) includes edt-Parameters;

1> the size of the resulting MAC PDU including the total UL data is expected to be smaller than or equal to the TBS signalled in edt-TBS as specified in TS 36.321 [6], clause 5.1.1;

1> EDT fallback indication has not been received from lower layers for this establishment or resumption procedure;

NOTE 1: Upper layers request or resume an RRC connection. The interaction with NAS is up to UE implementation.

NOTE 2: It is up to UE implementation how the UE determines whether the size of UL data is suitable for EDT.

[TS 36.331 5.3.3.2]

The UE initiates the procedure when upper layers request establishment or resume of an RRC connection while the UE is in RRC_IDLE.

Except for NB-IoT, upon initiation of the procedure, the UE shall:

…..

1> if the UE is resuming an RRC connection from a suspended RRC connection:

2> initiate transmission of the RRCConnectionResumeRequest message in accordance with 5.3.3.3a;

1> else if the UE is resuming an RRC connection from RRC_INACTIVE:

2> set the variable pendingRnaUpdate to ‘FALSE’;

2> initiate transmission of the RRCConnectionResumeRequest message in accordance with 5.3.3.3a;

1> else:

2> if stored, discard the UE AS context, UE Inactive AS context and resumeIdentity;

2> release rrc-InactiveConfig, if configured;

2> if the UE is initiating CP-EDT in accordance with conditions in 5.3.3.1b:

3> initiate transmission of the RRCEarlyDataRequest message in accordance with 5.3.3.3b;

2> else:

3> initiate transmission of the RRCConnectionRequest message in accordance with 5.3.3.3;

[TS 36.331 5.3.3.3b]

The UE shall set the contents of RRCEarlyDataRequest message as follows:

1> set the s-TMSI to the value received from upper layers;

1> set the establishmentCause in accordance with the information received from upper layers;

1> if the UE is a NB-IoT UE:

2> if the UE supports DL channel quality reporting and cqi-Reporting is present in SystemInformationBlockType2-NB:

3> set the cqi-NPDCCH to include the latest results of the downlink channel quality measurements of the serving cell as specified in TS 36.133 [16];

NOTE: The downlink channel quality measurements may use measurement period T1 or T2, as defined in TS 36.133 [16]. In case period T2 is used the RRC-MAC interactions are left to UE implementation.

1> set the dedicatedInfoNAS to include the information received from upper layers;

The UE shall configure the lower layers to use EDT and submit the RRCEarlyDataRequest message to the lower layers for transmission.

[TS 36.331 5.3.3.3c]

Upon indication from lower layers that EDT is cancelled, the UE shall:

1> start or restart timer T300;

1> if the fallback is indicated by lower layers in response to the RRCEarlyDataRequest:

2> initiate transmission of RRCConnectionRequest message in accordance with 5.3.3.3;

[TS 36.331 5.3.3.4]

The UE shall:

….

1> set the content of RRCConnectionSetupComplete message as follows:

…

2> if the RRCConnectionSetup is received in response to RRCEarlyDataRequest:

3> set the dedicatedInfoNAS to a zero-length octet string;

2> else:

3> set the dedicatedInfoNAS to include the information received from upper layers;

…

[TS 36.331 5.3.3.4b]

The UE shall:

1> indicate to upper layers that the RRC connection has been established;

1> if stored, discard the cell reselection priority information provided by the idleModeMobilityControlInfo or inherited from another RAT;

1> if stored, discard the dedicated offset provided by the redirectedCarrierOffsetDedicated;

1> stop timer T300;

1> stop timer T302, if running;

1> stop timer T303, if running;

1> stop timer T305, if running;

1> stop timer T306, if running;

1> stop timer T308, if running;

1> perform the actions as specified in 5.3.3.7;

1> stop timer T320, if running;

1> stop timer T322, if running;

1> forward the dedicatedInfoNAS, if received, to the upper layers;

1> reset MAC and release the MAC configuration;

1> if the RRCEarlyDataComplete message includes redirectedCarrierInfo indicating redirection to geran; and

1> if upper layers indicate that redirect to GERAN without AS security is not allowed:

2> perform the actions upon leaving RRC_CONNECTED as specified in 5.3.12, with release cause ‘other’, upon which the procedure ends;

1> if the RRCEarlyDataComplete message includes idleModeMobilityControlInfo:

2> store the cell reselection priority information provided by the idleModeMobilityControlInfo;

2> if the t320 is included:

3> start timer T320, with the timer value set according to the value of t320;

1> else:

2> apply the cell reselection priority information broadcast in the system information;

1> for NB-IoT, if the RRCEarlyDataComplete message includes redirectedCarrierInfo:

2> if the redirectedCarrierOffsetDedicated is included in the redirectedCarrierInfo:

3> store the dedicated offset for the frequency in redirectedCarrierInfo;

3> start timer T322, with the timer value set according to the value of T322 in redirectedCarrierInfo;

1> if the extendedWaitTime is present; and

1> if the UE supports delay tolerant access or the UE is a NB-IoT UE:

2> forward the extendedWaitTime to upper layers;

indicate the release of the RRC connection to upper layers together with the release cause ‘other’, upon which the procedure ends;

[TS 24.301 5.6.1.2.2]

…

For case b in subclause 5.6.1.1,

– if the UE has pending IP or non-IP user data that is to be sent via the control plane radio bearers, the Control plane service type of the CONTROL PLANE SERVICE REQUEST message shall indicate "mobile originating request". The UE shall include an ESM DATA TRANSPORT message in the ESM message container IE. If the UE supports the CP-EDT (see 3GPP TS 36.300 [20]), the UE shall provide the CONTROL PLANE SERVICE REQUEST message in the NAS request to the lower layer to establish a RRC connection as specified in subclause 5.3.1.1.

…

23.1.3.3 Test description

23.1.3.3.1 Pre-test conditions

System Simulator:

– Cell 1.

– System information combination 1 as defined in TS 36.508 [18] clause 4.4.3.1 is used in Cell 1;

– TS 36.508 [18] condition CIoT-test apply

UE:

Control Plane Early Data Transmission is supported by the UE.

Preamble:

– The UE shall be in Registered, Idle Mode state (State 2 or 2-CE) according to TS 36.508 [18].

23.1.3.3.2 Test procedure sequence

Table 23.1.3.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	Trigger the UE to send Early Data. NOTE: It is FFS how this action is performed.	–	–	–	–
2	Check: Does the UE transmit an RRCEarlyDataRequest message and a CONTROL PLANE SERVICE REQUEST message containing user data encapsulated in an ESM DATA TRANSPORT message included in the ESM message container IE?	–>	RRC: RRCEarlyDataRequest NAS: CONTROL PLANE SERVICE REQUEST NAS: ESM DATA TRANSPORT	1	P
3	The SS transmits an RRCEarlyDataComplete message.	<–	RRC: RRCEarlyDataComplete NAS: SERVICE ACCEPT	–	–
4	Trigger the UE to send Early Data. NOTE: It is FFS how this action is performed.	–	–	–	–
5	The UE transmits an RRCEarlyDataRequest message and a CONTROL PLANE SERVICE REQUEST message containing user data encapsulated in an ESM DATA TRANSPORT message included in the ESM message container IE.	–>	RRCEarlyDataRequest NAS: CONTROL PLANE SERVICE REQUEST NAS: ESM DATA TRANSPORT	–	–
6	The SS transmits an RRCConnectionSetup message.	<–	RRC: RRCConnectionSetup NAS: SERVICE ACCEPT	–	–
7	Check: Does the UE transmit an RRCConnectionSetupComplete Message including a zero length dedicatedInfoNAS IE	–>	RRC: RRCConnectionSetupComplete	2	P
8	The SS transmits an RRCConnectionRelease message.	<–	RRC: RRCConnectionRelease	–	–

23.1.3.3.3 Specific message contents

Table 23.1.3.3.3-1: SystemInformationBlockType2 (preamble and all steps Table 23.1.3.3.2-1)

Derivation Path: 36.508 clause 4.4.3.3-1
Information Element	Value/remark	Comment	Condition
SystemInformationBlockType2 ::= SEQUENCE {
cIoT-EPS-OptimisationInfo-r13 SEQUENCE (SIZE (1.. maxPLMN-r11)) OF SEQUENCE {
up-CIoT-EPS-Optimisation-r13	false
}
cp-EDT-r15	true

Table 23.1.3.3.3-2: Message RRCEarlyDataRequest (steps 2 and 5, Table 23.1.3.3.2-1)

Derivation path: TS 36.331 [17], clause 6.2.2
Information Element	Value/Remark	Comment	Condition
RRCEarlyDataRequest-r15 ::= SEQUENCE {
criticalExtensions CHOICE {
rrcEarlyDataRequest-r15 SEQUENCE {
s-TMSI-r15	Any allowed value
establishmentCause-r15	mo-Data
dedicatedInfoNAS-r15	CONTROL PLANE SERVICE REQUEST message in Table 23.1.3.3.3-3
}
}
}

Table 23.1.3.3.3-3: Message CONTROL PLANE SERVICE REQUEST (steps 2 and 5, Table 23.1.3.3.2-1)

Derivation path: TS 36.508 [18], Table 4.7.2-28.
Information Element	Value/Remark	Comment	Condition
Control plane service type	‘000’B	mobile originating request
ESM message container	ESM DATA TRANSPORT message in Table 23.1.3.3.3-4
EPS bearer context status	Not present

Table 23.1.3.3.3-4: Message ESM DATA TRANSPORT (steps 2 and 5, Table 23.1.3.3.2-1)

Derivation path: TS 36.508 [18], table 4.7.3-12A.
Information Element	Value/Remark	Comment	Condition
User data container	Any non-zero length data

Table 23.1.3.3.3-5: RRCEarlyDataComplete (step 3, Table 23.1.3.3.2-1)

Derivation path: TS 36.331 [17], clause 6.2.2
Information Element	Value/Remark	Comment	Condition
RRCEarlyDataComplete-r15 ::= SEQUENCE {
criticalExtensions CHOICE {
rrcEarlyDataRequest-r15 SEQUENCE {
dedicatedInfoNAS-r15	SERVICE ACCEPT message according to TS 36.508 [18], Table 4.7.2-21A
}
}
}

Table 23.1.3.3.3-6: Message RRCConnectionSetupComplete (steps 7, Table 23.1.3.3.2-1)

Derivation path: TS 36.508 [18], table 4.6.1-18
Information Element	Value/Remark	Comment	Condition
RRCConnectionSetupComplete ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE {
rrcConnectionSetupComplete-r8 SEQUENCE {
dedicatedInfoNAS	Zero length octet string
}
}
}
}

23.2 User Plane

23.2.1 CIoT Optimization / User Plane

23.2.1.1 Test Purpose (TP)

(1)

with { UE with CIoT Optimization and with User Plane data configured, with RRC Connection suspended }

ensure that {

when { MT data transfer is triggered }

then { performs resumption of a suspended RRC connection by transmitting RRCConnectionResumeRequest, transit to RRC_CONNECTED state and receives the downlink data }

}

(2)

with { UE with CIoT Optimization and with User Plane data configured, with RRC Connection suspended }

ensure that {

when { MO data transfer is triggered }

then { performs resumption of a suspended RRC connection by transmitting RRCConnectionResumeRequest, transit to RRC_CONNECTED state and transmits the uplink data }

}

23.2.1.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clauses 5.3.1.1, and 5.3.12.

[TS 36.331, clause 5.3.1.1]

RRC connection establishment involves the establishment of SRB1. E-UTRAN completes RRC connection establishment prior to completing the establishment of the S1 connection, i.e. prior to receiving the UE context information from the EPC. Consequently, AS security is not activated during the initial phase of the RRC connection. During this initial phase of the RRC connection, the E-UTRAN may configure the UE to perform measurement reporting, but the UE only sends the corresponding measurement reports after successful security activation. However, the UE only accepts a handover message when security has been activated.

NOTE: In case the serving frequency broadcasts multiple overlapping bands, E-UTRAN can only configure measurements after having obtained the UE capabilities, as the measurement configuration needs to be set according to the band selected by the UE.

Upon receiving the UE context from the EPC, E-UTRAN activates security (both ciphering and integrity protection) using the initial security activation procedure. The RRC messages to activate security (command and successful response) are integrity protected, while ciphering is started only after completion of the procedure. That is, the response to the message used to activate security is not ciphered, while the subsequent messages (e.g. used to establish SRB2 and DRBs) are both integrity protected and ciphered.

After having initiated the initial security activation procedure, E-UTRAN initiates the establishment of SRB2 and DRBs, i.e. E-UTRAN may do this prior to receiving the confirmation of the initial security activation from the UE. In any case, E-UTRAN will apply both ciphering and integrity protection for the RRC connection reconfiguration messages used to establish SRB2 and DRBs. E-UTRAN should release the RRC connection if the initial security activation and/ or the radio bearer establishment fails (i.e. security activation and DRB establishment are triggered by a joint S1-procedure, which does not support partial success).

For SRB2 and DRBs, security is always activated from the start, i.e. the E-UTRAN does not establish these bearers prior to activating security.

For some radio configuration fields, a critical extension has been defined. A switch from the original version of the field to the critically extended version is allowed using any connection reconfiguration. The UE reverts to the original version of some critically extended fields upon handover and re-establishment as specified elsewhere in this specification. Otherwise, switching a field from the critically extended version to the original version is only possible using the handover or re-establishment procedure with the full configuration option. This also applies for fields that are critically extended within a release (i.e. original and extended version defined in same release).

After having initiated the initial security activation procedure, E-UTRAN may configure a UE that supports CA, with one or more SCells in addition to the PCell that was initially configured during connection establishment. The PCell is used to provide the security inputs and upper layer system information (i.e. the NAS mobility information e.g. TAI). SCells are used to provide additional downlink and optionally uplink radio resources. When not configured with DC all SCells the UE is configured with, if any, are part of the MCG. When configured with DC however, some of the SCells are part of a SCG. In this case, user data carried by a DRB may either be transferred via MCG (i.e. MCG-DRB), via SCG (SCG-DRB) or via both MCG and SCG in DL while E-UTRAN configures the CG used in UL (split DRB). An RRC connection reconfiguration message may be used to change the DRB type from MCG-DRB to SCG-DRB or to split DRB, as well as from SCG-DRB or split DRB to MCG-DRB.

SCG change is a synchronous SCG reconfiguration procedure (i.e. involving RA to the PSCell) including reset/ re-establishment of layer 2 and, if SCG DRBs are configured, refresh of security. The procedure is used in a number of different scenarios e.g. SCG establishment, PSCell change, Key refresh, change of DRB type. The UE performs the SCG change related actions upon receiving an RRCConnectionReconfiguration message including mobilityControlInfoSCG, see clause 5.3.10.10.

The release of the RRC connection normally is initiated by E-UTRAN. The procedure may be used to re-direct the UE to an E-UTRA frequency or an inter-RAT carrier frequency. Only in exceptional cases, as specified within this specification, TS 36.300 [9], TS 36.304 [4] or TS 24.301 [35], may the UE abort the RRC connection, i.e. move to RRC_IDLE without notifying E-UTRAN.

The suspension of the RRC connection is initiated by E-UTRAN. When the RRC connection is suspended, the UE stores the UE AS context and the resumeIdentity, and transitions to RRC_IDLE state. The RRC message to suspend the RRC connection is integrity protected and ciphered. Suspension can only be performed when at least 1 DRB is successfully established.

The resumption of a suspended RRC connection is initiated by upper layers when the UE has a stored UE AS context, RRC connection resume is permitted by E-UTRAN and the UE needs to transit from RRC_IDLE state to RRC_CONNECTED state. When the RRC connection is resumed, RRC configures the UE according to the RRC connection resume procedure based on the stored UE AS context and any RRC configuration received from E-UTRAN. The RRC connection resume procedure re-activates security and re-establishes SRB(s) and DRB(s). The request to resume the RRC connection includes the resumeIdentity. The request is not ciphered, but protected with a message authentication code.

In response to a request to resume the RRC connection, E-UTRAN may resume the suspended RRC connection, reject the request to resume and instruct the UE to either keep or discard the stored context, or setup a new RRC connection.

[TS 36.331, clause 5.3.3.3a]

The UE shall set the contents of RRCConnectionResumeRequest message as follows:

1> if the UE is a NB-IoT UE; or

1> if field useFullResumeID is signalled in SystemInformationBlockType2:

2> set the resumeID to the stored resumeIdentity;

1> else

2> set the truncatedResumeID to include bits in bit position 9 to 20 and 29 to 40 from the left in the stored resumeIdentity.

if the UE supports mo-VoiceCall establishment cause and UE is resuming the RRC connection for mobile originating MMTEL voice and SystemInformationBlockType2 includes voiceServiceCauseIndication:

2> set the resumeCause to mo-VoiceCall;

1> else

2> set the resumeCause in accordance with the information received from upper layers;

1> set the shortResumeMAC-I to the 16 least significant bits of the MAC-I calculated:

2> over the ASN.1 encoded according to clause 8 (i.e., a multiple of 8 bits) VarShortResumeMAC-Input (or VarShortResumeMAC-Input-NB in NB-IoT);

2> with the K_RRCint key and the previously configured integrity protection algorithm; and

2> with all input bits for COUNT, BEARER and DIRECTION set to binary ones;

1> restore the RRC configuration and security context from the stored UE AS context:

1> restore the PDCP state and re-establish PDCP entities for SRB1;

1> resume SRB1;

NOTE: Until successful connection resumption, SRB1 is used only for transferring the RRCConnectionResume message.

The UE shall submit the RRCConnectionResumeRequest message to lower layers for transmission.

The UE shall continue cell re-selection related measurements as well as cell re-selection evaluation. If the conditions for cell re-selection are fulfilled, the UE shall perform cell re-selection as specified in clause 5.3.3.5.

23.2.1.3 Test description

23.2.1.3.1 Pre-test conditions

System Simulator:

– Cell 1.

– System information combination 1 as defined in TS 36.508 [18] clause 4.4.3.1 is used in Cell 1;

UE:

User Plane CIoT Optimisation is supported by UE (UE capability), pc_User_Plane_CIoT_Optimisation.

Preamble:

– The UE shall be in Loopback Activation state 4A-UP using the UE TEST LOOP MODE B and with IP_PDU_delay set to 10 seconds.

23.2.1.3.2 Test procedure sequence

Table 23.2.1.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	The SS transmits an RRCConnectionRelease message including resumeIdentity and rrc-Suspend as releaseCause.	<–	RRC: RRCConnectionRelease	–	–
2	The SS transmits a Paging message including a matched identity.	<–	RRC: Paging	–	–
3	Check: Does the UE transmit an RRCConnectionResumeRequest message including the resumeIdentity and AS security context stored at Step 1?	–>	RRC: RRCConnectionResumeRequest	1	P
4	The SS transmits an RRCConnectionResume message.	<–	RRC: RRCConnectionResume	–	–
5	The UE transmits an RRCConnectionResumeComplete message.	–>	RRC: RRCConnectionResumeComplete	–	–
6	The SS transmits one IP packet to the UE on the DRB associated with the default EPS bearer context on Cell 1.	<–	IP packet	–	–
7	The SS transmits an RRCConnectionRelease message including a new resumeIdentity and rrc-Suspend as releaseCause.	<–	RRCConnectionRelease	–	–
8	Check: Does the UE transmit an RRCConnectionResumeRequest message including the resumeIdentity and AS security context stored at Step 7?	–>	RRC: RRCConnectionResumeRequest	2	P
9	The SS transmits an RRCConnectionResume message.	<–	RRC: RRCConnectionResume	–	–
10	The UE transmits an RRCConnectionResumeComplete message.	–>	RRC: RRCConnectionResumeComplete	–	–
11	The UE loops back the IP packet received in Step 6 on the DRB associated with the default EPS bearer context on Cell 1.	–>	IP packet	–	–

23.2.1.3.3 Specific message contents

Table 23.2.1.3.3-1: RRCConnectionRelease (step 1 and 7, table 23.2.1.3.2-1)

Derivation Path: 36.331 clause 6.2.2
Information Element	Value/remark	Comment	Condition
RRCConnectionRelease ::= SEQUENCE {
rrc-TransactionIdentifier	RRC-TransactionIdentifier-DL
criticalExtensions CHOICE {
c1 CHOICE {
rrcConnectionRelease-r8 SEQUENCE {
releaseCause	rrc-Suspend-v1320
redirectedCarrierInfo	Not present
idleModeMobilityControlInfo	Not present
nonCriticalExtension SEQUENCE {
nonCriticalExtension SEQUENCE {
nonCriticalExtension SEQUENCE {
nonCriticalExtension SEQUENCE {
resumeIdentity-r13	BIT STRING (SIZE(40))	Any value; Different value in step 1 and 7
}
}
}
}
}
}
}
}
}

Table 23.2.1.3.3-2: RRCConnectionResumeRequest (step 3, Table 23.2.1.3.2-1)

Derivation Path: 36.331 clause 6.2.2
Information Element	Value/remark	Comment	Condition
RRCConnectionResumeRequest ::= SEQUENCE {
criticalExtensions CHOICE {
rrcConnectionResumeRequest-r13 SEQUENCE {
resumeIdentity-r13 CHOICE {
truncatedResumeID	BIT STRING (SIZE(24))	Same value as Step 1 include bits in bit position 9 to 20 and 29 to 40 from the left
}
resumeMAC-I-r13	The same value as the 16 least significant bits of the MAC-I value calculated by SS.
resumeCause-r13	mt-Access
spare	Present but contents not checked
}
}
}

Table 23.2.1.3.3-3: RRCConnectionResumeRequest (step 8, Table 23.2.1.3.2-1)

Derivation Path: 36.331 clause 6.2.2
Information Element	Value/remark	Comment	Condition
RRCConnectionResumeRequest ::= SEQUENCE {
criticalExtensions CHOICE {
rrcConnectionResumeRequest-r13 SEQUENCE {
resumeIdentity-r13 CHOICE {
truncatedResumeID	BIT STRING (SIZE(24))	Same value as Step 7, include bits in bit position 9 to 20 and 29 to 40 from the left
}
resumeMAC-I-r13	The same value as the 16 least significant bits of the MAC-I value calculated by SS.
resumeCause-r13	mo-Data
spare	Present but contents not checked
}
}
}

23.2.2 CIoT / RRC connection suspend-resume / Success / different cell

23.2.2.1 Test Purpose (TP)

(1)

with { UE in RRC_IDLE state when the RRC connection is suspended }

ensure that {

when { UE detects the cell ranked as the best cell }

then { UE reselects the new cell and transmits an RRCConnectionResumeRequest message }

}

23.2.2.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clauses 5.3.3.2.

[TS 36.331, clause 5.3.3.2]

The UE initiates the procedure when upper layers request establishment or resume of an RRC connection while the UE is in RRC_IDLE.

Except for NB-IoT, upon initiation of the procedure, the UE shall:

…

1> if the UE is resuming an RRC connection:

2> initiate transmission of the RRCConnectionResumeRequest message in accordance with 5.3.3.3a;

23.2.2.3 Test description

23.2.2.3.1 Pre-test conditions

System Simulator:

– Cell 1 and Cell 2.

– System information combination 1 as defined in TS 36.508 [18] clause 4.4.3.1 is used in Cell 1;

UE:

None.

Preamble:

– UE is in State 3-UP, User Plane CIoT connection request according to TS 36.508 [18].

23.2.2.3.2 Test procedure sequence

Table 23.2.2.3.2-1 illustrates the downlink power levels and other changing parameters to be applied for the cells at various time instants of the test execution. The configuration marked "T1" is applied at the point indicated in the Main behaviour description in Table 23.2.2.3.2-2.

Table 23.2.2.3.2-1: Time instances of cell power level and parameter changes

	Parameter	Unit	Cell 1	Cell 2	Remark
T1	Cell-specific RS EPRE	dBm/15kHz	-85	-79	The power level values are assigned to satisfy R_{Cell 1} < R_{Cell 2.}

Table 23.2.2.3.2-2: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	The SS transmits an RRCConnectionRelease message including rrc-Suspend as releaseCause.	<–	RRC: RRCConnectionRelease	–	–
2	The SS changes Cell 2 level according to the row "T1" in table 23.2.2.3.2-1.	–	–	–	–
3	Check: Does the test result of generic test procedure in TS 36.508 subclause 6.4.2.7B indicate that the UE is camped on E-UTRAN Cell 2?	–	–	1	–

23.2.2.3.3 Specific message contents

Table 23.2.2.3.3-1: RRCConnectionRelease (step 1, table 23.2.2.3.2-2)

Derivation Path: 36.508, Table 4.6.1-15, condition UP-CIoT

23.2.3 CIoT / RRC connection suspend-resume / Network reject / different cell

23.2.3.1 Test Purpose (TP)

(1)

with { UE in RRC_IDLE state when the RRC connection is suspended }

ensure that {

when { UE receives an RRCConnectionReject with rrc-SuspendIndication }

then { UE restarts the ongoing NAS procedure and transmits an RRCConnectionResumeRequest message }

}

23.2.3.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.331, clauses 5.3.3.8 and TS 24.301, clause 5.3.1.3.

[TS 36.331, clause 5.3.3.8]

1> if the RRCConnectionReject is received in response to an RRCConnectionResumeRequest:

2> if the rrc-SuspendIndication is not present:

3> discard the stored UE AS context and resumeIdentity;

3> inform upper layers about the failure to resume the RRC connection without suspend indication and that access barring for mobile originating calls, mobile originating signalling, mobile terminating access and except for NB-IoT for mobile originating CS fallback is applicable, upon which the procedure ends;

2> else:

3> suspend SRB1;

3> inform upper layers about the failure to resume the RRC connection with suspend indication and that access barring for mobile originating calls, mobile originating signalling, mobile terminating access and except for NB-IoT for mobile originating CS fallback is applicable, upon which the procedure ends;

[TS 24.301, clause 5.3.1.3]

Suspend of the NAS signalling connection can be initiated by the network in EMM-CONNECTED mode when user plane CIoT EPS optimization is used. Resume of the suspended NAS signalling connection is initiated by the UE.

In the UE, when user plane CIoT EPS optimization is used:

…

– Upon indication from the lower layers that the RRC connection resume has failed and indication from the lower layers that the RRC connection is suspended, the UE shall enter EMM-IDLE mode with suspend indication and restart the ongoing NAS procedure if required; and

– Upon indication from the lower layers that the RRC connection resume has failed and indication from the lower layers that the RRC connection is not suspended, the UE shall enter EMM-IDLE mode without suspend indication and restart the ongoing NAS procedure if required.

23.2.3.3 Test description

23.2.3.3.1 Pre-test conditions

System Simulator:

– Cell 1 and Cell 2.

– System information combination 1 as defined in TS 36.508 [18] clause 4.4.3.1 is used in Cell 1;

UE:

None.

Preamble:

– UE is in State 3-UP, User Plane CIoT connection request according to TS 36.508 [18].

23.2.3.3.2 Test procedure sequence

Table 23.2.3.3.2-1 illustrates the downlink power levels and other changing parameters to be applied for the cells at various time instants of the test execution. The configuration marked "T1" is applied at the point indicated in the Main behaviour description in Table 23.2.3.3.2-2.

Table 23.2.3.3.2-1: Time instances of cell power level and parameter changes

	Parameter	Unit	Cell 1	Cell 2	Remark
T1	Cell-specific RS EPRE	dBm/15kHz	-85	-79	The power level values are assigned to satisfy R_{Cell 1} < R_{Cell 2.}

Table 23.2.3.3.2-2: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	The SS transmits an RRCConnectionRelease message including rrc-Suspend as releaseCause.	<–	RRC: RRCConnectionRelease	–	–
2	The SS changes Cell 2 level according to the row "T1" in table 23.2.3.3.2-1.	–	–	–	–
3	The UE transmits an RRCConnectionResumeRequest message.	–>	RRC: RRCConnectionResumeRequest	–	–
4	The SS responds with RRCConnectionReject message including rrc-SuspendIndication IE.	<–	RRC: RRCConnectionReject	–	–
5	Check: Does the test result of generic test procedure in TS 36.508 subclause 6.4.2.7B indicate that the UE is camped on E-UTRAN Cell 2?	–	–	1	–

23.2.3.3.3 Specific message contents

Table 23.2.3.3.3-1: RRCConnectionRelease (step 1, table 23.2.3.3.2-2)

Derivation Path: 36.508, Table 4.6.1-15, condition UP-CIoT

Table 23.2.3.3.3-2: RRCConnectionReject (step 4, table 23.2.3.3.2-2)

Derivation Path: 36.508, table 4.6.1-14.
Information Element	Value/remark	Comment	Condition
RRCConnectionReject ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE {
rrcConnectionReject-r8 SEQUENCE {
nonCriticalExtension SEQUENCE {
nonCriticalExtension SEQUENCE {
nonCriticalExtension SEQUENCE {
nonCriticalExtension SEQUENCE {
rrc-SuspendIndication-r13	True
nonCriticalExtension SEQUENCE {}	Not present
}
}
}
}
}
}
}
}

23.2.4 CIoT Optimization / User Plane / EDT

23.2.4.1 Test Purpose (TP)

(1)

with { UE with CIoT Optimization and with UP-EDT supported, with RRC Connection suspended }

ensure that {

when { EDT data transfer is triggered }

then { performs resumption of a suspended RRC connection by transmitting RRCConnectionResumeRequest and transfer the EDT user data on DTCH multiplexed with the RRCConnectionResumeRequest message on CCCH. }

}

(2)

with { UE with UP-EDT supported initiated by sending RRCConnectionResumeRequest }

ensure that {

when { UE receives the RRCConnectionResume message }

then { performs UP-EDT fallback by sending the RRCConnectionResumeComplete message }

}

23.2.4.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: TS 36.300, clause 7.3b.3, TS 36.331, clause 5.3.1.1, 5.3.3.1b and 5.3.3.3a.

[TS 36.331, clause 5.3.1.1]

…

In case of CP-EDT, the data are appended in the RRCEarlyDataRequest and RRCEarlyDataComplete messages, if available, and sent over SRB0. In case of UP-EDT, security is re-activated prior to transmission of RRC message using the nextHopChainingCount provided in the RRCConnectionRelease message with suspend indication during the preceding suspend procedure and the radio bearers are re-established. The uplink data are transmitted ciphered on DTCH multiplexed with the RRCConnectionResumeRequest message on CCCH. In the downlink, the data, if available, are transmitted on DTCH multiplexed with the RRCConnectionRelease message on DCCH. In response to a request for EDT, E-UTRAN may also choose to establish or resume the RRC connection.

…

[TS 36.331, clause 5.3.3.1b]