7.3.1 Maintenance of PDCP sequence numbers for radio bearers

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

7.3.1.1 Maintenance of PDCP sequence numbers / User plane / RLC AM

7.3.1.1.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE transmits a PDCP Data SDU on a DRB mapped on AM RLC }

then { UE increments SN with 1 for each transmitted PDU for SN=0 to Maximum_PDCP_SN }

}

(2)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE transmits a PDCP Data SDU on a DRB mapped on AM RLC and, after incrementation, Next_PDCP_TX_SN is larger than the Maximum_PDCP_SN }

then { UE sets SN to 0 in the next transmitted PDCP SDU}

}

7.3.1.1.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: 3GPP TS 36.323 clause 5.1.1, 5.1.2.2 and 6.2.3.

[TS 36.323, clause 5.1.1]

At reception of a PDCP SDU from upper layers, the UE shall:

– discardTimerstart the associated with this PDCP SDU (if configured);

For a PDCP SDU received from upper layers, the UE shall:

– associate the PDCP SN corresponding to Next_PDCP_TX_SN to this PDCP SDU;

– perform header compression of the PDCP SDU (if configured) as specified in the subclause 5.5.4;

– perform integrity protection (if applicable), and ciphering (if applicable) using COUNT based on TX_HFN and the PDCP SN associated with this PDCP SDU as specified in the subclause 5.7 and 5.6, respectively;

– increment Next_PDCP_TX_SN by one;

– if Next_PDCP_TX_SN > Maximum_PDCP_SN:

– set Next_PDCP_TX_SN to 0;

– increment TX_HFN by one;

– submit the resulting PDCP Data PDU to lower layer.

[TS 36.323, clause 5.1.2.1.2]

For DRBs mapped on RLC AM, at reception of a PDCP Data PDU from lower layers, the UE shall:

– if received PDCP SN – Last_Submitted_PDCP_RX_SN > Reordering_Window or 0 <= Last_Submitted_PDCP_RX_SN – received PDCP SN < Reordering_Window:

– if received PDCP SN > Next_PDCP_RX_SN:

– decipher the PDCP PDU as specified in the subclause 5.6, using COUNT based on RX_HFN – 1 and the received PDCP SN;

– else:

– decipher the PDCP PDU as specified in the subclause 5.6, using COUNT based on RX_HFN and the received PDCP SN;

– perform header decompression (if configured) as specified in the subclause 5.5.5;

– discard this PDCP SDU;

– else if Next_PDCP_RX_SN – received PDCP SN > Reordering_Window:

– increment RX_HFN by one;

– use COUNT based on RX_HFN and the received PDCP SN for deciphering the PDCP PDU;

– set Next_PDCP_RX_SN to the received PDCP SN + 1;

– else if received PDCP SN – Next_PDCP_RX_SN > =Reordering_Window:

– use COUNT based on RX_HFN – 1 and the received PDCP SN for deciphering the PDCP PDU;

– else if received PDCP SN >= Next_PDCP_RX_SN:

– use COUNT based on RX_HFN and the received PDCP SN for deciphering the PDCP PDU;

– set Next_PDCP_RX_SN to the received PDCP SN + 1;

– if Next_PDCP_RX_SN is larger than Maximum_PDCP_SN:

– set Next_PDCP_RX_SN to 0;

– increment RX_HFN by one;

– else if received PDCP SN < Next_PDCP_RX_SN:

– use COUNT based on RX_HFN and the received PDCP SN for deciphering the PDCP PDU;

– if the PDCP PDU has not been discarded in the above:

– perform deciphering and header decompression (if configured) for the PDCP PDU as specified in the subclauses 5.6 and 5.5.5, respectively;

– if a PDCP SDU with the same PDCP SN is stored:

– discard this PDCP SDU;

– else:

– store the PDCP SDU;

– if the PDCP PDU received by PDCP is not due to the re-establishment of lower layers:

– deliver to upper layers in ascending order of the associated COUNT value:

– all stored PDCP SDU(s) with an associated COUNT value less than the COUNT value associated with the received PDCP SDU;

– all stored PDCP SDU(s) with consecutively associated COUNT value(s) starting from the COUNT value associated with the received PDCP SDU;

– set Last_Submitted_PDCP_RX_SN to the PDCP SN of the last PDCP SDU delivered to upper layers;

– else if received PDCP SN = Last_Submitted_PDCP_RX_SN + 1 or received PDCP SN = Last_Submitted_PDCP_RX_SN – Maximum_PDCP_SN:

– deliver to upper layers in ascending order of the associated COUNT value:

– all stored PDCP SDU(s) with consecutively associated COUNT value(s) starting from the COUNT value associated with the received PDCP SDU;

– set Last_Submitted_PDCP_RX_SN to the PDCP SN of the last PDCP SDU delivered to upper layers.

[TS 36.323, clause 6.2.3]

Figure 6.2.3.1 shows the format of the PDCP Data PDU when a 12 bit SN length is used. This format is applicable for PDCP Data PDUs carrying data from DRBs mapped on RLC AM or RLC UM.

Figure 6.2.3.1: PDCP Data PDU format for DRBs using a 12 bit SN

7.3.1.1.3 Test description

7.3.1.1.3.1 Pre-test conditions

System Simulator

– Cell 1

– SS PDCP set to Transparent Mode

UE:

None.

Preamble

– The UE is in state Loopback Activated (state 4) according to [18].

7.3.1.1.3.2 Test procedure sequence

Table 7.3.1.1.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
–	EXCEPTION: Steps 1 and 2 shall be repeated for k=0 to Maximum_PDCP_SN (increment=1).
1	SS transmits a PDCP Data PDU on DRB1 containing one IP packet without header compression.	<–	PDCP Data PDU (SN = k)
2	CHECK: Does UE transmit a PDCP Data PDU with SN=0 for the first iteration and then incremented by 1 at each iteration?	–>	PDCP Data PDU (SN = k)	1	P
3	SS transmits a PDCP Data PDU on DRB1 containing one IP packet without header compression.	<–	PDCP Data PDU (SN = 0)
4	CHECK: Does UE transmit a PDCP Data PDU with SN=0?	–>	PDCP Data PDU (SN = 0)	2	P
5	SS sends a PDCP Data PDU on DRB1 containing one IP packet without header compression.	<–	PDCP Data PDU (SN = 1)
6	CHECK: Does UE transmit a PDCP Data PDU with SN=1?	–>	PDCP Data PDU (SN = 1)	1	P

7.3.1.1.3.3 Specific message contents

None

7.3.1.2 Maintenance of PDCP sequence numbers / User plane / RLC UM / Short PDCP SN (7 bits)

7.3.1.2.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE transmits a PDCP Data SDU on a DRB mapped on UM RLC and configured for short PDCP SN size (7 bits)}

then { UE increments SN with 1 for each transmitted PDU for SN=0 to Maximum_PDCP_SN }

}

(2)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE transmits a PDCP Data SDU on a DRB mapped on UM RLC and configured for short PDCP SN size (7 bits); and, after incrementation, Next_PDCP_TX_SNis larger than the Maximum_PDCP_SN }

then { UE sets SN to 0 in the next transmitted PDCP SDU}

}

7.3.1.2.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: 3GPP TS 36.323 clause 5.1.1 , 5.1.2.1.3 and 6.2.4.

[TS 36.323, clause 5.1.1]

At reception of a PDCP SDU from upper layers, the UE shall:

– start the discardTimer associated with this PDCP SDU (if configured);

For a PDCP SDU received from upper layers, the UE shall:

– associate the PDCP SN corresponding to Next_PDCP_TX_SN to this PDCP SDU;

– perform header compression of the PDCP SDU (if configured) as specified in the subclause 5.5.4;

– increment Next_PDCP_TX_SN by one;

– if Next_PDCP_TX_SN > Maximum_PDCP_SN:

– set Next_PDCP_TX_SN to 0;

– increment TX_HFN by one;

– submit the resulting PDCP Data PDU to lower layer.

[TS 36.323, clause 5.1.2.1.3]

For DRBs mapped on RLC UM, at reception of a PDCP Data PDU from lower layers, the UE shall:

– if received PDCP SN < Next_PDCP_RX_SN:

– increment RX_HFN by one;

– decipher the PDCP Data PDU using COUNT based on RX_HFN and the received PDCP SN as specified in the subclause 5.6;

– set Next_PDCP_RX_SN to the received PDCP SN + 1;

– if Next_PDCP_RX_SN > Maximum_PDCP_SN:

– set Next_PDCP_RX_SN to 0;

– increment RX_HFN by one;

– perform header decompression (if configured) of the deciphered PDCP Data PDU as specified in the subclause 5.5.5;

– deliver the resulting PDCP SDU to upper layer.

[TS 36.323, clause 6.2.4]

Figure 6.2.4.1 shows the format of the PDCP Data PDU when a 7 bit SN length is used. This format is applicable for PDCP Data PDUs carrying data from DRBs mapped on RLC UM.

Figure 6.2.4.1: PDCP Data PDU format for DRBs using 7 bit SN

7.3.1.2.3 Test description

7.3.1.2.3.1 Pre-test conditions

System Simulator

– Cell 1

– SS PDCP set to Transparent Mode

UE:

None.

Preamble

– The UE is in state Loopback Activated (state 4) according to [18].

– The condition SRB2-DRB(1,1) is used for step 8 in 4.5.3A.3 according to [18].

7.3.1.2.3.2 Test procedure sequence

Table 7.3.1.2.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
–	EXCEPTION: Steps 1 and 2 shall be repeated for k=0 to Maximum_PDCP_SN (increment=1).
1	SS transmits a PDCP Data PDU on UM DRB containing one IP packet without header compression.	<–	PDCP Data PDU (SN = k)
2	CHECK: Does UE transmit a PDCP Data PDU with SN=0 for the first iteration and then incremented by 1 at each iteration?	–>	PDCP Data PDU (SN = k)	1	P
3	SS transmits a PDCP Data PDU on UM DRB containing one IP packet without header compression.	<–	PDCP Data PDU (SN = 0)
4	CHECK: Does UE transmit a PDCP Data PDU with SN=0?	–>	PDCP Data PDU (SN = 0)	2	P
5	SS sends a PDCP Data PDU on UM DRB containing one IP packet without header compression.	<–	PDCP Data PDU (SN = 1)
6	CHECK: Does UE transmit a PDCP Data PDU with SN=1?	–>	PDCP Data PDU (SN = 1)	1	P

7.3.1.2.3.3 Specific message contents

None

7.3.1.3 Maintenance of PDCP sequence numbers / User plane / RLC UM / Long PDCP SN (12 bits)

7.3.1.3.1 Test Purpose (TP)

(1)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE transmits a PDCP Data SDU on a DRB mapped on UM RLC and configured for long PDCP SN size (12 bits)}

then { UE increments SN with 1 for each transmitted PDU for SN=0 to Maximum_PDCP_SN }

}

(2)

with { UE in E-UTRA RRC_CONNECTED state }

ensure that {

when { UE transmits a PDCP Data SDU on a DRB mapped on UM RLC and configured for long PDCP SN size (12 bits); and, after incrementation, Next_PDCP_TX_SN is larger than the Maximum_PDCP_SN limit }

then { UE sets SN to 0 in the next transmitted PDCP SDU}

}

7.3.1.3.2 Conformance requirements

References: The conformance requirements covered in the present TC are specified in: 3GPP TS 36.323 clause 5.1.1 , 5.1.2.1.3 and 6.2.3.

[TS 36.323, clause 5.1.1]

At reception of a PDCP SDU from upper layers, the UE shall:

– start the discardTimer associated with this PDCP SDU (if configured);

For a PDCP SDU received from upper layers, the UE shall:

– associate the PDCP SN corresponding to Next_PDCP_TX_SN to this PDCP SDU;

– perform header compression of the PDCP SDU (if configured) as specified in the subclause 5.5.4;

– increment Next_PDCP_TX_SN by one;

– if Next_PDCP_TX_SN > Maximum_PDCP_SN:

– set Next_PDCP_TX_SN to 0;

– increment TX_HFN by one;

– submit the resulting PDCP Data PDU to lower layer.

[TS 36.323, clause 5.1.2.1.3]

For DRBs mapped on RLC UM, at reception of a PDCP Data PDU from lower layers, the UE shall:

– if received PDCP SN < Next_PDCP_RX_SN:

– increment RX_HFN by one;

– decipher the PDCP Data PDU using COUNT based on RX_HFN and the received PDCP SN as specified in the subclause 5.6;

– set Next_PDCP_RX_SN to the received PDCP SN + 1;

– if Next_PDCP_RX_SN > Maximum_PDCP_SN:

– set Next_PDCP_RX_SN to 0;

– increment RX_HFN by one;

– perform header decompression (if configured) of the deciphered PDCP Data PDU as specified in the subclause 5.5.5;

– deliver the resulting PDCP SDU to upper layer.

[TS 36.323, clause 6.2.3]

Figure 6.2.3.1 shows the format of the PDCP Data PDU when a 12 bit SN length is used. This format is applicable for PDCP Data PDUs carrying data from DRBs mapped on RLC AM or RLC UM.

Figure 6.2.3.1: PDCP Data PDU format for DRBs using a 12 bit SN

7.3.1.3.3 Test description

7.3.1.3.3.1 Pre-test conditions

System Simulator

– Cell 1

– SS PDCP set to Transparent Mode

UE:

None.

Preamble

– The UE is in state Loopback Activated (state 4) according to [18] with the RLC UM bearer configured for long PDCP SN size (12 bits).

– The condition SRB2-DRB(1,1) is used for step 8 in 4.5.3A.3 according to [18].

7.3.1.3.3.2 Test procedure sequence

Table 7.3.1.3.3.2-1: Main behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
–	EXCEPTION: Steps 1 and 2 shall be repeated for k=0 to Maximum_PDCP_SN (increment=1).
1	SS transmits a PDCP Data PDU on UM DRB containing one IP packet without header compression.	<–	PDCP Data PDU (SN = k)
2	CHECK: Does UE transmit a PDCP Data PDU with SN=0 for the first iteration and then incremented by 1 at each iteration?	–>	PDCP Data PDU (SN = k)	1	P
3	SS transmits a PDCP Data PDU on UM DRB containing one IP packet without header compression.	<–	PDCP Data PDU (SN = 0)
4	CHECK: Does UE transmit a PDCP Data PDU with SN=0?	–>	PDCP Data PDU (SN = 0)	2	P
5	SS sends a PDCP Data PDU on UM DRB containing one IP packet without header compression.	<–	PDCP Data PDU (SN = 1)
6	CHECK: Does UE transmit a PDCP Data PDU with SN=1?	–>	PDCP Data PDU (SN = 1)	1	P

7.3.1.3.3.3 Specific message contents

None