7.1.10 Fallback to R99 PRACH in CELL_FACH
34.123-13GPPPart 1: Protocol conformance specificationRelease 15TSUser Equipment (UE) conformance specification
7.1.10.1 Fallback to R99 PRACH in CELL_FACH / Network indicates fallback to R99 PRACH on CCCH
7.1.10.1.1 Definition and applicability
This test apply for Release 11 and later releases for a FDD UE that supports Fallback to R99 PRACH in CELL_FACH.
7.1.10.1.2 Conformance requirement
[TS 25.319, clause 23.2]
The sub-feature of fallback to R99 PRACH allows the network to indicate to the UE to use a RACH resource instead of a common E-DCH resource for an uplink transmission, when a UE attempts to access on common E-DCH in CELL_FACH state and IDLE mode.
If configured by the network, the UE may be indicated to fallback to R99 PRACH using a ‘NACK’ on E-AI. The network may configure fallback to R99 PRACH for the logical channels CCCH and DCCH independently. If the network indicates fallback and the UE has data to transmit on the logical channels for which fallback has been configured, the UE attempts to accesses again using the RACH random access procedure to obtain a R99 RACH resource for the uplink transmission. If the network indicates fallback and the UE has data to transmit only on the logical channels for which fallback is not configured, the UE does not fallback to R99 PRACH and instead interprets it as if a NACK is received.
[TS 25.321, clause 11.2.2]
MAC receives the following RACH transmission control parameters from RRC with the CMAC-CONFIG-Req primitive:
– a set of Access Service Class (ASC) parameters, which includes for each ASC, i=0,…,NumASC an identification of a PRACH partition and a persistence value Pi (transmission probability);
– maximum number of preamble ramping cycles Mmax;
– range of backoff interval for timer TBO1, given in terms of numbers of transmission 10 ms time intervals NBO1max and NBO1min, applicable when negative acknowledgement on AICH is received.
– Fallback R99 PRACH parameters.
…
When the preamble has been acknowledged on AICH, L1 access information with parameter value "ready for data transmission" is indicated to MAC with PHY-ACCESS-CNF primitive. Also, if CCCH or DCCH fallback is configured, Fallback transmission initiation is reported to higher layers with a CMAC-STATUS-Ind primitive. Then data transmission is requested with PHY-DATA-REQ primitive, and the PRACH transmission procedure shall be completed with transmission of the PRACH message part according to L1 specifications. Successful completion (TX status) of the MAC transmission control procedure shall be indicated to higher layer.
…
If CCCH or DCCH fallback is configured, both transmission failure of the MAC transmission control procedure (due to e.g. Maximum number of preamble ramping cycles reached for RACH in FDD) and transmission success upon finishing transmission of the PRACH message part according to L1 specifications trigger a CMAC-STATUS-Ind which informs the RRC about the Fallback transmission termination.
[ST 25.321, clause 11.2.2A]
The transmissions in Enhanced Uplink in CELL_FACH state and Idle mode are controlled by the UE MAC sublayer as outlined in figures 11.2.2A-1, 11.2.2A-2 and 11.2.2A-3.
NOTE: The figures shall illustrate the operation of the transmission control procedure as specified below. It shall not impose restrictions on implementation. MAC controls the timing of each initial preamble ramping cycle as well as successive preamble ramping cycles in case that no or a negative acknowledgement is received carried with an AI on AICH, if the use of E-AIs is not configured, and in case that none is received carried with an AI or a negative acknowledgement is received carried with an E-AI, if the use of E-AIs is configured.
MAC receives the following random access transmission control parameters from RRC with the CMAC-CONFIG-Req primitive:
– a set of Access Service Class (ASC) parameters, which includes for each ASC, i=0,…,NumASC an identification of a PRACH partition and a persistence value Pi (transmission probability);
– maximum number of preamble ramping cycles Mmax;
– range of backoff interval for timer TBO1, given in terms of numbers of transmission 10 ms time intervals NBO1max and NBO1min, applicable when negative acknowledgement is received carried with an E-AI, or carried with an AI, when the use of E-AIs is not configured;
– Fallback R99 PRACH parameters.
…
If not triggered due to reception of HS-SCCH order for NodeB triggered HS-DPCCH transmission, the procedure ends if a negative acknowledgement has been received with an E-AI on AICH if the use of E-AI is configured, and the UE has CCCH data to transmit on the uplink when CCCH fallback is configured or the UE has DCCH data to transmit on the uplink when DCCH fallback is configured. MAC provides an "E-DCH resource index" equal to -1 with the CMAC-STATUS-Ind primitive to the RRC.
…
Figure 7.1.10.1-1
Reference
3GPP TS 25.319 clause 23.2 and TS 25.321 clauses 11.2.2, 11.2.2A.
7.1.10.1.3 Test purpose
With UE in CELL_FACH with HS-DSCH and E-DCH configured and the network in SIB22 indicates fallback to R99 PRACH on CCCH, but not on DCCH:
1. To verify that UE, when UE has CCCH data to transmit in uplink and NodeB rejects a common E-DCH resource request, use the RACH random access procedure to obtain a R99 RACH resource to transmit the CCCH data in uplink.
2. To verify that UE, when UE has DCCH data to transmit in uplink, does not use the RACH random access procedure to obtain a R99 RACH resource, but instead request common E-DCH resources to transmit the DCCH data in uplink.
3. To verify that UE, when UE has DTCH data to transmit in uplink, does not use the RACH random access procedure to obtain a R99 RACH resource, but instead request common E-DCH resources to transmit the DTCH data in uplink.
7.1.10.1.4 Method of test
Initial Condition
System Simulator:
1 cell, default parameters, Ciphering Off, SIB configuration 10 according to TS 34.108 clause 6.10a2 using the specific message content for SIB1, SIB3, SIB4, SIB5 and SIB22 as specified below.
UE:
UE is in Enhanced CELL_FACH state with DTCH/DCCH on common E-DCH / HS-DSCH.
The SS establishes the reference radio bearer configuration specified in TS 34.108 clause 9.1 using condition “AM Packet to Enhanced CELL_FACH from Enhanced CELL_FACH in PS with SRBs mapped on common E-DCH/HS-DSCH”.
The radio bearer is placed in UE loop-back mode 1 with the UL SDU size set to 10 bytes.
Test Procedure
Table 7.1.10.1
|
Parameter |
Unit |
Cell 1 |
|
|
T0 |
T1 |
||
|
UTRA RF Channel Number |
Mid Range Test Frequency |
||
|
CPICH Ec (FDD) |
dBm/3.84MHz |
-60 |
-80 |
Table 7.1.10.1 illustrates the downlink power to be applied at various time instants of the test execution. Columns marked "T0" denote the initial conditions.
a) The UE is in Enhanced CELL_FACH state with DTCH/DCCH on common E-DCH/HS-DSCH. The SS configures its downlink transmission power settings according to columns "T1" in table 7.1.10.1 so that S<0. The UE shall detect that it is out of service area.
b) Following the expiry of periodic cell updating timer T305 according to the system information, and within the time interval equivalent to T307 timer value, SS configures its downlink transmission power settings according to columns "T0" in table 7.1.10.1 so that S>0.
c) The UE shall find that it is back in service area and initiate a CELL UPDATE procedure using E-DCH channel. The SS responds by a ‘NACK’ on E-AI. The UE initiates a PRACH preamble for R99 RACH.
d) The SS grants access to the R99 PRACH with a positive acquisition indication on AICH. The SS checks that UE transmits the CELL UPDATE message on CCCH in uplink.
NOTE: As CCCH Fallback IE is set to TRUE in the broadcasted SIB22 the UE shall fallback to R99 RACH resources to transmit the CELL UPDATE message on CCCH
e) The SS respond with a CELL UPDATE CONFIRM message to complete the CELL UPDATE procedure.
f) The SS transmits a UE CAPABILITY ENQUIRY message which includes the IE "Capability update requirement".
g) The SS checks that UE initiates a PRACH preamble and Acquisition Indication reception procedure for a new common E-DCH channel. The SS grants access with a positive acquisition on E-AI. The SS checks that UE transmits a UE CAPABILITY INFORMATION message on DCCH in uplink. The SS waits until the UE CAPABILITY INFORMATION message on DCCH has been received.
h) The SS transmits a UE CAPABILITY INFORMATION CONFIRM message to the UE to complete the UE capability enquiry procedure.
i) The SS explicitly instructs the UE to release the E-DCH resources
j) The SS sends a RLC SDU of size 10 bytes on the downlink.
k) The SS checks that UE initiates a PRACH preamble and Acquisition Indication for a new common E-DCH channel which is used to loop back the data. The SS checks the loop back data.
Expected sequence
|
Step |
Direction |
Message |
Comments |
|
|
UE |
SS |
|||
|
1 |
SS configures its downlink transmission power settings according to columns "T1" in table 7.1.10.1 so that its S value falls below 0. |
|||
|
2 |
The UE shall detect an "out of service" condition and it shall search for other cells to camp on. Upon expiry of timer T305, UE starts T307 timer.. |
|||
|
3 |
SS configures its downlink transmission power settings according to columns "T0" in table 7.1.10.1. |
|||
|
3A |
|
Access Preamble |
UE performs RACH random access procedure to obtain common E-DCH resources |
|
|
3B |
|
‘NACK’ |
The SS responds with a ‘NACK’ on E-AI. |
|
|
4 |
|
Access Preamble |
SS checks that UE performs RACH random access procedure to obtain a R99 RACH resource |
|
|
5 |
|
AICH = POS ACQUISITION IND |
SS acknowledges the RACH access |
|
|
6 |
|
CELL UPDATE |
SS checks that UE transmits the CELL UPDATE message on CCCH using the R99 RACH resource |
|
|
7 |
|
CELL UPDATE CONFIRM |
||
|
8 |
|
UE CAPABILITY ENQUIRY |
||
|
9 |
|
UE CAPABILITY INFORMATION |
SS checks that UE performs PRACH Preamble and Acquisition Indication reception procedure prior to acquiring common E-DCH resource and sending the UE CAPABILITY INFORMATION message on DCCH |
|
|
10 |
|
UE CAPABILITY INFORMATION CONFIRM |
||
|
11 |
|
Absolute grant set to INACTIVE |
The SS explicitly instructs the UE to release the E-DCH resources |
|
|
12 |
|
RLC SDU |
SS sends a RLC SDU of size 10 bytes |
|
|
13 |
UE acquires common E-DCH resource |
SS checks that UE initiates a PRACH preamble and Acquisition Indication reception procedure prior to acquiring a new common E-DCH channel |
||
|
14 |
|
Absolute Grant |
SS sends E-AGCH with serving grant 4 |
|
|
15 |
|
RLC SDU |
SS receives and checks loop back data on common E-DCH resource |
|
Specific Message Contents
SYSTEM INFORMATION BLOCK TYPE 1
Use the default parameter values for the system information block 1 with the same type specified in clause 6.1.1 of TS 34.108 with the following exception:
|
Information Element |
Value/remark |
|
T305 |
5 minutes |
|
T307 |
50 seconds |
SYSTEM INFORMATION BLOCK TYPE 3 and 4 (Preamble)
Use the default parameter values for the system information block 2 and 4 with the same type specified in clause 6.1.1 of TS 34.108 with the following exception:
|
Information Element |
Value/remark |
|
Qrxlevmin |
-35 (-69 dBm) |
SYSTEM INFORMATION BLOCK TYPE 5 (FDD) (Preamble)
Use the default parameter values for the system information block 5 with the same type specified in clause 6.1.1 of TS 34.108 for common E-DCH and HS-DSCH reception in CELL_FACH, with the following exceptions:
|
Information Element |
Value/remark |
|
– SIB22 Indicator |
TRUE |
SYSTEM INFORMATION BLOCK TYPE 22 (Preamble)
Use the default parameter values for the system information block 22 with the same type specified in clause 6.1.1 of TS 34.108 with the following exception:
|
Information Element |
Value/remark |
|
– Fallback R99 PRACH info |
|
|
– CCCH Fallback |
TRUE |
|
– DCCH Fallback |
FALSE |
7.1.10.1.4 Test requirement
At step 4 the UE shall perform a RACH random access procedure to obtain a R99 RACH resource.
At step 6 the UE shall transmit a CELL UPDATE message on CCCH using the R99 RACH resource.
At step 9 the UE shall perform a PRACH Preamble and Acquisition Indication reception procedure prior to acquiring common E-DCH resource and sending the UE CAPABILITY INFORMATION message on DCCH.
At step 13 the UE shall initiate a PRACH preamble and Acquisition Indication reception procedure for a new common E-DCH channel.
At step 15 the UE shall return a RLC SDU with same content as sent by the SS in downlink in step 12.
7.1.10.2 Fallback to R99 PRACH in CELL_FACH / Network indicates fallback to R99 PRACH on DCCH
7.1.10.2.1 Definition and applicability
This test apply for Release 11 and later releases for a FDD UE that supports Fallback to R99 PRACH in CELL_FACH.
7.1.10.2.2 Conformance requirement
Same as in 7.1.10.1.2.
7.1.10.2.3 Test purpose
With UE in CELL_FACH with HS-DSCH and E-DCH configured and the network in SIB22 indicates fallback to R99 PRACH on DCCH, but not on CCCH:
1. To verify that UE, when UE has DCCH data to transmit in uplink and when a common E-DCH is rejected by the NodeB uses the RACH random access procedure to obtain a R99 RACH resource to transmit the DCCH data in uplink.
2. To verify that UE, when UE has CCCH data to transmit in uplink, does not use the RACH random access procedure to obtain a R99 RACH resource, but instead request common E-DCH resources to transmit the CCCH data in uplink.
3. To verify that UE, when UE has DTCH data to transmit in uplink, does not use the RACH random access procedure to obtain a R99 RACH resource, but instead request common E-DCH resources to transmit the DTCH data in uplink.
7.1.10.2.4 Method of test
Initial Condition
System Simulator:
1 cell, default parameters, Ciphering Off, SIB configuration 10 according to TS 34.108 clause 6.10a2 using the specific message content for SIB1, SIB3, SIB4, SIB5 and SIB22 as specified below.
UE:
UE is in Enhanced CELL_FACH state with DTCH/DCCH on common E-DCH / HS-DSCH.
The SS establishes the reference radio bearer configuration specified in TS 34.108 clause 9.1 using condition “AM Packet to Enhanced CELL_FACH from Enhanced CELL_FACH in PS with SRBs mapped on common E-DCH/HS-DSCH”.
The radio bearer is placed in UE loop-back mode 1 with the UL SDU size set to 10 bytes.
Test Procedure
Table 7.1.10.2
|
Parameter |
Unit |
Cell 1 |
|
|
T0 |
T1 |
||
|
UTRA RF Channel Number |
Mid Range Test Frequency |
||
|
CPICH Ec (FDD) |
dBm/3.84MHz |
-60 |
-80 |
Table 7.1.10.2 illustrates the downlink power to be applied at various time instants of the test execution. Columns marked "T0" denote the initial conditions.
a) The UE is in Enhanced CELL_FACH state with DTCH/DCCH on common E-DCH/HS-DSCH. The SS configures its downlink transmission power settings according to columns "T1" in table 7.1.10.2 so that S<0. The UE shall detect that it is out of service area.
b) Following the expiry of periodic cell updating timer T305 according to the system information, and within the time interval equivalent to T307 timer value, SS configures its downlink transmission power settings according to columns "T0" in table 7.1.10.2 so that S>0.
c) The UE shall find that it is back in service area and initiate a CELL UPDATE procedure.
d) The SS checks that UE initiates a PRACH preamble and Acquisition Indication for a new common E-DCH channel which is used to transmit the CELL UPDATE message on CCCH in uplink. The SS waits until the CELL UPDATE message on CCCH has been received.
f) The SS respond with a CELL UPDATE CONFIRM message to complete the CELL UPDATE procedure.
g) The SS explicitly instructs the UE to release the E-DCH resources.
h) The SS transmits a UE CAPABILITY ENQUIRY message which includes the IE "Capability update requirement". UE initiates a PRACH preamble and Acquisition Indication for a new E-DCH channel to transmit UE CAPABILITY INFORMATION message. The SS responds by a ‘NACK’ on E-AI. The UE initiates a PRACH preamble and Acquisition Indication for R99 RACH
NOTE: As DCCH Fallback IE is set to TRUE in the broadcasted SIB22 the UE shall fallback to R99 RACH resources to transmit the UE CAPABILITY INFORMATION message on DCCH
i) The SS checks that UE perform a RACH random access procedure to obtain a R99 RACH resource and transmit the UE CAPABILITY INFORMATION message on DCCH in uplink.
j) The SS transmits a UE CAPABILITY INFORMATION CONFIRM message to the UE to complete the UE capability enquiry procedure.
k) The SS sends a RLC SDU of size 10 bytes on the downlink.
l) The SS checks that UE initiates a PRACH preamble and Acquisition Indication for a new common E-DCH channel which is used to loop back the data. The SS checks the loop back data.
Expected sequence
|
Step |
Direction |
Message |
Comments |
|
|
UE |
SS |
|||
|
1 |
SS configures its downlink transmission power settings according to columns "T1" in table 7.1.10.2 so that its S value falls below 0. |
|||
|
2 |
The UE shall detect an "out of service" condition and it shall search for other cells to camp on. Upon expiry of timer T305, UE starts T307 timer.. |
|||
|
3 |
SS configures its downlink transmission power settings according to columns "T0" in table 7.1.10.2. |
|||
|
4 |
|
CELL UPDATE |
SS checks that UE performs PRACH Preamble and Acquisition Indication reception procedure prior to acquiring common E-DCH resource and sending the CELL UPDATE message on CCCH |
|
|
5 |
|
CELL UPDATE CONFIRM |
||
|
6 |
|
Absolute grant set to INACTIVE |
The SS explicitly instructs the UE to release the E-DCH resources |
|
|
7 |
|
UE CAPABILITY ENQUIRY |
||
|
7A |
|
Access Preamble |
UE performs RACH random access procedure to obtain common E-DCH resources |
|
|
7B |
|
‘NACK’ |
The SS responds with a ‘NACK’ on E-AI. |
|
|
8 |
|
Access Preamble |
SS checks that UE performs RACH random access procedure to obtain a R99 RACH resource |
|
|
9 |
|
AICH = POS ACQUISITION IND |
SS acknowledges the RACH access |
|
|
10 |
|
UE CAPABILITY INFORMATION |
UE transmits the UE CAPABILITY INFORMATION message on DCCH using the R99 RACH resource |
|
|
11 |
|
UE CAPABILITY INFORMATION CONFIRM |
||
|
12 |
|
RLC SDU |
SS sends a RLC SDU of size 10 bytes |
|
|
13 |
UE acquires common E-DCH resource |
SS checks that UE initiates a PRACH preamble and Acquisition Indication for a new common E-DCH channel |
||
|
14 |
|
Absolute Grant |
SS sends E-AGCH with serving grant 4 |
|
|
15 |
|
RLC SDU |
SS receives and checks loop back data on common E-DCH resource |
|
Specific Message Contents
SYSTEM INFORMATION BLOCK TYPE 1
Use the default parameter values for the system information block 1 with the same type specified in clause 6.1.1 of TS 34.108 with the following exception:
|
Information Element |
Value/remark |
|
T305 |
5 minutes |
|
T307 |
50 seconds |
SYSTEM INFORMATION BLOCK TYPE 3 and 4 (Preamble)
Use the default parameter values for the system information block 3 and 4 with the same type specified in clause 6.1.1 of TS 34.108 with the following exception:
|
Information Element |
Value/remark |
|
Qrxlevmin |
-35 (-69 dBm) |
SYSTEM INFORMATION BLOCK TYPE 5 (Preamble)
Use the default parameter values for the system information block 5 with the same type specified in clause 6.1.1 of TS 34.108 for common E-DCH and HS-DSCH reception in CELL_FACH, with the following exception:
|
Information Element |
Value/remark |
|
– SIB22 indicator |
TRUE |
SYSTEM INFORMATION BLOCK TYPE 22 (Preamble)
Use the default parameter values for the system information block 22 with the same type specified in clause 6.1.1 of TS 34.108 with the following exception:
|
Information Element |
Value/remark |
|
– Fallback R99 PRACH info |
|
|
– CCCH Fallback |
FALSE |
|
– DCCH Fallback |
TRUE |
7.1.10.2.4 Test requirement
At step 4 the UE shall perform a PRACH Preamble and Acquisition Indication reception procedure prior to acquiring common E-DCH resource and sending the CELL UPDATE message on CCCH.
At step 8 the UE shall perform a RACH random access procedure to obtain a R99 RACH resource.
At step 10 the UE shall transmit a UE CAPABILITY INFORMATION message on DCCH using the R99 RACH resource.
At step 13 the UE shall initiate a PRACH preamble and Acquisition Indication for a new common E-DCH channel.
At step 15 the UE shall return a RLC SDU with same content as sent by the SS in downlink in step 12.