26.6.4 Test of the channel assignment procedure
3GPP51.010-1Mobile Station (MS) conformance specificationPart 1: Conformance specificationTS
An intracell change of channel can be requested by upper layers in order to change the channel type, or it may be initiated by the RR-sublayer, e.g. for an intra cell handover. This change is performed using the channel assignment procedure. If the procedure is incorrectly implemented in the MS, the establishment and maintenance of connections is endangered. This applies for the successful case and for the assignment failure: the MS’s correct return to the old channel after assignment failure is a necessary part of the GSM system design.
26.6.4.1 Dedicated assignment / successful case
26.6.4.1.1 Conformance requirements
1. Upon receipt of the ASSIGNMENT COMMAND message, the mobile station initiates a local end release of link layer connections, disconnects the physical channels, commands the switching to the assigned channels and initiates the establishment of lower layer connections (this includes the activation of the channels, their connection and the establishment of the main signalling links).
2. MM-messages and CM-messages using SAPI=0 sent from the mobile station to the network can be duplicated by the data link layer in the following case:
– a channel change of dedicated channels is required (assignment or handover procedure) and the last layer 2 frame has not been acknowledged by the peer data link layer before the mobile station leaves the old channel.
In this case, the mobile station does not know whether the network has received the message correctly. Therefore, the mobile station has to send the message again after the new dedicated channel is established.
3. An ASSIGNMENT COMMAND message may indicate a frequency change in progress, with a starting time and possibly alternative channel descriptions.
In the case of the reception of an ASSIGNMENT COMMAND message which contains only the description of a channel to be used after the starting time, and if the starting time has not already elapsed, the mobile station shall wait up to the starting time before accessing the channel.
4. The MS shall establish the link with the power level specified in the ASSIGNMENT COMMAND message.
The MS shall confirm the power control level that it is currently employing in the uplink SACCH L1 header. The indicated value shall be the power control level actually used by the mobile for the last burst of the previous SACCH period.
5. The MS shall apply the hopping frequencies specified in ASSIGNMENT COMMAND message in the Mobile Allocation IE or the Frequency List IE at the time of accessing the new channel using the last received Cell Allocation.
6. After receipt of the ASSIGNMENT COMMAND the MS shall perform the assignment and return an ASSIGNMENT COMPLETE without undue delay.
References
1, 3, 5. 3GPP TS 04.08 / 3GPP TS 44.018, subclause 3.4.3.
2. 3GPP TS 04.08 / 3GPP TS 44.018, subclause 3.1.4.3.
4. 3GPP TS 04.08 / 3GPP TS 44.018, subclause 3.4.3; 3GPP TS 05.08, subclause 4.2.
6. 3GPP TS 04.13, subclause 5.2.4.
26.6.4.1.2 Test purpose
1. To verify that upon receipt of an ASSIGNMENT COMMAND, the MS switches to the channel defined in the ASSIGNMENT COMMAND, establishes the link and sends an ASSIGNMENT COMPLETE message. This is tested for an MS supporting TCH in the special cases of a transition.
1.1 from non-hopping SDCCH to hopping TCH/F using a different timeslot;
1.2 from hopping TCH/F to non-hopping TCH/F using a different timeslot;
1.3 from non-hopping TCH/F to non-hopping TCH/F using a different timeslot;
1.4 from non-hopping TCH/F to hopping TCH/H using a different timeslot; this test purpose is only applicable if the MS supports TCH/H;
1.5 from hopping TCH/H to non-hopping TCH/H using a different timeslot; this test purpose is only applicable if the MS supports TCH/H;
1.6 from non-hopping TCH/H to hopping TCH/F using a different timeslot; this test purpose is only applicable if the MS supports TCH/H.
2. To verify that an MS supporting TCH, having sent an MM- or CM message which was not acknowledged on L2 before the channel assignment procedure was initiated and before the MS has left the old channel, repeats that message after completion of the assignment procedure without incrementing N(SD). This is tested in the special case of MM message AUTHENTICATION RESPONSE.
3. To verify that, if an MS supporting TCH has received an ASSIGNMENT COMMAND message which contains only the description of a channel to be used after the starting time, and if the starting time has not already elapsed, the mobile station shall wait up to the starting time before accessing the channel.
4. To verify that an MS supporting TCH, having received an ASSIGNMENT COMMAND, having sent an SABM frame to establish the main signalling link on the assigned channel, reports the power level specified in the ASSIGNMENT COMMAND message, in the uplink SACCH L1 header of the SACCH message sent in the SACCH period following the transmission of the SABM frame.
5. To verify that an MS supporting TCH, having received an ASSIGNMENT COMMAND, is able in the case of frequency hopping to decode the Mobile Allocation and Frequency List IEs correctly and applies the specified frequencies using the correct Cell Allocation.
6. To verify that after receipt of the ASSIGNMENT COMMAND the MS returns an ASSIGNMENT COMPLETE without undue delay.
26.6.4.1.3 Method of test
Initial Conditions
System Simulator:
1 cell, default parameters except:
|
BCCH ARFCN |
Throughout the test, the CA broadcast in System Information 1 is |
|
|
GSM 450 |
263 |
259, 261, 263, 265, 267, 269, 271, 273, 275, 277 |
|
GSM 480 |
310 |
306, 308, 310, 312, 314, 316, 318, 320, 322, 324 |
|
GSM 710 |
457 |
447, 454, 457, 463, 471, 479, 482, 483, 489, 496 |
|
GSM 750 |
457 |
447, 454, 457, 463, 471, 479, 482, 483, 489, 496 |
|
T-GSM 810 |
457 |
447, 454, 457, 463, 471, 479, 482, 483, 489, 496 |
|
GSM 850 |
147 |
137, 144, 147, 153, 161, 169, 172, 173, 179, 186 |
|
GSM 900 |
20 |
10, 17, 20, 26, 34, 42, 45, 46, 52, 59 |
|
DCS 1 800 |
747 |
734, 741, 747, 754, 759, 766, 773, 775, 779, 782 |
|
PCS 1 900 |
647 |
634, 641, 647, 654, 659, 666, 673, 675, 679, 682 |
|
Note that the actual CA of the cell contains other frequencies. |
Mobile Station:
The MS is in the "idle, updated" state with a TMSI allocated.
Specific PICS statements
– MS supports GSM HR (TSPC_AddInfo_Halfrate)
PIXIT statements
–
Foreseen Final State of the MS
"Idle, updated", with TMSI allocated.
Test Procedure
The SS pages the MS and allocates an SDCCH. Then 2 different channels are assigned with ASSIGNMENT COMMANDs. Each time the MS shall switch to the assigned channel, establish the link and send an ASSIGNMENT COMPLETE message.
Then the SS sends a AUTHENTICATION REQUEST message. The MS shall answer with an AUTHENTICATION RESPONSE message, which is not acknowledged on L2 by the SS. Immediately after the AUTHENTICATION RESPONSE message is received, the SS sends an ASSIGNMENT COMMAND. The MS shall switch to the assigned channel, establish the link with the commanded power level and send as ASSIGNMENT COMPLETE message. Then MS shall repeat the AUTHENTICATION RESPONSE message, with the same N(SD) value.
Then the SS sends an ASSIGNMENT COMMAND, which includes a Starting Time IE. The MS shall react as specified above, but this shall be done at the time specified in Starting Time IE.
For an MS not supporting TCH/H, the SS initiates the channel release procedure and the test ends here. For an MS supporting TCH/H, the channel assignment procedure is performed another three times, with half rate channels involved, and again it is checked that the MS correctly completes the procedures, before the SS initiates the channel release procedure.
Maximum Duration of Test
30 s.
Expected Sequence
NOTE: 3GPP TS 04.08 / 3GPP TS 44.018 appears to be unclear as to whether timer T3240 shall or shall not be started as a result of the AUTHENTICATION REQUEST message sent in step 10. To allow a variety of test equipment implementations, the IDENTITY REQUEST message is included in order to avoid an unexpected expiry of timer T3240 prior to the end of the expected sequence.
|
Step |
Direction |
Message |
Comments |
|
1 |
SS -> MS |
PAGING REQUEST TYPE 1 |
|
|
2 |
MS -> SS |
CHANNEL REQUEST |
|
|
3 |
SS -> MS |
IMMEDIATE ASSIGNMENT |
See specific message contents. |
|
4 |
MS -> SS |
PAGING RESPONSE |
|
|
5 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
6 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. This message shall be ready to be transmitted before 600 ms after the completion of step 5. |
|
7 |
SS |
The SS checks that the MS reports the requested power level in the layer 1 header of the SACCH message that is sent in the first SACCH multiframe following the SABM. |
|
|
8 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
9 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. This message shall be ready to be transmitted before 600 ms after the completion of step 8. |
|
10 |
SS -> MS |
AUTHENTICATION REQUEST |
|
|
11 |
MS -> SS |
AUTHENTICATION RESPONSE |
This message is not L2 acknowledged by the SS. |
|
12 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
13 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. This message shall be ready to be transmitted before 600 ms after the completion of step 12. |
|
14 |
MS -> SS |
AUTHENTICATION RESPONSE |
N(SD) shall be the same as in step 10. |
|
15 |
SS->MS |
IDENTITY REQUEST |
|
|
16 |
MS->SS |
IDENTITY RESPONSE |
|
|
17 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
18 |
SS |
The SS checks that there is no radio transmission on the new channel before the starting time. |
|
|
19 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. |
|
A |
This test part is performed if the MS does not support TCH/H (see PICS). |
||
|
A20 |
SS -> MS |
CHANNEL RELEASE |
The main signalling link is released. |
|
B |
This test part is performed if the MS supports TCH/H (see PICS). |
||
|
B20 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
B21 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. This message shall be ready to be transmitted before 600 ms after the completion of step B20. |
|
B22 |
SS -> MS |
IDENTITY REQUEST |
|
|
B23 |
MS -> SS |
IDENTITY RESPONSE |
|
|
B24 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
B25 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. This message shall be ready to be transmitted before 600 ms after the completion of step B24. |
|
B26 |
SS -> MS |
ASSIGNMENT COMMAND |
See specific message contents. |
|
B27 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the correct channel after establishment of the main signalling link. This message shall be ready to be transmitted before 600 ms after the completion of step B26. |
|
B28 |
SS -> MS |
CHANNEL RELEASE |
The main signalling link is released. |
Specific Message Contents
Step 3
IMMEDIATE ASSIGNMENT:
|
As default message contents except |
|
|
Channel Description |
|
|
– Channel Type |
SDCCH/8 |
|
TDMA offset |
Chosen arbitrarily |
|
– Timeslot Number |
N, chosen arbitrarily |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
Single RF Channel |
|
– ARFCN |
the ARFCN of the BCCH carrier |
Step 5
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type and TDMA offset |
TCH/F |
|
– Timeslot Number |
(N+1) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
RF hopping channel |
|
– MAIO |
Chosen arbitrarily from the set (0, 1 to N‑1) where N is the number of frequencies in the Mobile Allocation IE. |
|
– HSN |
Chosen arbitrarily from the set (1 to 63) |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Frequency list IE |
Not included |
|
Channel Mode |
|
|
– Mode |
Signalling |
|
Mobile Allocation |
Indicates all of the CA (broadcast on the BCCH) except for the BCCH carrier. |
|
Starting Time |
Not included |
Step 8
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type and TDMA offset |
TCH/F |
|
– Timeslot Number |
(N+3) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
Single RF Channel |
|
– ARFCN |
the ARFCN of the BCCH carrier |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Channel Mode |
A non-signalling mode arbitrarily selected from the full rate capabilities declared for the MS |
|
Frequency list IE |
Not Included |
|
Cell Channel Description |
See table below |
|
Mobile Allocation |
Not included |
|
Starting Time |
Not included |
|
ASSIGNMENT COMMAND |
||
|
Band |
Cell Channel Description |
|
|
Format |
ARFCNs |
|
|
GSM 450 |
Range 128 |
271, 273, 275, 277, 278, 279, 281, 282, 284, 287 and 289 |
|
GSM 480 |
Range 128 |
318, 320, 322, 324, 325, 326, 328, 329, 331, 334 and 336 |
|
GSM 710 |
Range 128 |
482, 483, 489, 496, 498, 500, 501, 502, 503, 506, 508 |
|
GSM 750 |
Range 128 |
482, 483, 489, 496, 498, 500, 501, 502, 503, 506, 508 |
|
T-GSM 810 |
Range 128 |
482, 483, 489, 496, 498, 500, 501, 502, 503, 506, 508 |
|
GSM 850 |
Range 128 |
172, 173, 179, 186, 193, 200, 201, 202, 203, 235, 241 |
|
GSM 900 |
Bitmap 0 |
45, 46, 52, 59, 66, 73, 74, 75, 76, 108, 114 |
|
DCS 1 800 |
Range 128 |
773, 775, 779, 782, 791, 798, 829, 832, 844 |
|
PCS 1 900 |
Range 128 |
673, 675, 679, 682, 691, 698, 729, 732, 744 |
Step 12
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type and TDMA offset |
TCH/F |
|
– Timeslot Number |
(N+4) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
RF hopping channel |
|
– MAIO |
Chosen arbitrarily from the set (0, 1 to N‑1) where N is the number of frequencies in the Mobile Allocation IE. |
|
– HSN |
Chosen arbitrarily from the set (1 to 63) |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Channel Mode |
Not included |
|
Frequency list IE |
Not included |
|
Cell Channel Description |
Not included (thus the CA from step 8 is used to decode the MA) |
|
Mobile Allocation |
Indicates frequencies – See table below |
|
Starting Time |
Not included |
|
ASSIGNMENT COMMAND |
|
|
Band |
Mobile Allocation |
|
ARFCNs |
|
|
GSM 450 |
271, 273, 279, 281, 282, 284, 287 and 289 |
|
GSM 480 |
318, 320, 326, 328, 329, 331, 334 and 336 |
|
GSM 710 |
482, 483, 500, 501, 502, 503, 506, 508 |
|
GSM 750 |
482, 483, 500, 501, 502, 503, 506, 508 |
|
T-GSM 810 |
482, 483, 500, 501, 502, 503, 506, 508 |
|
GSM 850 |
172, 173, 200, 201, 202, 203, 235, 241 |
|
GSM 900 |
45, 46, 73, 74, 75, 76, 108, 114 |
|
DCS 1 800 |
773, 775, 779, 829, 832, 844 |
|
PCS 1 900 |
673, 675, 679, 729, 732, 744 |
Step 17
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type and TDMA offset |
TCH/F |
|
– Timeslot Number |
(N+5) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
Single RF Channel |
|
– ARFCN |
See table below |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Channel Mode |
signalling |
|
Frequency list IE |
Not included |
|
Cell Channel Description |
Not included |
|
Mobile Allocation |
Not included |
|
Starting Time |
indicates (current frame number + 100 frames) mod 42 432 |
|
ASSIGNMENT COMMAND |
|
|
Band |
Channel Description |
|
ARFCN |
|
|
GSM 450 |
259 |
|
GSM 480 |
306 |
|
GSM 710 |
447 |
|
GSM 750 |
447 |
|
T-GSM 810 |
447 |
|
GSM 850 |
137 |
|
GSM 900 |
10 |
|
DCS 1 800 |
734 |
|
PCS 1 900 |
634 |
Step B20
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type |
TCH/H |
|
TDMA offset |
Chosen arbitrarily |
|
– Timeslot Number |
(N+6) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
RF hopping channel |
|
– MAIO |
Chosen arbitrarily from the set (0, 1 to N‑1) where N is the number of frequencies in the Frequency List IE. |
|
– HSN |
0 |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Channel Mode |
A non-signalling mode arbitrarily selected from the half rate capabilities declared for the MS |
|
Cell Channel Description |
Not included |
|
Frequency list IE |
See table below |
|
Mobile Allocation |
Not included |
|
Starting Time |
Not included |
|
ASSIGNMENT COMMAND |
||
|
Band |
Cell Channel Description |
|
|
Format |
ARFCNs |
|
|
GSM 450 |
Range 128 |
259, 267, 275, 279, 287 and 289 |
|
GSM 480 |
Range 128 |
306, 314, 322, 326, 334 and 336 |
|
GSM 710 |
Range 128 |
447, 471, 489, 500, 506, 508 |
|
GSM 750 |
Range 128 |
447, 471, 489, 500, 506, 508 |
|
T-GSM 810 |
Range 128 |
447, 471, 489, 500, 506, 508 |
|
GSM 850 |
Range 128 |
137, 161, 179, 200, 235, 241 |
|
GSM 900 |
Bitmap 0 |
10, 34, 52, 73, 108, 114 |
|
DCS 1 800 |
Range 1 024 |
734, 741, 759, 766, 773, 832, 844 |
|
PCS 1 900 |
Range 1 024 |
634, 641, 659, 666, 673, 732, 744 |
Step B24
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type |
TCH/H |
|
TDMA offset |
Chosen arbitrarily |
|
– Timeslot Number |
(N+7) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
Single RF Channel |
|
– ARFCN |
Chosen arbitrarily, but not the BCCH carrier |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Channel Mode |
Not included |
|
Frequency list IE |
Not included |
|
Cell Channel Description |
Not included |
|
Mobile Allocation |
Not included |
|
Starting Time |
Not included |
Step B26
ASSIGNMENT COMMAND:
|
Channel Description |
|
|
– Channel Type and TDMA offset |
TCH/F |
|
– Timeslot Number |
(N+1) mod 8 |
|
– Training Sequence Code |
Chosen arbitrarily |
|
– Hopping |
RF hopping channel |
|
– MAIO |
Chosen arbitrarily from the set (0, 1 to N‑1) where N is the number of frequencies in the Mobile Allocation IE. |
|
– HSN |
Chosen arbitrarily from the set (1 to 63) |
|
Power Command |
|
|
– Power level |
Chosen arbitrarily but with a changed value. |
|
Cell Channel Description |
See table below |
|
Frequency list IE |
Not included |
|
Mobile Allocation |
Indicates ARFCN See table below |
|
Starting Time |
Not included |
|
ASSIGNMENT COMMAND |
|||
|
Band |
Cell Channel Description |
Mobile Allocation |
|
|
Format |
ARFCNs |
ARFCN |
|
|
GSM 450 |
Range 128 |
261, 263 |
261 |
|
GSM 480 |
Range 128 |
308, 310 |
308 |
|
GSM 710 |
Range 128 |
454, 457 |
454 |
|
GSM 750 |
Range 128 |
454, 457 |
454 |
|
T-GSM 810 |
Range 128 |
454, 457 |
454 |
|
GSM 850 |
Range 128 |
144, 147 |
144 |
|
GSM 900 |
Bitmap 0 |
17, 20 |
17 |
|
DCS 1 800 |
Variable bitmap |
741, 747 |
741 |
|
PCS 1 900 |
Variable bitmap |
641, 647 |
641 |
26.6.4.2 Dedicated assignment / failure
26.6.4.2.1 Dedicated assignment / failure / failure during active state
26.6.4.2.1.1 Conformance requirements
On the mobile station side, if a lower layer failure happens on the new channel before the ASSIGNMENT COMPLETE message has been sent, the mobile station deactivates the new channels, reactivates the old channels, reconnects the TCHs if any and triggers the establishment of the main signalling link. It then sends a ASSIGNMENT FAILURE message, cause "protocol error unspecified" on the main DCCH and resumes the normal operation, as if no assignment attempt had occurred. The operational parameters (e.g. ciphering mode) when returning on the old channel are those applied before the procedure.
References
3GPP TS 04.08 / 3GPP TS 44.018 subclause 3.4.3.3.
3GPP TS 05.08 subclause 4.2.
3GPP TS 05.05 subclause 4.1.1.
26.6.4.2.1.2 Test purpose
To test that, when the MS fails to seize the new channel, the MS reactivates the old channel, reporting use of the last power level used on the old channel.
This is tested in the special cases of a transition:
– from TCH/F to hopping TCH/F in state U10 if the MS supports TCH/F and call control;
– from TCH/H to hopping TCH/H in state U10 if the MS supports TCH/H and call control.
26.6.4.2.1.3 Method of test
Initial Conditions
System Simulator:
1 cell, default parameters. The SS orders the MS to use a power level P, where P is a power level within the range supported by the Type of MS.
Mobile Station:
The MS is in the active state (U10) of a mobile terminated call.
Specific PICS statements
- MS supports GSM HR (TSPC_AddInfo_Halfrate)
- Power class (TSPC_Type_xxx)
PIXIT statements
–
Foreseen Final State of the MS
The active state (U10) of a mobile terminated call.
Test Procedure
The MS is in the active state (U10) of a mobile terminated call. The SS sends an ASSIGNMENT COMMAND allocating a new TCH/F, but does not activate the new channel. It is checked that the MS triggers the establishment of the main signalling link on the old channel and then sends an ASSIGNMENT FAILURE.
Maximum Duration of Test
30 s.
Expected Sequence
The test is repeated for execution counter k = 1, and for k=2 if the MS supports TCH/H.
|
Step |
Direction |
Message |
Comments |
|
1 |
SS -> MS |
ASSIGNMENT COMMAND |
Channel Type = TCH/F, if k = 1, Channel Type = TCH/H, if k = 2. Power level specified in power command is different from P, again where P is a power level within the range supported by the Type of MS. The MS attempts (and fails) to establish a signalling link on the new channel. |
|
2 |
The MS re-establishes the signalling link on the old channel. |
||
|
3 |
MS -> SS |
ASSIGNMENT FAILURE |
RR cause value = "protocol error unspecified". |
|
4 |
SS |
The SS checks that the MS reports power level P in the L1 header of the SACCH message that is sent in the first SACCH multiframe following the SABM. |
Specific Message Contents
None.
26.6.4.2.2 Dedicated assignment / failure / general case
26.6.4.2.2.1 Conformance requirements
On the mobile station side, if a lower layer failure happens on the new channel before the ASSIGNMENT COMPLETE message has been sent, the mobile station deactivates the new channels, reactivates the old channels, reconnects the TCHs if any and triggers the establishment of the main signalling link. It then sends a ASSIGNMENT FAILURE message, cause "protocol error unspecified" on the main DCCH and resumes the normal operation, as if no assignment attempt had occurred. The operational parameters (e.g. ciphering mode) when returning on the old channel are those applied before the procedure.
References
3GPP TS 04.08 / 3GPP TS 44.018 subclause 3.4.3.3.
26.6.4.2.2.2 Test purpose
To test that, when the MS fails to seize the new channel, the MS reactivates the old channel.
This is tested in the special cases of a transition:
– from SDCCH to hopping TCH/F; this test part is only applicable if the MS supports TCH/F.
– from non-hopping SDCCH to hopping TCH/H; this test part is only applicable if the MS supports TCH/H.
– from hopping TCH/F to hopping TCH/H; this test part is only applicable if the MS supports TCH/H.
NOTE: Subclause 26.6.8.4 contains the case of an assignment failure SDCCH -> SDCCH.
26.6.4.2.2.3 Method of test
Initial Conditions
System Simulator:
1 cell, default parameters.
Mobile Station:
The MS is "idle updated".
Specific PICS statements
– MS supports GSM HR (TSPC_AddInfo_Halfrate)
PIXIT statements
–
Foreseen Final State of the MS
The MS is "idle updated".
Test Procedure
A mobile terminated RR connection is established on an SDCCH. The SS sends an ASSIGNMENT COMMAND message allocating a hopping TCH/F, but does not activate the assigned channels. The MS shall try to activate the new channel (this is not verified) and shall then reactivate the old channel and trigger the establishment of the main signalling link on the old channel. Then the MS shall send an ASSIGNMENT FAILURE.
For an MS not supporting TCH/H, the SS initiates the channel release procedure and the test ends here. For an MS supporting TCH/H, the test sequence is repeated another two times, with half rate channels involved, and again it is checked that the MS correctly returns to the old channels, before the SS initiates the channel release procedure.
Maximum Duration of Test
30 s.
Expected Sequence
|
Step |
Direction |
Message |
Comments |
|
1 |
SS -> MS |
PAGING REQUEST TYPE 1 |
|
|
2 |
MS -> SS |
CHANNEL REQUEST |
|
|
3 |
SS -> MS |
IMMEDIATE ASSIGNMENT |
Channel Type: SDCCH. |
|
4 |
MS -> SS |
PAGING RESPONSE |
|
|
5 |
SS -> MS |
ASSIGNMENT COMMAND |
Channel Type = TCH/F, hopping. The MS attempts (and fails) to establish a signalling link on the new channel. |
|
6 |
The MS re-establishes the signalling link on the old channel. |
||
|
7 |
MS -> SS |
ASSIGNMENT FAILURE |
RR cause value = "protocol error unspecified". |
|
A |
This test part is performed if the MS does not support TCH/H. |
||
|
A8 |
SS -> MS |
CHANNEL RELEASE |
The main signalling link is released. |
|
B |
This test part is performed if the MS supports TCH/H (see PICS). |
||
|
B8 |
SS -> MS |
ASSIGNMENT COMMAND |
Channel Type = TCH/H, hopping. The MS attempts (and fails) to establish a signalling link on the new channel. |
|
B9 |
The MS re-establishes the signalling link on the old channel. |
||
|
B10 |
MS -> SS |
ASSIGNMENT FAILURE |
RR cause value = "protocol error unspecified". |
|
B11 |
SS -> MS |
ASSIGNMENT COMMAND |
Channel Type = TCH/F, hopping. |
|
B12 |
MS -> SS |
ASSIGNMENT COMPLETE |
Sent on the assigned channel after establishment of the main signalling link. |
|
B13 |
SS -> MS |
ASSIGNMENT COMMAND |
Channel Type = TCH/H, hopping. The MS attempts (and fails) to establish a signalling link on the new channel. |
|
B14 |
The MS re-establishes the signalling link on the old channel. |
||
|
B15 |
MS -> SS |
ASSIGNMENT FAILURE |
RR cause value = "protocol error unspecified". |
|
B16 |
SS -> MS |
CHANNEL RELEASE |
The main signalling link is released. |
Specific Message Contents
None.