8.1 Base station system network functions
8.1.3 Testing of the BSSMAP and RR functions
8.1.3.3 Random access by MS and immediate assignment
The purpose of the immediate assignment procedure is to establish a RR connection between MS and network on a dedicated channel, typically an SDCCH or a FACCH (the main signalling link). The procedure is always triggered by the MS, and can be triggered by a paging request or a mobile originated transaction.
NOTE 1: The immediate assignment procedure could also be triggered by other establishment causes. This transaction are not tested explicitly.
NOTE 2: The extended immediate assignment procedure is not tested explicitly because it is not specified when the BSS may use it.
8.1.3.3.1 Normal Case - SDCCH Test Purpose
To check the normal immediate assignment procedure in case of SDCCH assignment.
Test Case Initial Setup
An O&M message as defined by the operator or the manufacturer shall be input on the OMC-interface commanding the BSS to set the timer T3101 to an appropriate value A. The BSS shall be configured to use the SDCCH as the main signalling link.
Description
1. The BSSTE shall input a CHANNEL REQUEST message on the radio interface on the RACH. The response on any interface shall be recorded.
2. If an IMMEDIATE ASSIGNMENT message is received from the BSS on the CCCH, a LAPDm SABM frame containing CM SERVICE REQUEST shall be input on the radio interface on the main signalling link by the BSSTE before the time T3101. The response on any interface shall be recorded.
Message flow
MS BSS MSC CH REQ
--->
IMM ASS
< SABM(CM SERV REQ) | - - - > T3101 UA(CM SERV REQ) | <
SCCP establishment
COMPL L3 INFO (CM SERV REQ) --->
The messages from the BSSTE will be:
1 CHANNEL REQUEST on the Air interface, coded as specified in GSM 04.08 [4], 9.1.8 with:
Establishment cause = originating call Random reference = PAR1
2. SABM(CM SERVICE REQUEST) on the Air interface, coded as specified in GSM 04.08 [4], 9.2.9 and GSM 04.06 [3].
Conformance Requirement:
In the case of step 1, an IMMEDIATE ASSIGNMENT message shall occur on the radio interface on the CCCH including relevant channel assignment information. The channel assigned shall be an SDCCH.
The IA rest octets shall correspond to what is set by O&M.
In the case of step 2, a LAPDm UA frame acknowledging the SABM shall occur on the radio interface on the SDCCH. Then an SCCP connection shall be established and the exact CM SERVICE REQUEST message contained in the SABM shall occur on the MSC-interface. LAPDm UI fill frames shall occur continuously on the radio interface on the SDCCH.
The messages from the BSS shall be:
1. IMMEDIATE ASSIGNMENT on the Air interface, coded as specified in GSM 04.08 [4], 9.1.18 with:
Channel Description = SDCCH Request reference = PAR1 IA Rest Octets
2. CM SERVICE REQUEST in UA LAPDm frame on the Air interface, coded as specified in GSM 04.08 [4], 9.2.9 and in GSM 04.06 [3].
Requirement reference:
GSM 04.06 [3], 3.8.2.
GSM 04.08 [4], s 3.3.1.2, 3.3.1.3 and 3.3.1.4.
GSM 08.08 [10], 3.1.16.
8.1.3.3.2 Normal Case - TCH Test Purpose
To check the normal immediate assignment procedure in case of TCH assignment.
This test should be performed only if the BSS supports the TCH/FACCH assignment in the immediate assignment procedure.
Test Case Initial Setup
An O&M message as defined by the operator or the manufacturer shall be input on the OMC-interface commanding the BSS to set the timer T3101 to an appropriate value A. The BSS shall be configured to use the FACCH as the main signalling link.
Description
1. The BSSTE shall input a CHANNEL REQUEST message on the radio interface on the RACH. The response on any interface shall be recorded.
2. If an IMMEDIATE ASSIGNMENT message is received from the BSS on the CCCH, a LAPDm SABM frame containing CM SERVICE REQUEST shall be input on the radio interface on the main signalling link by the BSSTE before the time T3101. The response on any interface shall be recorded.
3. After having established the SCCP connection, an ASSIGNMENT REQUEST message shall be input on the MSC-interface requesting a TCH/FACCH for the use of speech and signalling. The response on any interface shall be recorded.
4. A CHANNEL MODE MODIFY ACKNOWLEDGE message shall be input on the radio interface on the FACCH.
Message flow
MS BSS MSC CH REQ
--->
IMM ASS
< SABM(CM SERV REQ) |
- - - > T3101 UA(CM SERV REQ) | <
COMPL L3 INFO (CM SERV REQ) --->
ASSIGNMENT REQUEST CHANNEL MODE MODIFY
CHANNEL MODE MODIFY ACK --->
ASSIGNMENT COMPLETE --->
The messages from the BSSTE will be:
1. CHANNEL REQUEST on the Air interface, coded as specified in GSM 04.08 [4], 9.1.8 with:
Establishment cause = originating call Random reference = PAR1
2. SABM(CM SERVICE REQUEST) on the Air interface, coded as specified in GSM 04.08 [4], 9.2.9 and GSM 04.06 [3].
3. ASSIGNMENT REQUEST on the A-interface, coded as specified in GSM 08.08 [10], 3.2.1.1 with:
Channel type = TCH
4. CHANNEL MODE MODIFY ACKNOWLEDGE on the Air interface, coded as specified in GSM 04.08 [4], 9.1.6, with:
Channel description = TCH Channel mode = speech Conformance Requirement:
In the case of step 1, an IMMEDIATE ASSIGNMENT message shall occur on the radio interface on the CCCH including relevant channel assignment information. The channel assigned shall be an TCH/FACCH.
The IA rest octets shall correspond to what is set by O&M.
In the case of step 2, a LAPDm UA frame acknowledging the SABM shall occur on the radio interface on the FACCH. Then an SCCP connection shall be established and the exact CM SERVICE REQUEST message contained in the SABM shall occur on the MSC-interface. LAPDm UI fill frames shall occur continuously on the radio interface on the FACCH.
In the case of step 3, after the ASSIGNMENT REQUEST message a CHANNEL MODE MODIFY message shall occur on the radio interface on the FACCH requesting a change from signalling to speech.
The transmission of LAPDm UI fill frames shall stop.
In the case of step 4, an ASSIGNMENT COMPLETE message shall occur on the MSC-interface.
The messages from the BSS shall be:
1. IMMEDIATE ASSIGNMENT on the Air interface, coded as specified in GSM 04.08 [4], 9.1.18 with:
Channel Description = TCH Request reference = PAR1 IA Rest Octets
2. CM SERVICE REQUEST in UA LAPDm frame on the Air interface, coded as specified in GSM 04.08 [4], 9.2.9 and in GSM 04.06 [3].
3. CHANNEL MODE MODIFY on the Air interface, coded as specified in GSM 04.08 [4], 9.1.5, with:
Channel description = TCH Channel mode = speech
4. ASSIGNMENT COMPLETE on the A-interface, coded as specified in GSM 08.08 [10], 3.2.12.
Requirement reference:
GSM 04.06 [3], 3.8.2.
GSM 04.08 [4], s 3.3.1.2, 3.3.1.3, 3.3.1.4 and 3.4.6.
GSM 08.08 [10], 3.1.16.
8.1.3.3.3 T3101 expiry case Test Purpose
To check the behaviour of the BSS in case T3101 elapses before the main signalling link is established.
Test Case Initial Setup
An O&M message as defined by the operator or the manufacturer shall be input on the OMC-interface commanding the BSS to set the timer T3101 to an appropriate value A. The BSS shall be configured to use the SDCCH as the main signalling link.
Description
1. The BSSTE shall input a CHANNEL REQUEST message on the radio interface on the RACH. The response on any interface shall be recorded.
2. If an IMMEDIATE ASSIGNMENT message is received from the BSS on the CCCH, a LAPDm SABM frame containing CM SERVICE REQUEST shall be input on the radio interface on the main signalling link by the BSSTE after the expiry of timer T3101 (T3101=A). The response on any interface shall be recorded.
Message flow
MS BSS MSC CH REQ
--->
IMM ASS
< | T3101 | SABM(CM SERV REQ) - - - >
The messages from the BSSTE will be:
1. CHANNEL REQUEST on the Air interface, coded as specified in GSM 04.08 [4], 9.1.8 with:
Establishment cause = originating call Random reference = PAR1
2. SABM(CM SERVICE REQUEST) on the Air interface, coded as specified in GSM 04.08 [4], 9.2.9 and GSM 04.06 [3].
Conformance Requirement:
In the case of step 1, an IMMEDIATE ASSIGNMENT message shall occur on the radio interface on the CCCH including relevant channel assignment information. The channel assigned shall be an SDCCH.
In the case of step 2, no messages shall occur on any interface.
The messages from the BSS shall be:
1. IMMEDIATE ASSIGNMENT on the Air interface, coded as specified in GSM 04.08 [4], 9.1.18 with:
Channel Description = SDCCH Request reference = PAR1 Requirement reference:
GSM 04.06 [3], 3.8.2 GSM 04.08 [4], 3.3.1.5 GSM 08.08 [10], 3.1.16
8.1.3.3.4 No radio resources available Test Purpose
To check the immediate assignment procedure in case no radio resources available.
Test Case Initial Setup
An O&M message as defined by the operator or the manufacturer shall be input on the OMC-interface commanding the BSS to set the timer T3101 to an appropriate value A. The BSS shall be configured to use the SDCCH as the main signalling link.
An O&M message as defined by the operator or the manufacturer shall be input on the OMC-interface by the BSSTE requesting the BSS to take all radio resources out of service.
Description
The BSSTE shall input a CHANNEL REQUEST message on the radio interface on the RACH. The response on any interface shall be recorded.
Message flow
MS BSS MSC CH REQ
--->
IMM ASS REJECT
<---The messages from the BSSTE will be:
1. CHANNEL REQUEST on the Air interface, coded as specified in GSM 04.08 [4], 9.1.8 with:
Establishment cause = originating call Random reference = PAR1
Conformance Requirement
In the case of step 1, an IMMEDIATE ASSIGNMENT REJECT message may occur on the radio interface on the CCCH. The IAR rest octets shall correspond to the specified bit pattern. Nothing shall occur on the MSC-interface.
The messages from the BSS shall be:
1. IMMEDIATE ASSIGNMENT REJECT on the Air interface, coded as specified in GSM 04.08 [4], 9.1.20, with:
Request reference = PAR1 IAR Rest Octets
Requirement reference GSM 04.08 [4], 3.3.1.3.2 GSM 08.08 [10], 3.1.16
8.1.3.3.5 Immediate assignment extended Test Purpose
To check the immediate assignment extended procedure in case of two CHANNEL REQUEST messages are following in a short period.
Test Case Initial Setup
The BSS shall be configured to use the SDCCH as the main signalling link.
Description
1. The BSSTE shall input two CHANNEL REQUEST messages with different random references on the radio interface on the RACH. The response on any interface shall be recorded.
Message flow
MS BSS MSC CH REQ (1)
--->
CH REQ (2)
--->
IMM ASS EXT
<---The messages from the BSSTE will be:
1. CHANNEL REQUEST on the Air interface, coded as specified in GSM 04.08 [4], 9.1.8 with:
Establishment Cause = Originating Call Random reference = PAR1
2. CHANNEL REQUEST on the Air interface, coded as specified in GSM 04.08 [4], 9.1.8 with:
Establishment Cause = Originating Call Random reference = PAR2
Conformance Requirement
In the case of step 1, an IMMEDIATE ASSIGNMENT EXTENDED message shall occur on the radio interface on the CCCH including relevant channel assignment information. The IAX Rest Octets shall correspond to the specified bit pattern.
The messages from the BSS shall be:
1. IMMEDIATE ASSIGNMENT EXTENDED on the Air interface, coded as specified in GSM 04.08 [4], 9.1.19, with:
Request reference1 = PAR1 Request reference2 = PAR2 IAX Rest Octets
Requirement reference GSM 04.08 [4]
GSM 08.08 [10]