This page is based on a call processing sequence between an MS and GSM Network Simulator. The details of the sequence and contents of the messages would differ from those from live network, but I think this would contain all the essential components of the call processing. The value in the "Time(sec.ms)/Memo" column is just for a reference to give you rough timing between each step and the next step. It is not the clean-cut/absolute value.
(This is at very early stages of the whole page that I am planning, so I will have on-going update for a long period).
The log covers two procedures that run one after the other. First the MS registers with Location Updating on an SDCCH, and the network releases that channel. Less than a second later, the network pages the MS and sets up a mobile terminated speech call on a TCH/F. Each message links to its decoded content, so you can check every field against 44.018 and 24.008.
- What is the overall message sequence ?
- What does the MS learn from System Information ?
- How does the MS get its first dedicated channel ?
- How does Location Updating register the MS ?
- How is a mobile terminated voice call set up ?
- Reference
What is the overall message sequence ?
Let's look at the whole flow in one table before we open any single message. Each row gives the direction, the owning protocol and the logical channel. The message name links to its capture further down the page.
|
Step |
Direction |
Message |
Channel |
Time(sec.ms)/Memo |
|
1 |
UE <-- NW |
BCCH / SACCH |
|
|
|
2 |
UE --> NW |
RACH |
07.770 |
|
|
3 |
UE <-- NW |
AGCH |
07.780 |
|
|
4 |
UE --> NW |
SDCCH |
08.020 |
|
|
5 |
UE <-- NW |
SDCCH |
08.030 |
|
|
6 |
UE --> NW |
SACCH |
08.160 |
|
|
7 |
UE --> NW |
SDCCH |
08.490 |
|
|
8 |
UE <-- NW |
SDCCH |
08.500 |
|
|
9 |
UE --> NW |
SACCH |
08.630 |
|
|
10 |
UE --> NW |
SDCCH |
08.960 |
|
|
11 |
UE <-- NW |
SDCCH |
08.970 |
|
|
12 |
UE --> NW |
SACCH |
09.100 |
|
|
13 |
UE --> NW |
SDCCH |
09.430 |
|
|
14 |
UE <-- NW |
SDCCH |
09.430 |
|
|
15 |
UE --> NW |
SACCH |
09.570 |
|
|
16 |
UE <-- NW |
PCH |
10.090 |
|
|
17 |
UE --> NW |
RACH |
10.260 |
|
|
18 |
UE <-- NW |
AGCH |
10.270 |
|
|
19 |
UE --> NW |
SACCH |
10.510 |
|
|
20 |
UE --> NW |
SDCCH |
10.600 |
|
|
21 |
UE <-- NW |
SDCCH |
10.600 |
|
|
22 |
UE --> NW |
SACCH |
10.980 |
|
|
23 |
UE --> NW |
SDCCH |
11.300 |
|
|
24 |
UE <-- NW |
SDCCH |
11.340 |
|
|
25 |
UE --> NW |
SACCH |
11.450 |
|
|
26 |
UE --> NW |
FACCH |
11.960 |
|
|
27 |
UE --> NW |
FACCH |
12.100 |
|
|
28 |
UE --> NW |
SACCH |
12.160 |
|
|
29 |
UE <--> NW |
< Voice Traffic > |
TCH |
|
The prefix in the Message column names the protocol that owns each message. RR messages are defined in 44.018, while MM and CC messages are defined in 24.008. So the prefix also tells you which part of the MS handles the message.
The Channel column shows how the signalling moves between logical channels. The MS starts on the RACH and the AGCH, and then does all of its NAS signalling on an SDCCH. The call moves to a TCH only after Assignment Command. From that point, Assignment Complete and Alerting travel on the FACCH of the new TCH/F.
The Time column gives a useful cross-check. Steps 2 and 17 are 2.49 seconds apart. The two Immediate Assignment captures below carry frame numbers that are 540 TDMA frames apart. 45.008 clause 8 puts 102 TDMA frames at 470.8 ms, so 540 frames also last about 2.49 seconds.
The flow is shorter than a live network trace. It has no Authentication and no Ciphering Mode Command. It also stops at Alerting, before Connect and Connect Acknowledge. A network simulator can skip security, so the missing steps are not an error in the MS.
One reading tip applies to every capture. The decoder prints a template row for each optional IE, including IEs that were not sent. Look at the marker after each IE name. OPTIONAL:Exist means the IE is in the message, and OPTIONAL:Omit means it is absent.
Two procedures share one log : Steps 2 to 15 are a Location Updating, and steps 16 to 29 are a mobile terminated call. The network releases the RR connection between them.RR moves the radio resources, while MM and CC carry the NAS : RR messages set up and change channels. MM registers the MS, and CC controls the call itself.The SDCCH is only a signalling channel : The MS needs Assignment Command to reach a TCH/F before any speech can flow.
What does the MS learn from System Information ?
Before the MS sends anything on the RACH, it needs the cell identity, the access rules and the layout of the control channels. System Information carries all of that. The MS reads it in idle mode, and every later step in this log depends on it.
RR : System Information Type
The six captures below come from one simulated cell. The network broadcasts types 1 to 4 on the BCCH to every MS in idle mode. Types 5 and 6 go on the SACCH once the MS has a dedicated channel, which is why the table row lists both channels.
Decoded message capture,
NAS:RR,System Information Type 1
System Information Type 1 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [21]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-System Information Type 1 Message Type ::= V
| +-Message Type ::= MSG [19]
+-Cell Channel Description ::= V
| +-Octet1-16 ::= DIVISION
| +-Format-ID bit128-127 ::= SWITCH [bit map 0]
| +-(Format-ID bit128-127)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Cell Allocation Absolute RF Channel Number bit124-121 ::= INT (0..15) [0]
| +-Cell Allocation Absolute RF Channel Number bit120-001 ::= OCTETARRAY SIZE(15..15)
[000000000000000000000000000000]
+-RACH Control Parameter ::= V
| +-Octet1 ::= DIVISION
| | +-Max retrans ::= CHOICE [Maximum 1 retransmission]
| | +-Tx-integer ::= CHOICE [3 slots used to spread transmission]
| | +-CELL_BAR_ACCESS ::= CHOICE [The cell is not barred]
| | +-Call reestablishment allowed ::= CHOICE [Call Reestablishment not allowed in the cell]
| +-Octet2-3 ::= DIVISION
| +-Access Control Class C15-C11 ::= INT (0..31) [0]
| +-Emergency Call allowed ::= CHOICE [Emergency call allowed in the cell to all MSs]
| +-Access Control Class C9-C0 ::= INT (0..1023) [0]
+-SI 1 Rest Octets ::= V
+-flg0 ::= SWITCH [L]
+-Band indicator ::= CHOICE [ARFCN indicates 1800 band]
+-spare padding ::= PAD SIZE(23..23) [2B]
Decoded message capture,
NAS:RR,System Information Type 2
System Information Type 2 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [22]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-System Information Type 2 Message Type ::= V
| +-N(SD)or0 ::= FIX [0]
| +-Message Type ::= MSG [1A]
+-BCCH Frequency List ::= V
| +-Octet1 ::= DIVISION
| | +-bit128-127 ::= INT (0..3) [0]
| | +-EXT-IND ::= CHOICE [The information element carries the complete BA]
| | +-BA-IND ::= INT (0..1) [0]
| | +-bit124-121 ::= INT (0..15) [0]
| +-Octet2-16 ::= DIVISION
| +-bit120-001 ::= OCTETARRAY SIZE(15..15) [000000000000000000000000000200]
+-NCC Permitted ::= V
| +-NCC permitted ::= INT (0..255) [255]
+-RACH Control Parameter ::= V
+-Octet1 ::= DIVISION
| +-Max retrans ::= CHOICE [Maximum 1 retransmission]
| +-Tx-integer ::= CHOICE [3 slots used to spread transmission]
| +-CELL_BAR_ACCESS ::= CHOICE [The cell is not barred]
| +-Call reestablishment allowed ::= CHOICE [Call Reestablishment not allowed in the cell]
+-Octet2-3 ::= DIVISION
+-Access Control Class C15-C11 ::= INT (0..31) [0]
+-Emergency Call allowed ::= CHOICE [Emergency call allowed in the cell to all MSs]
+-Access Control Class C9-C0 ::= INT (0..1023) [0]
Decoded message capture,
NAS:RR,System Information Type 3
System Information Type 3 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [18]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-System Information Type 3 Message Type ::= V
| +-Message Type ::= MSG [1B]
+-Cell Identity ::= V
| +-CI value ::= INT (0..65535) [1]
+-Location Area Identification ::= V
| +-Octet1 ::= DIVISION
| | +-MCC digit 2 ::= INT (0..15) [0]
| | +-MCC digit 1 ::= INT (0..15) [0]
| +-Octet2 ::= DIVISION
| | +-MNC digit 3 ::= INT (0..15) [15]
| | +-MCC digit 3 ::= INT (0..15) [1]
| +-Octet3 ::= DIVISION
| | +-MNC digit 2 ::= INT (0..15) [1]
| | +-MNC digit 1 ::= INT (0..15) [0]
| +-Octet4-5 ::= DIVISION
| +-LAC ::= INT (0..65535) [1]
+-Control Channel Description ::= V
| +-Octet1 ::= DIVISION
| | +-MSC Release ::= CHOICE [MSC is Release '98 or older]
| | +-Attach-detach allowed ::= CHOICE [MSs in the cell shall apply]
| | +-BS-AG-BLKS-RES ::= INT (0..7) [0]
| | +-CCCH-CONF ::= CHOICE [1 basic physical channel used for CCCH: not combined with SDCCHs]
| +-Octet2 ::= DIVISION
| | +-spare ::= FIX [0]
| | +-CBQ3 ::= CHOICE [Iu mode not supported]
| | +-spare ::= FIX [0]
| | +-BS-PA-MFRMS ::= CHOICE [2 multiframes period]
| +-Octet3 ::= DIVISION
| +-T3212 time-out value ::= INT (0..255) [0]
+-Cell Options ::= V
| +-DN-IND ::= CHOICE [Dynamic ARFCN mapping is not used by the PLMN]
| +-PWRC ::= CHOICE [PWRC is set]
| +-DTX ::= CHOICE [2-The MS shall not use uplink discontinuous transmission]
| +-RADIO-LINK-TIMEOUT ::= CHOICE [16]
+-Cell Selection Parameters ::= V
| +-Octet1 ::= DIVISION
| | +-CELL-RESELECT-HYSTERESIS ::= CHOICE [0 dB RXLEV hysteresis for LA re-selection]
| | +-MS-TXPWR-MAX-CCH ::= INT (0..31) [8]
| +-Octet2 ::= DIVISION
| +-ACS ::= CHOICE [System information type 16 and 17 are not broadcast on the BCCH]
| +-NECI ::= CHOICE [New establishment causes are not supported]
| +-RXLEV-ACCESS-MIN ::= INT (0..63) [0]
+-RACH Control Parameters ::= V
| +-Octet1 ::= DIVISION
| | +-Max retrans ::= CHOICE [Maximum 1 retransmission]
| | +-Tx-integer ::= CHOICE [3 slots used to spread transmission]
| | +-CELL_BAR_ACCESS ::= CHOICE [The cell is not barred]
| | +-Call reestablishment allowed ::= CHOICE [Call Reestablishment not allowed in the cell]
| +-Octet2-3 ::= DIVISION
| +-Access Control Class C15-C11 ::= INT (0..31) [0]
| +-Emergency Call allowed ::= CHOICE [Emergency call allowed in the cell to all MSs]
| +-Access Control Class C9-C0 ::= INT (0..1023) [0]
+-SI 3 Rest Octets ::= V
+-Optional selection parameters ::= DIVISION
Decoded message capture,
NAS:RR,System Information Type 4
System Information Type 4 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [12]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-System Information Type 4 Message Type ::= V
| +-Message Type ::= MSG [1C]
+-Location Area Identification ::= V
| +-Octet1 ::= DIVISION
| | +-MCC digit 2 ::= INT (0..15) [0]
| | +-MCC digit 1 ::= INT (0..15) [0]
| +-Octet2 ::= DIVISION
| | +-MNC digit 3 ::= INT (0..15) [15]
| | +-MCC digit 3 ::= INT (0..15) [1]
| +-Octet3 ::= DIVISION
| | +-MNC digit 2 ::= INT (0..15) [1]
| | +-MNC digit 1 ::= INT (0..15) [0]
| +-Octet4-5 ::= DIVISION
| +-LAC ::= INT (0..65535) [1]
+-Cell Selection Parameters ::= V
| +-Octet1 ::= DIVISION
| | +-CELL-RESELECT-HYSTERESIS ::= CHOICE [0 dB RXLEV hysteresis for LA re-selection]
| | +-MS-TXPWR-MAX-CCH ::= INT (0..31) [8]
| +-Octet2 ::= DIVISION
| +-ACS ::= CHOICE [System information type 16 and 17 are not broadcast on the BCCH]
| +-NECI ::= CHOICE [New establishment causes are not supported]
| +-RXLEV-ACCESS-MIN ::= INT (0..63) [0]
+-RACH Control Parameters ::= V
| +-Octet1 ::= DIVISION
| | +-Max retrans ::= CHOICE [Maximum 1 retransmission]
| | +-Tx-integer ::= CHOICE [3 slots used to spread transmission]
| | +-CELL_BAR_ACCESS ::= CHOICE [The cell is not barred]
| | +-Call reestablishment allowed ::= CHOICE [Call Reestablishment not allowed in the cell]
| +-Octet2-3 ::= DIVISION
| +-Access Control Class C15-C11 ::= INT (0..31) [0]
| +-Emergency Call allowed ::= CHOICE [Emergency call allowed in the cell to all MSs]
| +-Access Control Class C9-C0 ::= INT (0..1023) [0]
+-CBCH Channel Description ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Description IEI ::= IEI [64]
| +-Octet2 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [1]
| | +-Timeslot number ::= INT (0..7) [0]
| +-Octet3-4 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [0]
+-CBCH Mobile Allocation ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Mobile Allocation IEI ::= IEI [72]
| +-Octet2 ::= DIVISION
| | +-Length of mobile allocation contents ::= LEN (0..255) [0]
| +-Octet3- ::= DIVISION
| +-Mobile Allocation RF Channel ::= OCTETARRAY SIZE(0..8)
+-SI 4 Rest Octets ::= V
+-SI4 Rest Octets_O ::= DIVISION
| +-Optional selection parameters ::= DIVISION
| | +-flg21 ::= SWITCH [L]
| +-Optional Power offset ::= DIVISION
| | +-flg31 ::= SWITCH [L]
| +-flg11 ::= SWITCH [L]
+-flg1 ::= SWITCH [L]
+-(flg1)=L ::= BRANCH
| +-Break indicator ::= CHOICE [Additional parameters are not sent in SYSTEM INFORMATION TYPE 7 and 8]
+-spare padding ::= PAD SIZE(23..23) [2B]
Decoded message capture,
NAS:RR,System Information Type 5
System Information Type 5 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [18]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-System Information Type 5 Message Type ::= V
| +-N(SD)or0 ::= FIX [0]
| +-Message Type ::= MSG [1D]
+-BCCH Frequency List ::= V
+-Octet1 ::= DIVISION
| +-bit128-127 ::= INT (0..3) [0]
| +-EXT-IND ::= CHOICE [The information element carries the complete BA]
| +-BA-IND ::= INT (0..1) [0]
| +-bit124-121 ::= INT (0..15) [0]
+-Octet2-16 ::= DIVISION
+-bit120-001 ::= OCTETARRAY SIZE(15..15) [000000000000000000000000000200]
Decoded message capture,
NAS:RR,System Information Type 6
System Information Type 6 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [11]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-System Information Type 6 Message Type ::= V
| +-Message Type ::= MSG [1E]
+-Cell Identity ::= V
| +-CI value ::= INT (0..65535) [1]
+-Location Area Identification ::= V
| +-Octet1 ::= DIVISION
| | +-MCC digit 2 ::= INT (0..15) [0]
| | +-MCC digit 1 ::= INT (0..15) [0]
| +-Octet2 ::= DIVISION
| | +-MNC digit 3 ::= INT (0..15) [15]
| | +-MCC digit 3 ::= INT (0..15) [1]
| +-Octet3 ::= DIVISION
| | +-MNC digit 2 ::= INT (0..15) [1]
| | +-MNC digit 1 ::= INT (0..15) [0]
| +-Octet14-5 ::= DIVISION
| +-LAC ::= INT (0..65535) [1]
+-Cell Options ::= V
| +-DTX_1 ::= BITARRAY SIZE(1..1) [0]
| +-PWRC ::= CHOICE [PWRC is set]
| +-DTX_2 ::= BITARRAY SIZE(2..2) [10]
| +-RADIO-LINK-TIMEOUT ::= CHOICE [16]
+-NCC Permitted ::= V
| +-NCC permitted ::= INT (0..255) [255]
+-SI 6 Rest Octets ::= V
+-flg1 ::= SWITCH [L]
+-flg2 ::= SWITCH [L]
+-DTM_support ::= SWITCH [DTM is not supported in the serving cell]
+-Band indicator ::= CHOICE [ARFCN indicates 1800 band]
+-flg3 ::= SWITCH [L]
+-flg4 ::= SWITCH [L]
+-implicit spare ::= PAD SIZE(19..19) [2B]
Let's pick out the fields that shape the rest of this call flow. Most of them sit in System Information Type 3, which shares several IEs with types 1, 2 and 4.
Cell Identity is 1, and the LAI is MCC 001, MNC 01 and LAC 1. The MS compares this LAI with the one stored on its SIM. The Location Updating Request below carries LAC 10, so the MS is in a new location area and has to register.
The RACH Control Parameters set Max retrans to 1 and Tx-integer to 3. So the MS sends at most M + 1 = 2 Channel Request messages. This cell uses one CCCH that is not combined with SDCCHs. For that case, 44.018 Table 3.3.1.1.2.1 gives S = 55, so two successive requests are 55 to 57 RACH slots apart.
The Control Channel Description gives BS-AG-BLKS-RES = 0 and BS-PA-MFRMS = 2 multiframes. For this CCCH configuration, 44.018 counts (9 - BS-AG-BLKS-RES) x BS-PA-MFRMS paging subchannels, so this cell has 18 of them. The T3212 timeout value is 0, which means periodic location updating is not used in this cell.
NECI reads "New establishment causes are not supported". This value decides which rows of 44.018 Table 9.1.8.1 apply to the Channel Request. Every access class bit is 0, and 44.018 codes 0 as not barred, so any MS may access this cell.
The LAI decides whether the MS registers : A LAC that differs from the stored one starts the Location Updating that follows.RACH Control Parameters limit the random access : Max retrans and Tx-integer set how many Channel Request messages the MS may send and how far apart they are.NECI selects the Channel Request coding : With NECI not set, the MS uses the older establishment cause codes, such as 000xxxxx for location updating.
How does the MS get its first dedicated channel ?
An MS in idle mode has no dedicated resource at all. It asks for one on the RACH with Channel Request, and the network answers on the AGCH with Immediate Assignment. Both steps happen before the MS can send any NAS message.
RR : Channel Request
Channel Request has various functionalities and the one right after power-on is is equivalent to RACH process of UMTS and LTE. Simply put, this message is to tell the network "I want to camp on you, please allocate me a radio resource that I initiate the connection process".
The one for the initial registration is as follows. (In good channel condition and in open space, the first Channel Request would reach the NW and get the immdediate Assignement with only one Channel Request. Following is a kind of worst case where the initial channel request fail to decoded by NW or UE fails to decode initial immediate assignements)
Note : T3126 starts when the last retransmission of 'Channel Request' and it stops when UE gets 'Immediate Assignement'. If UE does not get 'Immediate Assignement' until T3126 expires, UE starts cell reselection.
Two details in the diagram above need care. First, 44.018 defines no timer for the gap between two Channel Request messages. The MS waits a random number of RACH slots drawn from {S, ..., S + T - 1}. So the T3120 label marks a waiting period, not a 44.018 timer. Second, the number of attempts comes from Max retrans in System Information. The cell on this page sets Max retrans to 1, so its MS sends at most two Channel Request messages, not three.
When T3126 expires, 44.018 subclause 3.3.1.1.2 aborts the procedure and reports a random access failure to the MM sublayer. The cell reselection in the note above is the consequence that 24.008 and 45.008 describe for that failure.
The exact functionality of a channel request is determined by the first 8 bits of its message and the description of the first byte is specified by the following table in 44.018.
< 44.018 - Table 9.1.8.1: CHANNEL REQUEST message content >
The page has no capture of this Channel Request. The message is only 8 bits long and carries no layer 3 header. Its content still appears later in the log, because the network copies it into the RA field of the Request Reference. In the Immediate Assignment below, RA = 16, which is 00010000 in binary. With NECI not set, the leading 000 matches Location updating in the table above.
RR : Immediate Assignment
Immediate Assignement is the answering message to the initial "Channel Request" explained above. This is to say to MS "OK, I will accept your 'channel request' and here goes the radio resource you can use for the following steps".
One of the Channel Request example would be as follows. The most important thing you have to notice is that Immediate Assignment should play back the whole Channel Request message. All MS(UE) trying to connect a cell would receive the same 'Immediate Assignement', but if the 'Channel Request' portion contained in 'Immediate Assignement' does not match the Channel Request Bytes it sent, UE should discard the Immediate Assignement message since it is not for itself.
Each three-byte value in the trace above is a Request Reference. It holds the RA byte, followed by two bytes with the T1', T3 and T2 parts of the frame number. That is why the MS can tell the first two requests apart, although both carry RA 1B. Strictly, the Immediate Assignment echoes this Request Reference rather than the whole Channel Request.
Note also that the answer to the first request arrives after the MS has sent the second one. 44.018 subclause 3.3.1.1.3.1 lets the MS accept an answer to any of its last three requests.
Decoded message capture,
NAS:RR,Immediate assignment
Immediate assignment ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [11]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Immediate assignment Message Type ::= V
| +-Message Type ::= MSG [3F]
+-Dedicated mode or TBF ::= V
| +-spare ::= FIX [0]
| +-TMA-Downlink-T/D ::= CHOICE [This message assigns a dedicated mode resource]
+-Page Mode ::= V
| +-spare ::= FIX [0]
| +-spare ::= FIX [0]
| +-PM ::= CHOICE [Normal paging]
+-Channel Description ::= V OPTIONAL:Exist
| +-Octet1 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [8]
| | +-Timeslot number ::= INT (0..7) [4]
| +-Octet2-3 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [129]
+-Packet Channel Description ::= V OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel type ::= INT (0..31) [1]
| | +-Timeslot Number ::= INT (0..7) [0]
| +-Octet2-3 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-flg1 ::= SWITCH [0]
| +-(flg1)=0 ::= BRANCH
| +-flg11 ::= SWITCH [0]
| +-(flg11)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [0]
+-Request Reference ::= V
| +-Octet1 ::= DIVISION
| | +-Random Access Information ::= INT (0..255) [16]
| +-Octet2-3 ::= DIVISION
| +-T1' ::= INT (0..31) [9]
| +-T3 ::= INT (0..63) [16]
| +-T2 ::= INT (0..31) [21]
+-Timing Advance ::= V
| +-Timing Advance value ::= INT (0..255) [0]
+-Mobile Allocation ::= LV
| +-Octet1 ::= DIVISION
| | +-Length of mobile allocation contents ::= LEN (0..255) [0]
| +-Octet2-9 ::= DIVISION
| +-Mobile Allocation RF Channel ::= OCTETARRAY SIZE(0..8)
+-Starting Time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Starting Time IEI ::= IEI [7C]
| +-Octet2-3 ::= DIVISION
| +-T1' ::= INT (0..31) [0]
| +-T3 ::= INT (0..63) [0]
| +-T2 ::= INT (0..31) [0]
+-IA Rest Octets ::= V
+-flg3 ::= SWITCH [LL]
+-(flg3)=LL ::= BRANCH
| +-Compressed InterRAT HO INFO IND ::= CHOICE
[A compressed version of the INTER RAT HANDOVER INFO message shall not be used]
+-spare padding ::= PAD SIZE(23..23) [2B]
Let's decode the capture above field by field. Channel type and TDMA offset is 8, which is 01000 in binary. 44.018 Table 10.5.2.5.1 reads 01TTT as SDCCH/8, so the network assigns SDCCH/8 subchannel 0. The channel sits on timeslot 4 of ARFCN 129 without frequency hopping, and Timing Advance is 0.
The Request Reference carries RA = 16, T1' = 9, T3 = 16 and T2 = 21. A note under 44.018 Table 10.5.2.30.1 rebuilds the frame number as 51 x ((T3 - T2) mod 26) + T3 + 51 x 26 x T1'. The result is frame 13021 modulo 42432. That is the frame in which the network received the Channel Request.
After this message the MS moves to the SDCCH and keeps the channel mode at signalling only. It then sends an SABM that already carries its first layer 3 message, the Location Updating Request (44.018 subclause 3.3.1.1.3.1).
The Request Reference ties the answer to one request : The RA value alone can repeat, so the frame number fields tell the MS which of its requests was answered.Immediate Assignment grants a signalling channel : Here it is an SDCCH/8, and the channel mode stays signalling only until a later Assignment Command.T3126 limits the wait : If no answer to its last requests arrives before T3126 expires, the MS aborts the access, and MM sees a random access failure.
How does Location Updating register the MS ?
The LAI in System Information differs from the one on the SIM, so the MS must tell the network where it is. The MSC needs this location to page the MS later. The whole exchange runs on the SDCCH granted above, and it ends when the network releases that channel.
MM : Location Updating Request
This is the first layer 3 message on the new SDCCH. The MS sends it inside the SABM that sets up the signalling link, so the network learns the purpose of the access immediately.
Decoded message capture,
NAS:MM,Location updating request
Location updating request ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-Location updating request Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [08]
+-Ciphering Key Sequence Number ::= V
| +-Octet1 ::= DIVISION
| +-spare ::= FIX [0]
| +-Key sequence ::= CHOICE [No key is available (MS to network)/Reserved (network to MS)]
+-Location updating type ::= V
| +-Octet1 ::= DIVISION
| +-FOR ::= CHOICE [No follow-on request pending]
| +-spare ::= FIX [0]
| +-LUT ::= CHOICE [Normal location updating]
+-Location Area Identification ::= V
| +-Octet1 ::= DIVISION
| | +-MCC digit 2 ::= INT (0..15) [0]
| | +-MCC digit 1 ::= INT (0..15) [0]
| +-Octet2 ::= DIVISION
| | +-MNC digit 3 ::= INT (0..15) [15]
| | +-MCC digit 3 ::= INT (0..15) [1]
| +-Octet3 ::= DIVISION
| | +-MNC digit 2 ::= INT (0..15) [1]
| | +-MNC digit 1 ::= INT (0..15) [0]
| +-Octet4 ::= DIVISION
| | +-LAC ::= INT (0..255) [0]
| +-Octet5 ::= DIVISION
| +-LAC (continued) ::= INT (0..255) [10]
+-Mobile Station Classmark 1 ::= V
| +-Octet1 ::= DIVISION
| +-spare ::= FIX [0]
| +-Revisionlevel ::= CHOICE [Used by GSM phase 2 mobile stations]
| +-ESIND ::= CHOICE [Controlled Early Classmark Sending option is implemented in the MS]
| +-A5/1 ::= CHOICE [encryption algorithm A5/1 available]
| +-RF powercapability ::= CHOICE [class 4]
+-Mobile Identity ::= LV
| +-Octet1 ::= DIVISION
| | +-Length of mobile identity contents ::= LEN (0..255) [5]
| +-Octet2 ::= DIVISION
| | +-Identity digit 1 ::= INT (0..15) [15]
| | +-Odd/even indication ::= CHOICE [even number of identity digits and also when the TMSI/P-TMSI is used]
| | +-Type of identity ::= CHOICE [TMSI/P-TMSI]
| +-Octet3-Octet10 ::= DIVISION
| +-Identity digit p ::= OCTETARRAY SIZE(0..8) [21436587]
+-Mobile Station Classmark 2 ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-Mobile station classmark 2 IEI ::= IEI [33]
+-Octet2 ::= DIVISION
| +-Length of mobile station classmark 2 contents ::= LEN (0..255) [3]
+-Octet3 ::= DIVISION
| +-spare ::= FIX [0]
| +-Revisionlevel ::= CHOICE [Reserved for GSM phase 1]
| +-ESIND ::= CHOICE [Controlled Early Classmark Sending option is not implemented in the MS]
| +-A5/1 ::= CHOICE [encryption algorithm A5/1 available]
| +-RF powercapability ::= CHOICE [class 1]
+-Octet4 ::= DIVISION
| +-spare ::= FIX [0]
| +-PScapa. ::= CHOICE [PS capability not present]
| +-SS Screen.Indicator ::= CHOICE [default value of phase 1]
| +-SM capabi. ::= CHOICE [Mobile station does not support mobile terminated point to point SMS]
| +-VBS ::= CHOICE [no VBS capability or no notifications wanted]
| +-VGCS ::= CHOICE [no VGCS capability or no notifications wanted]
| +-FC ::= CHOICE [When a GSM 900 band is used The MS does not support the E-GSM or R-GSM band (For definition of frequency bands see GSM 05.05)/ Reserved for future use (for definition of frequency bands see GSM05.05)]
+-Octet5 ::= DIVISION
+-CM3 ::= CHOICE [The MS does not support any options that are indicated in CM3]
+-spare ::= FIX [0]
+-LCSVACAP ::= CHOICE [location request notification via CS domain not supported]
+-UCS2 ::= CHOICE [the ME has a preference for the default alphabet over UCS2.]
+-SoLSA ::= CHOICE [The ME does not support SoLSA.]
+-CMSP ::= CHOICE [Network initiated MO CM connection request not supported.]
+-A5/3 ::= CHOICE [encryption algorithm A5/3 not available]
+-A5/2 ::= CHOICE [encryption algorithm A5/2 not available]
Location updating type is Normal location updating, and no follow-on request is pending. The Ciphering Key Sequence Number, CKSN, says that no key is available, so the MS holds no valid ciphering key from an earlier authentication.
The LAI is MCC 001, MNC 01 and LAC 10, which is the location area stored on the SIM. The Mobile Identity is a TMSI, and the decoder prints its four octets as 21436587. Mobile Station Classmark 1 reports a GSM phase 2 MS with A5/1 and RF power capability class 4. The Classmark 2 rows below it are marked OPTIONAL:Omit, so they are only the decoder's template.
MM : Identity Request - IMSI
The network now asks the MS for its permanent identity. A TMSI has only local significance, within the area of the VLR that allocated it (23.003), and this one arrived with LAC 10. The Identity type IE carries the single value IMSI.
Decoded message capture,
NAS:MM,Identity request(MM)
Identity request ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-Identity requestMessage type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [18]
+-Spare Half Octet ::= V
| +-Octet1 ::= DIVISION
| +-Spare Half Octet ::= FIX [0]
+-Identity type ::= V
+-Octet1 ::= DIVISION
+-spare ::= FIX [0]
+-type of identity ::= CHOICE [IMSI]
RR : Measurement Report
While the MS holds the SDCCH, it reports radio measurements on the SACCH once per reporting period. The table shows eight such reports, four in each procedure, and all of them link to the single capture below.
Decoded message capture,
NAS:RR,Measurement Report
Measurement Report ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Measurement Report Message Type ::= V
| +-N(SD)or0 ::= FIX [0]
| +-Message Type ::= MSG [15]
+-Measurement Results ::= V
+-Octet1 ::= DIVISION
| +-BA-USED ::= INT (0..1) [0]
| +-DTXUSED ::= CHOICE [DTX was not used]
| +-RXLEV-FULL-SERVING-CELL ::= INT (0..63) [0]
+-Octet2 ::= DIVISION
| +-3G-BA-USED ::= INT (0..1) [0]
| +-MEAS-VALID ::= CHOICE [the measurement results are not valid]
| +-RXLEV-SUB-SERVING-CELL ::= INT (0..63) [0]
+-Octet3-16 ::= DIVISION
+-spare ::= FIX [0]
+-RXQUAL-FULLSERVING-CELL ::= INT (0..7) [0]
+-RXQUAL-SUBSERVING-CELL ::= INT (0..7) [0]
+-NO-NCELL-M ::= CHOICE [Neighbour cell information not available for serving cell]
+-RXLEV-NCELL 1 ::= INT (0..63) [0]
+-BCCH-FREQ-NCELL 1 ::= INT (0..31) [0]
+-BSIC-NCELL 1 ::= INT (0..63) [0]
+-RXLEV-NCELL 2 ::= INT (0..63) [0]
+-BCCH-FREQ-NCELL 2 ::= INT (0..31) [0]
+-BSIC-NCELL 2 ::= INT (0..63) [0]
+-RXLEV-NCELL 3 ::= INT (0..63) [0]
+-BCCH-FREQ-NCELL 3 ::= INT (0..31) [0]
+-BSIC-NCELL 3 ::= INT (0..63) [0]
+-RXLEV-NCELL 4 ::= INT (0..63) [0]
+-BCCH-FREQ-NCELL 4 ::= INT (0..31) [0]
+-BSIC-NCELL 4 ::= INT (0..63) [0]
+-RXLEV-NCELL 5 ::= INT (0..63) [0]
+-BCCH-FREQ-NCELL 5 ::= INT (0..31) [0]
+-BSIC-NCELL 5 ::= INT (0..63) [0]
+-RXLEV-NCELL 6 ::= INT (0..63) [0]
+-BCCH-FREQ-NCELL 6 ::= INT (0..31) [0]
+-BSIC-NCELL 6 ::= INT (0..63) [0]
For an SDCCH, 45.008 clause 8 sets the measurement period to 102 TDMA frames, or 470.8 ms. The Time column agrees, because steps 6, 9, 12 and 15 are 470 ms apart.
MEAS-VALID reads "the measurement results are not valid", which is bit value 1 in 44.018. So the zero RXLEV and RXQUAL values carry no radio information. NO-NCELL-M reads "Neighbour cell information not available for serving cell", so the six neighbour rows are empty as well.
MM : Identity Response
The MS answers with its IMSI in the Mobile Identity IE. The digits are BCD coded, two per octet with the lower nibble first. The decoder prints each octet as a hex byte, so every pair of digits appears swapped.
Decoded message capture,
NAS:MM,Identity response(MM)
Identity response ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-Identity response Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [1]
| +-Message type ::= MSG [19]
+-Mobile Identity ::= LV
+-Octet1 ::= DIVISION
| +-Length of mobile identity contents ::= LEN (0..255) [8]
+-Octet2 ::= DIVISION
| +-Identity digit 1 ::= INT (0..15) [0]
| +-Odd/even indication ::= CHOICE [odd number of identity digits]
| +-Type of identity ::= CHOICE [IMSI]
+-Octet3-Octet10 ::= DIVISION
+-Identity digit p ::= OCTETARRAY SIZE(0..8) [10101032547698]
Identity digit 1 is 0, and the octets 10 10 10 32 54 76 98 read as 01 01 01 23 45 67 89. The IMSI is therefore 001010123456789, with MCC 001 and MNC 01, which matches the cell. Odd/even indication says odd, and 15 digits is indeed an odd count.
MM : Identity Request - IMEI
The network asks for a second identity with the same message. This time the Identity type is IMEI, which identifies the handset rather than the subscription on the SIM. The rest of the message is the same as the IMSI request above.
Decoded message capture,
NAS:MM,Identity request(MM)
Identity request ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-Identity requestMessage type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [18]
+-Spare Half Octet ::= V
| +-Octet1 ::= DIVISION
| +-Spare Half Octet ::= FIX [0]
+-Identity type ::= V
+-Octet1 ::= DIVISION
+-spare ::= FIX [0]
+-type of identity ::= CHOICE [IMEI]
MM : Identity Response
The MS returns its IMEI in the same Mobile Identity IE, now with Type of identity set to IMEI. The IMEI has 15 digits, so the Odd/even indication again says odd. The digits are packed in the same swapped order as the IMSI above.
Decoded message capture,
NAS:MM,Identity response(MM)
Identity response ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-Identity response Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [19]
+-Mobile Identity ::= LV
+-Octet1 ::= DIVISION
| +-Length of mobile identity contents ::= LEN (0..255) [8]
+-Octet2 ::= DIVISION
| +-Identity digit 1 ::= INT (0..15) [0]
| +-Odd/even indication ::= CHOICE [odd number of identity digits]
| +-Type of identity ::= CHOICE [IMEI]
+-Octet3-Octet10 ::= DIVISION
+-Identity digit p ::= OCTETARRAY SIZE(0..8) [40041143637903]
MM : Location Updating Accept
The network accepts the registration and returns the LAI in which the MS is now registered. This LAI shows LAC 1, the same value that System Information Type 3 broadcasts.
Decoded message capture,
NAS:MM,Location updating accept
Location updating accept ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-Location updating accept Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [02]
+-Location Area Identification ::= V
| +-Octet1 ::= DIVISION
| | +-MCC digit 2 ::= INT (0..15) [0]
| | +-MCC digit 1 ::= INT (0..15) [0]
| +-Octet2 ::= DIVISION
| | +-MNC digit 3 ::= INT (0..15) [15]
| | +-MCC digit 3 ::= INT (0..15) [1]
| +-Octet3 ::= DIVISION
| | +-MNC digit 2 ::= INT (0..15) [1]
| | +-MNC digit 1 ::= INT (0..15) [0]
| +-Octet4 ::= DIVISION
| | +-LAC ::= INT (0..255) [0]
| +-Octet5 ::= DIVISION
| +-LAC (continued) ::= INT (0..255) [1]
+-Mobile identity ::= TLV OPTIONAL:Exist
| +-Octet1 ::= DIVISION
| | +-Mobile Identity IEI ::= IEI [17]
| +-Octet2 ::= DIVISION
| | +-Length of mobile identity contents ::= LEN (0..255) [5]
| +-Octet3 ::= DIVISION
| | +-Identity digit 1 ::= INT (0..15) [15]
| | +-Odd/even indication ::= CHOICE [even number of identity digits and also when the TMSI/P-TMSI is used]
| | +-Type of identity ::= CHOICE [TMSI/P-TMSI]
| +-Octet4-Octet11 ::= DIVISION
| +-Identity digit p ::= OCTETARRAY SIZE(0..8) [21436587]
+-Follow-on Proceed ::= T OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-Follow-on Proceed IEI ::= IEI [A1]
+-CTS permission ::= T OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-CTS Permission IEI ::= IEI [A2]
+-PLMN list ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-PLMN List IEI ::= IEI [4A]
| +-Octet2 ::= DIVISION
| | +-Length of PLMN List contents ::= LEN (0..255) [3]
| +-Octet3 ::= DIVISION
| | +-MCC digit 2 PLMN 1 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 1 ::= INT (0..15) [0]
| +-Octet4 ::= DIVISION
| | +-MNC digit 3 PLMN 1 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 1 ::= INT (0..15) [0]
| +-Octet5 ::= DIVISION
| | +-MNC digit 2 PLMN 1 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 1 ::= INT (0..15) [0]
| +-Octet6 ::= DIVISION
| | +-MCC digit 2 PLMN 2 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 2 ::= INT (0..15) [0]
| +-Octet7 ::= DIVISION
| | +-MNC digit 3 PLMN 2 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 2 ::= INT (0..15) [0]
| +-Octet8 ::= DIVISION
| | +-MNC digit 2 PLMN 2 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 2 ::= INT (0..15) [0]
| +-Octet9 ::= DIVISION
| | +-MCC digit 2 PLMN 3 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 3 ::= INT (0..15) [0]
| +-Octet10 ::= DIVISION
| | +-MNC digit 3 PLMN 3 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 3 ::= INT (0..15) [0]
| +-Octet11 ::= DIVISION
| | +-MNC digit 2 PLMN 3 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 3 ::= INT (0..15) [0]
| +-Octet12 ::= DIVISION
| | +-MCC digit 2 PLMN 4 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 4 ::= INT (0..15) [0]
| +-Octet13 ::= DIVISION
| | +-MNC digit 3 PLMN 4 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 4 ::= INT (0..15) [0]
| +-Octet14 ::= DIVISION
| | +-MNC digit 2 PLMN 4 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 4 ::= INT (0..15) [0]
| +-Octet15 ::= DIVISION
| | +-MCC digit 2 PLMN 5 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 5 ::= INT (0..15) [0]
| +-Octet16 ::= DIVISION
| | +-MNC digit 3 PLMN 5 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 5 ::= INT (0..15) [0]
| +-Octet17 ::= DIVISION
| | +-MNC digit 2 PLMN 5 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 5 ::= INT (0..15) [0]
| +-Octet18 ::= DIVISION
| | +-MCC digit 2 PLMN 6 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 6 ::= INT (0..15) [0]
| +-Octet19 ::= DIVISION
| | +-MNC digit 3 PLMN 6 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 6 ::= INT (0..15) [0]
| +-Octet20 ::= DIVISION
| | +-MNC digit 2 PLMN 6 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 6 ::= INT (0..15) [0]
| +-Octet21 ::= DIVISION
| | +-MCC digit 2 PLMN 7 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 7 ::= INT (0..15) [0]
| +-Octet22 ::= DIVISION
| | +-MNC digit 3 PLMN 7 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 7 ::= INT (0..15) [0]
| +-Octet23 ::= DIVISION
| | +-MNC digit 2 PLMN 7 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 7 ::= INT (0..15) [0]
| +-Octet24 ::= DIVISION
| | +-MCC digit 2 PLMN 8 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 8 ::= INT (0..15) [0]
| +-Octet25 ::= DIVISION
| | +-MNC digit 3 PLMN 8 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 8 ::= INT (0..15) [0]
| +-Octet26 ::= DIVISION
| | +-MNC digit 2 PLMN 8 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 8 ::= INT (0..15) [0]
| +-Octet27 ::= DIVISION
| | +-MCC digit 2 PLMN 9 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 9 ::= INT (0..15) [0]
| +-Octet28 ::= DIVISION
| | +-MNC digit 3 PLMN 9 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 9 ::= INT (0..15) [0]
| +-Octet29 ::= DIVISION
| | +-MNC digit 2 PLMN 9 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 9 ::= INT (0..15) [0]
| +-Octet30 ::= DIVISION
| | +-MCC digit 2 PLMN 10 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 10 ::= INT (0..15) [0]
| +-Octet31 ::= DIVISION
| | +-MNC digit 3 PLMN 10 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 10 ::= INT (0..15) [0]
| +-Octet32 ::= DIVISION
| | +-MNC digit 2 PLMN 10 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 10 ::= INT (0..15) [0]
| +-Octet33 ::= DIVISION
| | +-MCC digit 2 PLMN 11 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 11 ::= INT (0..15) [0]
| +-Octet34 ::= DIVISION
| | +-MNC digit 3 PLMN 11 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 11 ::= INT (0..15) [0]
| +-Octet35 ::= DIVISION
| | +-MNC digit 2 PLMN 11 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 11 ::= INT (0..15) [0]
| +-Octet36 ::= DIVISION
| | +-MCC digit 2 PLMN 12 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 12 ::= INT (0..15) [0]
| +-Octet37 ::= DIVISION
| | +-MNC digit 3 PLMN 12 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 12 ::= INT (0..15) [0]
| +-Octet38 ::= DIVISION
| | +-MNC digit 2 PLMN 12 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 12 ::= INT (0..15) [0]
| +-Octet39 ::= DIVISION
| | +-MCC digit 2 PLMN 13 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 13 ::= INT (0..15) [0]
| +-Octet40 ::= DIVISION
| | +-MNC digit 3 PLMN 13 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 13 ::= INT (0..15) [0]
| +-Octet41 ::= DIVISION
| | +-MNC digit 2 PLMN 13 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 13 ::= INT (0..15) [0]
| +-Octet42 ::= DIVISION
| | +-MCC digit 2 PLMN 14 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 14 ::= INT (0..15) [0]
| +-Octet43 ::= DIVISION
| | +-MNC digit 3 PLMN 14 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 14 ::= INT (0..15) [0]
| +-Octet44 ::= DIVISION
| | +-MNC digit 2 PLMN 14 ::= INT (0..15) [0]
| | +-MNC digit 1 PLMN 14 ::= INT (0..15) [0]
| +-Octet45 ::= DIVISION
| | +-MCC digit 2 PLMN 15 ::= INT (0..15) [0]
| | +-MCC digit 1 PLMN 15 ::= INT (0..15) [0]
| +-Octet46 ::= DIVISION
| | +-MNC digit 3 PLMN 15 ::= INT (0..15) [0]
| | +-MCC digit 3 PLMN 15 ::= INT (0..15) [0]
| +-Octet47 ::= DIVISION
| +-MNC digit 2 PLMN 15 ::= INT (0..15) [0]
| +-MNC digit 1 PLMN 15 ::= INT (0..15) [0]
+-Emergency Number List ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-Emergency Number List IEI ::= IEI [34]
+-Octet2 ::= DIVISION
| +-Length of Emergency Number List IE contents ::= LEN (0..255) [0]
+-Octet3 ::= DIVISION
+-Number digit ::= DIGIT SIZE(0..400)
The Mobile identity IE is marked OPTIONAL:Exist, and it carries a TMSI. 24.008 subclause 4.4.4.6 says the MS stores this TMSI on the SIM and returns TMSI REALLOCATION COMPLETE. The TMSI value is the same 21436587 that the MS sent in its request, so this simulator reallocates the old value.
Follow-on Proceed is omitted, so the network gives the MS no permission to start a new MM connection on this channel. The PLMN list is also omitted, although the decoder prints fifteen empty PLMN entries for it.
MM : TMSI ReAllocation Complete
This short message confirms that the MS has stored the TMSI. It carries nothing beyond the protocol discriminator and the message type, because the confirmation is the whole content.
Decoded message capture,
NAS:MM,TMSI reallocation complete
TMSI reallocation complete ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-Mobility management protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [5]
+-TMSI reallocation complete Message type ::= V
+-N(SD)or0_1 ::= INT (0..1) [0]
+-N(SD)or0_2 ::= INT (0..1) [1]
+-Message type ::= MSG [1B]
On receipt, the network stops T3250 and treats the new TMSI as valid (24.008 subclause 4.3.1.3). The MS has no follow-on proceed, so it starts T3240 and waits for the network to release the RR connection (24.008 subclause 4.4.4.8).
RR : Channel Release
The network ends the Location Updating by releasing the SDCCH. RR cause Normal event tells the MS that the release is expected, and the MS returns to idle mode on this cell.
Decoded message capture,
NAS:RR,Channel Release
Channel Release ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Channel Release Message Type ::= V
| +-Message Type ::= MSG [0D]
+-RR Cause ::= V
| +-RR cause value ::= CHOICE [Normal event]
+-BA Range ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-BA RANGE IEI ::= IEI [73]
| +-Octet2 ::= DIVISION
| | +-Length of BA Range contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-Number of Ranges ::= INT (0..255) [0]
| +-Octet4- ::= DIVISION
| +-RANGE ::= REPEAT
+-Group Channel Description ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Group Channel Description IEI ::= IEI [74]
| +-Octet2 ::= DIVISION
| | +-Length of Mobile Allocation Contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [1]
| | +-Timeslot number ::= INT (0..7) [0]
| +-Octet4-5 ::= DIVISION
| | +-Training Sequence Code ::= INT (0..7) [0]
| | +-Hopping channel ::= SWITCH [Single RF channel]
| | +-(Hopping channel)=0 ::= BRANCH
| | +-spare ::= FIX [0]
| | +-Absolute RF Channel Number ::= INT (0..1023) [0]
| +-Octet6-13 ::= DIVISION
| +-Mobile Allocation RF Channel ::= OCTETARRAY SIZE(0..8)
+-Group Cipher Key Number ::= TV OPTIONAL:Omit
| +-Group Cipher Key Number IEI ::= IEI [8-]
| +-Group Cipher Key Number ::= CHOICE [spare]
+-GPRS Resumption ::= TV OPTIONAL:Omit
| +-GPRS Resumption IEI ::= IEI [C-]
| +-spare ::= FIX [0]
| +-ACK ::= CHOICE [resumption of GPRS services not successfully acknowledged]
+-BA List Pref ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-BA RANGE IEI ::= IEI [75]
| +-Octet2 ::= DIVISION
| | +-LENGTH OF BA LIST PREF ::= LEN (0..255) [0]
| +-Octet3- ::= DIVISION
| +-Range Limits ::= REPEAT
| | +-Range Limits Terminate ::= INT (0..1) [0]
| +-BA Freq ::= REPEAT
| | +-BA Freq Terminate ::= INT (0..1) [0]
| +-spare padding ::= PAD SIZE(0..20) [2B]
+-UTRAN Freq List ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-UTRAN Freq List IEI ::= IEI [76]
| +-Octet2 ::= DIVISION
| | +-LENGTH OF UTRAN FREQ LIST ::= LEN (0..255) [0]
| +-Octet3- ::= DIVISION
| +-FDD_ARFCN ::= REPEAT
| | +-FDD_ARFCN Terminate ::= INT (0..1) [0]
| +-TDD_ARFCN ::= REPEAT
| | +-TDD_ARFCN Terminate ::= INT (0..1) [0]
| +-spare ::= PAD SIZE(0..20) [0]
+-Cell Channel Description ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Cell Channel Description IEI ::= IEI [62]
| +-Octet2-17 ::= DIVISION
| +-Format-ID bit128-127 ::= SWITCH [bit map 0]
| +-(Format-ID bit128-127)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Cell Allocation Absolute RF Channel Number bit124-121 ::= INT (0..15) [0]
| +-Cell Allocation Absolute RF Channel Number bit120-001 ::= OCTETARRAY SIZE(15..15) [000000000000000000000000000000]
+-Cell selection indicator after release of all TCH and SDCCH ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Cell selection indicator after release of all TCH and SDCCH IEI ::= IEI [77]
| +-Octet2 ::= DIVISION
| | +-Length of Cell selection indicator after release of all TCH and SDCCH value part ::= LEN (0..255) [0]
| +-Octet3- ::= DIVISION
| +-Cell selection indicator after release of all TCH and SDCCH value part ::= SWITCH [GSM Description]
| +-(Cell selection indicator after release of all TCH and SDCCH value part)=0 ::= BRANCH
| +-GSM Description ::= REPEAT
| +-GSM Description Terminate ::= INT (0..1) [0]
+-Enhanced DTM CS Release Indication ::= TV OPTIONAL:Omit
| +-Enhanced DTM CS Release Indication IEI ::= IEI [A-]
| +-spare ::= FIX [0]
| +-IND ::= CHOICE [the mobile station is not allowed to continue in packet transfer mode]
+-VGCS Ciphering Parameters ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-VGCS Ciphering Parameters IEI ::= IEI [04]
| +-Octet2 ::= DIVISION
| | +-Length of VGCS Ciphering Parameters ::= LEN (0..255) [0]
| +-Octet3- ::= DIVISION
| +-spare ::= FIX [0]
| +-RAND_IND ::= SWITCH [VSTK_RAND not present]
| +-(RAND_IND)=0 ::= BRANCH
| +-LAC_IND_1 ::= SWITCH [Location Area Identification not present]
| +-(LAC_IND_1)=0 ::= BRANCH
| +-CELL_IND_1 ::= SWITCH [Cell Identification not present]
| +-(CELL_IND_1)=0 ::= BRANCH
| +-B22_COUNT ::= INT (0..1) [0]
| +-CELL_GLOBAL_COUNT ::= INT (0..3) [0]
+-Group Channel Description 2 ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-Group Channel Description 2 IEI ::= IEI [78]
+-Octet2 ::= DIVISION
| +-Length of Group Channel Description 2 ::= LEN (0..255) [0]
+-Octet3 ::= DIVISION
| +-Channel type and TDMA offset ::= INT (0..31) [1]
| +-Timeslot number ::= INT (0..7) [0]
+-Octet4-5 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-spare ::= FIX [0]
| +-MAIO ::= INT (0..63) [0]
| +-Hopping Sequence Number ::= INT (0..63) [0]
+-Octet6-13 ::= DIVISION
+-Frequency Short List 2 ::= DIVISION
+-Format-ID bit8-7 ::= FIX [2]
+-spare ::= FIX [0]
+-Format-ID bit4 ::= SWITCH [1024 range]
+-(Format-ID bit4)=0 ::= BRANCH
+-Frequency 0 Indicator ::= CHOICE
+-W(1) ::= INT (0..1023) [0]
+-W(2) ::= INT (0..511) [0]
+-W(3) ::= INT (0..511) [0]
+-W(4) ::= INT (0..255) [0]
+-W(5) ::= INT (0..255) [0]
+-W(6) ::= INT (0..255) [0]
+-spare ::= FIX [0]
Every optional IE in the capture is marked OPTIONAL:Omit, so the message carries only the RR cause. The MS is now registered in LAC 1 with its TMSI, and it listens to its paging subchannel again.
The LAC change triggers the registration : The request carries the old LAC 10, and Location Updating Accept confirms the new LAC 1.The network collects both permanent identities : The network asks for the IMSI and then the IMEI, and each answer uses the same Mobile Identity IE.A TMSI in the accept needs a confirmation : The MS answers with TMSI Reallocation Complete before the network releases the channel.This log skips authentication : CKSN says no key is available, and no Authentication Request appears. A live network may authenticate the MS at this point (24.008 subclause 4.4.4.3).
How is a mobile terminated voice call set up ?
Less than a second after the release, the network has a call for this MS. It must find the MS with paging, give it a signalling channel and agree on the bearer. Only then can it move the call to a traffic channel.
RR : Paging Request Type 1
The network pages the MS on the PCH of the CCCH. The message names the MS and tells it which channel type the call will need. The MS uses that hint to code its Channel Request.
Decoded message capture,
NAS:RR,Paging Request Type 1
Paging Request Type 1 ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [12]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Paging Request Type 1 Message Type ::= V
| +-Message Type ::= MSG [21]
+-Channels Needed for Mobiles 1 and 2 ::= V
| +-CHANNEL(second) ::= CHOICE [Any channel]
| +-CHANNEL(first) ::= CHOICE [Any channel]
+-Page Mode ::= V
| +-spare ::= FIX [0]
| +-spare ::= FIX [0]
| +-PM ::= CHOICE [Normal paging]
+-Mobile Identity 1 ::= LV
| +-Octet1 ::= DIVISION
| | +-Length of mobile identity contents ::= LEN (0..255) [8]
| +-Octet2 ::= DIVISION
| | +-Identity digit 1 ::= INT (0..15) [0]
| | +-Odd/even indication ::= CHOICE [odd number of identity digits]
| | +-Type of identity ::= CHOICE [IMSI]
| +-Octet3-Octet10 ::= DIVISION
| +-Identity digit p ::= OCTETARRAY SIZE(0..8) [10101032547698]
+-Mobile Identity 2 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Mobile Identity IEI ::= IEI [17]
| +-Octet2 ::= DIVISION
| | +-Length of mobile identity contents ::= LEN (0..255) [1]
| +-Octet3 ::= DIVISION
| | +-Identity digit 1 ::= INT (0..15) [0]
| | +-Odd/even indication ::= CHOICE [even number of identity digits and also when the TMSI/P-TMSI is used]
| | +-Type of identity ::= CHOICE [No Identity]
| +-Octet4-Octet11 ::= DIVISION
| +-Identity digit p ::= OCTETARRAY SIZE(0..8)
+-P1 Rest Octets ::= V
+-flg1 ::= SWITCH [L]
+-flg2 ::= SWITCH [L]
+-flg3 ::= SWITCH [L]
+-flg4 ::= SWITCH
+-Packet Page Indication 1 ::= CHOICE [paging procedure for RR connection establishment]
+-Packet Page Indication 2 ::= CHOICE [paging procedure for RR connection establishment]
+-flg8 ::= SWITCH [null]
+-spare padding ::= PAD SIZE(23..23) [2B]
Mobile Identity 1 is the IMSI 001010123456789, not the TMSI that the network confirmed a moment ago. The network may page with either identity. 24.008 subclause 10.5.1.4 then requires the MS to answer with the same identity type. Channel Needed for the first MS is Any channel, and Mobile Identity 2 is omitted, so this message pages one MS only.
RR : Channel Request
The log has no capture for this Channel Request, but its content can be recovered. The Immediate Assignment below echoes RA = 137, which is 10001001 in binary. 44.018 Table 9.1.8.2 maps Any channel to 100xxxxx for every MS capability. So the leading 100 marks this request as an answer to paging, and the last five bits are the random reference that the MS drew.
RR : Immediate Assignment
This Immediate Assignment matches the one used for Location Updating. The network again assigns SDCCH/8 subchannel 0 on timeslot 4 of ARFCN 129, and only the Request Reference differs.
Decoded message capture,
NAS:RR,Immediate assignment
Immediate assignment ::= DIVISION
+-L2 Pseudo Length ::= V
| +-L2 Pseudo Length value ::= INT (0..63) [11]
| +-N(SD)or0_1 ::= FIX [0]
| +-N(SD)or0_2 ::= FIX [1]
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Immediate assignment Message Type ::= V
| +-Message Type ::= MSG [3F]
+-Dedicated mode or TBF ::= V
| +-spare ::= FIX [0]
| +-TMA-Downlink-T/D ::= CHOICE [This message assigns a dedicated mode resource]
+-Page Mode ::= V
| +-spare ::= FIX [0]
| +-spare ::= FIX [0]
| +-PM ::= CHOICE [Normal paging]
+-Channel Description ::= V OPTIONAL:Exist
| +-Octet1 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [8]
| | +-Timeslot number ::= INT (0..7) [4]
| +-Octet2-3 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [129]
+-Packet Channel Description ::= V OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel type ::= INT (0..31) [1]
| | +-Timeslot Number ::= INT (0..7) [0]
| +-Octet2-3 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-flg1 ::= SWITCH [0]
| +-(flg1)=0 ::= BRANCH
| +-flg11 ::= SWITCH [0]
| +-(flg11)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [0]
+-Request Reference ::= V
| +-Octet1 ::= DIVISION
| | +-Random Access Information ::= INT (0..255) [137]
| +-Octet2-3 ::= DIVISION
| +-T1' ::= INT (0..31) [10]
| +-T3 ::= INT (0..63) [46]
| +-T2 ::= INT (0..31) [15]
+-Timing Advance ::= V
| +-Timing Advance value ::= INT (0..255) [0]
+-Mobile Allocation ::= LV
| +-Octet1 ::= DIVISION
| | +-Length of mobile allocation contents ::= LEN (0..255) [0]
| +-Octet2-9 ::= DIVISION
| +-Mobile Allocation RF Channel ::= OCTETARRAY SIZE(0..8)
+-Starting Time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Starting Time IEI ::= IEI [7C]
| +-Octet2-3 ::= DIVISION
| +-T1' ::= INT (0..31) [0]
| +-T3 ::= INT (0..63) [0]
| +-T2 ::= INT (0..31) [0]
+-IA Rest Octets ::= V
+-flg3 ::= SWITCH [LL]
+-(flg3)=LL ::= BRANCH
| +-Compressed InterRAT HO INFO IND ::= CHOICE [A compressed version of the INTER RAT HANDOVER INFO message shall not be used]
+-spare padding ::= PAD SIZE(23..23) [2B]
The Request Reference carries T1' = 10, T3 = 46 and T2 = 15, and the same formula gives frame 13561 modulo 42432. The first Immediate Assignment gave 13021. So the two Channel Request messages are 540 TDMA frames apart, which is the 2.49 second gap in the Time column.
RR : Paging Response
The first layer 3 message on the new SDCCH is now a Paging Response, not a Location Updating Request. It is an RR message, but it carries the same MM data: the ciphering key sequence number, the classmark and the mobile identity.
Decoded message capture,
NAS:RR,Paging Response
Paging Response ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Paging Response Message Type ::= V
| +-N(SD)or0 ::= FIX [0]
| +-Message Type ::= MSG [27]
+-Spare Half Octet ::= V
| +-spare ::= FIX [0]
+-Ciphering Key Sequence Number ::= V
| +-Octet1 ::= DIVISION
| +-spare ::= FIX [0]
| +-Key sequence ::= CHOICE [No key is available (MS to network)/Reserved (network to MS)]
+-Mobile Station Classmark ::= LV
| +-Octet1 ::= DIVISION
| | +-Length of mobile station classmark 2 contents ::= LEN (0..255) [3]
| +-Octet2 ::= DIVISION
| | +-spare ::= FIX [0]
| | +-Revision level ::= CHOICE [Used by GSM phase 2 mobile stations]
| | +-ES IND ::= CHOICE [Controlled Early Classmark Sending option is implemented in the MS]
| | +-A5/1 ::= CHOICE [encryption algorithm A5/1 available]
| | +-RF power capability ::= CHOICE [class 4]
| +-Octet3 ::= DIVISION
| | +-spare ::= FIX [0]
| | +-PS capability ::= CHOICE [PS capability present]
| | +-SS Screening Indicator ::= CHOICE [capability of handling of ellipsis notation and phase 2 error handling]
| | +-SM capability ::= CHOICE [Mobile station supports mobile terminated point to point SMS]
| | +-VBS notification reception ::= CHOICE [no VBS capability or no notifications wanted]
| | +-VGCS notification reception ::= CHOICE [no VGCS capability or no notifications wanted]
| | +-FC Frequency Capability ::= CHOICE [The MS does not support the E-GSM or R-GSM band (For definition of frequency bands see GSM 05.05)]
| +-Octet4 ::= DIVISION
| +-CM3 ::= CHOICE [The MS supports options that are indicated in classmark 3 IE]
| +-spare ::= FIX [0]
| +-LCS VA capability ::= CHOICE [LCS value added location request notification capability not supported]
| +-UCS2 treatment ::= CHOICE [The ME has a preference for the default alphabet over UCS2.]
| +-SoLSA ::= CHOICE [The ME does not support SoLSA.]
| +-CM Service Prompt ::= CHOICE ["Network initiated MO CM connection request" not supported.]
| +-A5/3 algorithm supported ::= CHOICE [encryption algorithm A5/3 available]
| +-A5/2 algorithm supported ::= CHOICE [encryption algorithm A5/2 not available]
+-Mobile Identity ::= LV
+-Octet1 ::= DIVISION
| +-Length of mobile identity contents ::= LEN (0..255) [8]
+-Octet2 ::= DIVISION
| +-Identity digit 1 ::= INT (0..15) [0]
| +-Odd/even indication ::= CHOICE [odd number of identity digits]
| +-Type of identity ::= CHOICE [IMSI]
+-Octet3-Octet10 ::= DIVISION
+-Identity digit p ::= OCTETARRAY SIZE(0..8) [10101032547698]
Mobile Identity is the IMSI, which matches the identity type in Paging Request Type 1. CKSN still says that no key is available, because the Location Updating ran without authentication. Mobile Station Classmark 2 reports A5/1 and A5/3 as available and A5/2 as not available.
CC : Setup
With the RR connection in place, the network starts call control. Setup opens a CC transaction with TI value 0, and the TI flag shows that the network originated this transaction.
Decoded message capture,
NAS:CC,Setup (Network to MS direction)
Setup (Network to MS direction) ::= DIVISION
+-Transaction identifier ::= V
| +-TI flag ::= CHOICE [The message is sent from the side that originates the TI]
| +-TIO ::= CHOICE [TI value 0]
+-Call control Protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [3]
+-Setup Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [05]
+-BC repeat indicator ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-repeat indicatorIEI ::= IEI [D-]
| +-repeat indication ::= CHOICE [Circular for successive selection"mode 1 alternate mode 2"]
+-Bearer capability 1 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Bearer capability IEI ::= IEI [04]
| +-Octet2 ::= DIVISION
| | +-Length of the bearer capability contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-Octet3a ext ::= SWITCH [1]
| | +-radiochannelrequirement ::= CHOICE [full rate support only MS]
| | +-Coding standard ::= CHOICE [GSM standardized coding as described below]
| | +-transfermode ::= CHOICE [circuit mode]
| | +-informationtransfercapability ::= CHOICE [speech]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Compression ::= CHOICE [data compression possible(n to MS)/data compression allowed(MS to n)]
| | +-structure ::= CHOICE [service data unit integrity]
| | +-Duplex mode ::= CHOICE [half duplex]
| | +-Configuration ::= CHOICE [point-to-point]
| | +-NIRR ::= CHOICE [No meaning is associated with this value.]
| | +-Establishment ::= CHOICE [demand]
| +-Octet5 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-access id. ::= CHOICE [octet identifier]
| | +-rate adaption ::= CHOICE [no rate adaption]
| | +-signalling access protocol ::= CHOICE [reserved 0]
| +-Octet5a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Other ITC ::= CHOICE [restricted digital information]
| | +-Other rate adaption ::= CHOICE [V.120]
| | +-Spare ::= FIX [0]
| +-Octet5b ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Rate adaption header/no header ::= CHOICE [Rate adaption header not included]
| | +-Multiple frame establishment support in data link ::= CHOICE [Multiple frame establishment not supported only UI frames allowed]
| | +-Mode of operation ::= CHOICE [Bit transparent mode of operation]
| | +-Logical link identifier negotiation ::= CHOICE [Default LLI]
| | +-Assignor/Assignee ::= CHOICE [Message originator is "default assignee"]
| | +-In band/Out of band negotiation ::= CHOICE [Negotiation is done in-band using logical link zero]
| | +-Spare ::= FIX [0]
| +-Octet6 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-layer 1 id. ::= CHOICE [octet identifier]
| | +-User information layer 1 protocol ::= CHOICE [default layer 1 protocol]
| | +-Synchronous/asynchronous ::= CHOICE [synchronous]
| +-Octet6a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Number of Stop Bits ::= CHOICE [1bit(This value is also used in the case of synchronous mode)]
| | +-Negotiation ::= CHOICE [in-band negotiation not possible]
| | +-Number of data bits excluding parity bit if present ::= CHOICE [7 bits]
| | +-user rate ::= CHOICE [0.3 kbit/s Recommendation X.1 and V.110]
| +-Octet6b ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Intermediate rate ::= CHOICE [reserved 0]
| | +-NICon TX ::= CHOICE [does not require to send data with network independent clock]
| | +-NICon RX ::= CHOICE [cannot accept data with network independent clock (i.e. sender does not support this optional procedure)]
| | +-Parity information ::= CHOICE [odd]
| +-Octet6c ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-connectionelement ::= CHOICE [transparent]
| | +-modem type ::= CHOICE [none]
| +-Octet6d ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Othermodem type ::= CHOICE [no other modem type specified in this field]
| | +-Fixed network user rate ::= CHOICE [Fixed network user rate not applicable/No meaning is associated with this value.]
| +-Octet6e ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Acceptablechannelcodings14.4 ::= CHOICE [TCH/F14.4 not acceptable]
| | +-Spare ::= FIX [0]
| | +-Acceptablechannelcodings9.6 ::= CHOICE [TCH/F9.6 not acceptable]
| | +-Acceptablechannelcodings4.8 ::= CHOICE [TCH/F4.8 not acceptable]
| | +-Maximum number oftraffic channels ::= CHOICE [1 TCH]
| +-Octet6f ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-UIMI ::= CHOICE [User initiated modification not allowed/required/applicable]
| | +-Wanted air interfaceuser rate ::= CHOICE [Air interface user rate not applicable/No meaning associated with this value]
| +-Octet6g ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Acceptablechannel codings extended28.8 ::= CHOICE [TCH/F28.8 not acceptable]
| | +-Acceptablechannel codings extended32.0 ::= CHOICE [TCH/F32.0 not acceptable]
| | +-Acceptablechannel codings extended43.2 ::= CHOICE [TCH/F43.2 not acceptable]
| | +-Asymmetry Indication ::= CHOICE [Channel coding symmetry preferred]
| | +-Spare ::= FIX [0]
| +-Octet7 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-layer 2 id. ::= CHOICE [octet identifier]
| +-User information layer 2 protocol ::= CHOICE [reserved 0]
+-Bearer capability 2 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Bearer capability IEI ::= IEI [04]
| +-Octet2 ::= DIVISION
| | +-Length of the bearer capability contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-Octet3a ext ::= SWITCH [1]
| | +-radiochannelrequirement ::= CHOICE [full rate support only MS]
| | +-Coding standard ::= CHOICE [GSM standardized coding as described below]
| | +-transfermode ::= CHOICE [circuit mode]
| | +-informationtransfercapability ::= CHOICE [speech]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Compression ::= CHOICE [data compression possible(n to MS)/data compression allowed(MS to n)]
| | +-structure ::= CHOICE [service data unit integrity]
| | +-Duplex mode ::= CHOICE [half duplex]
| | +-Configuration ::= CHOICE [point-to-point]
| | +-NIRR ::= CHOICE [No meaning is associated with this value.]
| | +-Establishment ::= CHOICE [demand]
| +-Octet5 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-access id. ::= CHOICE [octet identifier]
| | +-rate adaption ::= CHOICE [no rate adaption]
| | +-signalling access protocol ::= CHOICE [reserved 0]
| +-Octet5a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Other ITC ::= CHOICE [restricted digital information]
| | +-Other rate adaption ::= CHOICE [V.120]
| | +-Spare ::= FIX [0]
| +-Octet5b ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Rate adaption header/no header ::= CHOICE [Rate adaption header not included]
| | +-Multiple frame establishment support in data link ::= CHOICE [Multiple frame establishment not supported only UI frames allowed]
| | +-Mode of operation ::= CHOICE [Bit transparent mode of operation]
| | +-Logical link identifier negotiation ::= CHOICE [Default LLI]
| | +-Assignor/Assignee ::= CHOICE [Message originator is "default assignee"]
| | +-In band/Out of band negotiation ::= CHOICE [Negotiation is done in-band using logical link zero]
| | +-Spare ::= FIX [0]
| +-Octet6 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-layer 1 id. ::= CHOICE [octet identifier]
| | +-User information layer 1 protocol ::= CHOICE [default layer 1 protocol]
| | +-Synchronous/asynchronous ::= CHOICE [synchronous]
| +-Octet6a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Number of Stop Bits ::= CHOICE [1bit(This value is also used in the case of synchronous mode)]
| | +-Negotiation ::= CHOICE [in-band negotiation not possible]
| | +-Number of data bits excluding parity bit if present ::= CHOICE [7 bits]
| | +-user rate ::= CHOICE [0.3 kbit/s Recommendation X.1 and V.110]
| +-Octet6b ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Intermediate rate ::= CHOICE [reserved 0]
| | +-NICon TX ::= CHOICE [does not require to send data with network independent clock]
| | +-NICon RX ::= CHOICE [cannot accept data with network independent clock (i.e. sender does not support this optional procedure)]
| | +-Parity information ::= CHOICE [odd]
| +-Octet6c ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-connectionelement ::= CHOICE [transparent]
| | +-modem type ::= CHOICE [none]
| +-Octet6d ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Othermodem type ::= CHOICE [no other modem type specified in this field]
| | +-Fixed network user rate ::= CHOICE [Fixed network user rate not applicable/No meaning is associated with this value.]
| +-Octet6e ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Acceptablechannelcodings14.4 ::= CHOICE [TCH/F14.4 not acceptable]
| | +-Spare ::= FIX [0]
| | +-Acceptablechannelcodings9.6 ::= CHOICE [TCH/F9.6 not acceptable]
| | +-Acceptablechannelcodings4.8 ::= CHOICE [TCH/F4.8 not acceptable]
| | +-Maximum number oftraffic channels ::= CHOICE [1 TCH]
| +-Octet6f ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-UIMI ::= CHOICE [User initiated modification not allowed/required/applicable]
| | +-Wanted air interfaceuser rate ::= CHOICE [Air interface user rate not applicable/No meaning associated with this value]
| +-Octet6g ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Acceptablechannel codings extended28.8 ::= CHOICE [TCH/F28.8 not acceptable]
| | +-Acceptablechannel codings extended32.0 ::= CHOICE [TCH/F32.0 not acceptable]
| | +-Acceptablechannel codings extended43.2 ::= CHOICE [TCH/F43.2 not acceptable]
| | +-Asymmetry Indication ::= CHOICE [Channel coding symmetry preferred]
| | +-Spare ::= FIX [0]
| +-Octet7 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-layer 2 id. ::= CHOICE [octet identifier]
| +-User information layer 2 protocol ::= CHOICE [reserved 0]
+-Facility ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Facility IEI ::= IEI [1C]
| +-Octet2 ::= DIVISION
| | +-Length of facility contents ::= LEN (0..255) [0]
| +-Octet3-Octet255 ::= DIVISION
| +-Facility information ::= OCTETARRAY SIZE(0..253)
+-Progress indicator(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Progress indicator IEI ::= IEI [1E]
| +-Octet2 ::= DIVISION
| | +-Length of progress indicator contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-codingstandard ::= CHOICE [Standardized coding as described in ITU-T Rec. Q.931]
| | +-spare ::= FIX [0]
| | +-location ::= CHOICE [User]
| +-Octet4 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-progress description ::= CHOICE [1.Call is not end-to-end PLMN/ISDN further call progress information may be available in-band]
+-Signal(network to mobile station direction) ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Signal IEI ::= IEI [34]
| +-Octet2 ::= DIVISION
| +-Signal value ::= CHOICE [dial tone on]
+-Calling party BCD Number(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Calling party BCD number IEI ::= IEI [5C]
| +-Octet2 ::= DIVISION
| | +-Length of calling party BCD number contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-type of number ::= CHOICE [unknown]
| | +-Numbering planidentification ::= CHOICE [unknown Numberdigit]
| +-Octet3a ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-presentat indicator ::= CHOICE [Presentation allowed]
| | +-spare ::= FIX [0]
| | +-screening indicator ::= CHOICE [User-provided not screened]
| +-Octet4-13 ::= DIVISION
| +-Number digit ::= DIGIT SIZE(0..20)
+-Calling party sub-Address ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Calling party Subaddress IEI ::= IEI [5D]
| +-Octet2 ::= DIVISION
| | +-Length of calling party subaddress contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-type of subaddress ::= CHOICE [NSAP (X.213/ISO 8348 AD2)]
| | +-Odd/even indicator ::= CHOICE [even number of address signals]
| | +-spare ::= FIX [0]
| +-Octet4-Octet23 ::= DIVISION
| +-Subaddress information ::= OCTETARRAY SIZE(0..20)
+-Called party BCD Number ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Called party BCD number IEI ::= IEI [5E]
| +-Octet2 ::= DIVISION
| | +-Length of called party BCD number contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-type of number ::= CHOICE [unknown]
| | +-Numbering planidentification ::= CHOICE [unknown Numberdigit]
| +-Octet4-19 ::= DIVISION
| +-Number digit ::= DIGIT SIZE(0..32)
+-Called party sub-Address ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Called party Subaddress IEI ::= IEI [6D]
| +-Octet2 ::= DIVISION
| | +-Length of called party subaddress contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-type of subaddress ::= CHOICE [NSAP (X.213/ISO 8348 AD2)]
| | +-Odd/even indicator ::= CHOICE [even number of address signals]
| | +-spare ::= FIX [0]
| +-Octet4-Octet23 ::= DIVISION
| +-Subaddress information ::= OCTETARRAY SIZE(0..20)
+-Redirecting party BCD number(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Redirecting party BCD number IEI ::= IEI [74]
| +-Octet2 ::= DIVISION
| | +-Length of redirecting party BCD number contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-type of number ::= CHOICE [unknown]
| | +-Numbering planidentification ::= CHOICE [unknown Numberdigit]
| +-Octet3a ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-presentat indicator ::= CHOICE [Presentation allowed]
| | +-spare ::= FIX [0]
| | +-screening indicator ::= CHOICE [User-provided not screened]
| +-Octet5-18 ::= DIVISION
| +-Number digit ::= DIGIT SIZE(0..28)
+-Redirecting party subaddress(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Redirecting party Subaddress IEI ::= IEI [75]
| +-Octet2 ::= DIVISION
| | +-Length of redirecting party subaddress contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-type of subaddress ::= CHOICE [NSAP (X.213/ISO 8348 AD2)]
| | +-Odd/even indicator ::= CHOICE [even number of address signals]
| | +-spare ::= FIX [0]
| +-Octet4-Octet23 ::= DIVISION
| +-Subaddress information ::= OCTETARRAY SIZE(0..20)
+-LLC repeat indicator ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-repeat indicatorIEI ::= IEI [D-]
| +-repeat indication ::= CHOICE [Circular for successive selection"mode 1 alternate mode 2"]
+-Low layer Compatibility 1 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Low layer compatibility IEI ::= IEI [7C]
| +-Octet2 ::= DIVISION
| | +-Length of the low layer compatibility contents ::= LEN (0..255) [0]
| +-Octet3-Octet18 ::= DIVISION
| +-The following octets are codedas described inITU Recommendation Q.931 ::= OCTETARRAY SIZE(0..16)
+-Low layer Compatibility 2 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Low layer compatibility IEI ::= IEI [7C]
| +-Octet2 ::= DIVISION
| | +-Length of the low layer compatibility contents ::= LEN (0..255) [0]
| +-Octet3-Octet18 ::= DIVISION
| +-The following octets are codedas described inITU Recommendation Q.931 ::= OCTETARRAY SIZE(0..16)
+-HLC repeat indicator ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-repeat indicatorIEI ::= IEI [D-]
| +-repeat indication ::= CHOICE [Circular for successive selection"mode 1 alternate mode 2"]
+-High layer Compatibility 1 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-High layer compatibility IEI ::= IEI [7D]
| +-Octet2 ::= DIVISION
| | +-Length of high layer compatibility contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-codingstandard ::= INT (0..3) [0]
| | +-interpretation ::= INT (0..7) [0]
| | +-presentat.method ofprotocolprofile ::= INT (0..3) [0]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-High layer characteristics identification ::= INT (0..127) [0]
| +-Octet4a ::= DIVISION
| +-ext ::= EXT1 [1]
| +-Extended high layer characteristicsidentification ::= INT (0..127) [0]
+-High layer Compatibility 2 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-High layer compatibility IEI ::= IEI [7D]
| +-Octet2 ::= DIVISION
| | +-Length of high layer compatibility contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-codingstandard ::= INT (0..3) [0]
| | +-interpretation ::= INT (0..7) [0]
| | +-presentat.method ofprotocolprofile ::= INT (0..3) [0]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-High layer characteristics identification ::= INT (0..127) [0]
| +-Octet4a ::= DIVISION
| +-ext ::= EXT1 [1]
| +-Extended high layer characteristicsidentification ::= INT (0..127) [0]
+-User-user ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-User-user IEI ::= IEI [7E]
| +-Octet2 ::= DIVISION
| | +-Length of user-user contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-User-user protocol discriminator ::= CHOICE [User specific protocol]
| +-Octet4-Octet35 ::= DIVISION
| +-User-user information ::= OCTETARRAY SIZE(0..32)
+-Priority(network to mobile station direction) ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-Priority LevelIEI ::= IEI [8-]
| +-spare ::= FIX [0]
| +-call priority ::= CHOICE [no priority applied]
+-Alerting Pattern $(NIA)$(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Alerting Pattern IEI ::= IEI [19]
| +-Octet2 ::= DIVISION
| | +-length of alerting pattern content ::= LEN (0..255) [1]
| +-Octet3 ::= DIVISION
| +-spare ::= FIX [0]
| +-Alerting Pattern value ::= CHOICE [alerting pattern 1]
+-Network Call Control Capabilities(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Network Call Control Capabilities IEI ::= IEI [2F]
| +-Octet2 ::= DIVISION
| | +-Length of NW Call Control Cap. contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| +-spare ::= FIX [0]
| +-MCS ::= CHOICE [This value indicates that the network does not support the multicall]
+-Cause of No CLI(network to mobile station direction) ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Cause of No CLI IEI ::= IEI [3A]
| +-Octet2 ::= DIVISION
| | +-Length of Cause of No CLI contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| +-Cause of No CLI ::= CHOICE [Unavailable]
+-Backup bearer capability ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-Backup bearer capability IEI ::= IEI [04]
+-Octet2 ::= DIVISION
| +-Length of the backup bearer capability contents ::= LEN (0..255) [0]
+-Octet3 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-radiochannelrequirement ::= CHOICE [full rate support only MS]
| +-Coding standard ::= CHOICE [GSM standardized coding as described below]
| +-transfermode ::= CHOICE [circuit mode]
| +-informationtransfercapability ::= CHOICE [speech]
+-Octet4 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-Compression ::= CHOICE [data compression possible(n to MS)/data compression allowed(MS to n)]
| +-structure ::= CHOICE [service data unit integrity]
| +-Duplex mode ::= CHOICE [half duplex]
| +-Configuration ::= CHOICE [point-to-point]
| +-NIRR ::= CHOICE [No meaning is associated with this value.]
| +-Establishment ::= CHOICE [demand]
+-Octet5 ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-access id. ::= CHOICE [octet identifier]
| +-rate adaption ::= CHOICE [no rate adaption]
| +-signalling access protocol ::= CHOICE [reserved 0]
+-Octet5a ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-Other ITC ::= CHOICE [restricted digital information]
| +-Other rate adaption ::= CHOICE [V.120]
| +-Spare ::= FIX [0]
+-Octet6 ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-layer 1 id. ::= CHOICE [octet identifier]
| +-User information layer 1 protocol ::= CHOICE [default layer 1 protocol]
| +-Synchronous/asynchronous ::= CHOICE [synchronous]
+-Octet6a ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-Number of Stop Bits ::= CHOICE [1bit(This value is also used in the case of synchronous mode)]
| +-Negotiation ::= CHOICE [in-band negotiation not possible]
| +-Number of data bits excluding parity bit if present ::= CHOICE [7 bits]
| +-user rate ::= CHOICE [0.3 kbit/s Recommendation X.1 and V.110]
+-Octet6b ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-Intermediate rate ::= CHOICE [reserved 0]
| +-NICon TX ::= CHOICE [does not require to send data with network independent clock]
| +-NICon RX ::= CHOICE [cannot accept data with network independent clock (i.e. sender does not support this optional procedure)]
| +-Parity information ::= CHOICE [odd]
+-Octet6c ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-connectionelement ::= CHOICE [transparent]
| +-modem type ::= CHOICE [none]
+-Octet6d ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-Othermodem type ::= CHOICE [no other modem type specified in this field]
| +-Fixed network user rate ::= CHOICE [Fixed network user rate not applicable/No meaning is associated with this value.]
+-Octet6e ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-Acceptablechannelcodings14.4 ::= CHOICE [TCH/F14.4 not acceptable]
| +-Spare ::= FIX [0]
| +-Acceptablechannelcodings9.6 ::= CHOICE [TCH/F9.6 not acceptable]
| +-Acceptablechannelcodings4.8 ::= CHOICE [TCH/F4.8 not acceptable]
| +-Maximum number oftraffic channels ::= CHOICE [1 TCH]
+-Octet6f ::= DIVISION
| +-ext ::= EXT (0..1) [1]
| +-UIMI ::= CHOICE [User initiated modification not allowed/required/applicable]
| +-Wanted air interfaceuser rate ::= CHOICE [Air interface user rate not applicable/No meaning associated with this value]
+-Octet6g ::= DIVISION
| +-ext ::= EXT1 [1]
| +-Acceptablechannel codings extended28.8 ::= CHOICE [TCH/F28.8 not acceptable]
| +-Acceptablechannel codings extended32.0 ::= CHOICE [TCH/F32.0 not acceptable]
| +-Acceptablechannel codings extended43.2 ::= CHOICE [TCH/F43.2 not acceptable]
| +-Asymmetry Indication ::= CHOICE [Channel coding symmetry preferred]
| +-Spare ::= FIX [0]
+-Octet7 ::= DIVISION
+-ext ::= EXT1 [1]
+-layer 2 id. ::= CHOICE [octet identifier]
+-User information layer 2 protocol ::= CHOICE [reserved 0]
Every optional IE in this Setup is marked OPTIONAL:Omit. So there is no Bearer capability, no Calling party BCD number and no Signal IE. 24.008 subclause 9.3.23.1.2 allows the network to omit Bearer capability 1 when the subscriber has one directory number for all services. The MS then states its own bearer in Call Confirmed.
Without a Calling party BCD number, the MS also has no caller number to display.
CC : Call Confirmed
The MS accepts the incoming call with Call Confirmed. The TI flag now says the message goes to the side that originated the TI, so this message travels from the MS to the network.
Decoded message capture,
NAS:CC,Call confirmed
Call confirmed ::= DIVISION
+-Transaction identifier ::= V
| +-TI flag ::= CHOICE [The message is sent to the side that originates the TI]
| +-TIO ::= CHOICE [TI value 0]
+-Call control Protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [3]
+-Call confirmed Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [0]
| +-Message type ::= MSG [08]
+-repeat indicator ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| +-repeat indicatorIEI ::= IEI [D-]
| +-repeat indication ::= CHOICE [Circular for successive selection"mode 1 alternate mode 2"]
+-Bearer capability 1 ::= TLV OPTIONAL:Exist
| +-Octet1 ::= DIVISION
| | +-Bearer capability IEI ::= IEI [04]
| +-Octet2 ::= DIVISION
| | +-Length of the bearer capability contents ::= LEN (0..255) [6]
| +-Octet3 ::= DIVISION
| | +-Octet3a ext ::= SWITCH [0]
| | +-radiochannelrequirement ::= CHOICE [dual rate support MS/full rate preferred]
| | +-Coding standard ::= CHOICE [GSM standardized coding as described below]
| | +-transfermode ::= CHOICE [circuit mode]
| | +-informationtransfercapability ::= CHOICE [speech]
| | +-(Octet3a ext)=0 ::= BRANCH
| | +-Octet3a_etc_1 ::= DIVISION
| | +-Octet3b ext ::= SWITCH [0]
| | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | +-CTM ::= CHOICE [CTM text telephony is not supported]
| | +-spare ::= FIX [0]
| | +-speech versionindication ::= CHOICE [GSM full rate speech version 3]
| | +-(Octet3b ext)=0 ::= BRANCH
| | +-Octet3b_etc_1 ::= DIVISION
| | | +-ext ::= EXT (0..1) [0]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 2]
| | +-Octet3b_etc_2 ::= DIVISION
| | | +-ext ::= EXT (0..1) [0]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_3 ::= DIVISION
| | | +-ext ::= EXT (0..1) [0]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM half rate speech version 3]
| | +-Octet3b_etc_4 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM half rate speech version 1]
| | +-Octet3b_etc_5 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_6 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_7 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_8 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_9 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_10 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_11 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_12 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_13 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_14 ::= DIVISION
| | | +-ext ::= EXT (0..1) [1]
| | | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | | +-spare ::= FIX [0]
| | | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| | +-Octet3b_etc_15 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Coding ::= CHOICE [octet used for extension of information transfer capability]
| | +-spare ::= FIX [0]
| | +-speech versionindication ::= CHOICE [GSM full rate speech version 1]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Compression ::= CHOICE [data compression possible(n to MS)/data compression allowed(MS to n)]
| | +-structure ::= CHOICE [service data unit integrity]
| | +-Duplex mode ::= CHOICE [half duplex]
| | +-Configuration ::= CHOICE [point-to-point]
| | +-NIRR ::= CHOICE [No meaning is associated with this value.]
| | +-Establishment ::= CHOICE [demand]
| +-Octet5 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-access id. ::= CHOICE [octet identifier]
| | +-rate adaption ::= CHOICE [no rate adaption]
| | +-signalling access protocol ::= CHOICE [reserved 0]
| +-Octet5a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Other ITC ::= CHOICE [restricted digital information]
| | +-Other rate adaption ::= CHOICE [V.120]
| | +-Spare ::= FIX [0]
| +-Octet5b ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Rate adaption header/no header ::= CHOICE [Rate adaption header not included]
| | +-Multiple frame establishment support in data link ::= CHOICE [Multiple frame establishment not supported only UI frames allowed]
| | +-Mode of operation ::= CHOICE [Bit transparent mode of operation]
| | +-Logical link identifier negotiation ::= CHOICE [Default LLI]
| | +-Assignor/Assignee ::= CHOICE [Message originator is "default assignee"]
| | +-In band/Out of band negotiation ::= CHOICE [Negotiation is done in-band using logical link zero]
| | +-Spare ::= FIX [0]
| +-Octet6 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-layer 1 id. ::= CHOICE [octet identifier]
| | +-User information layer 1 protocol ::= CHOICE [default layer 1 protocol]
| | +-Synchronous/asynchronous ::= CHOICE [synchronous]
| +-Octet6a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Number of Stop Bits ::= CHOICE [1bit(This value is also used in the case of synchronous mode)]
| | +-Negotiation ::= CHOICE [in-band negotiation not possible]
| | +-Number of data bits excluding parity bit if present ::= CHOICE [7 bits]
| | +-user rate ::= CHOICE [0.3 kbit/s Recommendation X.1 and V.110]
| +-Octet6b ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Intermediate rate ::= CHOICE [reserved 0]
| | +-NICon TX ::= CHOICE [does not require to send data with network independent clock]
| | +-NICon RX ::= CHOICE [cannot accept data with network independent clock (i.e. sender does not support this optional procedure)]
| | +-Parity information ::= CHOICE [odd]
| +-Octet6c ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-connectionelement ::= CHOICE [transparent]
| | +-modem type ::= CHOICE [none]
| +-Octet6d ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Othermodem type ::= CHOICE [no other modem type specified in this field]
| | +-Fixed network user rate ::= CHOICE [Fixed network user rate not applicable/No meaning is associated with this value.]
| +-Octet6e ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Acceptablechannelcodings14.4 ::= CHOICE [TCH/F14.4 not acceptable]
| | +-Spare ::= FIX [0]
| | +-Acceptablechannelcodings9.6 ::= CHOICE [TCH/F9.6 not acceptable]
| | +-Acceptablechannelcodings4.8 ::= CHOICE [TCH/F4.8 not acceptable]
| | +-Maximum number oftraffic channels ::= CHOICE [1 TCH]
| +-Octet6f ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-UIMI ::= CHOICE [User initiated modification not allowed/required/applicable]
| | +-Wanted air interfaceuser rate ::= CHOICE [Air interface user rate not applicable/No meaning associated with this value]
| +-Octet6g ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Acceptablechannel codings extended28.8 ::= CHOICE [TCH/F28.8 not acceptable]
| | +-Acceptablechannel codings extended32.0 ::= CHOICE [TCH/F32.0 not acceptable]
| | +-Acceptablechannel codings extended43.2 ::= CHOICE [TCH/F43.2 not acceptable]
| | +-Asymmetry Indication ::= CHOICE [Channel coding symmetry preferred]
| | +-Spare ::= FIX [0]
| +-Octet7 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-layer 2 id. ::= CHOICE [octet identifier]
| +-User information layer 2 protocol ::= CHOICE [reserved 0]
+-Bearer capability 2 ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Bearer capability IEI ::= IEI [04]
| +-Octet2 ::= DIVISION
| | +-Length of the bearer capability contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-Octet3a ext ::= SWITCH [1]
| | +-radiochannelrequirement ::= CHOICE [full rate support only MS]
| | +-Coding standard ::= CHOICE [GSM standardized coding as described below]
| | +-transfermode ::= CHOICE [circuit mode]
| | +-informationtransfercapability ::= CHOICE [speech]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Compression ::= CHOICE [data compression possible(n to MS)/data compression allowed(MS to n)]
| | +-structure ::= CHOICE [service data unit integrity]
| | +-Duplex mode ::= CHOICE [half duplex]
| | +-Configuration ::= CHOICE [point-to-point]
| | +-NIRR ::= CHOICE [No meaning is associated with this value.]
| | +-Establishment ::= CHOICE [demand]
| +-Octet5 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-access id. ::= CHOICE [octet identifier]
| | +-rate adaption ::= CHOICE [no rate adaption]
| | +-signalling access protocol ::= CHOICE [reserved 0]
| +-Octet5a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Other ITC ::= CHOICE [restricted digital information]
| | +-Other rate adaption ::= CHOICE [V.120]
| | +-Spare ::= FIX [0]
| +-Octet5b ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Rate adaption header/no header ::= CHOICE [Rate adaption header not included]
| | +-Multiple frame establishment support in data link ::= CHOICE [Multiple frame establishment not supported only UI frames allowed]
| | +-Mode of operation ::= CHOICE [Bit transparent mode of operation]
| | +-Logical link identifier negotiation ::= CHOICE [Default LLI]
| | +-Assignor/Assignee ::= CHOICE [Message originator is "default assignee"]
| | +-In band/Out of band negotiation ::= CHOICE [Negotiation is done in-band using logical link zero]
| | +-Spare ::= FIX [0]
| +-Octet6 ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-layer 1 id. ::= CHOICE [octet identifier]
| | +-User information layer 1 protocol ::= CHOICE [default layer 1 protocol]
| | +-Synchronous/asynchronous ::= CHOICE [synchronous]
| +-Octet6a ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Number of Stop Bits ::= CHOICE [1bit(This value is also used in the case of synchronous mode)]
| | +-Negotiation ::= CHOICE [in-band negotiation not possible]
| | +-Number of data bits excluding parity bit if present ::= CHOICE [7 bits]
| | +-user rate ::= CHOICE [0.3 kbit/s Recommendation X.1 and V.110]
| +-Octet6b ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Intermediate rate ::= CHOICE [reserved 0]
| | +-NICon TX ::= CHOICE [does not require to send data with network independent clock]
| | +-NICon RX ::= CHOICE [cannot accept data with network independent clock (i.e. sender does not support this optional procedure)]
| | +-Parity information ::= CHOICE [odd]
| +-Octet6c ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-connectionelement ::= CHOICE [transparent]
| | +-modem type ::= CHOICE [none]
| +-Octet6d ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Othermodem type ::= CHOICE [no other modem type specified in this field]
| | +-Fixed network user rate ::= CHOICE [Fixed network user rate not applicable/No meaning is associated with this value.]
| +-Octet6e ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-Acceptablechannelcodings14.4 ::= CHOICE [TCH/F14.4 not acceptable]
| | +-Spare ::= FIX [0]
| | +-Acceptablechannelcodings9.6 ::= CHOICE [TCH/F9.6 not acceptable]
| | +-Acceptablechannelcodings4.8 ::= CHOICE [TCH/F4.8 not acceptable]
| | +-Maximum number oftraffic channels ::= CHOICE [1 TCH]
| +-Octet6f ::= DIVISION
| | +-ext ::= EXT (0..1) [1]
| | +-UIMI ::= CHOICE [User initiated modification not allowed/required/applicable]
| | +-Wanted air interfaceuser rate ::= CHOICE [Air interface user rate not applicable/No meaning associated with this value]
| +-Octet6g ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-Acceptablechannel codings extended28.8 ::= CHOICE [TCH/F28.8 not acceptable]
| | +-Acceptablechannel codings extended32.0 ::= CHOICE [TCH/F32.0 not acceptable]
| | +-Acceptablechannel codings extended43.2 ::= CHOICE [TCH/F43.2 not acceptable]
| | +-Asymmetry Indication ::= CHOICE [Channel coding symmetry preferred]
| | +-Spare ::= FIX [0]
| +-Octet7 ::= DIVISION
| +-ext ::= EXT1 [1]
| +-layer 2 id. ::= CHOICE [octet identifier]
| +-User information layer 2 protocol ::= CHOICE [reserved 0]
+-Cause ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Cause IEI ::= IEI [08]
| +-Octet2 ::= DIVISION
| | +-Length of cause contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-Octet3a ext ::= SWITCH [1]
| | +-codingstandard ::= CHOICE [Standardized coding as described in ITU-T Rec. Q.931]
| | +-spare ::= FIX [0]
| | +-location ::= CHOICE [User]
| +-Octet4 ::= DIVISION
| | +-ext ::= EXT1 [1]
| | +-cause value ::= CHOICE [1.Unassigned (unallocated) number]
| +-Octet5-Octet32 ::= DIVISION
| +-diagnostic(s) if any ::= OCTETARRAY SIZE(0..27)
+-Call Control Capabilities ::= TLV OPTIONAL:Exist
| +-Octet1 ::= DIVISION
| | +-Call Control Capabilities IEI ::= IEI [15]
| +-Octet2 ::= DIVISION
| | +-Length of Call Control Capabilities contents ::= LEN (0..255) [2]
| +-Octet3 ::= DIVISION
| | +-Maximum number of supported bearers ::= CHOICE [1 bearer supported]
| | +-spare ::= FIX [0]
| | +-ENICM ::= CHOICE [The Enhanced Network-initiated In-Call Modification not supported]
| | +-PCP ::= CHOICE [This value indicates that the mobile station does not support the Prolonged Clearing Procedure]
| | +-DTMF1 ::= CHOICE
| +-Octet4 ::= DIVISION
| +-spare ::= FIX [0]
| +-Maximum number of speech bearers ::= INT (0..15) [0]
+-Stream Identifier ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Stream Identifier IEI ::= IEI [2D]
| +-Octet2 ::= DIVISION
| | +-Length of Stream Identifier contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| +-Stream Identifier Value ::= CHOICE [No bearer]
+-Supported Codecs ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-Supported Codec List IEI ::= IEI [40]
+-Octet2 ::= DIVISION
| +-Length Of Supported Codec list ::= LEN (0..255) [0]
+-Octet3- ::= DIVISION
+-System Identification ::= REPEAT
Bearer capability 1 is marked OPTIONAL:Exist here, because the Setup did not carry one (24.008 subclause 9.3.2.2). It declares speech and a dual rate MS with full rate preferred. It also lists the speech versions, and 24.008 orders that list by preference, highest first. This MS prefers GSM full rate speech version 3, then full rate versions 2 and 1, then half rate versions 3 and 1.
The Length of the bearer capability contents is 6. Those six octets are octet 3 and the five speech version octets, so the data rows printed after them are only the decoder's template. Call Control Capabilities is also present, and it reports support for one bearer.
RR : Assignment Command
The call now needs a traffic channel, so the network moves the MS from the SDCCH to a TCH with Assignment Command. The command goes out on the SDCCH, and the MS answers on the new channel.
Decoded message capture,
NAS:RR,Assignment command
Assignment command ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Assignment command Message Type ::= V
| +-N(SD)or0 ::= FIX [0]
| +-Message Type ::= MSG [2E]
+-Description of the First Channel. after time ::= V
| +-Octet1 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [1]
| | +-Timeslot number ::= INT (0..7) [4]
| +-Octet2-3 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [129]
+-Power Command ::= V
| +-spare ::= FIX [0]
| +-EPC_mode ::= SWITCH [Channel(s) not in EPC mode]
| +-(EPC_mode)=0 ::= BRANCH
| | +-FPC ::= CHOICE [FPC not in use]
| +-Power level ::= INT (0..31) [8]
+-Frequency List. after time ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Frequency List IEI ::= IEI [05]
| +-Octet2 ::= DIVISION
| | +-Length of frequency list contents ::= LEN (0..255) [0]
| +-Octet3-132 ::= DIVISION
| +-Format-ID bit8-7 ::= SWITCH [bit map 0]
| +-(Format-ID bit8-7)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number bit124-121 ::= INT (0..15) [0]
| +-Absolute RF Channel Number bit120-001 ::= OCTETARRAY SIZE(15..15) [000000000000000000000000000000]
+-Cell Channel Description ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Cell Channel Description IEI ::= IEI [62]
| +-Octet2-17 ::= DIVISION
| +-Format-ID bit128-127 ::= SWITCH [bit map 0]
| +-(Format-ID bit128-127)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Cell Allocation Absolute RF Channel Number bit124-121 ::= INT (0..15) [0]
| +-Cell Allocation Absolute RF Channel Number bit120-001 ::= OCTETARRAY SIZE(15..15) [000000000000000000000000000000]
+-Description of the multislot configuration ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Multislot alloction IEI ::= IEI [10]
| +-Octet2 ::= DIVISION
| | +-Length of the multislot allocation contents ::= LEN (0..255) [0]
| +-Octet3-12 ::= DIVISION
| +-ext ::= SWITCH [1]
| +-Downlink assignment ::= INT (0..127) [0]
| +-Channel set n ::= OCTETARRAY SIZE(0..8) [00]
+-Mode of the First Channel (Channel Set 1) ::= TV OPTIONAL:Exist
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [63]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [speech full rate or half rate version 2]
+-Mode of Channel Set 2 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [11]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mode of Channel Set 3 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [13]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mode of Channel Set 4 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [14]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mode of Channel Set 5 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [15]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mode of Channel Set 6 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [16]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mode of Channel Set 7 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [17]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mode of Channel Set 8 ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [18]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Description of the Second Channel. after time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Description IEI ::= IEI [64]
| +-Octet2 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [1]
| | +-Timeslot number ::= INT (0..7) [0]
| +-Octet3-4 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [0]
+-Mode of the Second Channel ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Mode IEI ::= IEI [66]
| +-Octet2 ::= DIVISION
| +-Mode ::= CHOICE [signalling only]
+-Mobile Allocation. after time ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Mobile Allocation IEI ::= IEI [72]
| +-Octet2 ::= DIVISION
| | +-Length of mobile allocation contents ::= LEN (0..255) [0]
| +-Octet3-10 ::= DIVISION
| +-Mobile Allocation RF Channel ::= OCTETARRAY SIZE(0..8)
+-Starting Time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Starting Time IEI ::= IEI [7C]
| +-Octet2-3 ::= DIVISION
| +-T1' ::= INT (0..31) [0]
| +-T3 ::= INT (0..63) [0]
| +-T2 ::= INT (0..31) [0]
+-Frequency List. before time ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Frequency List IEI ::= IEI [19]
| +-Octet2 ::= DIVISION
| | +-Length of frequency list contents ::= LEN (0..255) [0]
| +-Octet3-132 ::= DIVISION
| +-Format-ID bit8-7 ::= SWITCH [bit map 0]
| +-(Format-ID bit8-7)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number bit124-121 ::= INT (0..15) [0]
| +-Absolute RF Channel Number bit120-001 ::= OCTETARRAY SIZE(15..15) [000000000000000000000000000000]
+-Description of the First Channel. before time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Frequency List IEI ::= IEI [1C]
| +-Octet2 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [1]
| | +-Timeslot number ::= INT (0..7) [0]
| +-Octet3-4 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [0]
+-Description of the Second Channel. before time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Channel Description IEI ::= IEI [1D]
| +-Octet2 ::= DIVISION
| | +-Channel type and TDMA offset ::= INT (0..31) [1]
| | +-Timeslot number ::= INT (0..7) [0]
| +-Octet3-4 ::= DIVISION
| +-Training Sequence Code ::= INT (0..7) [0]
| +-Hopping channel ::= SWITCH [Single RF channel]
| +-(Hopping channel)=0 ::= BRANCH
| +-spare ::= FIX [0]
| +-Absolute RF Channel Number ::= INT (0..1023) [0]
+-Frequency channel sequence before time ::= TV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Frequency Channel Sequence IEI ::= IEI [1E]
| +-Octet2 ::= DIVISION
| | +-spare ::= FIX [0]
| | +-Lowest ARFCN ::= INT (0..127) [1]
| +-Octet3-10 ::= DIVISION
| +-inc skip of ARFCN 01 ::= INT (0..15) [0]
| +-inc skip of ARFCN 02 ::= INT (0..15) [0]
| +-inc skip of ARFCN 03 ::= INT (0..15) [0]
| +-inc skip of ARFCN 04 ::= INT (0..15) [0]
| +-inc skip of ARFCN 05 ::= INT (0..15) [0]
| +-inc skip of ARFCN 06 ::= INT (0..15) [0]
| +-inc skip of ARFCN 07 ::= INT (0..15) [0]
| +-inc skip of ARFCN 08 ::= INT (0..15) [0]
| +-inc skip of ARFCN 09 ::= INT (0..15) [0]
| +-inc skip of ARFCN 10 ::= INT (0..15) [0]
| +-inc skip of ARFCN 11 ::= INT (0..15) [0]
| +-inc skip of ARFCN 12 ::= INT (0..15) [0]
| +-inc skip of ARFCN 13 ::= INT (0..15) [0]
| +-inc skip of ARFCN 14 ::= INT (0..15) [0]
| +-inc skip of ARFCN 15 ::= INT (0..15) [0]
| +-inc skip of ARFCN 16 ::= INT (0..15) [0]
+-Mobile Allocation. before time ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Mobile Allocation IEI ::= IEI [21]
| +-Octet2 ::= DIVISION
| | +-Length of mobile allocation contents ::= LEN (0..255) [0]
| +-Octet3-10 ::= DIVISION
| +-Mobile Allocation RF Channel ::= OCTETARRAY SIZE(0..8) [01]
+-Cipher Mode Setting ::= TV OPTIONAL:Omit
| +-Ciph Mod Set IEI ::= IEI [9-]
| +-algorithm identifier ::= CHOICE [cipher with algorithm A5/1]
| +-SC ::= CHOICE [No ciphering]
+-VGCS target mode Indication ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-VGCS target mode Indication IEI ::= IEI [01]
| +-Octet2 ::= DIVISION
| | +-Length of VGCS target mode Indication ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| +-Target mode ::= CHOICE [dedicated mode]
| +-Group cipher key number ::= CHOICE [no ciphering]
| +-spare ::= FIX [1]
| +-spare ::= FIX [1]
+-Multi-Rate configuration ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Multirate speech configuration IEI ::= IEI [03]
| +-Octet2 ::= DIVISION
| | +-Length ::= LEN (0..255) [0]
| +-Octet3-8 ::= DIVISION
| +-MultiRate speech version ::= CHOICE [Adaptive Multirate speech version 1]
| +-Noise Suppression Control Bit ::= CHOICE [Noise Suppression can be used (default)]
| +-Initial Codec Mode Indicator ::= CHOICE [The initial codec mode is defined by the implicit rule provided in 3GPP TS 05.09]
| +-spare ::= FIX [0]
| +-Start Mode ::= SWITCH [CODEC_MODE_1]
| +-(Start Mode)=0 ::= BRANCH
| +-Octet4-8 ::= DIVISION
| +-Set of AMR Codec Modes Field Bit 8 ::= CHOICE [12:2 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 7 ::= CHOICE [10:2 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 6 ::= CHOICE [7:95 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 5 ::= CHOICE [7:40 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 4 ::= CHOICE [6:70 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 3 ::= CHOICE [5:90 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 2 ::= CHOICE [5:15 kbit/s codec rate is not part of the subset]
| +-Set of AMR Codec Modes Field Bit 1 ::= CHOICE [4:75 kbit/s codec rate is not part of the subset]
+-VGCS Ciphering Parameters ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-VGCS Ciphering Parameters IEI ::= IEI [04]
+-Octet2 ::= DIVISION
| +-Length of VGCS Ciphering Parameters ::= LEN (0..255) [0]
+-Octet3- ::= DIVISION
+-spare ::= FIX [0]
+-RAND_IND ::= SWITCH [VSTK_RAND not present]
+-(RAND_IND)=0 ::= BRANCH
+-LAC_IND_1 ::= SWITCH [Location Area Identification not present]
+-(LAC_IND_1)=0 ::= BRANCH
+-CELL_IND_1 ::= SWITCH [Cell Identification not present]
+-(CELL_IND_1)=0 ::= BRANCH
+-B22_COUNT ::= INT (0..1) [0]
+-CELL_GLOBAL_COUNT ::= INT (0..3) [0]
Channel type and TDMA offset is 1, which is 00001 in binary and means TCH/F + ACCHs. The TCH/F uses timeslot 4 of ARFCN 129, the same timeslot and carrier as the SDCCH before it. The Power level is 8.
Mode of the First Channel is speech full rate or half rate version 2. So the network chose version 2 from the list in Call Confirmed, not the first choice of the MS. The Multi-Rate configuration IE is omitted. 44.018 subclause 9.1.2.11 includes that IE when the channel mode indicates a multi-rate speech codec, so its absence is consistent with version 2.
RR : Assignment Complete
The MS confirms the move on the FACCH of the new TCH/F. RR cause Normal event means the assignment succeeded. The network then releases the old SDCCH and stops T3107 (44.018 subclause 3.4.3.2).
Decoded message capture,
NAS:RR,Assignment complete
Assignment complete ::= DIVISION
+-Skip Indicator ::= V
| +-Skip Indicator ::= FIX [0]
+-RR management Protocol Discriminator ::= V
| +-Protocol Discriminator ::= PD [6]
+-Assignment complete Message Type ::= V
| +-N(SD)or0 ::= FIX [0]
| +-Message Type ::= MSG [29]
+-RR Cause ::= V
+-RR cause value ::= CHOICE [Normal event]
CC : Alerting
Alerting tells the network that the MS is now ringing the user. It travels on the FACCH, because the SDCCH was released after Assignment Complete. The TI flag again shows the MS to network direction.
Decoded message capture,
NAS:CC,Alerting (MS to network direction)
Alerting (MS to network direction) ::= DIVISION
+-Transaction identifier ::= V
| +-TI flag ::= CHOICE [The message is sent to the side that originates the TI]
| +-TIO ::= CHOICE [TI value 0]
+-Call control Protocol discriminator ::= V
| +-Protocol Discriminator ::= PD [3]
+-Alerting Message type ::= V
| +-N(SD)or0_1 ::= INT (0..1) [0]
| +-N(SD)or0_2 ::= INT (0..1) [1]
| +-Message type ::= MSG [01]
+-Facility ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-Facility IEI ::= IEI [1C]
| +-Octet2 ::= DIVISION
| | +-Length of facility contents ::= LEN (0..255) [0]
| +-Octet3-Octet255 ::= DIVISION
| +-Facility information ::= OCTETARRAY SIZE(0..253)
+-User-user ::= TLV OPTIONAL:Omit
| +-Octet1 ::= DIVISION
| | +-User-user IEI ::= IEI [7E]
| +-Octet2 ::= DIVISION
| | +-Length of user-user contents ::= LEN (0..255) [0]
| +-Octet3 ::= DIVISION
| | +-User-user protocol discriminator ::= CHOICE [User specific protocol]
| +-Octet4-Octet131 ::= DIVISION
| +-User-user information ::= OCTETARRAY SIZE(0..128)
+-SS Version Indicator(mobile station to network direction) ::= TLV OPTIONAL:Omit
+-Octet1 ::= DIVISION
| +-SS version indicator IEI ::= IEI [7F]
+-Octet2 ::= DIVISION
| +-Length of SS version indicator contents ::= LEN (0..255) [0]
+-Octet3 ::= DIVISION
+-SS version information ::= INT (0..255) [0]
All optional IEs are marked OPTIONAL:Omit, and the log stops at this point. A complete call continues with Connect from the MS when the user answers (24.008 subclause 5.2.2.5). The network then returns Connect Acknowledge (24.008 subclause 5.2.2.6), and speech flows on the TCH/F.
Paging sets the identity and the access cause : The MS answers with the identity type it was paged with, and Channel Needed decides the Channel Request code.A missing bearer in Setup moves the choice to the MS : Call Confirmed then carries Bearer capability 1 with the speech versions in order of preference.The network picks the speech version : Assignment Command sets the channel mode, here version 2, whatever order the MS listed.Alerting already uses the TCH : After Assignment Complete, the remaining CC messages travel on the FACCH.
Reference
- 3GPP TS 44.018 V19.0.0 : Mobile radio interface layer 3 specification; GSM/EDGE Radio Resource Control (RRC) protocol
- 3GPP TS 24.008 V20.0.0 : Mobile radio interface Layer 3 specification; Core network protocols; Stage 3
- 3GPP TS 45.008 V19.0.0 : GSM/EDGE Radio subsystem link control
- 3GPP TS 23.003 V20.0.0 : Numbering, addressing and identification