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2G/GSM

System Information Type 2

The main purpose of System Information Type 2 is to carry BCCH information (Frequency Information and RACH information) for the neighbour cells. The informations carried by this message are as follows :

BCCH Frequency List : Type of information element varies depending on GSM Band
EXT-IND : This indicates whether this message contains all the information or require another extended message (e.g, System Information Type 2 bis or System Information Type 2 ter) to carry more information.
BA-IND : This indicates the contents of BCCH Frequency List has been changed or not from previous transmission. it toggles between 0 and 1 when the contents changes
NCC Permitted
RACH Control Paramete

Max retrans
Tx-integer
CELL_BAR_ACCESS
Call reestablishment allowed

'Not Allowed' means that Call Restablishement is not allowed even after losing TCH
'Allowed' means that if an MS using a TCH looses contact with the network, it is allowed to attempt to re-establish the contact using the old TCH within a certain interval

Access Control Class C15-C11

0 in the bit map indicates 'Not Barred'
1 'in the bit map indicates 'Barred'

Emergency Call allowed

0 means that all MSs are allowed to make emergency calls,
1 means that only MSs belonging to priority classes 11-15 are allowed to make emergency calls.

Access Control Class C9-C0

0 in the bit map indicates 'Not Barred'
1 'in the bit map indicates 'Barred'

Example 01 > No Neighour

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]

Example 02 > No Neighour

GSM CCCH - System Information Type 2

L2 Pseudo Length

0101 10.. = L2 Pseudo Length value: 22

.... 0110 = Protocol discriminator: Radio Resources Management messages (0x6)

0000 .... = Skip Indicator: No indication of selected PLMN (0)

Message Type: System Information Type 2

Neighbour Cell Description - BCCH Frequency List

..0. .... = EXT-IND: The information element carries the complete BA (0)

...0 .... = BA-IND: 0

00.. 000. = Format Identifier: bit map 0 (0x00)

List of ARFCNs =

NCC Permitted

1111 1111 = NCC Permitted: 0xff

RACH Control Parameters

00.. .... = Max retrans: Maximum 1 retransmission (0)

..00 00.. = Tx-integer: 3 slots used to spread transmission (0)

.... ..0. = CELL_BARR_ACCESS: The cell is not barred (0)

.... ...1 = RE: Call Reestablishment not allowed in the cell (1)

0000 0000 0000 0000 = ACC: 0x0000

Example 03 > One GSM Neighour

GSM CCCH - System Information Type 2

L2 Pseudo Length

0101 10.. = L2 Pseudo Length value: 22

.... 0110 = Protocol discriminator: Radio Resources Management messages (0x6)

0000 .... = Skip Indicator: No indication of selected PLMN (0)

Message Type: System Information Type 2

Neighbour Cell Description - BCCH Frequency List

..0. .... = EXT-IND: The information element carries the complete BA (0)

...0 .... = BA-IND: 0

10.. 111. = Format Identifier: variable bit map (0x47)

List of ARFCNs = 4 5

NCC Permitted

1111 1111 = NCC Permitted: 0xff

RACH Control Parameters

00.. .... = Max retrans: Maximum 1 retransmission (0)

..00 00.. = Tx-integer: 3 slots used to spread transmission (0)

.... ..0. = CELL_BARR_ACCESS: The cell is not barred (0)

.... ...1 = RE: Call Reestablishment not allowed in the cell (1)

0000 0000 0000 0000 = ACC: 0x0000

HEX : 59 06 1A 8E 02 40 00 00 00 00 00 00 00 00 00 00 00 00 00 FF 01 00 00

Example 04> One GSM Neighour + One LTE Neighbour

GSM CCCH - System Information Type 2quater

L2 Pseudo Length

0101 00.. = L2 Pseudo Length value: 20

.... 0110 = Protocol discriminator: Radio Resources Management messages (0x6)

0000 .... = Skip Indicator: No indication of selected PLMN (0)

Message Type: System Information Type 2quater

SI 2quater Rest Octets

0... .... = BA-IND: 0

.0.. .... = 3G BA-IND: 0

..0. .... = Measurement Parameter Change Mark: 0

...0 000. = SI2quater Index: 0

.... ...0 001. .... = SI2quater Count: 1

...0 .... = Measurement Parameters Description: Not Present

.... 0... = GPRS Real Time Difference Description: Not Present

.... .0.. = GPRS BSIC Description: Not Present

.... ..0. = GPRS Report Priority Description: Not Present

.... ...0 = GPRS Measurement Parameters Description: Not Present

1... .... = NC Measurement Parameters: Present

NC Measurement Parameters

.00. .... = Network Control Order: NC0 (0)

.... 000. = NC Non DRX Period: No non-DRX mode after a measurement report has been sent (0)

.... ...0 10.. .... = NC Reporting Period I: 1.92 s (2)

..01 0... = NC Reporting Period T: 1.92 s (2)

...1 .... = NC Periods: Present

.... .0.. = SI 2quater Extension Information: Not Present

.... ..0. = 3G Neighbour Cell Description: Not Present

.... ...1 = 3G Measurement Parameters Description: Present

3G Measurement Parameters Description

0111 .... = Qsearch I: Always (7)

.... 0... = QSearch C Initial: use Qsearch I

.... .1.. = FDD Information: Present

.... ..01 10.. .... = FDD Qoffset: -8 dB (6)

..0. .... = FDD Rep Quant: RSCP

...0 1... = FDD Multirat Reporting: 1

.... .000 = FDD Qmin: -20 dB (0)

1... .... = TDD Information: Present

.101 1... = TDD Qoffset: 12 dB (11)

.... .01. = TDD Multirat Reporting: 1

.... ...1 = GPRS 3G Measurement Parameters Description: Present

GPRS 3G Measurement Parameters Description

0111 .... = Qsearch P: Always (7)

.... 1... = 3G Search Prio (ignored in Rel-8): 3G cells may be searched when BSIC decoding is required

.... .1.. = FDD Parameters: Present

.... ..0. = FDD Rep Quant: RSCP

.... ..0. = Reporting Quantity: RSCP

.... ...0 1... .... = FDD Multirat Reporting: 1

.0.. .... = FDD Reporting Parameters: Not Present

..1. .... = TDD Multirat Reporting: Present

...0 1... = TDD Multirat Reporting: 1

.... .0.. = TDD Reporting Parameters: Not Present

.... ..H. = Additions in Rel-5: Present

.... ...0 = 3G Additional Measurement Parameters Description: Not Present

0... .... = 3G Additional Measurement Parameters Description 2: Not Present

.H.. .... = Additions in Rel-6: Present

..0. .... = 3G CCN Active: CCN towards 3G cells is disabled in the cell

...H .... = Additions in Rel-7: Present

.... 0... = 700 Reporting: Not Present

.... .0.. = 810 Reporting: Not Present

.... ..H. = Additions in Rel-8: Present

.... ...1 = 3G Supplementary Parameters Description: Present

Priority and E-UTRAN Parameters Description

1... .... = Serving Cell Priority Parameters Description: Present

Serving Cell Priority Parameters Description

.010 .... = GERAN_PRIORITY: 2

.... 1111 = THRESH_Priority_Search: Always search (15)

0000 .... = THRESH_GSM_low: 0 dB (0)

.... 00.. = H_PRIO: disabled (0)

.... ..00 = T_Reselection: 5 s (0)

0... .... = 3G Priority Parameters Description: Not Present

.1.. .... = E-UTRAN Parameters Description: Present

E-UTRAN Parameters Description

..0. .... = E-UTRAN_CCN_ACTIVE: The broadcast E-UTRAN_CCN_ACTIVE parameter shall apply if applicable. Otherwise, CCN towards E-UTRAN cells is disabled in the cell

...1 .... = E-UTRAN Start: This is the first instance of the message

.... 1... = E-UTRAN Stop: This is the last instance of the message

.... .1.. = E-UTRAN Measurement Parameters Description: Present

.... ..00 00.. .... = Qsearch_C_E-UTRAN_Initial: search if signal is below -98 dBm (0)

..0. .... = E-UTRAN Reporting Quantity: RSRP

...0 1... = E-UTRAN_MULTIRAT_REPORTING (nb of E-UTRAN cells to be included in measurement report): 1

.... .0.. = Reporting: 6 bit

.... ..0. = E-UTRAN FDD FDD 3 bit Reporting: Not Present

.... ...0 = E-UTRAN TDD TDD 3 bit Reporting: Not Present

1... .... = GPRS E-UTRAN Measurement Parameters Description: Present

.000 0... = Qsearch_P_E-UTRAN: 0

.... .0.. = E-UTRAN Reporting Quantity: RSRP

.... ..01 = E-UTRAN_MULTIRAT_REPORTING (nb of E-UTRAN cells to be included in measurement report): 1

0... .... = E-UTRAN FDD Reporting: Not Present

.0.. .... = E-UTRAN TDD Reporting: Not Present

..0. .... = Repeated E-UTRAN Neighbour Cells: Not Present

...0 .... = Repeated E-UTRAN Not Allowed Cells: Not Present

.... 0... = Repeated E-UTRAN PCID to TA mapping: Not Present

.... .0.. = 3G CSG Description: Not Present

.... ..0. = E-UTRAN CSG Description: Not Present

Padding Bits: default padding

HEX : 51 06 07 00 20 90 91 75 88 DB 7C A8 51 AF 00 5C 08 81 01 2B 2B 2B 2B