2G/GSM

  

 

 

 

System Information Type 3

 

This is one of the most important system informaton that carries the most of the information about the serving cells and Cell Selection Parameters. The information carried by this system information are as follows :

  • Cell Identity

    • Location Area Identification

    • MCC/MNC

    • LAI

  • Control Channel Description

    • MSC Release

    • Attach-detach allowed : this tells whether or not the MS is to perform IMSI Attach and IMSI Detach procedures

    • BS-AG-BLKS-RES : This is the number of CCCH blocks reserved for the AGCH,CBCH or BCCH Extended. The range of this parameter is 0-2 if CCCH is combined with SDCCH and 0-7 for non-combined CCCH.

    • CCCH-CONF : This is the number of Basic Physical Channels(BPC) used for the CCCH. (1-4 BPCs when not combined with SDCCH, 1 BPC if combined).

    • BS-PA-MFRMS : This is the number of 51 multiframe periods for transmission of Paging Request messages in the same paging group (2-9).

    • T3212 time-out value

  • Cell Options

    • DN-IND

    • PWRC : Power Control Indicator

    • DTX

    • RADIO-LINK-TIMEOUT

  • Cell Selection Parameters

    • CELL-RESELECT-HYSTERESIS

    • MS-TXPWR-MAX-CCH : MS Power Level. The maximum Tx power that UE is allowed to transmit when attaching.

    • ACS : Indicate whether additional SIBs are required or not.

    • NECI : New Establishment Cause Indicator. It indicates whether the phase 2 establishment causes are supported by the system. The establishment cause is included in the channel request message on the RACH

    • RXLEV-ACCESS-MIN : The minimum received power at which UE is allowed to try attaching.

  • 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 >

 

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

 

 

 

Example 02 >

 

GSM CCCH - System Information Type 3

L2 Pseudo Length

0100 10.. = L2 Pseudo Length value: 18

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

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

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

Message Type: System Information Type 3

Cell Identity - CI (0)

Cell CI: 0x0000 (0)

Location Area Identification (LAI)

Location Area Identification (LAI) - 001/01/0

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

Location Area Code (LAC): 0x0000 (0)

Control Channel Description

1... .... = MSCR: MSC is Release '99 onwards (1)

.1.. .... = ATT: MSs in the cell shall apply IMSI attach and detach procedure (1)

..00 1... = BS_AG_BLKS_RES: 1

.... .000 = CCCH-CONF: 1 basic physical channel used for CCCH, not combined with SDCCHs (0)

.00. .... = CBQ3: Iu mode not supported (0)

.... .101 = BS-PA-MFRMS: 5

T3212: 0

Cell Options (BCCH)

.1.. .... = PWRC: True

..10 .... = DTX (BCCH): The MSs shall not use uplink discontinuous transmission (2)

.... 0011 = Radio Link Timeout: 16 (3)

Cell Selection Parameters

001. .... = Cell Reselection Hysteresis: 1

...0 1000 = MS TXPWR MAX CCH: 8

0... .... = ACS: False

.0.. .... = NECI: 0

..10 1001 = RXLEV-ACCESS-MIN: -70 <= x < -69 dBm (41)

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

SI 3 Rest Octets

L... .... = Selection Parameters: Not Present

.L.. .... = Optional Power Offset: Not Present

..L. .... = SYSTEM INFORMATION TYPE 2ter: Not available

...L .... = Early Classmark Sending: Not Allowed

.... L... = Scheduling if and where: Not Present

.... .H.. = GPRS Indicator: Present

GPRS Indicator

.... ..00 1... .... = GPRS RA Colour: 1

.0.. .... = SI13 Position: SYSTEM INFORMATION TYPE 13 message is sent on BCCH Norm (0)

..L. .... = 3G Early Classmark Sending Restriction: Neither UTRAN, CDMA2000 nor GERAN IU MODE CLASSMARK CHANGE message shall be sent with the Early classmark sending

...H .... = SI2quater Indicator: Present

.... 0... = SI2quater Position: SYSTEM INFORMATION TYPE 2 quater message is sent on BCCH Norm

.... .H.. = SI21 Indicator: Present

.... ..1. = SI21 Position: SYSTEM INFORMATION TYPE 21 message is sent on BCCH Ext

Padding Bits: default padding

 

HEX : 49 06 1B 00 00 00 F1 10 00 00 C8 03 00 63 28 29 01 00 00 2C B7 2B 2B