01-3 system information

M900/M1800 Base Station Subsystem Signaling Analysis Manual Contents

Issue 06 (2006-08-20) Huawei Technologies Proprietary i

Contents

3 System Information ...................................................................................................................3-1 3.1 Overview.......................................................................................................................................................3-2 3.2 Detailed Description of System Information.................................................................................................3-2

3.2.1 System Information Type 1..................................................................................................................3-2 3.2.2 System Information Type 2, 2bis & 2ter ..............................................................................................3-5 3.2.3 System Information Type 3..................................................................................................................3-7 3.2.4 System Information Type 4................................................................................................................3-10 3.2.5 System Information type 5, 5bis & 5ter .............................................................................................3-11 3.2.6 System Information Type 6................................................................................................................3-12 3.2.7 System Information Type 7................................................................................................................3-12 3.2.8 System Information Type 8................................................................................................................3-13 3.2.9 System Information 2quater...............................................................................................................3-13 3.2.10 System Information MEASUREMENT INFORMATION ..............................................................3-13

3.3 Internal Handling of BSC............................................................................................................................3-14

Tables M900/M1800 Base Station Subsystem

Signaling Analysis Manual

ii Huawei Technologies Proprietary Issue 06 (2006-08-20)

Tables

Table 3-1 Cell Channel Description Formats......................................................................................................3-3

Table 3-2 Cell channel description formats ........................................................................................................3-3

Table 3-3 S and T Parallelism.............................................................................................................................3-5

Table 3-4 Meaning of multiband indication........................................................................................................3-7

Table 3-5 CCCH CONF code meaning ..............................................................................................................3-8

Table 3-6 Cell selection or reselection priority decided by CBQ and CBA......................................................3-11

Table 3-7 Correspondence between RACH control parameters and the [System information table] ...............3-14

Table 3-8 Correspondence between the control channel parameters in SYSTEM INFORMATION TYPE 3 and the [System information table] ..........................................................................................................................3-15

Table 3-9 Correspondence between the cell options in SYSTEM INFORMATION TYPE 3 and the [System information table]..............................................................................................................................................3-15

Table 3-10 Correspondence between the cell selection parameters in SYSTEM INFORMATION TYPE 3 and the [System information table] ..........................................................................................................................3-15

Table 3-11 Correspondence between SI 4 Rest Octets and the [System information table] .............................3-16

M900/M1800 Base Station Subsystem Signaling Analysis Manual 3 System Information

Issue 06 (2006-08-20) Huawei Technologies Proprietary 3-1

3 System Information

About This Chapter

The following table lists the contents of this chapter.

Title Description

3.1 Overview Introduces commonly used system information block types in the BSS and the classification of the system information.

3.2 Detailed Description of System Information

Describes the contents and functions of system information.

3.3 Internal Handling of BSC Describes the internal system information handlign procedures of the BSC.

3 System Information M900/M1800 Base Station Subsystem


3-2 Huawei Technologies Proprietary Issue 06 (2006-08-20)

3.1 Overview System information includes the major radio network parameters on Um interface. Specifically, it includes network identification parameter, cell selection parameter, system control parameter and network function parameter. By receiving system information, MS can properly access the network, perform network selection, fully utilize the various services provided by the network and communicate with the network normally.

Common system information can be classified into two parts:

The system information transmitted on the BCCH, including 1, 2, 2bis, 2ter, 3, 4, 7, 8 and 2quater.

The system information transmitted on the SACCH, including 5, 5bis, 5ter, 6, and MEASUREMENT INFORMATION.

System information type 9 includes the control information for BCCH. If system information type 9 is used, the receiving location of system information type 9 is indicated in system information type 3. Generally, it is not used.

If system supports GPRS, system information type 13 should be used.

The following describes common system information in detailed.

The system information transmitted on BCCH belongs to common channel information. The system

information transmitted on SACCH belongs to TRX management information. When interface tracing is to be performed in BSC Maintenance System, the options of common channel information and TRX management information must be selected. Only in this way can all system information be observed.

System information type 1, 2, 2ter, 3, 4, 5, 5ter and 6 can be delivered to cells by default. 2bis and 5bis are mainly transmitted over DCS1800 cells conditionally. When the BSC is configured with 3G external neighbor cell, the system information 2quater and MEASUREMENT INFORMATION are sent.

3.2 Detailed Description of System Information 3.2.1 System Information Type 1

Purpose System information type 1 mainly describes RACH control information and CA (Cell Allocation table). It is transmitted on BCCH.

Information content SYS INFO 1 - - Cell Channel Desc.

-- RACH Control Para.

Step 1 CA

BSC supports the configuration of max. 64 cell frequencies. Due to the restriction of cell channel description formats, actually, cell frequencies cannot be configured randomly.



BSC selects different cell channel description formats according to the actual frequency configuration.

There are 5 channel description formats with the format ID as bit128, bit127, bit124, bit123 and bit122, which are respectively determined by the second byte in the cell channel description, as shown in Table 3-1, Table 3-2.

Table 3-1 Cell Channel Description Formats

8 7 6 5 4 3 2 1

Cell Channel Description IEI octet 1

Bit 128

Bit 127

0 Spare

0 Spare

Bit 124

Bit 123

Bit 122

Bit 121

octet 2

… … … … … … … … …

Bit 008

Bit 007

Bit 006

Bit 005

Bit 004

Bit 003

Bit 002

Bit 001

octet 17

Table 3-2 Cell channel description formats

Bit128 Bit127 Bit124 Bit123 Bit122 Format notation

0 0 X X X Bit map 0

1 0 0 X X 1024 range

1 0 1 0 0 512 range

1 0 1 0 1 256 range

1 0 1 1 0 128 range

1 0 1 1 1 Variable bit map

The corresponding number of the cell configurable absolute frequencies of each cell channel description format is not the same as the number of configurable absolute frequencies in one cell (the same frequencies and illegal frequencies excluded), and ARFCN (i) (i=1,...,n) denotes the corresponding radio frequency, the number of configurable frequencies of each channel description format will be as follows.

Bit map 0

Bit map 0 can be used for 900M frequency. The actual number of cell configurable frequencies can reach 64. Moreover, the frequencies can be configured randomly, so long as they satisfy "1 ≤ ARFCN (i) ≤ 124".

1024 range format

When this format is adopted, the actual number of cell configurable frequencies is less than or equal to 16 (n≤16), but the frequencies can be freely configured. For 900M, 1 ≤ ARFCN (i) ≤ 124. For 1800M, 512 ≤ ARFCN (i) ≤ 885.




512 range format

When this format is adopted, the actual number of cell configurable frequencies is less than or equal to 18 (n ≤ 18), but the following condition should also be satisfied. Assuming that m denotes the max. interval between two configured frequencies, "m < 512" should be satisfied.

256 range format

When this format is adopted, the actual number of cell configurable frequencies is less than or equal to 22 (n≤22), but the following condition should also be satisfied. Assuming that m denotes the maximum interval between two configured frequencies, "m<256" should be satisfied. For example, when this format is adopted, frequency 512 and frequency 812 cannot be configured at the same time.

128 range format

When this format is adopted, the actual number of cell configurable frequencies is less than or equal to 29 (n≤29), but the following condition should also be satisfied. Assuming that m denotes the max. interval between two configured frequencies, "m<128" should be satisfied. For example, when this format is adopted, frequency 512 and frequency 712 cannot be configured at the same time.

Variable bit map

When this format is adopted, the actual number of cell configurable frequencies can also reach 64, but the following condition should also be satisfied. Assuming that m denotes the max. interval between two configured frequencies, "1≤m≤111" should be satisfied. For example, it is feasible to configure the frequencies 512, 513, 514, ..., 575 (increased by 1, total 64 frequencies), but it is unfeasible to configure the frequencies 512, 514, 516, ..., 638 (increased by 2, total 64 frequencies).

Step 2 RACH control information

RACH control information includes the following parameters.

MAX retrans indicates the max. allowed number of Channel Request message retransmissions before MS receives an Immediate Assignment message, i.e. the number of channel requests that can be sent by MS is "M + 1". It is a 2-bit code. The maximum number of retransmissions that corresponds to 0–3 is 1, 2, 4 and 7 respectively. Tx_interger (Extended transmit TS number) indicates the number of timeslots between two successive retransmissions when MS continuously sends multiple Channel Request messages

CBA (CELL_BAR_ACCESS) indicates whether MS is allowed to access the current cell. It is a 1-bit code. "0" indicates cell access is allowed, and "1" indicates that cell access is barred. This parameter has no impact upon handover access.

AC denotes access restricted user level. AC can be classified into AC 0–AC 9 and AC 11–AC 15. Generally, each MS is allocated with an AC. Each AC is indicated by one bit. "1" indicates that the MS of the corresponding AC is not allowed to access the current cell, and "0" indicates the MS is allowed to access the current cell. Compared with the MSs of AC 0 –AC 9, the MSs of AC 11–AC15 have higher access priorities. However, between the ACs within 0– 9, or the ACs within 11–15, different ACs do not denote different access priorities.

RE (bit allowed for call reestablishment) indicates whether the network allows connection reestablishment after MS initiates the call reestablishment procedure. It is a 1-bit code. "0" indicates that the current cell allows call reestablishment, and "1" indicates that the current cell does not allow call reestablishment.

EC (bit allowed for emergency call) indicates whether MS is allowed to initiate an emergency call in the case that the MS has no SIM card or its AC is disabled by the current



cell. It is a 1-bit code. "0" indicates that emergency call is allowed, and "1" indicates that emergency call is not allowed (excluding the MSs of AC 11– AC 15).

The extend transmit TS number is a random value, and belongs to the collection of {S,S+1,....S+T-1}. The measurement unit is TDMA frame. Of the collection, S depends on common channel configuration, and T denotes the extended transmit TS number (Tx_interger). See Table 3-3 for the values of S.

Table 3-3 S and T Parallelism

Tx_interger CCCH uncombined CCCH combined

3, 8, 14, 50 55 41

49. 16 76 52

5, 10, 20 109 58

6, 11, 25 163 86

7, 12, 32 217 115

When satellite transmission is adopted, to lessen the impact of satellite Tx delay, it is recommended that [MAX retrans] is set as "4", and [Tx_interger] is set as "32".

----End

3.2.2 System Information Type 2, 2bis & 2ter

Purpose System information type 2 mainly describes RACH control information, NCC permission and CA of the adjacent cells (namely, BA1 table). It is transmitted on BCCH. Generally, system information type 2, 2bis and 2ter respectively describe different parts of BA1. By reading and decoding BA1 table, MS can implement cell reselection in idle mode. The GSM900 MS in Phase 1 only recognizes the adjacent cell frequencies described in system information type 2 and skips those contained in 2bis and 5ter.

Type 2bis mainly describes RACH control information and the extended frequency allocation table of adjacent cells (part of BA1 table). It is optional, and is transmitted on BCCH. Generally, because the number of frequencies described in the frequency allocation table in system information type 2 is limited, system information type 2bis contains the information of other frequencies in BA1 which are in the same frequency band as system information type 2.

Type 2ter mainly describes the extended frequency allocation table of adjacent cells (part of BA1 table). It is transmitted on BCCH. Only the multi-band MS can read this information. The single-band GSM 900 or GSM 1800 MS will skip this information. Because the frequencies contained in this information are in a frequency band which is different from that of the current cell, such information is not needed by the single-band MS.

Information content SYS INFO 2 - - Neighbor Cell Desc.




- - NCC permitted

- - RACH Control Para.

SYS INFO 2 BIS - - Neighbor Cell Desc.


SYS INFO 2TER - - Neighbor Cell Desc.

Step 1 BA1

BA1 (adjacent cell description) mainly describes the absolute frequency No. of the BCCH TRX of the adjacent cell. Currently, the max. number of adjacent cells supported by Huawei is 32. Except the 5th bit (BA-IND) and 6th bit (EXT-IND) of the second byte in BA1, the coding mode of other information is the same as that of the cell channel description table (Refer to subsection 1) of 3.2.1 II).

EXT_IND (Extension Indication) is transmitted in system information type 2 and 5, indicating whether there are other extended adjacent cell frequencies to be transmitted in system information type 2bis and 5bis. It is a 1-bit code. "0" indicates that system information type 2 and 5 already contain the complete BA table, and "1" indicates that type 2 and type 5 only contain part of BA table.

BA Indication (BA_IND) is transmitted in system information type 2 and 5. It is a 1-bit code, and is used by MS to select the data in BA1 and BA 2 before or after modification. In other words, if the adjacent cell relation of the current cell and the BA2 table is changed during a session, BA_IND in system information type 5 will be 1 instead of 0. This indicates that MS should perform decoding for the adjacent cell frequencies indicated in the system information type 5 again.

Step 2 NCC Permitted

NCC Permitted is transmitted in system information type 2 and type 5. It is an 8-bit code, and contains the collection of the NCCs to be measured by MS. In other words, if 0≤N≤7 (N denotes the number of bits), MS will not measure the cell level that satisfies "NCC=N", i.e. MS will not be handed over to the network that satisfies "NCC=N". This parameter is mostly used in handover.


Refer to subsection 2) of 3.2.1 "System Information."

Step 4 Extended adjacent cell description

It is mainly transmitted in system information type 2ter and 5ter. Except the 5th bit (BA-IND) and the 6th–7th bit (Multiband Reporting), the codes of other information are the same as those in cell channel description (Refer to subsection 1) of 3.2.1 II for relevant description).

Multiband Reporting (MBR) is transmitted in system information type 2ter and 5ter. It is a 2-bit code, indicating whether MS reports adjacent cell information on multiple frequency bands. It is applicable to multiband MS only. The details are listed below.



Table 3-4 Meaning of multiband indication

Contents of multiband indication (2 bits)

Meaning

00 MS should report the measurement result of 6 adjacent cells with the strongest signal strength, no matter which frequency band it is allocated with.

01 MS should report the measurement result of 1 adjacent cell (if it exists and is permitted) which is allocated with a frequency band different from that of the current cell, and report the measurement result of 5 adjacent cells which are allocated with the same frequency band as the current cell.

10 MS should report the measurement result of 2 adjacent cells (if they exist and are permitted) which are allocated with a frequency band different from that of the current cell, and report the measurement result of 4 adjacent cells which are allocated with the same frequency band as the current cell.

11 MS should report the measurement result of 3 adjacent cells (if they exist and are permitted) which are allocated with a frequency band different from that of the current cell, and report the measurement result of 3 adjacent cells which are allocated with the same frequency band as the current cell.

----End

3.2.3 System Information Type 3

Purpose System information type 3 mainly describes LAI, cell ID, RACH control information and the parameters related to cell selection. It is mandatory, and is transmitted on BCCH.

Information content SYS INFO 3 - - Cell Identity

- - LAI

- - Control Channel Desc.

- - Cell Option (BCCH)

- - Cell Selection Para.


Step 1 CGI

CGI (Cell Global Identity) is composed of LAI and CI, of which, LAI includes MCC, MNC and LAC. System information type 3, type 6 and type 4 contain all or part of CGI information. Based on the received system information, MS decodes CGI and decides whether to access




the network in this cell according to the MCC and MNC indicated by the CGI. CGI is also used to check whether the current location area has changed, so that MS can determine whether the location updating procedure need be initiated.

MCC, consisting of 3 decimal digits, is allocated worldwide in unified way. For example, the MCC of China is 460. MNC, consisting of two decimal digits, is allocated by the country in unified way. For example, the MNC of China Mobile is "00", and the MNC of China Unicom is "01". LAC and CI, both consisting of 2 bytes, are arranged by each GSM operator in unified way. Note that the value range of CI is 0X0001–0XFFFE, while 0X0000 and 0XFFFF are reserved.

Step 2 Control channel description

Control channel description includes the following parameters.

IMSI attach and detach allowed (ATT) is used to notify MS whether the local cell allows IMSI attach/detach procedure. ATT is a 1-bit code. "0" indicates that MS is not allowed to initiate IMSI attach/detach procedure, and "1" indicates that MS must initiate the IMSI attach/detach procedure.

CCCH CONF decides the integration mode of the CCCH in the cell. CCCH CONF is a 3-bit code. See Table 3-5 for detailed description.

Table 3-5 CCCH CONF code meaning

CCCH CONF (3 bits)

Meaning Number of CCCH information blocks per BCCH multiframe

000 CCCH uses a basic physical channel which is not shared with SDCCH.

9

001 CCCH uses a basic physical channel which is shared with SDCCH.

3

010 CCCH uses two basic physical channels which are not shared with SDCCH.

18

100 CCCH uses three basic physical channels which are not shared with SDCCH.

27

110 CCCH uses four basic physical channels which are not shared with SDCCH.

36

Others Reserved

BS_AG_BLKS_RES is used together with CCCH CONF to decide the number of CCCH information blocks in each BCCH mutiframe of the current cell. After CCCH CONF is set, BS AG BLKS RES will actually be used to arrange the occupancy ratio between AGCH and PCH on CCCH. By adjusting this parameter, the bearing status of AGCH and PCH can be balanced.



BS PA MFRAMS defines how many multi-frames make up a cycle of a paging sub-channel. This parameter actually defines how many sub-channels the PCH of a cell will be divided into. BS PA MFRAMS is a 3-bit code. The value range is 0–7, indicating that the number of multi-frames of a paging group cycled on the PCH is 2–9 respectively.

Periodic location updating timer (T3212) defines the frequency of periodic location updating. It is an 8-bit code. The value range is 0–255, each unit of which denotes the duration of six minutes. "0" indicates no location updating.

Step 3 Cell option

Cell option includes the following parameters.

PWRC is used to notify MS whether the Rx level value obtained from the timeslots of BCCH TRX should be subtracted when it measures the Rx level in the frequency hopping procedure. It is value range is "0" or "1". "0" indicates that the Rx level value obtained from the timeslots of BCCH TRX should not be subtracted, and "1" indicates that the Rx level value obtained from the timeslots of BCCH TRX should be subtracted.

DTX indicates whether MS can use the DTX function. In system information type 3, it is a 2-bit code. In system information type 6, it is a 3-bit code.

Radio_Link_Timeout is a 4-bit code. The value range is 0–15, which corresponds to 4–64 actually. When the MS receives a SACCH message, the actual value increases by 2. When MS fails to receive an SAACH message, the actual value decreases by 1. If the value is 0, MS will report a radio link fault to BTS.

Step 4 Cell selection parameters

Cell selection parameters have impact upon the behaviors of MS after it is powered on. The major parameters are as follows.

Cell Reselection Hysteresis is used for cell reselection. MS cannot implement cell reselection unless the level of the adjacent cell (Here, the adjacent cell and the current cell do not belong to the same location area) minus the C2 of the current cell is greater than the specified value of cell selection hysteresis. It is a 3-bit code. The value range is 0–7, denoting 0dB –14dB respectively.

MS_TXPWR_MAX_CCH indicates the Tx power used by MS before it receives a power control command. It is a 5-bit code. The valid value range is 0–31, which respectively correspond to an MS output power.

RXLEV_ACCESS_MIN indicates the min. Rx level allowed for MS to access the network. It is a 6-bit code. The value range is 0–63, denoting -110dBm–-47dBm respectively.

ACS is used to notify MS whether to adopt C2 in the cell reselection procedure. It is a 1-bit code and is meaningless in system information type 3. In system information type 4, if the value is 0, it indicates that MS adopts SI4 REST of system information type 4 to calculate C2-related parameters, or else, MS adopts REST of system information type 7 or type 8 to calculate c2-related parameters.

NECI is used to notify MS whether the current cell supports half-rate services. It is a 1-bit code. "0" indicates that the current cell does not support half-rate services, and "1" indicates the current cell supports half-rate services.

Step 5 RACH control parameters


----End





Purpose System information type 4 mainly describes LAI, RACH control information, cell selection parameters and optional CBCH information. It is mandatory, and is transmitted on BCCH. When the system supports cell broadcast, the optional IE CBCH description and MA will be used, and will describe CBCH configuration and the corresponding frequency information.

Information content SYS INFO 4 - - LAI

- - Cell Selection Para.


- - CBCH Channel Desc.(optional)

- - CBCH Mobile Allocation (optional)

- SI4 Rest Oct.

Step 1 LAI

Refer to subsection 1) of 3.2.3 2 II for relevant description.

Step 2 Cell selection parameters

Refer to subsection 4) of 3.2.3 II for relevant description.



Step 4 CBCH description and CBCH MA

The two parameters are optional. When the system supports cell broadcast, CBCH description contains the formation about CBCH configuration. When CBCH description is in frequency hopping mode, CBCH MA is mandatory.

Step 5 SI4 Rest Oct.

When ACS of the cell selection parameters is set as "No", the relevant parameters in SI4 Rest Oct. will be used to calculate the value of the cell reselection parameter C2.

Cell reselection criteria:

When PENALTY_TIME = 31, C2=C1-CELL_RESELECT_OFFSET

When PENALTY_TIME≠31, C2=C1+CELL_RESELECT_OFFSET-TEMPORARY_OFFSET*H(PENALTY_TIME-T) Where, For the non-serving cell: When x<0, H(x)=0; when x>=0, H(x)=1 For the serving cell, H(x)=0

SI4 Rest Oct. contains the following parameters.



PI (Cell Reselection Parameter Indication) indicates whether MS adopts C2 as the cell reselection parameter, and whether the parameters used for calculating C2 exist. It is a 1-bit code. "0" indicates that C1 substitutes C2 and serves as the cell reselection criteria. "1" indicates that parameters are extracted from system information for calculating C2, which will serve as the cell reselection criteria.

CBQ (Cell Bar Qualify) is a 1-bit code. CBQ and CBA (CELL_BAR_ACCESS) jointly form cell priority status. For details, refer to Table 3-6.

Table 3-6 Cell selection or reselection priority decided by CBQ and CBA

CBQ CBA Cell selection priority Cell reselection status

0 0 Normal Normal

0 1 Barred Barred

1 0 Low Normal

1 1 Low Normal

CRO (CELL_RESELECT_OFFSET) is used to manually correct C2. It is a 6bit code and each bit stands for 0–126dB respectively. CRO, TO and PT are jointly used form the manual correction value of C2.

TO (TEMPORARY_OFFSET): The value range is 0–7. Each level denotes 10dB. 0->0dB, 1->10dB…6->60dB, 7-> infinite.

PT (PENALTY_TIME): The value range is 0–31. Each level denotes 20s. 0->20s,…, 30->620s. When the value is 31, TO will be disregarded, and CRO will offset C2 with a negative value.

----End

3.2.5 System Information type 5, 5bis & 5ter

Purpose System information type 5 mainly describes the frequency information of adjacent cells (namely, BA2) . It is mandatory, and is transmitted on SACCH. The difference between system information type 2 and type 5 is that the MS in session state can read the frequencies described in system information type 5 and report the relevant information of adjacent cells in the measurement report, which will serve as the reference for handover. Likewise, the GSM900 MS in Phase 1 only recognizes the adjacent cell frequencies described in system information type 5 and skips those contained in 5bis and 5ter.

Type 5bis mainly describes the frequency information of adjacent cells (part of BA2). It is optional, and is transmitted on SACCH. Generally, the number of frequencies described in the frequency allocation table in system information type 5 is limited. Therefore, system information 5bis contains the information of other frequencies in BA2 which are in the same frequency band as system information 5.

Type 5ter mainly describes the frequency information of adjacent cells (part of BA2), and is transmitted on SACCH. Likewise, only the multiband MS can read this information. The single-band GSM 900 or GSM 1800 MS will skip this information.




Information content SYS INFO 5- - Neighbor Cell Desc.

SYS INFO 5 BIS - - Neighbor Cell Desc.

SYS INFO 5TER - - Neighbor Cell Desc.

Step 1 Adjacent cell description

For relevant description, please Refer to subsection 1) of 3.2.2 II

Step 2 Extended adjacent cell description

For relevant description, please Refer to subsection 4) of 3.2.2 II

----End


Purpose System information type 6 mainly describes LAI, cell ID and the parameters used for describing cell functions. It is mandatory, and is transmitted on SACCH.

Information content SYS INFO 6 - - Cell Identity

- - LAI

- - Cell Option (SACCH)

- NCC Permitted

Step 1 CGI

Refer to subsection 1) of 3.2.3 II

Step 2 Cell option

Refer to subsection 3) of 3.2.3 II

Step 3 NCC permitted


----End


Purpose System information type 7 is mandatory, and is transmitted on BCCH. It contains cell reselection information.



Information content SYS INFO 7---- SI 7 Rest Octets

SI 7 Rest Octets contains the parameters used by MS for cell reselection. It can also contain the information of the parameter POWER OFFSET used by DCS1800 Class 3 MS.

The coding format of SI 7 Rest Octets is the same with SI 4 Rest Octets. See the related description in "5) SI 4 Rest Oct" of 3.2.4.


Purpose This system information is mandatory, and is transmitted on BCCH. It contains cell reselection information.

Information content SYS INFO 8 ---- SI 8 Rest Octets

SI 8 Rest Octets contains the parameters used by MS for cell reselection. It can also contain the information of the parameter POWER OFFSET used by DCS1800 Class 3 MS.

The coding format of SI 8 Rest Octets is the same with SI 4 Rest Octets. See the related description in "5) SI 4 Rest Oct" of 3.2.4.

3.2.9 System Information 2quater

Purpose To support the idle dual band UE camp on the GSM network to return to the 3G network through cell reselection, BSC needs to send the system information to inform the dual band UE 3G about information of the neighbor cells. The information is in the SI 2quater.

The GSM protocol does not define the SI2quater. It is defined in 3GPP 04.18. The message describes about the 3G cell reselection, measurement and report.

Information Content Except for the common message header of the Um interface, the SI2quater contains only one SI2quater Rest Octets IE. It length is 23 bytes, the same as that of the SYSTEM INFORMATION TYPE 2, 2bis, 2ter .The information in the SI2quater is sent according to the instances. The measurement parameters are sent first, and then the neighbor cell information.

If the 3G neighbor cells with the same frequency are more than 16 in the 2G/3G neighbor cells, use the first 16 cells of this frequency after being sorted.

3.2.10 System Information MEASUREMENT INFORMATION

Purpose After the MS enters into the dedicated mode, it needs to regenerate the neighbor cell list according to the system information on the SACCH.




SI5, SI5bis, and SI5ter provide the information of the GSM neighboring cells.

MEASUREMENT INFORMATION provides the information of the 3G neighboring cells.

Information Content The message MEASUREMENT INFORMATION (MI) has 23 bytes. It contains multiple instances. It contains the 3G neighbor cell information, and measurement information.

3.3 Internal Handling of BSC The internal handling of the BSC is given below:

Step 1 The BSC retrieves cell frequencies in SYSTEM INFORMATION TYPE 1 from the [Cell Allocation Table].

Table 3-7 shows the correspondence between the RACH control parameters in SYSTEM INFORMATION TYPE 1 and the [System information table].

Table 3-7 Correspondence between RACH control parameters and the [System information table]

RACH control parameters in SYSTEM INFORMATION TYPE 1

System information table

Maximum number of retransmissions (MAX retrans)

MS MAX retrans

Number of slots to spread transmission (Tx_integer)

Tx_integer

Cell Barred for Access (CELL_BAR_ACCESS)

CBA

Access Control Class (AC) Controlled by common access control class and Special access control class

Call reestablishment allowed (RE) Call re-establishment allowed

Emergency Call allowed (EC) EC allowed

“MAX retrans” and “Tx_integer” vary with the current traffic class of the cell if the BSC enables the cell flow control function.

Step 2 The BSC retrieves neighbor cell frequencies in SYSTEM INFORMATION TYPEs 2, 2bis and 2ter from the [BA1 Table]. Specifically, it retrieves NCC Permitted in SYSTEM INFORMATION TYPE 2 from the “NCC permitted” field in the [System information Table]. The RACH control parameters in SYSTEM INFORMATION TYPEs 2 and 2bis are the same as that in SYSTEM INFORMATION TYPE 1, as listed in Table 3-7.

Step 3 The BSC retrieves CGI in SYSTEM INFORMATION TYPE 3 from the [BSC Cell Table]. Table 3-8 shows the correspondence between the control channel parameters in SYSTEM INFORMATION TYPE 3 and the [System information table].



Table 3-8 Correspondence between the control channel parameters in SYSTEM INFORMATION TYPE 3 and the [System information table]

Control channel parameters in SYSTEM INFORMATION TYPE 3


Attach-Detach allowed (ATT) ATT

CCCH-CONF CCCH-CONF

BS_AG_BLKS_RES BS_AG_BLKS_RES

BS-PA-MFRAMS BS-PA-MFRAMS

T3212 T3212

Table 3-9 shows the correspondence between the cell options in SYSTEM INFORMATION TYPE 3 and the [System information table].

Table 3-9 Correspondence between the cell options in SYSTEM INFORMATION TYPE 3 and the [System information table]

Cell options in SYSTEM INFORMATION TYPE 3


Power control indicator (PWRC) PWRC

DTX indicator (DTX) DTX

Radio_Link_Timeout Radio Link Timeout

Table 3-10 shows the correspondence between the cell selection parameters in SYSTEM INFORMATION TYPE 3 and the [System information table].

Table 3-10 Correspondence between the cell selection parameters in SYSTEM INFORMATION TYPE 3 and the [System information table]

Cell selection parameters in SYSTEM INFORMATION TYPE 3


Cell Reselection Hysteresis CRH

MS_TXPWR_MAX_CCH MS_TXPWR_MAX_CCH

RXLEV_ACCESS_MIN RXLEV_ACCESS_MIN

ADDITIONAL RESELECT PARAM IND (ACS) ACS

HALF RATE SUPPORT (NECI) Half rate supported

The RACH control parameters in SYSTEM INFORMATION TYPE 3 are the same as that in SYSTEM INFORMATION TYPE 1, as listed in Table 3-7.




Step 4 The BSC retrieves Location Area Identification in SYSTEM INFORMATION TYPE 4 from the [BSC Cell Table]. The cell selection parameters in type 4 are the same as that in type 3, as listed Table 3-10. The RACH control parameters in type 4 are the same as that in type 1, as listed in Table 3-7. The BSC receives CBCH Channel from the [Carrier Configuration Table] and CBCH Mobile Allocation from the [Frequency Hopping Table]. Table 3-11 shows the correspondence between SI 4 Rest Octets and the [System information table].

Table 3-11 Correspondence between SI 4 Rest Octets and the [System information table]

SI 4 Rest Octets System information table

Cell Reselection Parameter Indicator (PI) PI

CELL_BAR_QUALIFY (CBQ) CBQ

CELL_RESELECT_OFFSET (CRO) CRO

TEMPORARY_OFFSET (TO) TO

PENALTY_TIME (PT) PT

Step 5 The BSC retrieves neighbor cell frequencies in SYSTEM INFORMATION TYPEs 5, 5bis and 5ter from the [BA2 (SACCH) Table].

Step 6 The BSC retrieves CGI in SYSTEM INFORMATION TYPE 6 from the [BSC Cell Table]. The cell options in this type are the same as that in type 3, as listed in Table 3-9. The BSC retrieves NCC Permitted from the “NCC permitted” field in the [System information table].

Step 7 SI 7 Rest Octets are the same as SI 4 Rest Octets, as listed in Table 3-11.

Step 8 SI 8 Rest Octets are the same as SI 4 Rest Octets, as listed in Table 3-11.

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01-3 system information

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