9.1.43r EC System information type 3

3GPP44.018GSM/EDGE Radio Resource Control (RRC) protocolMobile radio interface Layer 3 specificationRelease 16TS

This message is sent on the EC-BCCH if EC-GSM-IoT is supported in the cell. It is sent by the network providing cell reselection parameters for the serving and neighbour cells and EC-BCCH allocation information for the neighbour cells. Multiple instances of this message may be sent by the network. The requirements for transmission of this message are defined in 3GPP TS 45.002.

Message type: EC SYSTEM INFORMATION TYPE 3

Significance: dual

Direction: network to mobile station

< EC System Information Type 3 > ::=

< Message Type : bit (3) >

< EC SI 3_INDEX : bit (2) >

< EC SI 3_COUNT : bit (2) >

< EC SI_CHANGE_MARK : bit (5) >

< EC SI 4 Indicator : bit (1) >

{ 0 | 1 < EC Cell Reselection Parameters : < EC Cell Reselection Parameters struct >> }

{ 0 | 1 < EC Neighbour Cell Description : < EC Neighbour Cell Description struct >> }

{ 0 | 1 < EC Neighbour Cell Reselection Parameters : < EC Neighbour Cell Reselection Parameters struct >> }

< spare padding > ;

< EC Cell Reselection Parameters struct > ::=

< CELL_RESELECT_HYSTERESIS : bit (3) >

< CELL_RESELECT_OFFSET : bit (6) >

{ 0 | 1 < C1_DELTA_MIN : bit (2) >

< C1_DELTA_MAX : bit (3) > } ;

< EC Neighbour Cell Description struct > ::=

< NumberOfOctets : bit (5) >

< Neighbour Frequency List Information : bit (val(NumberOfOctets + 1)*8) > ;

< EC Neighbour Cell Reselection Parameters struct > ::=

< Nb_NCELL : bit (5) >

{

{ 0 | 1

{ 0 < BSIC : bit (6) >

| 1 < BSIC : bit (9) > }

}

< CELL_TYPE : bit (1) >

{ 0 — The previously listed EC Neighbour Cell Reselection Parameters applies

| 1 — The indicated EC Neighbour Cell Reselection Parameters applies

{ 0 | 1 < CELL_BAR_ACCESS : bit (1) >

< SAME_RA_AS_SERVING_CELL : bit (1) > }

{ 0 | 1 < EC_RXLEV_ACCESS_MIN : bit (6) >

< MS_TXPWR_MAX_CCH : bit (5) > }

{ 0 | 1 < CELL_RESELECT_OFFSET : bit (6) > }

{ 0 | 1 < CE_AUTH_OFFSET : bit (2) > }

}

} * (val(Nb_NCELL)+1) ;

Figure 9.1.43r.1: EC SYSTEM INFORMATION TYPE 3 message content

Table 9.1.43r.1: EC SYSTEM INFORMATION TYPE 3 information element details

Message Type (3 bits)
The Message Type field is encoded according to Table 10.4 .4.

EC SI 3_INDEX (2 bits) and EC SI 3_COUNT (2 bits)
The purpose of these fields is to indicate the number of individual message instances within the sequence of EC SI 3 messages and to assign an index to identify each instance. The EC SI 3_INDEX field is binary coded, range 0 to 3, and provides an index to identify an individual EC SI 3 message instance. The EC SI 3_COUNT field is binary coded, range 0 to 3, and provides the value of the highest indexed message instance in the sequence of EC SI 3 messages.

EC SI_CHANGE_MARK (5 bits)
This field is defined in Table 9.1.43p.1.

EC SI 4 Indicator (1 bit)
This field indicates whether or not the EC SYSTEM INFORMATION TYPE 4 message is broadcast by the network. It is coded as follows:

Bit
0 The EC SYSTEM INFORMATION TYPE 4 message is not available.
1 The EC SYSTEM INFORMATION TYPE 4 message is available.

EC Cell Reselection parameters
This structure provides the cell reselection parameters used in the reselection criteria C2 for the serving cell.

CELL_RESELECT_HYSTERESIS (3 bits)
The usage of this field is defined in 3GPP TS 45.008. It is coded as specified in sub-clause 10.5.2.4.

CELL_RESELECT_OFFSET (6 bits)
The CELL_RESELECT_OFFSET field is coded as the binary representation of the "CELL_RESELECT_OFFSET" in 3GPP TS 45.008. It is a value used by the mobile station to apply a positive or negative offset to the value of C2 as defined in 3GPP TS 23.022 and 3GPP TS 45.008.

C1_DELTA_MIN (2 bits)
The C1_DELTA_MIN field indicates the minimum value of C1_DELTA. It is used by the mobile station to compare the current C1 value with the best C1 value experienced since entering the serving cell. The C1_DELTA_MIN field is coded as defined in 3GPP TS 45.008.

C1_DELTA_MAX (3 bits)
The C1_DELTA_MAX field indicates the maximum value of C1_DELTA. It is used by the mobile station to compare the current C1 value with the best C1 value experienced since entering the serving cell. The C1_DELTA_MAX field is coded as defined in 3GPP TS 45.008.

EC Neighbour Cell Description struct
The EC Neighbour Cell Description structure determines the BA (EC-BCCH) list which identifies the BCCH carriers of the neighbour cells.

NumberOfOctets (5 bits)
This field indicates the number of octets used to provide the neighbour frequency list information.
It is coded as follows:

Bits
5 4 3 2 1
0 0 0 0 0 1 octet
0 0 0 0 1 2 octets

1 1 1 1 1 32 octets

Neighbour Frequency List Information
This field defines the BCCH carriers of the neighbour cells as a set of ARFCNs. It consists of the value part of the Frequency List IE defined in sub-clause 10.5.2.13. The value part starts from octet 3 and the length of the value part is determined by the NumberOfOctets field.

The number of BCCH carriers (ARFCNs) included in the Neighbour Frequency List Information field (excluding any duplication of ARFCN) is denoted NF. The BCCH carriers provided in one or more instances of this message shall be arranged by the receiver of this field in the order of ascending ARFCN, except for ARFCN = 0, if included, which shall be put last. Each BCCH carrier shall then be assigned an NCELL_LIST_INDEX value, ranging from zero, for the first BCCH carrier, to NF-1, for the last BCCH carrier.

EC Neighbour Cell Reselection Parameters struct
This structure provides a set of cell reselection parameters for each BCCH carrier included in the EC Neighbour Cell Description struct. The first set of cell reselection parameters in the EC Neighbour Cell Reselection Parameters struct refers to the BCCH carrier with NCELL_LIST_INDEX value = 0, the second set of cell reselection parameters refers to the BCCH carrier with NCELL_LIST_INDEX value = 1 and so on.

General rules for handling of the neighbour cell reselection parameter default values are as follows:

If the first set of cell reselection parameters in the EC Neighbour Cell Reselection Parameters struct does not include all the cell reselection parameters, the following default values shall be applied:

Field name Default value

CELL_BAR_ACCESS : Serving cell CELL_BAR_ACCESS
SAME_RA_AS_SERVING_CELL : 1 (The neighbour cell is in the same Routing Area as the serving cell)
EC_RXLEV_ACCESS_MIN : Serving cell EC_RXLEV_ACCESS_MIN
MS_TXPWR_MAX_CCH : Serving cell MS_TXPWR_MAX_CCH
CELL_RESELECT_OFFSET : C2=C1, see 3GPP TS 45.008

In the absence of any neighbour cell reselection parameter for any given BCCH carrier, the cell reselection parameter value of the previous BCCH carrier shall apply. This principle also applies when going from EC SI 3 instance i over to EC SI 3 instance i+1.

Nb_NCELL (5 bits)
This field indicates the number of neighbour BCCH carriers for which cell reselection parameters are provided. The value of the Nb_NCELL field shall equal the number of BCCH carriers (NF) included in the Neighbour Frequency List Information field.
The Nb_NCELL field is coded as follows:

Bits
5 4 3 2 1
0 0 0 0 0 1 neighbour cell
0 0 0 0 1 2 neighbour cells

1 1 1 1 1 32 neighbour cells

CE_AUTH_OFFSET (2 bits)

See table 9.1.43q.1.

BSIC (6 or 9 bits)
The BSIC field identifies the neighbour base station for which the indicated cell reselection parameters are valid. The BSIC field is encoded either as a 6 bit field or as a 9 bit field, see 3GPP TS 45.002.
The use of the BSIC field is defined in 3GPP TS 45.008.

CELL_TYPE (1 bit)
The CELL_TYPE field identifies whether or not the neighbour cell supports EC-GSM-IoT.

Bit
0 The neighbour cell supports EC-GSM-IoT
1 The neighbour cell does not support EC-GSM-IoT

CELL_BAR_ACCESS (1 bit)
This field indicates whether the neighbour cell is bared for access. It is encoded as the CELL_BAR_ACCESS field in the RACH Control Parameters IE defined in sub-clause 10.5.2.29.

SAME_RA_AS_SERVING_CELL (1 bit)
This field indicates whether the neighbour cell belongs to the same Routing Area as the serving cell.

Bit
0 The neighbour cell is in a different Routing Area compared to the serving cell
1 The neighbour cell is in the same Routing Area as the serving cell

EC_RXLEV_ACCESS_MIN (6 bits)
MS_TXPWR_MAX_CCH
(5 bits)
See table 9.1.43q.1 for the corresponding fields.