EC SI 1_INDEX (2 bits) and EC SI 1_COUNT (2 bits)
The purpose of these fields is to indicate the number of individual message instances within the sequence of EC SI 1 messages and to assign an index to identify each instance. The EC SI 1_INDEX field is binary coded, range 0 to 3, and provides an index to identify an individual EC SI 1 message instance. The EC SI 1_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 1 messages.

EC SI_CHANGE_MARK (5 bits)
This field contains a bitmap indicating the status of each EC SI message broadcasted in the cell. Whenever the content of a given EC SI message is modified the associated bit position within the bitmap (EC SI N) is changed to "0" or "1" depending on its previous value; N = 1, 2, 3, 4.
An Overflow Control bit (bit 1 in the bitmap) indicates whether one or more of the EC SI messages have changed more than once during a given time period (see sub-clause 3.10.4).

The EC SI_CHANGE_MARK field is encoded as follows.

Bits
5 4 3 2 1
x x x x x EC SI 4 EC SI 3 EC SI 2 EC SI 1 Overflow Control bit

EC Cell Channel Description struct
The EC Cell Channel Description struct identifies the list of frequencies in the serving cell.

NumberOfOctets (5 bits)
This field indicates the number of octets used to provide the serving cell 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

Frequency List Information
This field defines the radio frequency channels in the cell 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 radio frequency channels (ARFCNs) included in the Frequency List Information field (excluding any duplication of ARFCN) is denoted NF. The radio frequency channels 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 radio frequency channel shall then be assigned an ARFCN_INDEX value, ranging from zero, for the first radio frequency channel, to NF-1, for the last radio frequency channel.

EC Mobile Allocation List (construction)
This construction is the representation of the EC Mobile Allocation set(s) defined for the cell. An EC_MA_NUMBER field preceding the EC Mobile Allocation set identifies each individual EC Mobile Allocation set. The EC Mobile Allocation List may be provided in more than one instance of the EC SI 1 message.

EC_MA_NUMBER (5 bits)
This field identifies the EC Mobile Allocation set provided in the EC Mobile Allocation List struct. It is coded as follows:

Bits
5 4 3 2 1
0 0 0 0 0 EC Mobile Allocation set 1
0 0 0 0 1 EC Mobile Allocation set 2
…
1 1 1 1 1 EC Mobile Allocation set 32

MAIO (6 bits)
This field is the binary representation of the mobile allocation index offset (MAIO), see 3GPP TS 45.002.

ARFCN (10 bits)
This field is the binary representation of the absolute radio frequency channel number (ARFCN) defined in 3GPP TS 45.005.

HSN (6 bits)
The HSN field is the binary representation of the hopping sequence number, see 3GPP TS 45.002.

MA_LENGTH (6 bits)
This field indicates the length of the MA_BITMAP field in number of bits.
It is coded as follows:

Bits
6 5 4 3 2 1
0 0 0 0 0 0 1 bit
0 0 0 0 0 1 2 bits
…
1 1 1 1 1 1 64 bits

MA_BITMAP (variable length, 1 to 64 bits field)
This field is a bitmap representing the radio frequency channels belonging to a given EC Mobile Allocation set. The number of bit positions in MA_BITMAP is determined by the MA_LENGTH field and shall equal the number of radio frequency channels (NF) provided in the EC Cell Channel Description struct. The first bit position in MA_BITMAP (bit position 1) corresponds to ARFCN_INDEX = NF-1 and the last bit position (bit position NF) corresponds to ARFCN_INDEX = 0, as follows:

Bit position ARFCN_INDEX
NF, NF-1 … 2, 1 0,1 … NF-2, NF-1

In the absence of this field, the MA_BITMAP field of the previous EC Mobile Allocation set described in this message shall be used for the current EC Mobile Allocation set.

Each bit position in the MA_BITMAP field is coded:

0 the corresponding radio frequency channel does not belong to the EC Mobile Allocation set.
1 the corresponding radio frequency channel belongs to the EC Mobile Allocation set.

Band Indicator (1 bit)
The Band Indicator associates the ARFCN channel numbers provided in the EC Cell Channel Description struct and in the EC Mobile Allocation List struct to the DCS 1800 respectively to the PCS 1900 band, see 3GPP TS 45.005. If no ARFCN channel numbers associated to DCS 1800 or PCS 1900 are included in the EC Cell Channel Description struct or in the EC Mobile Allocation List struct, the Band Indicator shall be set to 0.

Value
0 ARFCN indicates 1800 band
1 ARFCN indicates 1900 band

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

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

EC Cell Selection Parameters struct
This structure provides the cell selection parameters for the serving cell.

Location Area Identification (40 bits)
The Location Area Identification field is coded as the value part of the Location Area Identification IE specified in sub-clause 10.5.1.3.

Routing Area Code (8 bits)
This field is the binary representation of the Routing Area Code, see 3GPP TS 23.003.

Cell Identity (16 bits)
The Cell Identity field is coded as the value part of the Cell Identity IE specified in sub-clause 10.5.1.1.

EC_BS_CC_CHANS (2 bits)
This field indicates the number of extended coverage common control channels (EC-CCCHs) supported in the cell.

Value
00 1 EC-CCCH supported
01 2 EC-CCCHs supported
10 3 EC-CCCHs supported
11 4 EC-CCCHs supported

If the Access_Timeslots field provided in this message indicates that 2 TS EC-RACH mapping shall be applied in the cell, then the number of EC-CCCHs supported in the cell shall be equal to or lower than the number of common control channels (CCCHs) configured in the same cell.

EC_RXLEV_ACCESS_MIN (6 bits)
The EC_RXLEV_ACCESS_MIN field is coded as the binary representation of the minimum received signal level at the MS for which it is permitted to access the system, see 3GPP TS 45.008.

MS_TXPWR_MAX_CCH (5 bits)
The MS_TXPWR_MAX_CCH field is coded as the binary representation of the "power control level" in 3GPP TS 45.005 corresponding to the maximum TX power level an MS may use when accessing the system on the (EC-)CCCH. This value shall be used by the Mobile Station according to 3GPP TS 45.008.

LB_MS_TXPWR_MAX_CCH (5 bits)
The LB_MS_TXPWR_MAX_CCH field is coded as the binary representation of the "power control level" in 3GPP TS 45.005 corresponding to the maximum TX power level an MS may use on all other than DCS 1800 and PCS 1900 frequency bands when accessing the system on the (EC-)CCCH. This value shall be used by the Mobile Station according to 3GPP TS 45.008.

CELL_SELECTION_RLA_MARGIN (3 bits)
The CELL_SELECTION_RLA_MARGIN field provides the MS with information whether RLA_EC and RLA_GC based measurements may be omitted or not. The use of this field is defined in 3GPP TS 45.008.

CE_AUTH_OFFSET (2 bits)

The CE_AUTH_OFFSET field is the coverage enhancement authorization offset corresponding to the level of desensitization of a MS in restricted use of enhanced coverage compared to the non-restricted use of enhanced coverage.

Bits

00 5 dB

01 10 dB

10 15 dB

11 20 dB

Coverage Class Selection Parameters struct
This structure provides information for the MS to estimate its uplink and downlink coverage class.

DL_CC_Selection (1 bit)
This field indicates the method for selecting the downlink coverage class to be used by the MS.

Bit
0 RLA_EC based coverage class selection
1 SLA based coverage class selection

The use of this field is defined in 3GPP TS 45.008.

BT_Threshold_DL (5 bits)
This field indicates the threshold below which blind physical layer transmissions are used on EC-CCCH. The use of this field is defined in 3GPP TS 45.008.

CC2_Range_DL (5 bits)
CC3_Range_DL (5 bits)
These fields are optionally sent by the network to indicate the signal level range of the indicated downlink coverage classes. The presence of one or both of the above fields indicates network support of the associated downlink coverage class.
The use of these fields is defined in 3GPP TS 45.008.

BT_Threshold_UL (5 bits)
This field indicates the signal level threshold below which blind physical layer transmissions are used on EC-RACH. The use of this field is defined in 3GPP TS 45.008.

CC2_Range_UL (5 bits)
CC3_Range_UL (5 bits)
These fields are optionally sent by the network to indicate the signal level range of the indicated uplink coverage classes. The presence of one or both of the above fields indicates network support of the associated uplink coverage class.
The use of these fields is defined in 3GPP TS 45.008.

CC4_Range_UL (5 bits)
This field is optionally sent by the network to indicate the signal level range of coverage class CC4. Presence of this field indicates that network support uplink coverage class CC5. The use of this field is defined in 3GPP TS 45.008.

CC5_EC-RACH_FORMAT_IND (1 bit)

This field indicates the EC-RACH format that has to be used by EC-GSM-IoT device that uses CC5 as its Uplink coverage class.

Bit
0 EDAB method supported for EC-RACH CC5
1 ESAB method supported for EC-RACH CC5

If the parameter CC5_EC-RACH_FORMAT_IND is set to 0 and Access_Timeslot is set to 0, then CC4 EC-RACH transmissions on TN1 and the second access burst transmission (see 3GPP TS 45.002 [32]) of EDAB use TS7.

BSPWR (6 bits)
This field indicates the BTS output power transmitted on FCCH and EC-SCH.
The use of this field is defined in 3GPP TS 45.008.

DL_Signal_Strength_Step_Size (2 bits)
This field indicates the step-size in signal level above BT_Threshold_DL possible to report by the MS in the EC Packet Channel Request message (see sub-clause 9.1.65). It is encoded as follows:

Bits
2 1
0 0 X = 2
0 1 X = 4
1 0 X = 6
1 1 X = 8

EC_Reduced_PDCH_Allocation (1 bit)

This field indicates that the number of consecutive PDCHs the network allocates when assigning an EC TBF to a MS indicating Coverage Class CC2, CC3 or CC4 on the uplink or downlink during packet access.

Bit

0 Four consecutive PDCHs are always allocated to MS for an EC TBF.

1 Two consecutive PDCHs are always allocated to MS for an EC TBF.

EC-RACH Control Parameters struct
The EC-RACH Control Parameters contains the access control parameters needed when accessing the network on the EC-RACH.

EC_Max_Retrans (2 bits)
This field indicates the maximum number of retransmissions on EC-RACH (see sub-clause 3.5.2.1.2a). It is encoded as the Max retrans field in the RACH Control Parameters IE defined in sub-clause 10.5.2.29.

Sm (2 bits)
This field is used by a MS to determine the number of multiframes it needs to read on the EC-AGCH in an attempt to find a response matching its last EC-RACH transmission (see sub-clause 3.5.2.1.2a).

Bits
2 1
0 0 1 or more multiframes
0 1 2 or more multiframes
1 0 3 or more multiframes
1 1 4 or more multiframes

Tm (2 bits)
This field is used by a MS to determine the number of multiframes on the EC-RACH from which it randomly selects a transmission/retransmission opportunity (see sub-clause 3.5.2.1.2a).

Bits
2 1
0 0 1 or more multiframes
0 1 2 or more multiframes
1 0 3 or more multiframes
1 1 4 or more multiframes

Access_Timeslots (1 bit)
This field indicates whether random access mapped over two timeslots (e.g. TS 0 and TS 1, or, TS 2 and TS 3) shall be applied or not (see sub-clause 3.5.2.1.2a).

Bit
0 1 TS EC-RACH mapping shall be applied.
1 2 TS EC-RACH mapping shall be applied if uplink Coverage Class 2, Coverage Class 3 or Coverage Class 4 has been selected.

The number of EC-RACH supported in the cell is indicated by the EC_BS_CC_CHANS field provided in this message.

CC_Access_Adaptation (2 bits)
This field indicates whether the mobile station is allowed to increment its Coverage Class after one or more failed access attempts on the EC-RACH (see sub-clause 3.5.2.1.2a).

Bits
2 1
0 0 Coverage Class adaptation not allowed
0 1 Coverage Class adaptation after 1 failed EC-RACH transmission attempt
1 0 Coverage Class adaptation after 2 failed EC-RACH transmission attempts
1 1 Coverage Class adaptation after 3 failed EC-RACH transmission attempts

Cell_Bar_Access (1 bit)
This field indicates whether the 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.

EC_Access_Control_Class (7 bits)
This field contains a bitmap indicating the barring status for Access Control Classes 0 to 15 (AC C0 to AC C15) applicable for the Common PLMN provided in this message.
The EC_Access_Control_Class field is encoded as follows.

Bits
7 6 5 4 3 2 1
x x x x x x x AC C15 AC C14 AC C13 AC C12 AC C11 AC C10 AC C0 to AC C9

For a mobile station with AC C = N access is not barred if the AC CN bit is coded with a "0"; N = 0, 1, .. 9, 11, .., 15. Access control for mobile stations belonging to one of the access control classes 0 to 9 (AC C0 to AC C9) is indicated by the first bit in the bitmap (bit 1). If this field is not present and the MS has selected the common PLMN it shall assume its access class is not barred.

For an MS in EC operation the AC C10 field is not used in this version of the specification.

Exception_Report_Status (1 bit)

This field indicates whether sending of exception reports are allowed or not. It is encoded as follows:

Bit
0 Sending of exception reports allowed in the cell for all MSs
1 Sending of exception reports not allowed in the cell except for the MSs that belong to one of the authorized Access Control Classes 11 to 15.

If this field is not present and the MS has selected the common PLMN it shall assume exception reports are not barred.

BT_Threshold_UL_Margin (3 bits)
This optional field indicates the power margin above BT_Threshold_UL used for (EC-)RACH open-loop power control. The use of this field is defined in 3GPP TS 45.008.

Short RACH Control Parameters struct
The Short RACH Control Parameters contains the access control parameters needed when accessing the network on the RACH on the common control channel (CCCH) on TS 0.

Max_Retrans (2 bits)
This field indicates the maximum number of retransmissions on RACH. It is encoded as the Max retrans field in the RACH Control Parameters IE defined in sub-clause 10.5.2.29.

Tx-integer (4 bits)
This field indicates the number of slots to spread the transmission on RACH. It is encoded as the Tx-integer field in the RACH Control Parameters IE defined in sub-clause 10.5.2.29.

Access_Control_Class (16 bits)
This field contains a bitmap indicating the barring status for Access Control Classes 0 to 15 (AC C0 to AC C15) applicable for the Common PLMN provided in this message. In the absence of this field, the Access Control Class information provided in the EC-RACH Control Parameters struct shall be used instead.

The Access_Control_Class field is encoded as follows.

Bits
16 15 … 1
x x … x AC C15 AC C14 … AC C0

For an MS in EC operation the AC C10 field is not used in this version of the specification.

EC Cell Options struct

ALPHA (4 bits)
This field is the binary representation of the parameter  for MS output power control in units of 0.1, see 3GPP TS 45.008. For encoding and description of the ALPHA field see the Global Power Control Parameters IE in 3GPP TS 44.060.

T3168 (3 bits)
T3192 (3 bits)
These fields are defined in 3GPP TS 44.060.

T3226 (3 bits)
This field is the binary representation of the timeout value of timer T3226. Range: 0 to 7.
The timeout values are given in the following table.

Bits
3 2 1
0 0 0 20 ms
0 0 1 60 ms
0 1 0 100 ms
0 1 1 200 ms
1 0 0 500 ms
1 0 1 700 ms
1 1 0 1000 ms
1 1 1 1200 ms

T3248 (2 bits)
This field is the binary representation of the timeout value of timer T3248. Range: 0 to 3.
The timeout values are given in the following table.

Bits
2 1
0 0 not used
0 1 1 second
1 0 2 seconds
1 1 3 seconds

MTA_BITMAP (4 bits)
See sub-clause 10.5.2.37b.

MS_ASSISTED_DCN
See sub-clause 10.5.2.37b.

EC paging indication channel support (1 bit)
This field indicates if paging indication on EC-PICH is supported in the cell.

Bit
0 EC paging indication channel is not supported
1 EC paging indication channel is supported

IMM Cell Group Definition struct

This structure provides identifier, change mark indication as well as common and specific cell parameters of the IMM Cell Group which the serving cell belongs to. Common cell parameters across cells in the same IMM Cell Group are contained in the IMM Cell Group Definition structure (see below) and further refer to following cell parameters outside the IMM Cell Group Definition structure, if sent for the serving cell in EC SI type 2 and EC SI type 3 (i.e. these parameters broadcasted by the serving cell are interpreted as common parameters of the IMM Cell Group):

Common cell parameters outside the IMM Cell Group Definition structure in EC SI type 2:

Parameters in EC Cell Selection Parameters structure:

Routing Area Code : bit (8)

EC_BS_CC_CHANS : bit (2)

EC_RXLEV_ACCESS_MIN : bit (6)

MS_TXPWR_MAX_CCH : bit (5)

LB_MS_TXPWR_MAX_CCH : bit (5)

CELL_SELECTION_RLA_MARGIN : bit (3)

Parameters in Coverage Class Selection Parameters structure:

DL_CC_Selection: bit (1)

BT_Threshold_DL: bit (5)

CC2_Range_DL : bit (5)

CC3_Range_DL : bit (5)

Parameters in EC-RACH Control Parameters structure:

Cell_Bar_Access : bit (1)

Common cell parameters outside the IMM Cell Group Definition structure in EC SI type 3:

Parameters in EC Cell Reselection Parameters struct:

CELL_RESELECT_HYSTERESIS : bit (3)

CELL_RESELECT_OFFSET : bit (6)

C1_DELTA_MIN : bit (2)

C1_DELTA_MAX : bit (3)

IMM Cell Group Identifier (3 bits)

This field is the binary representation of the identity of the IMM Cell Group. Range: 1 to 7. The code point "000" is not used, as it indicates on EC-SCH that IMM Cell Group description is not broadcasted, see subclause 9.1.30c.

Bits
3 2 1
0 0 0 not used
0 0 1 Cell Group Identity 1
0 1 0 Cell Group Identity 2
0 1 1 Cell Group Identity 3
1 0 0 Cell Group Identity 4
1 0 1 Cell Group Identity 5
1 1 0 Cell Group Identity 6
1 1 1 Cell Group Identity 7

IMM Change Mark (2 bits)

This field is the binary representation of the IMM Change Mark value N indicating the status of the IMM Cell Group description, referring to parameters belonging to the IMM Cell Group Definition struct and to specific parameters in EC SI type 2 and EC SI type 3. Range: 0 to 3. Whenever the value of parameters belonging to the IMM Cell Group description is modified, the IMM Change Mark value N is incremented to (N+1) modulo 4. If only parameters are modified that belong to the IMM Cell Group Definition struct, the

EC SI_CHANGE_MARK field shall not be modified.

Timeout Read Complete SI (2 bits)

This field indicates the timeout for triggering the acquisition of the complete set of EC System Information messages in the serving cell, if the last acquisition of the complete set of System Information messages has been performed in a different cell. It is coded as follows.

Bits
2 1
0 0 [2] minutes
0 1 [5] minutes
1 0 [15] minutes
1 1 reserved

NumberOfOctets (5 bits)

This field is coded in the same way as in EC SI type 3.

Broadcast Frequency List Information
This field defines all BCCH carriers, as a set of ARFCNs, of cells belonging to the same IMM Cell Group as the serving cell belongs to. It is coded in the same way as the field Neighbour Frequency List Information in EC SI type 3.

IMM Cell Group Specific Parameters struct

This structure provides specific cell parameters of neighbour cells belonging to the same IMM Cell Group as the serving cell.

Nb_NCELL (5 bits)
This field indicates the number of neighbour BCCH carriers belonging to the same IMM Cell Group as the serving cell for which the number of extended coverage common control channels (EC-CCCHs) or the cell barring status deviates from the default parameter EC_BS_CC_CHANS_DEFAULT or CELL_BAR_ACCESS_DEFAULT, respectively. The same coding as for Nb_NCELL field in EC SI type 3 applies.

BSIC (6 or 9 bits)
The BSIC field identifies the neighbour base station for which the specific IMM Cell Group parameters (rather than the default values) 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.

EC_BS_CC_CHANS_SPECIFIC (2 bits)

This field indicates the number of extended coverage common control channels (EC-CCCHs) that shall be applied for a cell sharing the same IMM Cell Group as the serving cell, if the BSIC of that cell is contained in the cell description of the IMM Cell Group Definition struct. It is coded as the field EC_BS_CC_CHANS (sent in EC SI type 2). It overwrites the default parameter EC_BS_CC_CHANS_DEFAULT for that cell.

CELL_BAR_ACCESS_SPECIFIC (1 bit)

This field indicates the cell barring status that shall be applied for a cell sharing the same IMM Cell Group as the serving cell, if the BSIC of that cell is contained in the cell description of the IMM Cell Group Definition struct. It is coded as the field Cell_Bar_Access (sent in EC SI type 2). It overwrites the default parameter CELL_BAR_ACCESS_DEFAULT for that cell.

EC_BS_CC_CHANS_DEFAULT (2 bits)

This field indicates the number of extended coverage common control channels (EC-CCCHs) that shall be used by default for a cell sharing the same IMM Cell Group as the serving cell, if the BSIC of that cell is not contained in the cell description of the IMM Cell Group Definition struct. It is coded as the field EC_BS_CC_CHANS (sent in EC SI type 2). If this parameter is not broadcasted, the MS shall assume that all cells belonging to the same IMM Cell Group use the same value for this parameter and the value indicated in EC_BS_CC_CHANS (sent in EC SI type 2) applies.

CELL_BAR_ACCESS_DEFAULT (1 bit)

This field indicates the cell barring status that shall be used by default for a cell sharing the same IMM Cell Group as the serving cell, if the BSIC of that cell is not contained in the cell description of the IMM Cell Group Definition struct. It is coded as the field Cell_Bar_Access (sent in EC SI type 2). If this parameter is not broadcasted, the MS shall assume that all cells belonging to the same IMM Cell Group use the same value for this parameter and the value indicated in Cell_Bar_Access (sent in EC SI type 2) applies.