3.2.3 Signalling Field Element Coding
08.083GPPMobile-services Switching Centre - Base Station system (MSC-BSS) Interface Layer 3 SpecificationRelease 1999TS
The coding rules for signalling field elements are the same as the signalling element coding rules which are defined in sub-clause 3.2.2.
Signalling field elements shall always include a Field Length indicator. A Field Length indicator with a value of zero shall not be considered as an error.
Field Element Identifier Coding | Field Element name | Reference |
0000 0001 | Extra information | 3.2.3.1 |
0000 0010 | Current Channel Type 2 | 3.2.2.2 |
0000 0011 | Target cell radio information | 3.2.3.3 |
0000 0100 | GPRS Suspend information | 3.2.3.4 |
0000 0101 | MultiRate configuration information | 3.2.3.5 |
0000 0110 | Dual Transfer Mode information | 3.2.3.6 |
0000 0111 | Inter RAT Handover Info | 3.2.3.7 |
0000 1000 | cdma2000 Capability Information | 3.2.3.8 |
All other values are for future use.
3.2.3.1 Extra information
This field element provides a general flag mechanism that allows the old BSS to indicate to the new BSS flag information.
It is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Field Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
octet 3 |
Octet 2 is a binary indication of the length of the rest of the field element.
Octet 3 is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
spare | lcs | prec | octet 3 |
Bit 8 to 2 are flags that indicate no information.
prec = Pre-emption Recommendation
0 The old BSS recommends that this allocation request should not cause a pre-emption an existing connection.
1 The old BSS recommends that this allocation request is allowed to preempt an existing connection based on the information supplied in the Priority information element, if available.
In the case the "prec" bit is not present or the Extra Information field element is not present then the new BSS should run pre-emption as specified by the Priority information element, if available.
In the case where the Priority information element is not present in the request then the "prec" element, if present, shall be ignored.
lcs = Location Services (LCS) information
0 No ongoing LCS procedure.
1 An ongoing LCS procedure was interrupted by handover. The new BSS may notify the SMLC when the handover is completed.
3.2.3.2 Current Channel type 2
This Field Element contains a description of the channel allocated to the MS.
It is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
Channel mode | octet 3 | |||||||
Channel field | octet 4 |
The channel mode field is coded as follows:
Bit
4321
0000 signalling only
0001 speech (full rate or half rate)
0110 data, 14.5 kbit/s radio interface rate
0011 data, 12.0 kbit/s radio interface rate
0100 data, 6.0 kbit/s radio interface rate
0101 data, 3.6 kbit/s radio interface rate
1111 is reserved
All other values indicate that no information is provided.
Bits 8 to 5 are spare.
The channel field is coded as follows:
Bit
4321
0001 SDCCH
1000 1 Full rate TCH
1001 1 Half rate TCH
1010 2 Full Rate TCHs
1011 3 Full Rate TCHs
1100 4 Full Rate TCHs
1101 5 Full Rate TCHs
1110 6 Full Rate TCHs
1111 7 Full Rate TCHs
0100 8 Full Rate TCHs
0000 is reserved
All other values indicate that no information is provided.
Bits 8 to 5 are spare.
3.2.3.3 Target cell radio information
It is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
octet 3 |
Octet 2 is a binary indication of the length of the rest of the element.
Octet 3 is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
RXLEV-NCELL | octet 3 |
Bit 8 to 7 is spare, set to 0
Bit 6 to 1 is the RXLEV-NCELL field.
The RXLEV-NCELL field is coded as the binary representation of a value N. N corresponds according to the mapping defined in TS. 3GPP TS 05.08 to the received signal strength on the target cell.
3.2.3.4 GPRS Suspend Information
This Field Element contains the contents of the Gb interface SUSPEND ACK PDU.
It is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
Gb interface TLLI IEI | octet 3 | |||||||
Length of TLLI | octet 4 | |||||||
TLLI | oct 5 – 5+m | |||||||
Gb interface RAI IEI | octet 6+m | |||||||
Length of RAI | octet 7+m | |||||||
RAI | oct 7+m – n | |||||||
Gb interface SRN IEI | octet n+1 | |||||||
Length of SRN | octet n+2 | |||||||
Suspend reference number | oct n+3 -p |
The coding of the fields are not relevant to 3GPP TS 08.08
3.2.3.5 MultiRate configuration Information
This Field Element contains a description of the multi-rate speech codec configuration currently used.
It is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
Rest of element coded as in 3GPP TS 04.08, not including 3GPP TS 04.08 element identifier or 3GPP TS 04.08 octet length value | octet 3-n |
3.2.3.6 Dual Transfer Mode information
This Field Element contains information about a mobile in dual transfer mode. This information may be used for the target BSS to allocate the resources for the RR connection (e.g. TCH/H, TCH in an EGPRS transceiver).
It is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
Spare | EGPRS ind | STO ind | DTM ind | Octet 3 |
Octet 3
Bit 1 is the dual transfer mode indicator. It indicates whether the MS is in dedicated mode or in dual transfer mode. It is coded as follows:
Bit 1
0 The MS is in dedicated mode in the old cell
1 The MS is in dual transfer mode in the old cell
Bit 2 is the single timeslot operation indicator. It indicates whether the MS has a TCH/H and a PDCH/H; see 3GPP TS 05.02. It is coded as follows:
Bit 2
0 The MS is in multislot operation in the old cell
1 The MS is in single timeslot operation in the old cell
Bit 3 is the EGPRS indicator. It is coded as follows:
Bit 3
0 The MS has no TBF using E-GPRS in the old cell
1 The MS has a TBF using E-GPRS in the old cell
3.2.3.7 Inter RAT Handover Info
The Inter RAT Handover Info information element is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Field Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
Inter RAT Handover Info | octet 3-n |
Octets 3-n are encoded as Inter RAT Handover Info as defined in TS 3GPP TS 25.331.
3.2.3.8 cdma2000 Capability Information
The cdma2000 Capability Information element is coded as follows:
8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Field Element identifier | octet 1 | |||||||
Length | octet 2 | |||||||
cdma2000 capability information | octet 3-n |
Octets 3-n are encoded as octets 3-n of the cdma2000 Classmark Change message defined in TS 3GPP TS 04.18.