School of Specs 24.501v20.0.0

3GPP 24.501 v20.0.0 — the document's own text

9.11.3.70 Truncated 5G-S-TMSI configuration

Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).

The purpose of the Truncated 5G-S-TMSI configuration information element is to provide the size of the components of the truncated 5G-S-TMSI to the UE in NB-N1 mode to create the truncated 5G-S-TMSI.

The Truncated 5G-S-TMSI configuration information element is coded as shown in figure 9.11.3.70.1 and table 9.11.3.70.1.

The Truncated 5G-S-TMSI configuration is a type 4 information element with 3 octets length.

87654321
Truncated 5G-S-TMSI configuration IEIoctet 1
Length of Truncated 5G-S-TMSI configuration contentsoctet 2
Truncated AMF Set ID valueTruncated AMF Pointer valueoctet 3

Figure 9.11.3.70.1: Truncated 5G-S-TMSI configuration information element

Table 9.11.3.70.1: Truncated 5G-S-TMSI configuration information element

Truncated AMF Pointer value (bits 4 to 1 of octet 3)This field represents the size of the least significant bits of the AMF Pointer.
Bits
4321
0000reserved
00011 least significant bit of the AMF Pointer
00102 least significant bits of the AMF Pointer
00113 least significant bits of the AMF Pointer
01004 least significant bits of the AMF Pointer
01015 least significant bits of the AMF Pointer
01106 least significant bits of the AMF Pointer
All other values shall be interpreted as "6 least significant bits of the AMF Pointer" by this version of the protocol.
Truncated AMF Set ID value (bits 8 to 5 of octet 3)This field represents the size of the least significant bits of the AMF Set ID.
Bits
4321
0000reserved
00011 least significant bit of the AMF Set ID
00102 least significant bits of the AMF Set ID
00113 least significant bits of the AMF Set ID
01004 least significant bits of the AMF Set ID
01015 least significant bits of the AMF Set ID
01106 least significant bits of the AMF Set ID
01117 least significant bits of the AMF Set ID
10008 least significant bits of the AMF Set ID
10019 least significant bits of the AMF Set ID
101010 least significant bits of the AMF Set ID
All other values shall be interpreted as "10 least significant bits of the AMF Set ID" by this version of the protocol.
NOTE: Total sum of the "Truncated AMF Set ID value" and the "Truncated AMF Pointer value" in the Truncated 5G-S-TMSI configuration IE is specified in 3GPP TS 23.003 [4] and 3GPP TS 36.300 [25B].