8.17 RAT Type

29.2743GPP3GPP Evolved Packet System (EPS)Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C)Release 16Stage 3TS

RAT Type is coded as depicted in Figure 8.17-1.

Bits

Octets

8

7

6

5

4

3

2

1

1

Type = 82 (decimal)

2 to 3

Length = n

4

Spare

Instance

5

RAT Type

6 to (n+4)

These octet(s) is/are present only if explicitly specified

Figure 8.17-1: RAT Type

Table 8.17-1: RAT Type values

RAT Types

Values (Decimal)

<reserved>

0

UTRAN

1

GERAN

2

WLAN

3

GAN

4

HSPA Evolution

5

EUTRAN (WB-E-UTRAN)

6

Virtual

7

EUTRAN-NB-IoT

8

LTE-M

9

NR

10

<spare>

11-255

NOTE 1: For S4-SGSN, currently it is only possible to detect the difference between GERAN and UTRAN when GERAN Gb mode is used. If GERAN Iu mode is used, then an S4-SGSN may not be able to detect the difference between GERAN and UTRAN. Across the Gb interface, the SGSN may also not be able to detect the difference between GERAN and GAN. If S4-SGSN cannot detect that the HSPA Evolution 3GPP TR 25.999 [46] network is behind the Iu interface, the S4-SGSN will send the "UTRAN" RAT Type.

NOTE 2: For the Iu interface case, if the SGSN detects UTRAN or HSPA, it sets the RAT-Type to "UTRAN". If the SGSN detects HSPA+, it sets the RAT-Type to "HSPA Evolution", otherwise the SGSN will send the "UTRAN" RAT Type.

NOTE 3: The MME sets the LTE-M RAT-Type for a UE accessing E-UTRAN and indicating Category M in its UE radio capability, as specified in 3GPP TS 23.401 [3].