EPS attach type value (octet 1)
Bits
3 2 1
0 0 1 EPS attach
0 1 0 combined EPS/IMSI attach
1 1 0 EPS emergency attach
1 1 1 reserved
All other values are unused and shall be interpreted as “EPS attach”, if received by the network.
Bit 4 of octet 1 is spare and shall be coded as zero.
EPS attach result value (octet 1)
Bits
3 2 1
0 0 1 EPS only
0 1 0 combined EPS/IMSI attach
All other values are reserved.
Bit 4 of octet 1 is spare and shall be coded as zero.
EPS update type value (octet 1, bit 1 to 3)
Bits
3 2 1
0 0 0 TA updating
0 0 1 combined TA/LA updating
1 0 1 unused; shall be interpreted as “TA updating”, if received by the network.
0 1 0 combined TA/LA updating with IMSI attach
0 1 1 periodic updating
1 0 0 unused; shall be interpreted as “TA updating”, if received by the network.
All other values are reserved.
“Active” flag (octet 1, bit 4)
Bit
4
0 No bearer establishment requested
1 Bearer establishment requested
EPS update result value (octet 1, bit 1 to 3)
Bits
3 2 1
0 0 0 TA updated
0 0 1 combined TA/LA updated
1 0 0 TA updated and ISR activated (NOTE)
1 0 1 combined TA/LA updated and ISR activated (NOTE)
All other values are reserved.
Bit 4 of octet 1 is spare and shall be coded as zero.
NOTE: Values “TA updated and ISR activated” and “combined TA/LA updated and ISR activated” are used only for a UE supporting also A/Gb or Iu mode.
