US 11,930,549 B2
UE and communication method for same
Tsuyoshi Takakura, Sakai (JP)
Assigned to SHARP KABUSHIKI KAISHA, Sakai (JP)
Appl. No. 17/254,070
Filed by SHARP KABUSHIKI KAISHA, Sakai (JP)
PCT Filed Jun. 20, 2019, PCT No. PCT/JP2019/024607
§ 371(c)(1), (2) Date Dec. 18, 2020,
PCT Pub. No. WO2019/245007, PCT Pub. Date Dec. 26, 2019.
Claims priority of application No. 2018-117938 (JP), filed on Jun. 21, 2018.
Prior Publication US 2021/0267001 A1, Aug. 26, 2021
Int. Cl. H04W 76/18 (2018.01); H04W 76/50 (2018.01)
CPC H04W 76/18 (2018.02) [H04W 76/50 (2018.02)] 2 Claims
OG exemplary drawing
 
1. A User Equipment (UE) comprising:
control circuitry; and
transmitting and receiving circuitry, wherein:
the control circuitry is able to perform a second emergency call attempt in an Evolved Packet System (EPS) in a case of a failure of a first emergency call attempt in a 5G system (5GS),
the transmitting and receiving circuitry receives a Protocol Data Unit (PDU) SESSION ESTABLISHMENT REJECT message as the failure of the first emergency call attempt,
the control circuitry determines whether the system in which the UE performs the second emergency call attempt is the EPS or the 5GS, based on a cause value indicating a reason that the first emergency call attempt is rejected,
the control circuitry uses a first access network for the first emergency call attempt, and
the control circuitry uses a second access network for the second emergency call attempt.