USER EQUIPMENT (UE)
A User Equipment (UE) includes a controller configured to include first identification information in a registration request message in changing at least Mobile Station Classmark 2 and/or a codec to be supported in a case that the UE supports Single Radio Voice Call Continuity (SRVCC) from a Next Generation Radio Access Network (NG-RAN) to a Universal Terrestrial Radio Access Network (UTRAN), and a transmission and/or reception unit configured to transmit the registration request message including the first identification information to a core network, wherein the first identification information is capability information indicating support of the SRVCC from a Universal Terrestrial Radio Access Network (UTRAN) or a High Speed Packet Access (HSPA) or an Evolved UTRAN (E-UTRAN) or the NG-RAN to a 2G radio access network or the UTRAN. A control method to be performed by a user equipment, an access network apparatus, a core network apparatus, an IMS apparatus is provided to continue a voice call or video call even in a case that a network used by the user equipment is switched between different mobile communication systems including 5th Generation (5G) which is a next-generation mobile communication system.
1 - 6 . (canceled)
7 . A User Equipment (UE) comprising:
a controller configured to set, in a registration request message, first identification information, a Mobile Station Classmark 2, and supported codecs, in a case that the UE supports Single Radio Voice Call Continuity (SRVCC) from a Next Generation Radio Access Network (NG-RAN) to a Universal Terrestrial Radio Access Network (UTRAN); and
transmission and/or reception circuitry configured to transmit the registration request message to a core network,
wherein
the first identification information is capability information indicating support of the SRVCC from the NG-RAN to the UTRAN.
8 . The UE according to claim 7 , wherein the transmission and/or reception circuitry transmits the registration request message to the core network in a case that the UE changes at least the Mobile Station Classmark 2 or the supported codecs.
9 . A communication method performed by a User Equipment (UE), the communication method comprising:
setting, in a registration request message, first identification information, a Mobile Station Classmark 2, and supported codecs, in a case that the UE supports Single Radio Voice Call Continuity (SRVCC) from a Next Generation Radio Access Network (NG-RAN) to a Universal Terrestrial Radio Access Network (UTRAN); and
transmitting the registration request message to a core network,
wherein
the first identification information is capability information indicating support of the SRVCC from the NG-RAN to the UTRAN.
10 . The communication method according to claim 9 , wherein the UE transmits the registration request message to the core network in a case that the UE changes at least the Mobile Station Classmark 2 or the supported codecs.