US 12,245,315 B2
Ran node, radio terminal, and methods therefor
Hisashi Futaki, Tokyo (JP); and Sadafuku Hayashi, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Appl. No. 17/629,841
Filed by NEC Corporation, Tokyo (JP)
PCT Filed Nov. 30, 2020, PCT No. PCT/JP2020/044526
§ 371(c)(1), (2) Date Jan. 25, 2022,
PCT Pub. No. WO2021/161621, PCT Pub. Date Aug. 19, 2021.
Claims priority of application No. 2020-022471 (JP), filed on Feb. 13, 2020.
Prior Publication US 2022/0287137 A1, Sep. 8, 2022
Int. Cl. H04W 56/00 (2009.01); H04L 5/00 (2006.01); H04W 76/27 (2018.01); H04W 92/10 (2009.01)
CPC H04W 76/27 (2018.02) [H04L 5/0035 (2013.01); H04W 92/10 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A first Radio Access Network (RAN) node comprising:
at least one memory; and
at least one processor coupled to the at least one memory and configured to:
if a Radio Resource Control (RRC) resume request message not accompanied by uplink data is received from a radio terminal in an RRC_INACTIVE state and a radio terminal context of the radio terminal is not available in the first RAN node, send a first type of control message requesting the radio terminal context to a second RAN node that is a last serving RAN node for the radio terminal; and
if the uplink data together with the RRC resume request message is received, by the first RAN node, from the radio terminal in the RRC_INACTIVE state and the radio terminal context is not available in the first RAN node, then:
send to the second RAN node a second type of control message that requests the radio terminal context and is distinct from the first type of control message;
receive a third control message, from the second RAN node, after sending the second type of control message; and
send the uplink data, received from the radio terminal, to the second RAN node in response to the third control message indicating that the radio terminal context will not be relocated.