US 11,889,373 B2
Radio network node, a wireless device and methods therein for re-establishing a radio connection
Patrik Rugeland, Stockholm (SE); Gunnar Mildh, Sollentuna (SE); and Icaro L. J. Da Silva, Solna (SE)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Appl. No. 17/270,164
Filed by TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
PCT Filed Sep. 17, 2019, PCT No. PCT/SE2019/050875
§ 371(c)(1), (2) Date Feb. 22, 2021,
PCT Pub. No. WO2020/067959, PCT Pub. Date Apr. 2, 2020.
Claims priority of provisional application 62/735,876, filed on Sep. 25, 2018.
Prior Publication US 2021/0176692 A1, Jun. 10, 2021
Int. Cl. H04W 36/30 (2009.01); H04W 76/19 (2018.01); H04W 76/11 (2018.01); H04W 76/27 (2018.01); H04W 36/00 (2009.01); H04W 48/20 (2009.01)
CPC H04W 36/305 (2018.08) [H04W 36/0038 (2013.01); H04W 36/0072 (2013.01); H04W 48/20 (2013.01); H04W 76/11 (2018.02); H04W 76/19 (2018.02); H04W 76/27 (2018.02)] 12 Claims
OG exemplary drawing
 
1. A method performed by a wireless device for re-establishing a radio connection in a wireless communications network comprising a first Radio Access Technology, RAT, and a second RAT being different from the first RAT, wherein the wireless device is operating in a first cell served by a first radio network node operating in the first RAT, and wherein the method comprises:
when a connection failure with the first cell served by the first radio network node is detected:
performing a cell selection;
selecting a second cell served by a second radio network node operating in the second RAT, wherein the second cell is known by the wireless device to be a candidate for re-establishment;
determining a first set of parameters associated with the first cell, wherein the first set of parameters comprises at least one parameter identifying the wireless device or the first cell;
receiving a second set of parameters associated with the second cell, wherein the second set of parameters comprises at least one parameter identifying the wireless device or the second cell;
determining an updated version of one or more parameters of the first set of parameters or an updated version of one or more parameters of the second set of parameters;
determining a security token based on at least one out of: the first set of parameters and the updated version of the one or more parameters of the first set of parameters, and based on at least one out of: the second set of parameters and the updated version of the one or more parameters of the second set of parameters; and
transmitting to the second cell, a re-establishment request message comprising the determined security token.