US 11,943,722 B2
Uplink timing synchronization maintenance in secondary cell group
Naveen Kumar R. Palle Venkata, San Diego, CA (US); Fangli Xu, Beijing (CN); Dawei Zhang, Saratoga, CA (US); Haijing Hu, Beijing (CN); and Yuqin Chen, Shenzhen (CN)
Assigned to Apple Inc., Cupertino, CA (US)
Appl. No. 17/439,451
Filed by Apple Inc., Cupertino, CA (US)
PCT Filed Mar. 31, 2021, PCT No. PCT/CN2021/084431
§ 371(c)(1), (2) Date Sep. 15, 2021,
PCT Pub. No. WO2022/205078, PCT Pub. Date Oct. 6, 2022.
Prior Publication US 2023/0199676 A1, Jun. 22, 2023
Int. Cl. H04W 56/00 (2009.01); H04W 24/08 (2009.01); H04W 74/08 (2009.01); H04W 76/15 (2018.01)
CPC H04W 56/0005 (2013.01) [H04W 24/08 (2013.01); H04W 74/0833 (2013.01); H04W 76/15 (2018.02)] 20 Claims
OG exemplary drawing
 
1. A method of operating a wireless device, comprising:
by the wireless device:
establishing communication with a first base station of a cellular network, wherein the first base station is comprised in a master cell group (MCG);
establishing communication a second base station, wherein the second base station is comprised in a secondary cell group (SCG), wherein said establishing communication with the second base station comprises maintaining one or more timing advance (TA) parameters for performing uplink communication with the second base station;
receiving an indication to deactivate the SCG;
in response to the indication to deactivate the SCG, storing the one or more TA parameters;
performing a plurality of signal quality measurements of the second base station;
receiving an indication to activate the SCG;
comparing one or more of the plurality of signal quality measurements of the second base station to one or more signal quality thresholds;
based on said comparing, determining whether to use the stored one or more TA parameters or to obtain a new one or more TA parameters; and
communicating with the second base station based on said determining, wherein said communicating with the second base station uses the stored one or more TA parameters or the new one or more TA parameters.