US 12,445,981 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)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Feb. 7, 2024, as Appl. No. 18/435,665.
Application 18/435,665 is a continuation of application No. 17/439,451, granted, now 11,943,722, previously published as PCT/CN2021/084431, filed on Mar. 31, 2021.
Prior Publication US 2024/0224201 A1, Jul. 4, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04W 56/00 (2009.01); H04W 24/08 (2009.01); H04W 74/0833 (2024.01); 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, comprising:
communicating with a first cell of a master cell group (MCG) associated with a first base station of a cellular network;
receiving, for a second cell of a secondary cell group (SCG) associated with a second base station, a trigger to perform an uplink transmission with the second cell of the SCG;
in response to the trigger, performing the uplink transmission with the second cell of the SCG prior to a transition of the second cell of the SCG to a first state; and
receiving a first timing advance parameter based on the uplink transmission to use upon the transition of the second cell of the SCG to the first state to enable skipping of a random access channel (RACH) procedure to the second cell of the SCG.