US 12,010,639 B2
Secondary cell activation
Tao Yang, Shanghai (CN); and Karol Schober, Helsinki (FI)
Assigned to NOKIA TECHNOLOGIES OY, Espoo (FI)
Appl. No. 17/617,461
Filed by Nokia Technologies Oy, Espoo (FI)
PCT Filed Jul. 9, 2019, PCT No. PCT/CN2019/095322
§ 371(c)(1), (2) Date Dec. 8, 2021,
PCT Pub. No. WO2021/003678, PCT Pub. Date Jan. 14, 2021.
Prior Publication US 2022/0225251 A1, Jul. 14, 2022
Int. Cl. H04W 56/00 (2009.01); H04L 5/00 (2006.01); H04W 80/02 (2009.01)
CPC H04W 56/001 (2013.01) [H04L 5/0051 (2013.01); H04L 5/0053 (2013.01); H04W 80/02 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A first apparatus comprising:
at least one processor; and
at least one memory including computer program codes;
the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first apparatus to:
transmit, on a serving cell in an active status, a Media Access Control (MAC) layer command for activating at least one secondary cell to a second apparatus, the MAC layer command indicating a configuration on a procedure for activating the at least one secondary cell;
receive an acknowledgement for the MAC layer command from the second apparatus;
cause the second apparatus to synchronize, based on at least the configuration and the acknowledgement, with the first apparatus on the at least one secondary cell; and
wherein the configuration indicates that an aperiodic tracking reference signal is to be used by the second apparatus for synchronizing with the first apparatus on the at least one secondary cell, and wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first apparatus to:
in response to a first time offset between reception of the acknowledgement and transmission of the aperiodic tracking reference signal being indicated to the second apparatus,
determine, based on the first time offset and the reception of the acknowledgement, a first slot for transmitting the aperiodic tracking reference signal;
transmit, in the first slot, the aperiodic tracking reference signal to the second apparatus on the at least one secondary cell; and
wait for a time period after transmitting the aperiodic tracking reference signal, such that the second apparatus is synchronized, based on the aperiodic tracking reference signal, with the first apparatus on the at least one secondary cell.