US 12,483,880 B2
Data transmission method and related device
Dagang Zhang, Dongguan (CN); and Zhilong Zheng, Shenzhen (CN)
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed on Jan. 25, 2023, as Appl. No. 18/159,188.
Application 18/159,188 is a continuation of application No. PCT/CN2021/091332, filed on Apr. 30, 2021.
Claims priority of application No. 202010731310.6 (CN), filed on Jul. 27, 2020.
Prior Publication US 2023/0164548 A1, May 25, 2023
Int. Cl. H04W 12/03 (2021.01); H04W 12/0431 (2021.01); H04W 76/20 (2018.01); H04W 76/30 (2018.01)
CPC H04W 12/03 (2021.01) [H04W 12/0431 (2021.01); H04W 76/20 (2018.02); H04W 76/30 (2018.02)] 17 Claims
OG exemplary drawing
 
1. A data transmission method, comprising:
initiating, by a primary network device, a process of a carrier change, wherein the carrier change is performed by the primary network device;
in response to initiating the process of the carrier change, sending, by the primary network device, a first message to a terminal device, wherein the terminal device performs, before the carrier change, data encryption and decryption by using a key of the primary network device, and the first message indicates the terminal device to perform, after the carrier change, data encryption and decryption by using the key that is of the primary network device and that is stored in the terminal device;
controlling, by the primary network device, a packet data convergence protocol (PDCP) entity of the primary network device to send a downlink data packet to a radio link control (RLC) entity of the primary network device, wherein the downlink data packet is from the PDCP entity of the primary network device; and
controlling the RLC entity of the primary network device to send the downlink data packet to the terminal device, wherein the PDCP entity of the terminal device encrypts and decrypts the downlink data packet by using the key of the primary network device.