TECHNICAL FIELD

The present disclosure relates to the field of wireless communications technologies, and more particularly, to a base station, user equipment, and a related method for transmitting data in a packet duplication deactivated state.

BACKGROUND

In the 3rd Generation Partnership Project (3GPP) RAN #71 plenary meeting in March 2016, a new research project on 5G technical standards (see non-patent literature: RP-160671: New SID Proposal: Study on New Radio Access Technology) was proposed by NTT DOCOMO, and was approved. The goal of the research project is to develop a New Radio (NR) access technology to meet all of the application scenarios, requirements, and deployment environments of 5G. NR mainly has three application scenarios: Enhanced Mobile Broadband Communications (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC).

In the 3GPP RAN2 #96 meeting held in October 2016, it was agreed that research will be performed on multi-connection (including dual-connection) so as to satisfy the reliability requirement of the URLLC. The multi-connection can adopt mechanisms such as packet duplication or link selection. In the 3GPP NR AdHoc meeting held in January 2017, it was agreed that a packet duplication function of a user plane and a control plane is supported in an NR-PDCP entity; functions of a PDCP entity at a transmitting end support packet duplication; and functions of a PDCP entity at a receiving end support deletion of duplicate packets. In the 3GPP RAN2 #97 meeting held in February 2017, it was agreed that the following application is supported in both uplink and downlink conditions: in carrier aggregation, packet duplication is transmitted on two or more logical channels by using Packet Data Convergence Protocol (PDCP) Protocol Data Units (PDUs) and/or Service Data Units (SDUs), and duplicate PDCP PDUs are transmitted through different carriers. In the 3GPP RAN2 #98 meeting held in April 2017, it was agreed that an RRC configuration maps 2 duplicate logical channels to different carriers, i.e., duplicate logical channels cannot be mapped to the same carrier.

It is desirable to solve problems related to deactivating packet duplication in carrier aggregation and multi-connection scenarios that support packet duplication.

SUMMARY OF INVENTION

According to a first aspect of the present disclosure, a method in user equipment (UE) is provided, the UE operating in a carrier aggregation mode. The method comprises: receiving a Media Access Control (MAC) control element (CE) used for deactivating packet duplication; transmitting data from a Packet Data Convergence Protocol (PDCP) entity to a Radio Link Control (RLC) entity; and transmitting, at a MAC entity, the data only by a cell or cell group associated with the RLC entity in a packet duplication activated state, or by a cell or cell group selected from a set of cells or cell groups pre-configured for the UE.

According to a second aspect of the present disclosure, a method in user equipment (UE) is provided, the UE operating in a multi-connection mode. The method comprises: receiving a Media Access Control (MAC) control element (CE) used for deactivating packet duplication; and transmitting data only by a Radio Link Control (RLC) entity or a logical channel corresponding to a master cell group (MCG); or transmitting the data only by an RLC entity or a logical channel corresponding to a secondary cell group (SCG); or transmitting the data by the RLC entities or the logical channels corresponding to the MCG and the SCG in a link selection manner.

In an embodiment, the data is transmitted by an RLC entity or a logical channel corresponding a predefined one of the MCG or the SCG.

In an embodiment, the MAC CE carries indication information indicating whether the data is to be transmitted by the RLC entity or the logical channel corresponding to the MCG or the SCG. The data is transmitted, according to the indication information, by the RLC entity or the logical channel corresponding to the MCG or the SCG.

In an embodiment, the method further comprises: receiving, through Radio Resource Control (RRC) signaling, a data transmission configuration indicating whether the data is to be transmitted by the RLC entity or the logical channel corresponding to the MCG or the SCG in a packet duplication deactivated state. The data is transmitted, according to the data transmission configuration, by the RLC entity or the logical channel corresponding to the MCG or the SCG.

In an embodiment, the MAC CE is received from a MAC entity corresponding to the MCG or the SCG. Whether the data is transmitted by the RLC entity or the logical channel corresponding to the MCG or the SCG is selected according to whether the MAC CE is received from the MAC entity corresponding to the MCG or the SCG; or whether the data is transmitted by the RLC entity or the logical channel corresponding to the MCG or the SCG is selected according to indication information carried in the MAC CE.

In an embodiment, the MAC CE is received from a MAC entity corresponding to only one predefined cell group of the MCG and the SCG; or the method further comprises: receiving, through RRC signaling, an indication identifier indicating a MAC entity for transmitting the MAC CE; and determining, according to the indication identifier, whether the MAC CE is received from the MAC entity corresponding to the MCG or the SCG.

According to a third aspect of the present disclosure, user equipment (UE) is provided, comprising a transceiver, a processor, and a memory, the processor storing instructions executable by the processor so that the E performs the method according to the first or second aspect.

According to a fourth aspect of the present disclosure, a method in a base station is provided, comprising: transmitting a Media Access Control (MAC) control element (CE) used for deactivating packet duplication to user equipment (UE). The MAC CE carries indication information to indicate to the UE whether to transmit data by a Radio Link Control (RLC) entity or a logical channel corresponding to a master cell group (MCG) or a secondary cell group (SCG).

According to a fifth aspect of the present disclosure, a base station is provided, comprising a transceiver, a processor, and a memory, the processor storing instructions executable by the processor so that the base station performs the method according to the fourth aspect.

