TECHNICAL FIELD

The present disclosure relates to the field of wireless communications technologies. More specifically, the present disclosure relates to a related method for medium access control layer packetization, corresponding user equipment, and a corresponding base station.

BACKGROUND

With the rapid growth of mobile communications and great progress of technology, the world will move toward a fully interconnected network society where anyone or anything can acquire information and share data anytime and anywhere. It is estimated that there will be 50 billion interconnected devices by 2020, of which only about 10 billion may be mobile phones and tablet computers. The rest are not machines communicating with human beings but machines communicating with one another. Therefore, how to design a system to better support the Internet of Everything is a subject needing further and intensive study.

For this purpose, at the 3rd Generation Partnership Project (3GPP) RAN #64 plenary meeting held in March 2016, a research subject on new 5G radio access technology was proposed (see non-patent literature: RP-160671 New SID Proposal: Study on New Radio Access Technology). In the description of the work project, the operating frequency band of future new communication RATs can be expanded to 100 GHz, which will satisfy at least service requirements for enhanced mobile broadband, the demand for communication between massive Internet of Things terminals, service requirements of high reliability requirements, and so on. The research work of the project is expected to end in 2018.

A MAC (medium access control) layer adopts a multiplexing mode, and may assemble data from different logical channels into a MAC PDU (MAC protocol data unit), or may assemble a MAC CE (MAC control element) carrying control information and data into a MAC PDU. When receiving a UL grant (uplink resource grant), UE may perform packetization (namely, form a MAC PDU; the “packet” herein refers to a “MAC PDU”) according to the size of uplink resources allocated in the UL grant, and transmit a formed packet on the allocated uplink resources.

In the existing LTE technology, the priority of a MAC CE carrying a BSR (Buffer Status Report, namely, buffer status report, which is different in format from a padding BSR) is higher than the priority of data from any logical channel other than data from an uplink common control channel. As a person skilled in the art knows, the uplink common control channel is a kind of logical channel whose data always has the highest priority higher than any other data or a MAC CE, but the uplink common control channel does not have a logical channel number. As a result, the uplink common control channel is separately described herein, and unless otherwise indicated, logical channels herein all refer to logical channels other than the uplink common control channel. Moreover, the priority of a MAC CE carrying a recommended bit rate query or a padding BSR is lower than that of data from any logical channel.

Therefore, in the process of packetization, if a MAC CE having a higher priority (for example, a MAC CE carrying a BSR) exists, then the MAC CE is put into a packet firstly, then it is investigated in the remaining space of allocated uplink resources whether any data from a logical channel and other MAC CEs having lower priorities (for example, a MAC CE carrying a recommended bit rate query or padding BSR) exist, and the data and MAC CEs are sequentially put into the packet according to the priority order from high to low until the allocated uplink resources are used up.

However, in a 5G system, parameter configurations (numerology) and TTIs (transmission time interval) of physical resources used may be different in the uplink resource allocation process in order to meet service requirements, and when an uplink UL grant arrives, data of a logical channel matching the UL grant may be preferentially transmitted. If the priority of a MAC CE carrying a BSR is always set to be higher than that of data from any logical channel according to the existing LTE technology without considering the specific factor of the logical channel in judging the priorities of a MAC CE and data of a logical channel, then the MAC CE carrying the BSR occupies uplink transmission resources of the data of the logical channel, causing delay to data transmission of the logical channel.

SUMMARY

The present disclosure aims to solve the aforementioned technical problem. Specifically, the present disclosure aims to solve the technical problem of transmission delay of data from a logical channel having a high priority caused by preferential transmission of a MAC CE.

According to a first aspect of the present disclosure, a method performed at user equipment (UE) is provided, comprising: receiving an uplink grant (UL grant) from a base station, wherein the UL grant comprises information related to uplink resources allocated to the UE by the base station; obtaining a priority order, configured for the UE by the base station based on at least one of an uplink resource type, an uplink resource scheduling mode, and an uplink resource transmission mode, of a plurality of logical channels to which the uplink resources allocated in the UL grant are applicable; if a buffer status report (BSR) carried in a medium access control (MAC) control element (CE) does not comprise buffer status information of a logical channel having a highest priority, then setting a priority of the MAC CE carrying the BSR to be lower than a priority of data from the logical channel having the highest priority; and according to the set priority order of the data and the MAC CE, sequentially assembling the data and the MAC CE into a MAC protocol data unit (PDU) for transmission on the allocated uplink resources.

In one exemplary embodiment, the priority order of the plurality of logical channels is pre-configured by the base station through radio resource control (RRC) signaling or dynamically instructed to the UE in downlink control information (DCI) carried in a physical downlink control channel (PDCCH).

In one exemplary embodiment, if the buffer status report (BSR) carried in medium access control (MAC) control element (CE) does not comprise the buffer status information of the logical channel having the highest priority, then priority of the MAC CE carrying the BSR is further set to be higher than a priority of data from the other logical channels other than data from an uplink common control channel.

In one exemplary embodiment, if the buffer status report (BSR) carried in the medium access control (MAC) control element (CE) comprises the buffer status information of the logical channel having the highest priority, then the priority of the MAC CE carrying the BSR is set to be higher than a priority of data from any logical channel other than data from an uplink common control channel.

In one exemplary embodiment, the method further comprises:

if a space of the allocated uplink resources remaining after the data of the logical channel having the highest priority is assembled into the MAC PDU is insufficient to accommodate the MAC CE carrying the BSR, then generating a padding BSR according to the remaining space of the allocated uplink resources and causing the padding BSR to be carried in a MAC CE to be assembled into the MAC PDU, wherein the MAC CE carrying the padding BSR comprises at least buffer status information of a logical channel having a highest priority among the other logical channels.

In one exemplary embodiment, the method further comprises: if a MAC CE carries information related to link interruption recovery, then setting a priority of the MAC CE carrying the information related to link interruption recovery to be higher than the priority of the data from any logical channel other than the data from the uplink common control channel.

In one exemplary embodiment, the method further comprises: if a MAC CE carries information related to a recommended bit rate of a logical channel, then setting a priority of the MAC CE carrying the information related to the recommended bit rate of the logical channel to be lower than the priority of the MAC CE carrying the BSR and the priority of the data from any logical channel other than the data from the uplink common control channel, wherein when recommended bit rate queries of a plurality of logical channels need to be reported to the base station, a plurality of MAC CEs respectively carrying information related to recommended bit rates of the logical channels are generated, and priorities of the plurality of MAC CEs are determined according to priorities of the logical channels carried therein.

According to a second aspect of the present disclosure, UE is provided, comprising:

a communication interface, configured to perform communication;

a processor; and

a memory, storing computer-executable instructions, wherein when executed by the processor, the instructions cause the UE to perform the method described in the first aspect of the present disclosure.

According to a third aspect of the present disclosure, a method performed at a base station is provided, comprising: configuring, for user equipment (UE) based on at least one of an uplink resource type, an uplink resource scheduling mode, and an uplink resource transmission mode, a priority order of a plurality of logical channels to which uplink resources allocated in an uplink grant (UL grant) are applicable; and pre-configuring the priority order of the plurality of logical channels for the UE through radio resource control (RRC) signaling, or dynamically instructing the priority order of the plurality of logical channels to the UE in downlink control information (DCI) carried in a physical downlink control channel (PDCCH).

According to a fourth aspect of the present disclosure, a base station is provided, comprising:

a communication interface, configured to perform communication;

a processor; and

a memory, storing computer-executable instructions, wherein when executed by the processor, the instructions cause the base station to perform the method described in the third aspect of the present disclosure.

According to a fifth aspect of the present disclosure, a computer-readable medium is provided, having instructions stored thereon, wherein when executed by a processor, the instructions cause the processor to perform the methods described in the first and third aspects of the present disclosure.

According to the technical schemes described in the aforementioned aspects of the present disclosure, in the case in which a BSR carried in a MAC CE does not comprise buffer status information of a logical channel having a highest priority level, a priority of the MAC CE carrying the BSR is set to be lower than a priority level of data from the logical channel having the highest priority, so as to avoid transmission delay of data from a logical channel having a high priority level caused by preferential transmission of a MAC CE, and meet quality of service requirements for data transmission.

