WO2025065685A1

WO2025065685A1 - Buffer status calculation method considering expected packet discarding

Info

Publication number: WO2025065685A1
Application number: PCT/CN2023/122997
Authority: WO
Inventors: Abolfazl AMIRI; Claudio Rosa; Boyan Yanakiev; Zexian Li; Chunli Wu; Benoist Pierre Sebire; Carlos Santiago MOREJON GARCIA
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2025-04-03
Anticipated expiration: 2026-03-28

Abstract

Example embodiments of the present disclosure relate to methods, devices, apparatuses and computer readable storage medium for buffer status calculation method considering expected packet discarding. The method comprises: determining whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and generating at least one BSR based on the remaining data and the determination of the discarding; and transmitting, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.

Description

BUFFER STATUS CALCULATION METHOD CONSIDERING EXPECTED PACKET DISCARDING

FIELDS

Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for buffer status calculation method considering expected packet discarding.

BACKGROUND

Buffer status report (BSR) in wireless communication systems is used to provide an access node (e.g., a base station, a gNB, etc. ) with information as accurate as possible about an amount of data available for transmission in uplink (UL) at user equipment (UE) . Based on buffer status information, the base station can allocate to the UE UL resources that are needed for transmitting the corresponding amount of data.

SUMMARY

In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: determine whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and generate at least one BSR based on the remaining data and the determination of the discarding; and transmit, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.

In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: receive, from a first apparatus in an uplink allocation, a data transmission along with at least one BSR generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.

In a third aspect of the present disclosure, there is provided a method. The method comprises: determining whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and generating at least one BSR based on the remaining data and the determination of the discarding; and transmitting, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.

In a fourth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a first apparatus in an uplink allocation, a data transmission along with at least one BSR generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.

In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for determining whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and means for generating at least one BSR based on the remaining data and the determination of the discarding; and means for transmitting, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.

In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for receiving, from a first apparatus in an uplink allocation, a data transmission along with at least one BSR generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.

In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

FIG. 2 illustrates a signaling chart of communication according to some example embodiments of the present disclosure;

FIG. 3 illustrates an example of buffer status calculation considering expected packet discarding according to some example embodiments of the present disclosure;

FIG. 4 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 7 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first, ” “second, ” …, etc. in front of noun (s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun (s) . For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , the sixth generation (6G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , an NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As used herein, the term “resource, ” “transmission resource, ” “resource block, ” “physical resource block” (PRB) , “uplink resource, ” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and/or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. The communication environment 100 comprises a first apparatus 110 and a second apparatus 120, which may communicate with each other.

In the following, for the purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device (e.g., a UE) and the second apparatus 120 operating as a radio access network device (e.g., a gNB) . However, in some example embodiments, operations described in connection with a terminal device may be implemented at a radio access network device or other device, and operations described in connection with a radio access network device may be implemented at a terminal device or other device.

It is to be understood that the number of radio access network devices and terminal devices shown in FIG. 1 is given for the purpose of illustration without suggesting any limitations. The communication network 100 may include any suitable number of radio access network devices and terminal devices.

In some example embodiments, if the first apparatus 110 is a terminal device and the second apparatus 120 is a radio access network device, a link from the second apparatus 120 to the first apparatus 110 is referred to as a downlink (DL) , and a link from the first apparatus 110 to the second apparatus 120 is referred to as an uplink (UL) . In DL, the second apparatus 120 is a transmitting (TX) device (or a transmitter) and the first apparatus 110 is a receiving (RX) device (or a receiver) . In UL, the first apparatus 110 is a TX device (or a transmitter) and the second apparatus 120 is a RX device (or a receiver) .

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (5G) , the sixth generation (6G) , and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

The medium access control (MAC) entity in a UE determines the amount of UL data available for a logical channel according to the data volume calculation procedure after the MAC PDU with the BSR is built.

The Buffer Size field may identify the total amount of data available according to the data volume calculation procedure across all logical channels of a logical channel group after the MAC PDU has been built (i.e., after the logical channel prioritization procedure, which may result the value of the Buffer Size field to zero) . The amount of data is indicated in number of bytes.

The size of the Radio Link Control (RLC) headers and MAC subheaders are not considered in the buffer size computation. The length of this field for the Short BSR format and the Short Truncated BSR format is 5 bits. The length of this field for the Extended Short BSR format and the Extended Short Truncated BSR format is 8 bits. The length of this field for the Long BSR format, the Long Truncated BSR format, the Extended Long BSR format, and the Extended Long Truncated format is 8 bits.

For the Long BSR format, the Long Truncated BSR format, the Extended Long BSR format, and the Extended Long Truncated format, the Buffer Size fields are included in ascending order based on the logical channel group (LCG) . For the Long Truncated BSR format and the Extended Long Truncated format, the number of Buffer Size fields included is maximised, while not exceeding the number of padding bits.

For the Pre-emptive BSR format and the Extended Pre-emptive BSR format, the Buffer Size field identifies the total amount of the data expected to arrive at the IAB-MT of the node where the Pre-emptive BSR/Extended Pre-emptive BSR is triggered and does not include the volume of data currently available in the IAB-MT. Pre-emptive BSR format is identical to the Long BSR format. Extended Pre-emptive BSR format is identical to the Extended Long BSR format.

For the purpose of MAC buffer status reporting, the UE shall consider the following as RLC data volume:

- RLC Service Data Units (SDUs) and RLC SDU segments that have not yet been included in an RLC data PDU;

- RLC data PDUs that are pending for initial transmission;

- RLC data PDUs that are pending for retransmission (RLC AM) .

For the purpose of MAC buffer status reporting, the transmitting packet data convergence protocol (PDCP) entity shall consider the following as PDCP data volume:

- the PDCP SDUs for which no PDCP Data PDUs have been constructed;

- the PDCP Data PDUs that have not been submitted to lower layers;

- the PDCP Control PDUs;

- for Acknowledged Mode (AM) data radio bearers (DRBs) , the PDCP SDUs to be retransmitted;

- for AM DRBs, the PDCP Data PDUs to be retransmitted.

In addition, if a STATUS PDU has been triggered and t-StatusProhibit is not running or has expired, the UE shall estimate the size of the STATUS PDU that will be transmitted in the next transmission opportunity and consider this as part of RLC data volume.

For Extended Reality (XR) use cases, the discarding of PDCP PDUs is expected to happen more often than other legacy applications. This is due to the tight packet delay budget (PDB) or PDU set delay budget (PSDB) of these services (in the range of 5-30 ms) and the fact that some of the video frames become obsolete by the subsequent frames, and thus can be discarded. The impact of discarding at the PDCP on the lower layers is often overlooked as the assumption is that the discarded PDUs will not be visible to RLC/MAC.

One of the interactions between MAC and PDCP (and also RLC) happens during the preparation of the BSR. In some scenarios, while preparing the BSR, the PDCP layer may report the size of all the buffered PDUs even though some of them might be discarded right after (or any timer before the next UL occasion in PHY) .

According to the 3GPP specification, the impact of this discarding is not visible in the BSR, and hence, the gNB may (over-) allocate UL resources for the PDUs that do not exist anymore (i.e., discarded) and the resources may be wasted. It is worth mentioning again that for XR applications this is expected to be a relatively more frequent event than for eMBB traffic. Combined with the high data rates required by XR traffic already being rather demanding on the network, overallocations can quickly become a capacity issue.

For example, the MAC layer may prepare a transport block (TB) for the current UL allocation and in the meantime realizes the remaining buffered data size while collecting information from other layers for instance to prepare a (padding, regular, etc. ) BSR. In doing so, the MAC layer may report the size of a PDU in the PDCP buffer as the buffer size in the BSR.

However, the discard timer of this PDU expires before the next possible UL transmission opportunity (not scheduled yet) , and thus the UE’s buffer becomes empty by the next possible granted UL resource. In the meantime, the gNB may allocate an UL grant for the next possible UL occasion based on the requested BSR (i.e., the BSR transmitted in the “current UL allocation” ) . In the end, the UE ends up not transmitting any data (due to empty buffer) in the UL opportunity and the resources are wasted.

According to some example embodiments of the present disclosure, there is provided a solution for a buffer status calculation method considering expected packet discarding. In this solution, the first apparatus 110 determines whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation. The remaining data herein may comprise data buffered at the first apparatus 110 after a protocol data unit for a data transmission in the uplink allocation has been built. Based on the remaining data and the determination of the discarding, the first apparatus 110 generates at least one BSR and transmit the at least one BSR to the second apparatus 120.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Reference is made to FIG. 2, which illustrates a signaling flow 300 of communication in accordance with some embodiments of the present disclosure. For the purposes of discussion, the signaling flow 200 will be discussed with reference to FIG. 1, for example, by using the first apparatus 110 and the second apparatus 120. In some scenarios related to the process of FIG. 2, the first apparatus 110 may comprise a MAC layer 201 or a PDCP layer 202, wherein the MAC layer 201 is lower layer under the PDCP layer 202. It is to be understood that the process of FIG. 2 may involve other possible layer (s) such as RLC layer. For the sake of clarity, other possible layer (s) are omitted here.

It is to be understood that the operations at the first apparatus 110 and the second apparatus 120 should be coordinated. In other words, the second apparatus 120 and the first apparatus 110 should have common understanding about configurations, parameters and so on. Such common understanding may be implemented by any suitable interactions between the second apparatus 120 and the first apparatus 110 or both the second apparatus 120 and the first apparatus 110 applying the same rule/policy.

In the following, although some operations are described from a perspective of the first apparatus 110, it is to be understood that the corresponding operations should be performed by the second apparatus 120. Similarly, although some operations are described from a perspective of the second apparatus 120, it is to be understood that the corresponding operations should be performed by the first apparatus 110. Merely for brevity, some of the same or similar contents are omitted here.

FIG. 2 shows a possible implementation of the signaling between MAC layer 201 and upper layers (e.g., PDCP layer 202) in the first apparatus 110 with the proposed solution of the present disclosure.

The MAC layer 201 of the first apparatus 110 may request (205) data from the PDCP layer 202 of the first apparatus 110 to be included in the TB to be transmitted in the current UL transmission occasion. The current UL transmission occasion hereinafter may be a UL transmission occasion for which the UL resources has been allocated by the second apparatus 120.

The MAC layer 201 of the first apparatus 110 may also request (210) the PDCP layer 202 of the first apparatus 110 for data volume indication that is used to determine the BSR that is included in the TB.

The MAC layer 201 of the first apparatus 110 may indicate, to the PDCP layer 202 of the first apparatus 110, the time of the next possible UL transmission occasion. The next possible UL transmission occasion may be referred to as the earliest next possible UL transmission occasion or earliest possible subsequent UL transmission occasion, i.e., subsequent to the current UL transmission occasion.

For example, a physical (PHY) layer of the first apparatus 110 may indicate the time of the earliest possible subsequent UL transmission occasion to the MAC layer 201. As another option, the PHY layer may inform all possible subsequent UL transmission occasion (s) and their time (s) to the MAC layer 201. The MAC layer 201 may select the earliest one from all possible subsequent UL transmission occasion (s) based on their time (s) .

In some embodiment, the time of the next possible UL transmission occasion may be relative to the time when the indication is transmitted to the PDCP layer or relative to the timing of the PUSCH transmission with BSR included, i.e., the time of the next possible UL transmission occasion is in X ms from now or PUSCH transmission. In some other embodiments, the time of the next possible UL transmission occasion in the format of absolute time in case there is one common clock between MAC and upper layers.

It is to be understood that the MAC layer 210 may consider possible subsequent UL transmission occasion (s) associated with all activated carriers in case of carrier aggregation (CA) .

At the PDCP layer 202, upon receiving the request for the data from the PDCP layer 202 of the first apparatus 110 to be included in the TB to be transmitted in the current UL transmission occasion, the PDCP layer 202 may first determine (215) the data (i.e., the PDUs) that will be delivered to the MAC layer 201 to be included in the TB. Then the PDCP layer 202 may deliver (220) the corresponding PDUs to the lower layers (e.g., the MAC layer 201) .

The PDCP layer 202 may proceed (225) to discarding of the PDUs that have not yet been delivered to lower layers (e.g., the MAC layer 201) and whose value of the discard timer is lower than the time to the next UL transmission opportunity (e.g., X ms) based on the time of the possible next UL transmission occasion indicated by the MAC layer 201.

In this stage, it is also possible that the PDCP layer 202 may only determine that the PDUs that have not yet been delivered to lower layers (e.g., the MAC layer 201) and whose value of the discard timer is lower than the time to the next UL transmission opportunity, will be discarded, but may not discard them before sending the data volume indication to the MAC layer 201. That is, the PDUs may be kept in the PDCP buffer until an expiry of the discard timer.

Then the PDCP layer 202 may signal (230) , to the MAC layer 201, the data volume indication to the MAC layer 201 excluding the PDUs that have been discarded or to be discarded.

Furthermore, it is also possible that the PDCP layer 202 may signal an indication of a first data volume of the remaining data and a second data volume of the PDUs that have been discarded or to be discarded.

Then the MAC layer 201 may build the TB to be transmitted by including the PDUs delivered by the PDCP layer 202 and the BSR determined (also) based on the data volume indication received from the PDCP layer 202.

Upon the BSR has been determined, the first apparatus 110, e.g., the MAC layer 201 may transmit (240) the TB in the current UL transmission occasion to the second apparatus 120 including the BSR.

For the case where a first data volume of the remaining data and a second data volume of the PDUs that have been discarded or to be discarded have been indicated by the PDCP layer 202, two BSRs may be generated by the MAC layer 201. That is, a first BSR indicating a first data volume of the remaining data and a second BSR indicating a second data volume of the PDUs that have been discarded or to be discarded.

In some example embodiments, at least one of indication of the time of the next possible UL transmission and the data volume calculation can occur independently of data transmission.

In yet other possible implementations, the request of data from the PDCP layer 202 to be included in the TB to be transmitted in the current UL transmission occasion, the request (210) for data volume indication that is used to determine the BSR and the indication of the time of the possible next UL transmission occasion may be signaled from MAC layer 201 to PDCP layer 202 in the same message or primitive. In yet another implementation, they may also be signaled in separate messages or primitives.

In yet other possible implementations, the delivery of the corresponding PDUs to the lower layers (e.g., the MAC layer 201) may be performed after or at the same time as proceeding to discarding of and/or determining the PDUs that have not yet been delivered to lower layers (e.g., the MAC layer 201) and whose value of the discard timer is lower than the time to the next UL transmission opportunity.

In yet other possible implementations, PDCP layer 202 may discard PDUs whose discard timer is lower than the time to the next possible UL transmission opportunity after having determined the PDUs to be delivered to lower layers and before performing data volume calculation for the purpose of MAC buffer status reporting.

In other possible implementations, PDCP layer 202 may not discard PDUs whose discard timer is lower than the time to the next possible UL transmission opportunity. In this case, when performing data volume calculation for the purpose of MAC buffer status reporting, PDCP layer 202 excludes the PDUs whose discard timer is lower than the time to the next possible UL transmission opportunity.

In yet other possible implementations, the PDCP layer 202 can use secondary logical inputs to determine discard candidates, beyond the time signaled from MAC layer 201. An example of that can be a PDU from a PDU set with integrity flag set to 1, which is about to expire before the next UL occasion, can trigger discard operation (and exclusion from BSR reporting) for PDUs of the same PDU set that do have time until the next UL occasion but are judged not needed due to the PDU set integrity handling indication (PSIHI) flag dependency.

FIG. 3 illustrates an example of buffer status calculation considering expected packet discarding according to some example embodiments of the present disclosure. With reference to FIG. 3, an example of buffer status calculation process 300 considering expected packet discarding will be further described.

There may be three PDUs 301, 302 and 303 buffered in the PDCP buffer 310 currently. The PDCP layer may determine the PDUs 301, 302 are to be filled in a TB 321 for the current UL transmission occasion on the allocated resource 331.

The current UL transmission occasion may start at T0 and the earliest possible subsequent UL transmission occasion 332 may occur at T2. The PDCP layer may determine the discard timer of the PDU 303 will expire before T2, for example, at T1. Then the PDCP layer may determine the PDU 303 is to be discarded and no need to indicate the data volume of the PDU 303 in the BSR 322. The BSR 322 may indicate other PDUs that has not been filled to a TB and will not be discarded before T2.

Based on the BSR, the network may know the buffer status of the UE. If the network determines that there is no data to be transmitted from the UE, the network may consider no resource is to be allocated for the possible subsequent UL transmission occasion 332. In this way, a waste of the UL resource may be avoided.

As discussed above, example embodiments of the present disclosure propose a set of rules that result in avoiding UL resource waste due to packet discarding for TDD scenarios.

Every time the MAC layer is preparing a BSR and requests data volume from upper layers, it indicates to theses upper layers, the time of the next possible UL opportunity (relative to the time when BSR is being prepared or transmitted) . This can be a fixed parameter (e.g., in case of fixed TDD frame structure) or a dynamic variable (e.g., full duplex setups) . Note that in case of CA, the time of the next possible UL opportunity needs to consider all activated carriers.

Based on this time indication, the PDCP will do at least one of: exclude the PDUs that are expected to be discarded before the next possible UL opportunity from the data volume calculation for the purpose of MAC buffer status reporting up to and including the next possible UL opportunity, and discard those PDUs once it realizes that they do not have a chance for transmission even before the expiry of discarding timer ( “earlier discarding” ) for example.

As an alternative to excluding PDUs that are expected to be discarded before the next possible UL opportunity from the data volume calculation, a second BSR reporting those separately could also be transmitted.

This solution helps on mitigating scarce UL resource waste and increase the cell spectral efficiency. It may also help with power saving at the UE for the cases where due to the new BSR calculation rule (considering potential discards) the UE does not receive a grant and thus will not spend power for processing it.

Furthermore, the indication of the time of the next possible UL opportunity may be provided whenever the UE is requesting data from the upper layers to prepare a transport block (TB) , even if a BSR is not (at least initially) planned to be transmitted.

More generally, the indication may be provided even if the MAC layer is not preparing any TB. For example, if there is no allocation for transmitting in UL in correspondence of one UL transmission occasion, MAC may still indicate to the upper layers the time of the next possible UL transmission opportunity (relative to the time where the indication is provided) . The upper layers of the UE may still use this information to discard PDUs that do not have a chance of being transmitted. In this case, the advantage of discarding PDUs in advance may materialize in case the discarding of the PDU triggers a BSR.

One implementation example is to update the specification is listed as the following:

Table 1

FIG. 4 shows a flowchart of an example method 400 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the first apparatus 110 in FIG. 1.

At block 410, the first apparatus 110 determines whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.

At block 420, the first apparatus 110 generates at least one BSR based on the remaining data and the determination of the discarding.

At block 430, the first apparatus 110 transmits, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.

In some example embodiments, the method 400 further comprises: obtaining, at a lower layer of the first apparatus, a time of the possible subsequent uplink occasion; and transmitting, from the lower layer to an upper layer of the first apparatus, an indication of the time of the possible subsequent uplink occasion.

In some example embodiments, the method 400 further comprises: obtaining, at the lower layer of the first apparatus, respective time of one or more possible subsequent uplink occasions; determining the possible subsequent uplink occasion based on the respective time of the one or more possible subsequent uplink occasions; and transmitting, from the lower layer to an upper layer of the first apparatus, an indication of a time of the possible subsequent uplink occasion.

In some example embodiments, the time of the potential subsequent uplink occasion is relative to at least one of the following: a time when the indication is transmitted to the upper layer, a timing of the data transmission in the uplink allocation with the at least one BSR included, or a common clock between the lower layer and the upper layers.

In some example embodiments, the method 400 further comprises: determining the possible subsequent uplink occasion by considering all activated carriers for a carrier aggregation.

In some example embodiments, the method 400 further comprises: in accordance with a determination that the at least a portion of remaining data is to be discarded before the possible subsequent uplink occasion, determining data volume of the remaining data except for the at least a portion of remaining data to be discarded; and generating the least one BSR based at least on the data volume.

In some example embodiments, the method 400 further comprises: transmitting, from the upper layer to the lower layer, an indication of the data volume of the remaining data except for the at least a portion of remaining data to be discarded; and generating a BSR at the lower layer of the first apparatus based on the data volume.

In some example embodiments, the method 400 further comprises: transmitting, from the upper layer to the lower layer, an indication of a first data volume of the remaining data and a second data volume of the at least a portion of remaining data to be discarded; and generating a first BSR based on the first data volume and a second BSR based on the second data volume.

In some example embodiments, the method 400 further comprises: discarding, by the upper layer, the at least a portion of remaining data to be discarded before transmitting the indication of the data volume and/or before a time point when the at least a portion of remaining data is to be discarded.

In some example embodiments, the lower layer comprises a medium access control layer and the upper layer comprise a packet data convergence protocol layer and/or radio link control layer.

In some example embodiments, the possible subsequent uplink occasion is the earliest possible subsequent uplink occasion.

In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

FIG. 5 shows a flowchart of an example method 500 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the second apparatus 120 in FIG. 1.

At block 510, receiving, from a first apparatus in an uplink allocation, a data transmission along with at least one BSR generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.

In some example embodiments, the method 500 further comprises: receiving a first BSR indicating a first data volume of the remaining data and a second BSR indicating a second data volume of the at least a portion of remaining data to be discarded.

In some example embodiments, a first apparatus capable of performing any of the method 400 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

In some example embodiments, the first apparatus comprises means for determining whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and means for generating at least one BSR based on the remaining data and the determination of the discarding; and means for transmitting, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.

In some example embodiments, the first apparatus further comprises: means for obtaining, at a lower layer of the first apparatus, a time of the possible subsequent uplink occasion; and means for transmitting, from the lower layer to an upper layer of the first apparatus, an indication of the time of the possible subsequent uplink occasion.

In some example embodiments, the first apparatus further comprises: means for obtaining, at the lower layer of the first apparatus, respective time of one or more possible subsequent uplink occasions; means for determining the possible subsequent uplink occasion based on the respective time of the one or more possible subsequent uplink occasions; and means for transmitting, from the lower layer to an upper layer of the first apparatus, an indication of a time of the possible subsequent uplink occasion.

In some example embodiments, the first apparatus further comprises: means for determining the possible subsequent uplink occasion by considering all activated carriers for a carrier aggregation.

In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that the at least a portion of remaining data is to be discarded before the possible subsequent uplink occasion, determining data volume of the remaining data except for the at least a portion of remaining data to be discarded; and means for generating the least one BSR based at least on the data volume.

In some example embodiments, the first apparatus further comprises: means for transmitting, from the upper layer to the lower layer, an indication of the data volume of the remaining data except for the at least a portion of remaining data to be discarded; and means for generating a BSR at the lower layer of the first apparatus based on the data volume.

In some example embodiments, the first apparatus further comprises: means for transmitting, from the upper layer to the lower layer, an indication of a first data volume of the remaining data and a second data volume of the at least a portion of remaining data to be discarded; and means for generating a first BSR based on the first data volume and a second BSR based on the second data volume.

In some example embodiments, the first apparatus further comprises: means for discarding, by the upper layer, the at least a portion of remaining data to be discarded before transmitting the indication of the data volume and/or before a time point when the at least a portion of remaining data is to be discarded.

In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 400 or the first apparatus 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

In some example embodiments, a second apparatus capable of performing any of the method 500 (for example, the second apparatus 120 in FIG. 1) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 120 in FIG. 1.

In some example embodiments, the second apparatus comprises means for receiving, from a first apparatus in an uplink allocation, a data transmission along with at least one BSR generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.

In some example embodiments, the second apparatus further comprises: means for receiving a first BSR indicating a first data volume of the remaining data and a second BSR indicating a second data volume of the at least a portion of remaining data to be discarded.

In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 500 or the second apparatus 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the second apparatus.

FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown in FIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

The communication module 640 is for bidirectional communications. The communication module 640 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 640 may include at least one antenna.

The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

Acomputer program 630 includes computer executable instructions that are executed by the associated processor 610. The instructions of the program 630 may include instructions for performing operations/acts of some example embodiments of the present disclosure. The program 630 may be stored in the memory, e.g., the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

The example embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 5. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

FIG. 7 shows an example of the computer readable medium 700 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 700 has the program 630 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:

determine whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and

generate at least one buffer status report, BSR, based on the remaining data and the determination of the discarding; and

transmit, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.
The first apparatus of claim 1, wherein the first apparatus is caused to:

obtain, at a lower layer of the first apparatus, a time of the possible subsequent uplink occasion; and

transmit, from the lower layer to an upper layer of the first apparatus, an indication of the time of the possible subsequent uplink occasion.
The first apparatus of claim 1, wherein the first apparatus is caused to:

obtain, at the lower layer of the first apparatus, respective time of one or more possible subsequent uplink occasions;

determine the possible subsequent uplink occasion based on the respective time of the one or more possible subsequent uplink occasions; and

transmit, from the lower layer to an upper layer of the first apparatus, an indication of a time of the possible subsequent uplink occasion.
The first apparatus of claim 2, wherein the time of the potential subsequent uplink occasion is relative to at least one of the following:

a time when the indication is transmitted to the upper layer,

a timing of the data transmission in the uplink allocation with the at least one BSR included, or

a common clock between the lower layer and the upper layers.
The first apparatus of any of claims 2-4, wherein the first apparatus is caused to:

determine the possible subsequent uplink occasion by considering all activated carriers for a carrier aggregation.
The first apparatus of any of claims 2-5, wherein the first apparatus is caused to:

in accordance with a determination that the at least a portion of remaining data is to be discarded before the possible subsequent uplink occasion, determine data volume of the remaining data except for the at least a portion of remaining data to be discarded; and

generate the least one BSR based at least on the data volume.
The first apparatus of claim 6, wherein the first apparatus is caused to:

transmit, from the upper layer to the lower layer, an indication of the data volume of the remaining data except for the at least a portion of remaining data to be discarded; and

generate a BSR at the lower layer of the first apparatus based on the data volume.
The first apparatus of claim 6, wherein the first apparatus is caused to:

transmit, from the upper layer to the lower layer, an indication of a first data volume of the remaining data and a second data volume of the at least a portion of remaining data to be discarded; and

generate a first BSR based on the first data volume and a second BSR based on the second data volume.
The first apparatus of claim 7 or 8, wherein the first apparatus is caused to:

discard, by the upper layer, the at least a portion of remaining data to be discarded before transmitting the indication of the data volume and/or before a time point when the at least a portion of remaining data is to be discarded.
The first apparatus of any of claims 2-9, wherein the lower layer comprises a medium access control layer and the upper layer comprise a packet data convergence protocol layer and/or radio link control layer.
The first apparatus of any of claims 1-10, wherein the possible subsequent uplink occasion is the earliest possible subsequent uplink occasion.
The first apparatus of any of claims 1-11, wherein the first apparatus comprises a terminal device and the second apparatus comprises a network device.
A second apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:

receive, from a first apparatus in an uplink allocation, a data transmission along with at least one buffer status report, BSR, generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.
The second apparatus of claim 13, wherein the second apparatus is caused to:

receive a first BSR indicating a first data volume of the remaining data and a second BSR indicating a second data volume of the at least a portion of remaining data to be discarded.
The second apparatus of claim 13 or 14, wherein the possible subsequent uplink occasion is the earliest possible subsequent uplink occasion.
The second apparatus of any of claims 13-15, wherein the first apparatus comprises a terminal device and the second apparatus comprises a network device.
A method comprising:

determining whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and

generating at least one buffer status report, BSR, based on the remaining data and the determination of the discarding; and

transmitting, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.
The method of claim 17, further comprising:

obtaining, at a lower layer of the first apparatus, a time of the possible subsequent uplink occasion; and

transmitting, from the lower layer to an upper layer of the first apparatus, an indication of the time of the possible subsequent uplink occasion.
The method of claim 17, further comprising:

obtaining, at the lower layer of the first apparatus, respective time of one or more possible subsequent uplink occasions;

determining the possible subsequent uplink occasion based on the respective time of the one or more possible subsequent uplink occasions; and

transmitting, from the lower layer to an upper layer of the first apparatus, an indication of a time of the possible subsequent uplink occasion.
The method of claim 18, wherein the time of the potential subsequent uplink occasion is relative to at least one of the following:

a time when the indication is transmitted to the upper layer,

a timing of the data transmission in the uplink allocation with the at least one BSR included, or

a common clock between the lower layer and the upper layers.
The method of any of claims 18-20, further comprising:

determining the possible subsequent uplink occasion by considering all activated carriers for a carrier aggregation.
The method of any of claims 18-21, further comprising:

in accordance with a determination that the at least a portion of remaining data is to be discarded before the possible subsequent uplink occasion, determining data volume of the remaining data except for the at least a portion of remaining data to be discarded; and

generating the least one BSR based at least on the data volume.
The method of claim 22, further comprising:

transmitting, from the upper layer to the lower layer, an indication of the data volume of the remaining data except for the at least a portion of remaining data to be discarded; and

generating a BSR at the lower layer of the first apparatus based on the data volume.
The method of claim 22, further comprising:

transmitting, from the upper layer to the lower layer, an indication of a first data volume of the remaining data and a second data volume of the at least a portion of remaining data to be discarded; and

generating a first BSR based on the first data volume and a second BSR based on the second data volume.
The method of claim 23 or 24, further comprising:

discarding, by the upper layer, the at least a portion of remaining data to be discarded before transmitting the indication of the data volume and/or before a time point when the at least a portion of remaining data is to be discarded.
The method of any of claims 18-25, wherein the lower layer comprises a medium access control layer and the upper layer comprise a packet data convergence protocol layer and/or radio link control layer.
The method of any of claims 17-26, wherein the possible subsequent uplink occasion is the earliest possible subsequent uplink occasion.
The method of any of claims 17-27, wherein the first apparatus comprises a terminal device and the second apparatus comprises a network device.
A method comprising:

receiving, from a first apparatus in an uplink allocation, a data transmission along with at least one buffer status report, BSR, generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.
The method of claim 29, further comprising:

receiving a first BSR indicating a first data volume of the remaining data and a second BSR indicating a second data volume of the at least a portion of remaining data to be discarded.
The method of claim 29 or 30, wherein the possible subsequent uplink occasion is the earliest possible subsequent uplink occasion.
The method of any of claims 29-31, wherein the first apparatus comprises a terminal device and the second apparatus comprises a network device.
A first apparatus comprising:

means for determining whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after an uplink allocation, wherein the remaining data comprise data buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built; and

means for generating at least one buffer status report, BSR, based on the remaining data and the determination of the discarding; and

means for transmitting, to a second apparatus, the at least one BSR in the uplink allocation along with the data transmission.
A second apparatus comprising:

means for receiving, from a first apparatus in an uplink allocation, a data transmission along with at least one buffer status report, BSR, generated by the first apparatus based on whether at least a portion of remaining data in a buffer of the first apparatus to be discarded before a possible subsequent uplink occasion after the uplink allocation, wherein the remaining data comprise data to be buffered at the first apparatus after a protocol data unit for a data transmission in the uplink allocation has been built.
A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of any of claims 17-28 or the method of any of claims 29-32.