WO2025166793A1

WO2025166793A1 - Buffer status reporting in dual stack approach

Info

Publication number: WO2025166793A1
Application number: PCT/CN2024/077071
Authority: WO
Inventors: Benoist Pierre Sebire; Boyan Yanakiev; Claudio Rosa; Chunli Wu; Zexian Li
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: 2024-02-08
Filing date: 2024-02-08
Publication date: 2025-08-14
Anticipated expiration: 2026-08-08

Abstract

A method comprising: at a first apparatus, determine that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack; determine that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and transmit, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.

Description

BUFFER STATUS REPORTING IN DUAL STACK APPROACH

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 reporting in dual stack approach.

BACKGROUND

Radio protocol stack for the sixth generation mobile communications (6G) and beyond may rely on dual protocol stacks. Despite the flexibility introduced by the innovative dual protocol stack approach, there remain several unresolved technical challenges. For example, a key issue revolves around the effective management of the dual protocol stacks to ensure their seamless collaboration in diverse service scenarios, optimizing overall performance. Therefore, continued research is needed.

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 to: determine that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack; determine that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and transmit, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.

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 to:receive, from a first apparatus, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and determine, based on the buffer status information, that data is available for transmission with the first protocol stack.

In a third aspect of the present disclosure, there is provided a method. The method comprises: determining that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack; determining that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and transmitting, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.

In a fourth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a first apparatus, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and determining, based on the buffer status information, that data is available for transmission with the first protocol stack.

In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for determining that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack; means for determining that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and means for transmitting, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.

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, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and means for determining, based on the buffer status information, that data is available for transmission with the first protocol stack.

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 schematic diagram of different terminal device types according to some example embodiments of the present disclosure;

FIG. 3 illustrates a schematic diagram of an example structure of radio protocols according to some example embodiments of the present disclosure;

FIG. 4 illustrates a schematic diagram of the relationship between instantaneous load and the number of radio processing units (RPUs) ;

FIG. 5A illustrates a signaling flow of buffer status reporting in accordance with some embodiments of the present disclosure;

FIG. 5B illustrates a signaling flow of information exchanging between protocol stacks in accordance with some embodiments of the present disclosure;

FIG. 6 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

FIG. 7 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

FIG. 8 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 9 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.

As used herein, the term “buffer status report (BSR) ” may refer to a report in the field of communication systems, specifically in wireless communications. For example, such a report could encompass details regarding the size of the device buffer, including the total capacity and the remaining buffer capacity available for data storage. Additionally, it may include information on buffer utilization rate, data transfer rates, and/or latency metrics. These reports may play crucial role in optimizing mobile communication networks, aiding network operators and device manufacturers in efficiently managing data traffic, enhancing user experience, and ensuring the overall effectiveness of the network. It is noted that example embodiments of the present disclosure are equally applicable to other BSR in other domains.

As used herein, the term “protocol stack” may refer to a hierarchical structure of communication protocols designed for the exchange of data in various communication systems. In the context of communication domains, such as networking, the protocol stack typically consists of multiple layers, such as the physical layer, data link layer, network layer, transport layer, and application layer. This layered architecture facilitates the systematic handling and transmission of data between interconnected systems. It is noted that example embodiments of the present disclosure are equally applicable to other protocol stack in other domains.

As used herein, the term “message” may refer to a unit of data that is transmitted between communication endpoints in communication systems. A message can carry information, instructions, or data and is structured in a format suitable for transmission over a communication network. It is noted that example embodiments of the present disclosure are equally applicable to other message in other domains.

As used herein, the term “medium access control (MAC) layer” may refer to a part of data link protocol that controls access to the physical transmission medium. The term “medium access control control element (MAC CE) ” used herein refers to a MAC structure that carries control information which is transferred in MAC layer between MAC entities, such as MAC entities of different devices. The term “MAC header” used herein may refer to a data field added at the beginning of the MAC CE. As used herein, the term "common layer" refers to a shared or standardized layer within communication systems. The common layer serves as an intermediary or interface that facilitates communication and interaction between different components or entities within a system. It is noted that example embodiments of the present disclosure are equally applicable to other common layer in other domains.

As used herein, the term "time window" may refer to a specified and limited period during which a particular event or activity is expected to occur or be observed within a given system or process. For example, in the context of data processing, a time window could represent a specific timeframe within which data is collected, analyzed, or processed. It is noted that example embodiments of the present disclosure are equally applicable to other time window in other domains.

As used herein, the term "radio resource control configuration" may refer to the set of parameters and settings within a communication system, particularly in the context of radio resource control (RRC) . For example, in wireless networks such as cellular systems, the radio resource control configuration encompasses the specifications and configurations that govern the establishment, maintenance, and release of radio connections between user equipment (UE) and the network. It is noted that example embodiments of the present disclosure are equally applicable to other configuration in other domains.

As used herein, the term "logical channel" may refer to a communication channel in a communication system that represents a specific type of information flow with defined characteristics. For example, in wireless communication protocols, a logical channel can be a virtual channel that carries a particular type of data or information between entities within the system. It is noted that example embodiments of the present disclosure are equally applicable to other logical channel in other domains.

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

In the example of FIG. 1, the first apparatus 110 may be a terminal device, such as UE, and the second apparatus 120 may be a network device, such as a base station serving the UE. The serving area of the network device 120 may be called a cell 102.

It is to be understood that the number of apparatuses and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of apparatuses configured to implementing example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional apparatuses may be located in the cell 102, and one or more additional cells may be deployed in the communication environment 100.

In the following, for the purpose of illustration, some example embodiments are described with terminal device 110 operating as a terminal device and the network device 120 operating as a network device. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

In some example embodiments, if the first apparatus 110 is a terminal device and the second apparatus 120 is a 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.

FIG. 2 illustrates a schematic diagram of different terminal device types in which example embodiments of the present disclosure can be implemented. As shown in FIG. 2, a terminal device type 210 which may be called “low-cost UE” may have one protocol stack, such as anchor protocol stack (APS) 230 which is designed for low bitrate services, extensive coverage (e.g., bit-level optimizations) , and enhanced reliability, for example, incorporating features such as Radio Link Control (RLC) Automatic Repeat reQuest (ARQ) . The low-cost UE may possibly remove the need to introduce the equivalent of machine type communication (MTC) , Narrowband Internet of Things (NB-IoT) and/or Reduced Capability (RedCap) UEs. A terminal device type 220 which may be called “mainstream UE” and a terminal device type 250 which may be called “high-end UE” may include two protocol stacks, i.e., the APS 230 and a fast protocol stack (FPS) 240 designed for high bitrate service, where the focus is on a processing-friendly and implementation-friendly design employing the concept of radio processing units (RPU) , enabling parallel processing of the radio functions. Compared with the terminal device type 220, the FPS of the terminal device type 250 may incorporate larger number of RPUs that can support higher bitrates.

The first apparatus 110 can implement both APS 230 and FPS 240. For example, the first apparatus 110 may be implemented as the terminal device type 220, i.e., the mainstream UE. Alternatively, the the first apparatus 110 may be implemented as the terminal device type 250, i.e., high-end UE. It is noted that the first apparatus may be implemented as any proper UE type which includes more than one protocol stack.

FIG. 3 illustrates a schematic diagram of an example structure of radio protocols in the first apparatus 110. The structure of radio protocol in the first apparatus 110 may include a physical (PHY) layer 310, a MAC layer, an RLC layer, a packet data convergence protocol (PDCP) layer, and a service data application protocol (SDAP) layer. There may be a common layer (for example, a service data application protocol (SDAP) layer) 300 between the APS 230 and the FPS 240 in the first apparatus 110, and the common layer 300 may be used for overseeing the allocation of incoming packet data units (PDUs) to each RPU. In order to maximize the number of tasks that can be executed in parallel, the common layer 300 may be located as high up in the radio protocols as possible. The common layer 300 may locate in the higher part of the packet data convergence protocol (PDCP) layer, after sequence number (SN) allocation but before other functions such as security and header compression. This allows these other functions to be performed in parallel on each RPU while allowing the receiver to re-order the PDUs coming out of the RPUs. As shown in FIG. 3, the APS 230 and the FPS 240 may include MAC layer, RLC layer, and PDCP-low layer. It is noted the structure of radio protocol shown in FIG. 3 is only an example not limitation. The APS 230 and the FPS 240 may include any suitable number of protocol layers and any suitable protocols layers.

In some example embodiments, to maximize the power saving gains made possible by the RPU framework, the number of RPUs that are activated can be adjusted according to the instantaneous bitrate or load to be provided, as shown in FIG. 4, where a total of four RPUs are assumed to be available. Depending on whether the RPUs share a common memory and how they are activated, it is possible that some RPU management schemes would require specific mechanisms to be introduced in standards. For instance, if the RPUs operate on segregated memory resources, it is likely that each RPU would then host its own transmission and reception windows, thus impacting sequence numbers and status reports management. Conversely, RPUs operating on shared resources would allow common windows to be used, with no impact to sequence numbers or status reports.

Further, the APS 230 is a logical host for the control plane functions such as idle mode, connect mode and related configurations of the radio resource control (RRC) . By containing all control plane (CP) functions within the APS 230, not only is the FPS free to focus on user plane transfer for a simplified design, but it need not be active when the bitrate requirements are low.

Buffer Status Report (BSR) is a well-known MAC procedure that tells the network how much data the UE has buffered for transmission. The BSR of the logical channel group (s) that are mapped to the APS 230 is expected to follow that of previous generations while for logical channel groups that ate mapped to FPS 240, a new format is expected in order to achieve at least one of: potentially coping with fixed size PDU, for instance by reporting the number of such PDUs buffered, allowing much higher maximum bit rate, or potentially reporting the amount of data buffered per RPU.

In some example embodiments, resources are managed separately between the APS 230 and the FPS 240. For instance, the APS 230 and FPS 240 use different parts of the radio spectrum (e.g. the APS on frequency range (FR) 1, FPS on FR2) . Since the APS 230 and the FPS 240 are expected to run on different hardware, with minimum interaction, the APS 230 may need to be as isolated as possible from the FPS 240 and change. Thus, the BSR for the FPS 240 may be expected to be transmitted on resources for the FPS 240 and the BSR for the APS 230 may be expected to be transmitted on resources for the APS 230. In the Radio Resource Control Connected (RRC_CONNECTED) mode, a challenge arises when data accumulates in the buffers of logical channels mapped to FPS, but no FPS resources are available.

According to some example embodiments of the present disclosure, there is provided a solution to address the overarching concern of optimizing resource allocation within a framework where BSR sent on FPS resources and BSR sent on APS resources present distinct indications and formats. In particular, the proposed solution allows a UE to report the presence and/or quantity of buffered data in the FPS on APS resources. The merits of this approach lie in its dynamic nature, serving as an alternative to requesting resources via the FPS, particularly in scenarios where FPS resources are unavailable. Example embodiments of the present disclosure also contribute to improve efficiency in resource utilization.

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

Reference is made to FIG. 5A, which illustrates a signalling flow 500 of transmitting a message indicating buffer status information in accordance with some embodiments of the present disclosure. For the purpose of discussion, the signalling flow 500 will be discussed with reference to FIG. 1, for example, by using the first apparatus 110 and the second apparatus 120. As mentioned above, the first apparatus 110 may include more than one protocol stack (for example, a first protocol stack 510 and a second protocol stack 520) . In some embodiments, the first protocol stack 510 may be the FPS 240 and the second protocol stack 520 may be the APS 230. Alternatively, the first protocol stack 510 may be the APS 230 and the second protocol stack 520 may be the FPS 240. In some example embodiments, the FPS 240 may hold user plane for the first apparatus 110 and the APS 230 may hold control plane and user plane for the first apparatus 110. In some embodiments, the FPS 240 may be used for high bitrate services and the APS 230 may be used for low bitrate services. That is, the FPS 240 may be used for services that require higher bitrate than services for which APS 230 is used.

In some example embodiments, the second apparatus 120 transmits (5005) a configuration to the first apparatus 110. In other words, the first apparatus 110 receives (5005) the configuration from the second apparatus 120. For example, the configuration may be an RRC configuration from the second apparatus 120.

In some example embodiments, the configuration may indicate one or more BSR tables to be used for transmission of buffer status information on one or more available resource of the second protocol stack 520. For example, the first apparatus 110 is configured with a BSR table for the second protocol stack 520 on resources for the second protocol stack 520. Alternatively, or in addition, at least one BSR table in the one or more BSR tables may be configured to transmit the BSR for the first protocol stack 510 on one or more available resource allocated to the second protocol stack 520.

In some example embodiments, the configuration may include or indicate a specified time window within which a buffer status report may be transmitted. For example, the configuration may indicate a length of the time window. Alternatively, or in addition, the configuration may indicate a start time of the time window and/or an end time of the time window. In some example embodiments, the time window may be shared by the first protocol stack 510 and the second protocol stack 520.

In some example embodiments, the one or more BSR tables and/or the time window may be preconfigured at the first apparatus 110. In other words, the one or more BSR tables and/or the time window may be fixed and require no configuration from the second apparatus 120. For example, the reconfiguration may be implemented according to one or more standards.

In some example embodiments, the first apparatus 110 has at least one logical channel or logical channel group mapped to the first protocol stack 510. In some example embodiments, another logical channel or logical channel group may be mapped to the second protocol stack 520 of the first apparatus. I. e., different channels or channel groups may be mapped to different protocol stack 510, 520. The mapping may, for instance, follow logic described above with respect to user plane and control plane or high bitrate service (s) and low bitrate service (s) . Alternatively, the second protocol stack 520 may be utilized for at least one of a signaling radio bearer (SRB) or MAC Control Elements (CEs) . By way of example, at least one logical channel or logical channel group (LCH/LCG) is associated with the FPS 240, and another LCH/LCG with the APS 230. Alternatively, resources on the APS 230 may be used for SRB and/or MAC CEs, excluding certain MAC CE (for example, MAC CE used for transmitting the buffer status report for the FPS 240) .

In some example embodiments, resources dedicated to the first protocol stack 510 and the second protocol stack 520 are scheduled independently by the second apparatus 120. For example, separate downlink control information (DCI) may be transmitted by the second apparatus 120 to schedule the resources for the first protocol stack 510 and resources for the second protocol stack 520. Alternatively, a single DCI may be received from the second apparatus 120 to allocates separate resources for each protocol stack.

The first apparatus 110 may determine that a BSR for the first protocol stack 510 needs to be transmitted. For example, if new data arrived in the LCH or LCG mapped to the first protocol stack 510, the first apparatus 110 may determine that the BSR for the first protocol stack 510 needs to be transmitted, e.g., the BSR for the first protocol stack 510 is triggered.

The first apparatus 110 determines (5010) whether a BSR for the first protocol stack 510 can be transmitted on resources for the first protocol stack 510. In some embodiments, if for example the first protocol stack 510 is deactivated, the first apparatus 110 may determine that the BSR for the first protocol stack 510 cannot be transmitted on the resources for the first protocol stack 510. Alternatively, if there is no available resource allocated to the first protocol stack 510 (for example, due to data inactivity) , the BSR for the first protocol stack 510 is not able to be transmitted on the resource for the first protocol stack 510. In some embodiments, if the BSR for the first protocol stack 510 can be transmitted on the resources for the first protocol stack 510, the first apparatus 110 may transmit the BSR for the first protocol stack 510 on the resources for the first protocol stack 510.

In some embodiments, if the first apparatus 110 is configured with the time window for transmitting BSR, the first apparatus 110 may determine whether the BSR for the first protocol stack 510 can be transmitted based on whether there are recourses for the first protocol stack 510 within the time window. For example, the determination that the BSR for the first protocol stack 510 of the first apparatus is not able to be transmitted on the resource for the first protocol stack 510 is based on a determination that there are no allocated recourses for the first protocol stack 510 within a time window to transmit the BSR.

According to an embodiment, the first apparatus 110 determines, in step 5010, that BSR for the first protocol stack 510 cannot be transmitted. As described above, there may be multiple different reasons for this, one of which is that there may not be enough (or at all) resources to transmit the BSR via the first protocol stack.

If the BSR for the first protocol stack 510 cannot be transmitted on the resources for the first protocol stack 510 (e.g. as determined in step 5010 by the first apparatus 110) , the first apparatus 110 determines (5020) whether there are one or more available resources for the second protocol stack 520. In this case, if there are one or more available resources allocated to the second protocol stack 520, the first apparatus 110 transmits (5030) to the second apparatus 120, a message indicating buffer status information for the first protocol stack 510 on the one or more available resources. In other words, the second apparatus 120 receives (5030) the message indicating buffer status information for the first protocol stack 510 from the first apparatus 110 on the one or more available resources for the second protocol stack 520. In some example embodiments, the message may include an indication of how much data is buffered on the first protocol stack. For example, the message may indicate amount of buffered data across all LCH/LCGs mapped to the first protocol stack 510 (so that the second protocol stack 520 need not be aware of the LCH/LCG configuration of the first protocol stack 510) . Alternatively, the indication of how much data may rely on a BSR table specified for signaling the BSR of the first protocol stack 510 when transmitted on resources for the second protocol stack 520 (so that the second protocol stack 520 need not be aware of the BSR table defined for the first protocol stack 510) . In this way, it can reduce the latency of transmitting the BSR for the first protocol stack. Alternatively, if there are no available resources allocated to the second protocol stack 520, the first apparatus 110 may trigger a request for resources of the first protocol stack 510.

In some example embodiments, the message may be a MAC CE generated by the second protocol stack 520. FIG. 5B illustrates a signaling flow of information exchanging between protocol stacks for generating the MAC CE in accordance with some embodiments of the present disclosure.

According to an embodiment, the first apparatus 110 determines, in step 5020, that there are one or more resources available for the second protocol stack and transmits the message of step 5030 indicating buffer status information for the first protocol stack 510 on the one or more available resources (or on at least a subset of the one or more available resources) . For instance, step 5020 may be performed based on or in response to step 5010.

As shown in FIG. 5B, if the BSR for the first protocol stack 510 cannot be transmitted on the resources for the first protocol stack 510 and there are one or more available resources allocated to the second protocol stack 520, the first protocol stack 510 may inform (5110) the second protocol stack 520 of the buffer status information. For example, the buffer status information includes the data volume of one or more logical channels mapped to the first protocol stack 510.

In some example embodiments, the first protocol stack 510 may signal the buffer status information to the second protocol stack 520 based on the configuration. For example, the buffer status information is communicated using a granularity corresponding to the BSR table configured (5005) for transmitting the BSR for the first protocol stack 510 on resources allocated to the second protocol stack 520. In some example embodiments, the BSR table used for transmitting the BSR for the first protocol stack 510 on resources allocated to the second protocol stack 520 is different from the one used for transmitting the BSR for the first protocol stack 510 on resources allocated to the first protocol stack 510. In this way, it can reduce interactions between the first and second protocol stacks.

After receiving the buffer status information, the second protocol stack 520 may generate (5120) a MAC CE which comprises buffer status information (e.g., BSR) for the first protocol stack 510. The MAC CE may then be transmitted (5030) to the second apparatus 120 on one or more resources allocated to the second protocol stack 520. In some example embodiments, the priority of the MAC CE generated by the second protocol stack 520 is set to be higher than any other MAC CEs on the second protocol stack 520, ensuring timely requests for resources.

In some example embodiments, the MAC CE generated by the second protocol stack 520 (or by the first apparatus 110 for the second protocol stack 520) includes a BSR for the second protocol stack and an indication for requesting resources of the first protocol stack 510. For example, the BSR for the second protocol stack may be triggered and a “scheduling request bit” (i.e., the indication) may be toggled in a corresponding MAC header. Alternatively, if the BSR for the second protocol stack has been triggered, the “scheduling request bit” (i.e., the indication) may be toggled in a corresponding MAC header. Hence, the indication for the scheduling request may be implemented using a bit indicator.

In some other example embodiments, the MAC CE includes a MAC header with an indication for requesting resources of the first protocol stack 510. For example, the generated MAC CE may be a zero-size MAC CE, which means that it only includes a MAC header indicating a scheduling request for first protocol stack 510. In some embodiments, the MAC header may be a logical channel identity (LCID) .

In some further example embodiments, the MAC CE includes the BSR for the first protocol stack 510. For example, the transmission of a specified/configured BSR for the second protocol stack 520 may be triggered for reporting the buffer status of logical channel groups mapped to the first protocol stack 510.

In some example embodiments, the message indicating buffer status information for the first protocol stack 510 may be generated at a common layer (such as, the common layer 300) between the first protocol stack 510 and the second protocol stack 520. For example, the common layer may hold and collect triggers and data volume from two protocol stacks, and may prepare the BSR for the entity lacking resource allocation and request appropriately reduced transport block size from the other. In some other embodiments, the message may be generated at the PHY layer 310 of the first apparatus 110. In this way, it can remove the need for inter protocol stack communication entirely and both protocol stacks only communicate with the common entity.

Referring back to FIG. 5A, the second apparatus 120 determines (5040) that data is available for transmission with the first protocol stack 510 based on the buffer status information. In some embodiments, the second apparatus 120 transmits (5050) an indication regarding a set of resources (e.g., one or more resources) scheduled for the data on the first protocol stack 110. That is, the first apparatus 110 may receive (5050) the indication regarding a set of resources scheduled for the data on the first protocol stack 110.

In some embodiments, the set of scheduled resources may be transmitted in DCI which is separate from that of scheduling resources for the second protocols stack. Alternatively, a single DCI may indicate both the set of scheduled resources for the first protocol stack and the resources for the second protocols stack.

FIG. 6 shows a flowchart of an example method 600 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the first apparatus 110 in FIG. 1.

At block 610, the first apparatus 110 determines that a buffer status report for a first protocol stack of the first apparatus 110 is not able to be transmitted on a resource for the first protocol stack.

At block 620, the first apparatus 110 determines that there are one or more available resources allocated to a second protocol stack of the first apparatus 110, wherein the first protocol stack and the second protocol stack are different from each other.

At block 630, the first apparatus 110 transmits, to a second apparatus 120 and on the one or more available resources allocated to the second protocol stack 240, a message indicating buffer status information for the first protocol stack 230. Thus, the first apparatus 110 may be configured with at least two types of buffer status reports for the second protocol stack: one which indicates only buffer status information for the second protocol stack and another which indicates buffer status information for the second protocol stack and for the first protocol stack.

In some example embodiments, the method 600 further comprises: generating, at the second protocol stack, the MAC CE comprising the buffer status information for the first protocol stack; and transmitting, to the second apparatus 120, the MAC CE on the one or more available resources allocated to the second protocol stack.

In some example embodiments, the MAC CE comprises a buffer status report for the second protocol stack, and the MAC CE comprises an indication for a scheduling request of the first protocol stack. That is, the buffer status report for the second protocol stack may include an indicator (e.g., bit indicator) for indicating scheduling request for the first protocol stack.

In some example embodiments, the MAC CE comprises a MAC header that comprises an indication for a scheduling request of the first protocol stack.

In some example embodiments, the MAC CE comprises the buffer status report for the first protocol stack. Thus, for instance, the MAC CE may comprise buffer status report for both the first and second protocol stacks. Or buffer status report for the first and second protocol stacks may be transmitted in different MAC CEs.

In some example embodiments, a priority of the MAC CE is set to be higher than that of any other MAC CEs on the second protocol stack.

In some example embodiments, the method 600 further comprises: informing, by the first protocol stack, the second protocol stack about the buffer status information for the first protocol stack.

In some example embodiments, the buffer status information comprises data volume of one or more logical channels mapped to the first protocol stack, and wherein the buffer status information is informed using a granularity corresponding to a buffer status report table configured for a transmission of the buffer status report for the first protocol stack on resources allocated to the second protocol stack.

In some example embodiments, the buffer status report table is different from that configured for a transmission of the buffer status report for the first protocol stack on resource allocated to the first protocol stack.

In some example embodiments, the method 600 further comprises: generating, at a common layer between the first protocol stack and the second protocol stack, the message indicating buffer status information for the first protocol stack 230.

In some example embodiments, the determination that the buffer status report for the first protocol stack of the first apparatus 110 is not able to be transmitted on the resource for the first protocol stack is based on a determination that there are no allocated recourses for the first protocol stack within a time window to transmit the buffer status report.

In some example embodiments, the method 600 further comprises: receiving, from the second apparatus 120, a configuration that indicates the time window.

In some example embodiments, the method 600 further comprises: receiving from the second apparatus 120, a configuration that indicates one or more buffer status report tables for the second protocol stack.

In some example embodiments, the configuration is a radio resource control configuration.

In some example embodiments, at least one buffer status report table in the one or more buffer status report tables is configured for the transmission of the buffer status report for the first protocol stack on the one or more available resource allocated to the second protocol stack.

In some example embodiments, at least one logical channel or at least one logical channel group is mapped to the first protocol stack, and wherein another logical channel or another logical channel group is mapped to the second protocol stack, or the second protocol stack is used for at least one of: a signaling radio bearer or MAC CE.

In some example embodiments, resources allocated to the first protocol stack and resources allocated to the second protocol stack are scheduled separately by the second apparatus.

In some example embodiments, the method 600 further comprises: based on a determination that the first protocol stack is deactivated or there is no available resource allocated to the first protocol stack, determining that the buffer status report is not able to be transmitted on the resource for the first protocol stack.

In some example embodiments, the second protocol stack holds control plane and user plane for the first apparatus 110, and the first protocol stack holds user plane for the first apparatus 110, or wherein the first protocol stack holds control plane and user plane for the first apparatus 110, and the second protocol stack holds user plane for the first apparatus 110.

In some example embodiments, the second protocol is used for low bitrate services, and the first protocol stack is used for high bitrate services, or wherein the first protocol is used for low bitrate services, and the second protocol stack is used for high bitrate services.

In some example embodiments, the method 600 further comprises: receiving, from the second apparatus 120, an indication regarding a set of resources scheduled for data on the first protocol stack.

In some example embodiments, the first apparatus 110 is a terminal device, and the second apparatus 120 is a network device.

FIG. 7 shows a flowchart of an example method 700 implemented at a second apparatus 120 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the second apparatus 120 in FIG. 1.

At block 710, the second apparatus 120 receives, from a first apparatus 110, a message indicating buffer status information for a first protocol stack 230, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other.

At block 720, the second apparatus 120 determines, based on the buffer status information, that data is available for transmission with the first protocol stack.

In some example embodiments, the method 700 further comprises: transmitting, to the first apparatus 110, an indication regarding a set of resources scheduled for the data on the first protocol stack. That is, the second apparatus 120 may, for example, provide one or more resources for the first apparatus 110 for transmitting data, by the first apparatus 110, via the first protocol stack. The indication regarding the set of resources scheduled for the data on the first protocol stack may be provided via the second protocol stack from the second apparatus 120 to the first apparatus 110. Based on the indicated set of resources (or one or more resources) , the first apparatus 110 may perform data transmission via the first protocol stack 110.

In some example embodiments, the method 700 further comprises: receiving, from the first apparatus 110, the MAC CE comprising the buffer status information for the first protocol stack on the one or more available resources allocated to the second protocol stack.

In some example embodiments, the MAC CE comprises a buffer status report for the second protocol stack, and the MAC CE comprises an indication for requesting resources of the first protocol stack.

In some example embodiments, the MAC CE comprises a MAC header that comprises an indication for requesting resources of the first protocol stack.

In some example embodiments, the MAC CE comprises the buffer status report for the first protocol stack.

In some example embodiments, the method 700 further comprises: transmitting, to the first apparatus 110, a configuration that comprises at least one of: a time window, one or more buffer status report tables for the second protocol stack.

In some example embodiments, resources allocated to the first protocol stack and resources allocated to the second protocol stack 240 are scheduled separately by the second apparatus 120.

In some example embodiments, a first apparatus 110 capable of performing any of the method 600 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 600. 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 110 may be implemented as or included in the first apparatus 110 in FIG. 1.

In some example embodiments, the first apparatus 110 comprises means for determining that a buffer status report for a first protocol stack of the first apparatus 110 is not able to be transmitted on a resource for the first protocol stack; means for determining that there are one or more available resources allocated to a second protocol stack of the first apparatus 110, wherein the first protocol stack and the second protocol stack are different from each other; and means for transmitting, to a second apparatus 120 and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack 230.

In some example embodiments, the message is a medium access control control element, MAC CE, and wherein the first apparatus 110 further comprises: means for generating, at the second protocol stack, the MAC CE comprising the buffer status information for the first protocol stack; and means for transmitting, to the second apparatus 120, the MAC CE on the one or more available resources allocated to the second protocol stack.

In some example embodiments, the first apparatus 110 further comprises: means for informing, by the first protocol stack, the second protocol stack about the buffer status information for the first protocol stack.

In some example embodiments, the buffer status report table is different from that configured for a transmission of the buffer status report for the first protocol stack 230 on resource allocated to the first protocol stack.

In some example embodiments, the first apparatus 110 further comprises: means for generating, at a common layer between the first protocol stack and the second protocol stack, the message indicating buffer status information for the first protocol stack.

In some example embodiments, the first apparatus 110 further comprises: means for based on a determination that there are no allocated recourses for the first protocol stack within a time window to transmit the buffer status report, determining that the buffer status report for the first protocol stack of the first apparatus 110 is not able to be transmitted on the resource for the first protocol stack.

In some example embodiments, the determination that the buffer status report for the first protocol stack of the first apparatus is not able to be transmitted on the resource for the first protocol stack is based on a determination that there are no allocated recourses for the first protocol stack within a time window to transmit the buffer status report.

In some example embodiments, the first apparatus 110 further comprises: means for receiving, from the second apparatus 120, a configuration that indicates the time window.

In some example embodiments, the first apparatus 110 further comprises: means for receiving, from the second apparatus 120, a configuration that indicates one or more buffer status report tables for the second protocol stack 240.

In some example embodiments, resources allocated to the first protocol stack and resources allocated to the second protocol stack are scheduled separately by the second apparatus 120.

In some example embodiments, the first apparatus 110 further comprises: means for based on a determination that the first protocol stack is deactivated or there is no available resource allocated to the first protocol stack, determining that the buffer status report is not able to be transmitted on the resource for the first protocol stack.

In some example embodiments, the first apparatus 110 comprises means for receiving, from the second apparatus, an indication regarding a set of resources scheduled for data on the first protocol stack.

In some example embodiments, the first apparatus 110 further comprises means for performing other operations in some example embodiments of the method 600 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 110.

In some example embodiments, a second apparatus 120 capable of performing any of the method 700 (for example, the second apparatus 120 in FIG. 1) may comprise means for performing the respective operations of the method 700. 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 120 may be implemented as or included in the second apparatus 120 in FIG. 1.

In some example embodiments, the second apparatus 120 comprises means for receiving, from a first apparatus 110, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and means for determining, based on the buffer status information, that data is available for transmission with the first protocol stack.

In some example embodiments, the second apparatus 120 further comprises: means for transmitting, to the first apparatus 110, an indication regarding a set of resources scheduled for the data on the first protocol stack.

In some example embodiments, the message is a medium access control control element, MAC CE, and wherein the second apparatus 120 further comprises: means for receiving, from the first apparatus 110, the MAC CE comprising the buffer status information for the first protocol stack on the one or more available resources allocated to the second protocol stack.

In some example embodiments, the second apparatus 120 further comprises: means for transmitting, to the first apparatus 110, a configuration that comprises at least one of: a time window, one or more buffer status report tables for the second protocol stack.

In some example embodiments, the second apparatus 120 further comprises means for performing other operations in some example embodiments of the method 700 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 120.

FIG. 8 is a simplified block diagram of a device 800 that is suitable for implementing example embodiments of the present disclosure. The device 800 may be provided to implement a communication device, for example, the apparatus 110 or the second apparatus 120 as shown in FIG. 1. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processor 810, and one or more communication modules 840 coupled to the processor 810.

The communication module 840 is for bidirectional communications. The communication module 840 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 840 may include at least one antenna.

The processor 810 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 800 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 820 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) 824, 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) 822 and other volatile memories that will not last in the power-down duration.

A computer program 830 includes computer executable instructions that are executed by the associated processor 810. The instructions of the program 830 may include instructions for performing operations/acts of some example embodiments of the present disclosure. The program 830 may be stored in the memory, e.g., the ROM 824. The processor 810 may perform any suitable actions and processing by loading the program 830 into the RAM 822.

The example embodiments of the present disclosure may be implemented by means of the program 830 so that the device 800 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 7. 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 830 may be tangibly contained in a computer readable medium which may be included in the device 800 (such as in the memory 820) or other storage devices that are accessible by the device 800. The device 800 may load the program 830 from the computer readable medium to the RAM 822 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. 9 shows an example of the computer readable medium 900 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 900 has the program 830 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 to:

determine that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack;

determine that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and

transmit, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.
The first apparatus of claim 1, wherein the message is a medium access control control element, MAC CE, and wherein the first apparatus is caused to:

generate, at the second protocol stack, the MAC CE comprising the buffer status information for the first protocol stack; and

transmit, to the second apparatus, the MAC CE on the one or more available resources allocated to the second protocol stack.
The first apparatus of claim 2, wherein the MAC CE comprises a buffer status report for the second protocol stack, and the MAC CE comprises an indication for requesting resources of the first protocol stack.
The first apparatus of claim 2, wherein the MAC CE comprises a MAC header that comprises an indication for requesting resources of the first protocol stack.
The first apparatus of claim 2, wherein the MAC CE comprises the buffer status report for the first protocol stack.
The first apparatus of any of claims 2-5, wherein a priority of the MAC CE is set to be higher than that of any other MAC CEs on the second protocol stack.
The first apparatus of any of claims 2-6, wherein the first apparatus is caused to:

inform, by the first protocol stack, the second protocol stack about the buffer status information for the first protocol stack.
The first apparatus of claim 7, wherein the buffer status information comprises data volume of one or more logical channels mapped to the first protocol stack, and

wherein the buffer status information is informed using a granularity corresponding to a buffer status report table configured for a transmission of the buffer status report for the first protocol stack on resources allocated to the second protocol stack.
The first apparatus of 8, wherein the buffer status report table is different from that configured for a transmission of the buffer status report for the first protocol stack on resource allocated to the first protocol stack.
The first apparatus of claim 1, wherein the first apparatus is caused to:

generate, at a common layer between the first protocol stack and the second protocol stack, the message indicating buffer status information for the first protocol stack.
The first apparatus of any of claims 1-10, wherein the determination that the buffer status report for the first protocol stack of the first apparatus is not able to be transmitted on the resource for the first protocol stack is based on a determination that there are no allocated recourses for the first protocol stack within a time window to transmit the buffer status report.
The first apparatus of claim 11, wherein the first apparatus is caused to:

receive, from the second apparatus, a configuration that indicates the time window.
The first apparatus of any of claims 1-12, wherein the first apparatus is caused to:

receive, from the second apparatus, a configuration that indicates one or more buffer status report tables for the second protocol stack.
The first apparatus of claim 12 or 13, wherein the configuration is a radio resource control configuration.
The first apparatus of claim 13, wherein at least one buffer status report table in the one or more buffer status report tables is configured for the transmission of the buffer status report for the first protocol stack on the one or more available resource allocated to the second protocol stack.
The first apparatus of any of claims 1-15, wherein at least one logical channel or at least one logical channel group is mapped to the first protocol stack, and

wherein another logical channel or another logical channel group is mapped to the second protocol stack, or the second protocol stack is used for at least one of: a signaling radio bearer or MAC CE.
The first apparatus of any of claims 1-16, wherein resources allocated to the first protocol stack and resources allocated to the second protocol stack are scheduled separately by the second apparatus.
The first apparatus of any of claims 1-17, wherein the first apparatus is caused to:

based on a determination that the first protocol stack is deactivated or there is no available resource allocated to the first protocol stack, determine that the buffer status report is not able to be transmitted on the resource for the first protocol stack.
The first apparatus of any of claims 1-18, wherein the second protocol stack holds control plane and user plane for the first apparatus, and the first protocol stack holds user plane for the first apparatus, or

wherein the first protocol stack holds control plane and user plane for the first apparatus, and the second protocol stack holds user plane for the first apparatus.
The first apparatus of any of claims 1-18, wherein the second protocol is used for low bitrate services, and the first protocol stack is used for high bitrate services, or

wherein the first protocol is used for low bitrate services, and the second protocol stack is used for high bitrate services.
The first apparatus of any of claims 1-20, wherein the first apparatus is caused to:

receive, from the second apparatus, an indication regarding a set of resources scheduled for data on the first protocol stack.
The first apparatus of any of claims 1-21, wherein the first apparatus is a terminal device, and the second apparatus is 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 to:

receive, from a first apparatus, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and

determine, based on the buffer status information, that data is available for transmission with the first protocol stack.
The second apparatus of claim 23, wherein the second apparatus is caused to:

transmit, to the first apparatus, an indication regarding a set of resources scheduled for the data on the first protocol stack.
The second apparatus of claim 23, wherein the message is a medium access control control element, MAC CE, and wherein the second apparatus is caused to:

receive, from the first apparatus, the MAC CE comprising the buffer status information for the first protocol stack on the one or more available resources allocated to the second protocol stack.
The second apparatus of claim 25, wherein the MAC CE comprises a buffer status report for the second protocol stack, and the MAC CE comprises an indication for requesting resources of the first protocol stack.
The second apparatus of claim 25 or 26, wherein the MAC CE comprises a MAC header that comprises an indication for requesting resources of the first protocol stack.
The second apparatus of claim 25, wherein the MAC CE comprises the buffer status report for the first protocol stack.
The second apparatus of any of claims 25-28, wherein a priority of the MAC CE is set to be higher than that of any other MAC CEs on the second protocol stack.
The second apparatus of any of claims 23-29, wherein the second apparatus is caused to:

transmit, to the first apparatus, a configuration that comprises at least one of: a time window, one or more buffer status report tables for the second protocol stack.
The second apparatus of claim 30, wherein the configuration is a radio resource control configuration.
The second apparatus of claim 30, wherein at least one buffer status report table in the one or more buffer status report tables is configured for the transmission of the buffer status report for the first protocol stack on the one or more available resource allocated to the second protocol stack.
The second apparatus of any of claims 23-32, wherein at least one logical channel or at least one logical channel group is mapped to the first protocol stack, and

wherein another logical channel or another logical channel group is mapped to the second protocol stack, or the second protocol stack is used for at least one of: a signaling radio bearer or MAC CE.
The second apparatus of any of claims 23-33, wherein resources allocated to the first protocol stack and resources allocated to the second protocol stack are scheduled separately by the second apparatus.
The second apparatus of any of claims 23-34, wherein the second protocol stack holds control plane and user plane for the first apparatus, and the first protocol stack holds user plane for the first apparatus, or

wherein the first protocol stack holds control plane and user plane for the first apparatus, and the second protocol stack holds user plane for the first apparatus.
The second apparatus of any of claims 23-34, wherein the second protocol is used for low bitrate services, and the first protocol stack is used for high bitrate services, or

wherein the first protocol is used for low bitrate services, and the second protocol stack is used for high bitrate services.
The second apparatus of any of claims 23-36, wherein the first apparatus is a terminal device, and the second apparatus is a network device.
A method for a first apparatus, comprising:

determining that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack;

determining that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and

transmitting, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.
A method for a second apparatus, comprising:

receiving, from a first apparatus, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and

determining, based on the buffer status information, that data is available for transmission with the first protocol stack.
A first apparatus comprising:

means for determining that a buffer status report for a first protocol stack of the first apparatus is not able to be transmitted on a resource for the first protocol stack;

means for determining that there are one or more available resources allocated to a second protocol stack of the first apparatus, wherein the first protocol stack and the second protocol stack are different from each other; and

means for transmitting, to a second apparatus and on the one or more available resources allocated to the second protocol stack, a message indicating buffer status information for the first protocol stack.
A second apparatus comprising:

means for receiving, from a first apparatus, a message indicating buffer status information for a first protocol stack, wherein the message is transmitted on available one or more resources allocated to a second protocol stack, and the first protocol stack and the second protocol stack are different from each other; and

means for determining, based on the buffer status information, that data is available for transmission with the first protocol stack.
A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 38 or 39.