WO2022067542A1

WO2022067542A1 - Configuration of small data transmission

Info

Publication number: WO2022067542A1
Application number: PCT/CN2020/118970
Authority: WO
Inventors: Samuli Turtinen; Benoist SÉBIRE; Chunli Wu; Jussi-Pekka Koskinen
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2022-04-07
Also published as: EP4223056A4; EP4223056A1; CN116326142A

Abstract

Example embodiments of the present disclosure relate to configuration of small data transmission (SDT) for a flow (s). A first device determines a transmission configuration related to at least one flow from the first device to a second device. The transmission configuration indicates allowance or disallowance of a small data transmission mode for the at least one flow. If data associated with a flow of the at least one flow is to be transmitted, the first device determines, based on the transmission configuration, whether the small data transmission mode is allowed for the flow and transmits the data associated with the flow to the second device based on a result of the determination. Through the solution, it is possible to achieve finer control for SDT at the flow level, which can improve the control on quality of service for individual flows.

Description

CONFIGURATION OF SMALL DATA TRANSMISSION

FIELD

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 configuration of small data transmission.

BACKGROUND

In some communication systems, a terminal device can transition between an inactive state and a connected state. In the inactive state, the terminal device may not have a connection established with a network device for communications. To avoid unnecessary signaling overhead and power consumption for establishing or reestablishing a connection, it has been agreed to support small data transmission (SDT) for a terminal device in the inactive state, without requiring the terminal device to establish a connection with a network device. However, currently there is no specific solution for data transmission for a terminal device in an inactive state.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for configuration of small data transmission. Embodiments that do not fall under the scope of the claims, if any, are to be interpreted as examples useful for understanding various embodiments of the disclosure.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program code; where the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine a transmission configuration related to at least one flow from the first device to a second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determine, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and transmit the data associated with the flow to the second device based on a result of the determination of whether the small data transmission mode is allowed for the flow.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program code; where the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit, to a first device, configuration information indicating a transmission configuration related to at least one flow from the first device to the second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and receive data associated with a flow of the at least one flow from the first device, the data associated with the flow being received from the first device based on the transmission configuration.

In a third aspect, there is provided a method. The method comprises determining, at a first device, a transmission configuration related to at least one flow from the first device to a second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determining, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and transmitting the data associated with the flow to the second device based on a result of the determination of whether the small data transmission mode is allowed for the flow.

In a fourth aspect, there is provided a method. The method comprises transmitting, at a second device and to a first device, configuration information indicating a transmission configuration related to at least one flow from the first device to the second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and receiving data associated with a flow of the at least one flow from the first device, the data associated with the flow being received from the first device based on the transmission configuration.

In a fifth aspect, there is provided a first apparatus. The first apparatus comprises means for: determining a transmission configuration related to at least one flow from the first apparatus to a second apparatus, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determining, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and transmitting the data associated with the flow to the second apparatus based on a result of the determination of whether the small data transmission mode is allowed for the flow.

In a sixth aspect, there is provided a second apparatus. The second apparatus comprises means for: transmitting, to a first apparatus, configuration information indicating a transmission configuration related to at least one flow from the first apparatus to the second apparatus, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and receiving data associated with a flow of the at least one flow from the first apparatus, the data associated with the flow being received from the first apparatus based on the transmission configuration.

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

In an eighth aspect, there is provided a computer readable medium. The computer readable medium comprises program instructions 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 example flow-based architecture for communications between devices;

Fig. 3 illustrates a signaling flow for configuring SDT for a flow (s) according to some example embodiments of the present disclosure;

Fig. 4 illustrates a flowchart of a method implemented at a terminal device according to some other example embodiments of the present disclosure;

Fig. 5 illustrates a flowchart of a method implemented at a network device according to some other example embodiments of the present disclosure;

Fig. 6 illustrates a simplified block diagram of an apparatus 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” and “second” etc. 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. 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.

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 future fifth generation (5G) 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) , a 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.

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 (loT) 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. 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 resource enabling a communication, and the like. In the following, 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 shows an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a first device 110 and a second device 120 can communicate with each other.

In the example of Fig. 1, the first device 110 is illustrated as a terminal device while the second device 120 is illustrated as a network device serving the terminal device. The serving area of the second device 120 may be called a cell 102.

It is to be understood that the number of devices and their connections shown in Fig. 1 are only for the purpose of illustration without suggesting any limitation. The environment 100 may include any suitable number of devices adapted for implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell 102, and one or more additional cells may be deployed in the environment 100. It is noted that although illustrated as a network device, the second device 120 may be other device than a network device. Although illustrated as a terminal device, the first device 110 may be other device than a terminal device.

In some example embodiments, if the first device 110 is a terminal device and the second device 120 is a network device, a link from the second device 120 to the first device 110 is referred to as a downlink (DL) , while a link from the first device 110 to the second device 120 is referred to as an uplink (UL) . In DL, the second device 120 is a transmitting (TX) device (or a transmitter) and the first device 110 is a receiving (RX) device (or a receiver) . In UL, the first device 110 is a TX device (or a transmitter) and the second device 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) and the fifth generation (5G) and on 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.

3GPP Working Groups have introduced a new feature called an inactive state. A device (e.g., a terminal device) can transition between an inactive state and a connected state. The inactive state may sometimes be referred to as an inactive mode, an RRC_INACTIVE state, or an inactive state in a RRC_CONNECTED mode, and such terms are used interchangeably herein. The connected state may sometimes be referred to as a connected mode or an RRC_CONNECTED state, and such terms are used interchangeably herein.

In the inactive state, the terminal device does not have any dedicated resources (e.g., time and frequency resources) for transmission and/or reception. In the connected state, a connection is established between the terminal device and the network device and thus the terminal device can perform normal communication with the network device via the connection.

As mentioned above, there is a certain amount of signaling overhead and power consumption to transition the terminal device from an inactive state to a connected state by establishing or reestablishing a connection between the terminal device and the network device. If connection setup and subsequently release happens for each data transmission of the terminal device in the inactive state no matter how small and infrequent the data packets are, it may result in unnecessary power consumption and signalling overhead. Thus, allowing data transmission to and/or from a terminal device that is in inactive state makes sense if the terminal device has intermittent small data packets to transmit. It has been agreed to support small data transmission (SDT) for a terminal device in inactive state, without requiring the terminal device to establish a connection with a network device. As used herein, the term “SDT” refers to a type of transmission where a small amount of data is triggered, although other terms may also be used.

There are various applications that involve exchange of relatively small amounts of data. For example, in some applications of mobile devices, SDT may include traffic from Instant Messaging (IM) services, heart-beat or keep-alive traffic from IM or email clients and other services, push notifications in various applications, traffic from wearables (including, for example, periodic positioning information) , and/or the like. In some applications of non-mobile devices, SDT may include sensor data (e.g., temperature, pressure readings transmitted periodically or in an event-triggered manner in an IoT network) , metering and alerting information sent from smart meters, and/or the like.

Signalling overhead from terminal devices in the inactive state for small data packets is a general problem, not only for network performance and efficiency but also for the UE battery performance. In general, any device that has intermittent small data packets in the in active state will benefit from enabling SDT. In some example embodiments, SDT may be enabled using messages sent in random access channel (RACH) procedures, and/or configured grants.

In communication systems, communications between different devices may be supported based on flows, for example, Quality of Service (QoS) flows. QoS refers to a technology for smoothly transmitting various types of traffic (mail, data transmission, sounds, or images) to users depending on the characteristics thereof. The most fundamental QoS parameter is a bandwidth, a cell transfer delay (CTD) , a cell delay variation (CDV) , or a cell loss ratio (CLR) . In some example embodiments, QoS Flows may include QoS flows that require guaranteed flow bit rate (referred to as GBR QoS Flows) and QoS Flows that do not require guaranteed flow bit rate (referred to as non-GBR QoS Flows) .

Fig. 2 illustrates example flow-based architecture 200 for communications between devices, for example, between the first device 110 and the second device 120 in Fig. 1. For the first device 110, one or more sessions may be established for communications. In the example architecture 200 of Fig. 2, a session 210 between the first device 110 and the second device 120 is illustrated, although it would be appreciated that one or more other sessions may also be established. The session 210 may be a packet data unit (PDU) session.

Together with the session 210, at least one data radio bearer (DRB) is established to carry data packets from the first device 110 to the second device 120. In the example of Fig. 2, a DRB 220-1 and a DRB 220-2 are illustrated to be established for the session 210. For convenience of discussion, the DRB 220-1 and the DRB 220-2 are collectively or individually referred to as DRBs 220. Although two DRBs are explicitly illustrated in Fig. 2, one or more than two DRBs may also be possible in other examples.

In a session, one or more flows are established for data packet transmissions. Data packets with different characteristics may be identified as belonging to different flows. A flow is thus the finest granularity of QoS differentiation in a session. A flow is identified within a session by an identity (ID) . For example, a QoS flow is identified by a QoS Flow ID (QFI) . Thus, within a session, different flows may have unique identities.

To ensure quality of service, such as reliability and latency, data may be mapped to appropriate flows and DRB. Hence there is a 2-step mapping from data packets to flows and from flows to DRBs. As illustrated in the example of Fig. 2, flows 230-1, 230-2 are mapped to the DRB 220-1, and flows 230-3, 230-4 are mapped to the DRB 220-2. For convenience of discussion, the flows 230-1, 230-2, 230-3, 230-3 are collectively or individually referred to as flows 230. In the cases of differentiating flows with QoS, the flows 230 may also be referred to as QoS flows. It would be appreciated that although a specific number of flows are explicitly illustrated in Fig. 2, different numbers of flows may be mapped to the respective DRBs in other examples.

A DRB 220 may define the data packet treatment on the radio interface (Uu) . A DRB 220 serves packets with the same packet forwarding treatment. In some example embodiments, the flow-to-DRB mapping by NG-RAN may be based on identities of the flows and the associated QoS profiles (i.e. QoS parameters and QoS characteristics) . In some example embodiments, separate DRBs 220 may be established for flows 230 requiring different packet forwarding treatment, or several flows 230 belonging to the same session can be multiplexed in the same DRB 220.

In some example embodiments, the flow-to-DRB mapping may be configured by explicit signalling from the second device 120 to the first device 110 or implicitly via reflective mapping (also referred to as reflective QoS, RQoS) . With the reflective mapping, the first device 110 may derive the flow-to-DRB mapping for communication from the first device 110 to the second device 120 based on information available in communication in the reverse direction. For example, for a DRB 220, the first device 110 monitors identity (ies) of the flow (s) indicated in the packets as received from the second device 120. The first device 110 may then apply the same mapping for the flows from the first device 110 to the second device 120. That is, for a DRB 220, the first device 110 maps a flow corresponding to the identity and the session observed in the received packet for that DRB. For example, if the packet for the DRB 220-1 received from the second device 120 indicates an identity of a flow from the second device 120, a flow 230-1 of the first device 110 identified by the same identity may be mapped to the DRB 220-1 according to the reflective mapping.

In some example embodiments, a default DRB may be configured for the session 210. If a flow neither matches the explicit configuration nor the reflective mapping, the flow may be mapped to the default DRB and data associated with this flow may be transmitted via the default DRB.

Because the number of flows to deal with is typically very high, explicitly configuring the flow-to-DRB mapping rules in advance is seldom possible. With the reflective mapping, the allocation of DRB among the flows may still be controlled by the network, but explicit control signalling for configuring the mapping is limited. The control plane latency may also be reduced. In addition, by allowing non-configured flows to be mapped the default DRB, the network allows a mode of operation where 1) a default DRB with radio protocols configured to provide a default QoS is used to carry the bulk of traffic; and 2) only flows with specific requirements are dynamically (re) mapped onto dedicated DRBs as they appear, without involving control signalling. This greatly minimises the amount of signalling required and reduces control plane latency.

Since SDT may suffer from data losses (e.g. upon cell re-selection after the SDT transmission) , it is not desirable to use SDT for all communications in the flow-based architecture. Currently there is no specific solution for configuring SDT for the flow-based architecture between devices. The inventors have found that since the number of flows to deal with is typically very high, SDT for the flows needs to be carefully controlled. Therefore, there is a need for a solution to improve handling of small data transmissions in the flow-based architecture.

According to some example embodiments of the present disclosure, there is provided a solution for configuring SDT on a per flow basis. According to this solution, a first device (for example, a terminal device) can determine a transmission configuration related to one or more respective flows from the first device to a second device (for example, a network device) . The transmission configuration is used for configuring SDT on a per flow basis, indicating allowance or disallowance of a SDT mode for the one or more respective flows. Depending on the transmission configuration, the first device is able to determine whether data associated with a flow is allowed to be transmitted to the second device in the SDT mode or not. The second device may control the SDT for the flows transmitted from the first device by sending a transmission configuration to the first device or sending other information to the first device to configure the SDT together with a transmission configuration determined by the first device per se. Through the solution, it is possible to achieve finer control for SDT at the flow level, which can improve the control on QoS for individual flows.

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

Reference is now made to Fig. 3, which shows a signaling flow 300 for configuring SDT for a flow (s) according to some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 300 will be described with reference to the communication environment 100 in Fig. 1 and the flow-based architecture 200 in Fig. 2. The signaling flow 300 involves the first device 110 and the second device 120.

In operation, the first device 110 determines 305 a transmission configuration related to one or more flows 230 from the first device 110 to the second device 120. The flows 230, for example, may include QoS flows. The transmission configuration can indicate allowance or disallowance of a SDT mode for the one or more flows 230. Such transmission configuration may also be referred to as a transmission configuration for SDT or a SDT configuration, used for configuring SDT on a per flow basis.

In some example embodiments, the transmission configuration for SDT used by the first device 110 may be partially or entirely transmitted from the second device 120. In such example embodiments, the second device 120 transmits 310 configuration information indicating at least a part of the transmission configuration to the first device 110, as illustrated in Fig. 3. The configuration information may be communicated while the first device 110 is in the connected state and has a connection established with the second device 120. The second device 120 may control small data transmissions of the first device 110 by providing the configuration information. The configuration information may be transmitted from the second device 120 via dedicated signaling, for example, via radio resource control (RRC) signaling. The configuration information may also be transmitted via other types of signaling, such as broadcast signaling, for example, through system information block (s) (SIB) .

In some example embodiments, the transmission configuration for SDT used by the first device 110 may be partially or entirely specified in the first device 110. In this case, the first device 110 may determine how to configure SDT for the one or more flows, without increased signaling from the second device 120.

With the transmission configuration, the first device 110 is able to make a decision on SDT at a flow level. In some example embodiments, if the first device 110 is in the inactive state, the transmission configuration may be used to make the decision on SDT. Specifically, the first device 110 determines whether data associated with any flow 230 is to be transmitted, for example, whether data is buffered in a data buffer for a flow. If it is found that data associated with a flow 230 is to be transmitted, the first device 110 determines 315, based on the transmission configuration, whether the SDT mode is allowed for the flow 230. For any flow 230 from the first device 110 to the second device 120, the first device 110 may made similar decision at the flow level.

For a flow 230 with the SDT mode allowed, data associated with this flow 230 may be transmitted from the first device 110 in the SDT mode, for example, in the case that the first device 110 is in an inactive state, or at least the flow 230 may trigger the SDT mode transmission procedure from the first device 110. For a flow 230 with the SDT mode disallowed, the data associated with this flow may not be transmitted using the SDT mode but using a regular connection mode. In this case, if the first device 110 is in the inactive state, it may switch to the connected state by resuming a connection with the second device 120 and transmit the data via the connection.

In some example embodiments, any suitable layer in the first device, such as Packet Data Convergence Protocol (PDCP) , Service Data Adaptation Protocol (SDAP) or even higher (e.g. Non-Access-Stratum, NAS) layer, may be used to trigger either SDT or the regular connection mode. In some example embodiments, upon data associated with a flow arrives at a buffer for the flow, the RRC layer may be indicated, for example, by the PDCP or SDAP if the SDT mode is allowed or not for the flow 230 or if the RRC layer should trigger an SDT procedure or a connection resume procedure.

The transmission configuration may be defined in various ways to control SDT for the respective flow (s) from the first device 110 to the second device 120. In some example embodiments, the transmission configuration may indicate one or more IDs or one or more ranges of IDs (also referred to as identity spaces) of flows that are allowed or disallowed for the SDT mode.

In some example embodiments, the first device 110 may receive, from the second device 120, configuration information including one or more IDs of flows that are marked as allowed for the SDT mode, one or more IDs of flows that are marked as not allowed for the SDT mode, one or more ranges of IDs of flows that are marked as allowed for the SDT mode, and/or one or more ranges of IDs of flows that are marked as disallowed for the SDT mode. The second device 120 may control the transmission configuration for SDT by explicitly indicating the IDs of the flows allowed or disallowed for the SDT mode via the configuration information.

The first device 110 may maintain a list of IDs and/or ranges of IDs of flows that are allowed or disallowed for the SDT. If a flow 230 is found to have data to be transmitted in the case that the first device 110 is in the inactive state, the first device 110 may determine whether an ID of the flow 230 matches the maintained IDs or ranges of IDs, so as to determine whether the SDT mode is allowed for this flow 230. In some example embodiments, if the ID of the flow 230 matches an ID of a flow that is marked as allowed for the SDT mode or if the ID of the flow 230 falls into a range of IDs of flows that are marked as allowed for the SDT mode, the first device 110 determines that the SDT mode is allowed for this flow 230. In some example embodiments, if the ID of the flow 230 does not match any specific ID of flow or any range of IDs of flows that are marked as allowed, or if the ID of the flow 230 matches an ID of a flow that is marked as disallowed for the SDT mode or falls into a range of IDs of flows that are marked as disallowed for the SDT mode, the first device 110 determines that the SDT mode is not allowed for this flow 230.

In some example embodiments, the one or more IDs of flows and/or the ranges of IDs may identify flows 230 mapped to a same DRB 220 or a same session 210. Due to the flexible per-flow configuration, a plurality of flows 230 mapped to a same DRB 220 or a same session 210 may be each configured to be allowed or disallowed for the SDT mode. For example, in Fig. 2, a flow 230-1 mapped to the DRB 220-1 may be configured as allowed for the SDT mode while a flow 230-2 mapped to the DRB 220-1 may be configured as disallowed for the SDT mode. In some examples, it is also possible to achieve differentiation in configuring the SDT mode for a same DRB or a same session in the granularity of ranges of IDs of flows.

In some example embodiments, if a flow (s) 230 mapped to a same session 210 or a same DRB 220 that is not explicitly configured by the second device 120 as allowed for the SDT mode, it may be considered as disallowed for the SDT mode; vice versa, one or more flows 230 may be explicitly configured as disallowed for the SDT mode and thus all the other flows 230 may be determined as allowed for the SDT mode.

In some cases, a session 210 or a DRB 220 established between the first device 110 and the second device 120 may be configured as allowed or disallowed for the SDT. In such case, the per-flow configuration proposed in the present disclosure can still allow finer control on SDT. In particular, if the session 210 or the DRB 220 is configured as being allowed for the SDT mode, data associated with the disallowed flow (s) may not be transmitted using the SDT mode. As such, even if the first device 110 has only one DRB for a session with the second device 120, the transmission configuration for different flows may be flexibly controlled in terms of small data transmissions.

In some example embodiments, the transmission configuration may indicate that the SDT mode is allowed or disallowed for a new flow mapped to a default DRB established between the first device 110 and the second device 120. This transmission configuration may be indicated by the second device 120 through configuration information, or may be specified in the first device 110.

Depending on the transmission configuration related to the new flow, in determining whether the SDT mode is allowed for a flow 230 having associated data to be transmitted, the first device 110 may determine whether there is a stored flow-to-DRB mapping rule for the flow 230. A flow-to-DRB mapping rule stored at the first device 110 for a specific flow may indicate that this specific flow was mapped to a DRB previously, for example, before the first device 110 switches to the inactive state. The mapping of the specific flow to the DRB may be performed according to explicit configuration, reflective mapping from the second device 120, or according to a default rule which requires any flow mismatching the explicit configuration and the reflective mapping to map to the default DRB.

If no flow-to-DRB mapping rule stored for a flow 230 that is currently having associated data to be transmitted, it implies that this flow 230 is a new flow, and data associated with the new flow may not be transmitted to the second device 120 previously. In this case, according to the transmission configuration related to the new flow, the first device 110 may determine that the SDT mode is not allowed for this new flow 230. Alternatively, in this case, according to the transmission configuration related to the new flow, the first device 110 may determine that the SDT mode is allowed for this flow 230. In some example embodiments, if no flow-to-DRB mapping rule stored for a flow 230 that is currently having associated data to be transmitted, the first device 110 may switch to the connected state by resuming a connection with the second device 120 and transmit the data associated with the flow 230 via the connection.

In some example embodiments, if the default DRB is configured as a DRB that is allowed for SDT (referred to as a SDT-DRB) , the transmission configuration related to the new flow may be active for use. As compared with conventional solutions which allow any new flow mapped to the default SDT-DRB to utilize the SDT mode, the transmission configuration proposed in the present disclosure can control small data transmission for new flows that do not have valid mapping upon switching the first device 110 into the inactive state. By preventing the new flows from being mapped to the SDT-DRB, flows of which the second device 120 are unaware may not be allowed using the SDT mode. In this way, it is possible to avoid uncertainty for some critical data session to be exposed to data losses that the SDT may introduce. It would be appreciated that in other example embodiments, no matter whether the default DRB is configured a SDT-DRB or not, the transmission configuration related to the new flow may applicable for use.

In some example embodiments, additionally or as an alternative, the transmission configuration may indicate allowance or disallowance of the SDT mode on a per session basis, for example, on a per PDU session basis. Specifically, the transmission configuration may indicate whether the SDT is allowed or disallowed for a session 210 (e.g., a PDU session) established between the first device 110 and the second device 120. In an example embodiment, such a transmission configuration may be indicated by the second device 120 through configuration information.

In an example embodiment, if the transmission configuration indicates that the SDT is allowed for a certain session 210, all the flows mapped to this session 210 allows using the SDT mode for transmission. Thus, for any flow 230 that is currently having associated data to be transmitted, if it is determined that the flow 230 belongs to the allowed session 210, the first device 110 may determine that the SDT mode is allowed for this flow 230.

In an example embodiment, if the transmission configuration indicates that the SDT is not allowed for a certain session 210, all the flows mapped to this session 210 is not allowed to use the SDT mode for transmission. In this case, if it is determined that a flow 230 belongs to the disallowed session 210, the first device 110 may determine that the SDT mode is not allowed for this flow 230.

In some example embodiments, additionally or as an alternative, the transmission configuration may indicate a restriction criterion for allowance of the SDT mode in a remapping of the flows 230 between DRBs 220. This restriction criterion may be indicated by the second device 120 through configuration information, or may be specified in the first device 110.

The second device 120 may configure the SDT by controlling the remapping of the flows 230 via reflective mapping, which may save signaling overhead. For example, with the reflective mapping, the second device 120 may transmit information to the first device 110 indicating that a certain ID of a flow from the second device 120 is mapped to a second DRB 220. If a flow 230 identified by the certain ID indicted from the second device 120 is mapped to a different first DRB 220, the first device 110 may determine that this flow 230 needs to be remapped to the second DRB 220.

Upon the remapping of the flow 230 from a first DRB to a second DRB, the restriction criterion indicated by the transmission configuration is used to determine whether the SDT mode is still allowed or disallowed for the flow 230 after the remapping. In some example embodiments, the restriction criterion may indicate that allowance or disallowance of the SDT mode is restricted to a flow, to a DRB, or to both a flow and a DRB.

Specifically, allowance of the SDT mode being restricted to a flow means that the allowance of the SDT mode remains valid at a flow level. In other words, in the case of remapping of a flow 230 from a first DRB to a second DRB, if the SDT mode is allowed for this flow 230 when it is mapped to the first DRB, the SDT mode is still allowed for this flow 230 after it is remapped to the second DRB, no matter whether the second DRB is configured as not allowing for SDT. In other examples, if the SDT mode is disallowed for the flow 230 when it is mapped to the first DRB, the SDT mode is also not allowed after it is remapped to the second DRB.

Similarly, if allowance of the SDT mode is restricted to a DRB, whether or not a SDT mode is allowed for the flow 230 after the remapping may depend on whether or not the SDT mode is allowed for the second DRB to which the flow 230 is remapped. For example, if the SDT mode is allowed for transmission over the second DRB (which implies that the second DRB is a SDT-DRB) , the flow 230 may also be allowed using the SDT mode for transmission after remapping to the second DRB. In another example, if the flow 230 is remapped from a SDT-DRB to a non-SDT-DRB (for which the SDT mode is not allowed) , the flow 230 also becomes not allowed for the SDT mode. In this case, the remapping may automatically update the allowed list of flows for SDT.

In other examples, if allowance of the SDT mode is restricted to both a flow and a DRB, the SDT mode is allowed for the flow 230 after the remapping if both the flow 230 is allowed to use the SDT mode during its mapping to the first DRB and the SDT mode is also allowed for the second DRB. If the flow 230 is not allowed to use the SDT mode or the second DRB is configured as not allowed to use the SDT mode, the SDT mode is also disallowed for the flow after the remapping.

In operation, in order to determine whether the SDT mode is allowed for the flow 230 after the flow 230 is remapped to the second DRB, the first device 110 may determine, depending on the restriction criterion, whether the SDT mode is allowed for the flow 230 when this flow is mapped to the first DRB and/or whether the SDT mode is allowed for transmission over the second DRB.

In some example embodiments, additionally or as an alternative, the transmission configuration may indicate one or more respective trigger conditions for triggering the SDT mode for the one or more flows 230 from the first device 110 to the second device 120. In some examples, the trigger conditions may be configured on a per flow basis or on a per DRB basis. A respective trigger condition may be specific to one flow 230 or specific to one or more flows mapped to a specific DRB 220. The first device 110 may utilize the trigger condition specific to a flow 230 to determine whether the SDT mode is allowed or not for the flow 230. If the trigger condition is satisfied for the flow 230, the SDT mode is determined to be allowed for the flow 230

In some example embodiments, the trigger conditions may include data volume thresholds. The data volume thresholds may be used to control respective data sizes of the flows 230 that can be transmitted in the SDT mode. In determining whether the SDT mode is allowed for a flow 230 having associated data to be transmitted, the first device 110 may determine whether a volume of the associated data is below a data volume threshold specific for this flow 230. If the volume of the data associated with the flow is below the data volume threshold, the first device 110 may determine that the SDT mode is allowed for the flow 230. Otherwise, the first device 110 may determine that the SDT mode is disallowed for this flow 230.

Alternatively, or in addition, the trigger conditions may include channel quality thresholds. The channel quality thresholds may be measured as thresholds for reference signal received power (RSRP) , thresholds for reference signal received quality (RSRQ) , and/or other factors reflecting the channel quality between the first device 110 and the second device 120.

The channel quality thresholds may be used to control respective acceptable channel qualities for transmissions of the flows 230 in the SDT mode. In determining whether the SDT mode is allowed for a flow 230 having associated data to be transmitted, the first device 110 may determine whether a channel quality between the first device 110 and the second device exceeds a channel quality threshold specific to the flow 230. If the channel quality exceeds the channel quality threshold, the first device 110 may determine that the SDT mode is allowed for the flow 230. Otherwise, the first device 110 may determine that the SDT mode is disallowed for this flow 230 because the current channel quality is not satisfactory

In the above example embodiments, the trigger conditions, such as the data volume thresholds and the channel quality thresholds for the respective flows, may be configured by the second device 120. By configuring the trigger conditions, the second device 120 can control the SDT configured for the flows, thereby protecting some critical data session from being exposed to data losses in using the SDT mode for transmission.

Some example embodiments related to the transmission configuration have been discussed above. The transmission configuration discussed in different example embodiments may be combined for use. For example, the transmission configuration used by the first device 110 may indicate respective IDs or IDs of ranges of allowed or disallowed flows for the SDT mode, and may also indicate that the SDT mode is disallowed for a new flow mapped to a default DRB.

Still referring to Fig. 3, the first device 110 transmits 320 the data associated with the flow 230 based on a result of the determination of whether the SDT mode is allowed for this flow 230, and the second device 120 receives 325 the data transmitted from the first device 110. Specifically, if a flow 230 having data to be transmitted to the second device 120 is allowed to be transmitted in the SDT mode, the first device 110 may transmit the data associated with the flow 230 through SDT. For example, the first device 110 may transmit the data associated with the flow 230 without transitioning from the inactive state to a connected state. The procedure associated with small data transmissions may be performed between the first device 110 and the second device 120 to complete the transmissions of the data.

In some cases, if a flow 230 having data to be transmitted to the second device 120 is not allowed to be transmitted in the SDT mode, the first device 110 may not perform small data transmissions. Instead, the first device 110 may resume a connection with the second device 120 in order to transmit the data.

Fig. 4 shows a flowchart of an example method 400 implemented at a first device 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 device 110 with respect to Figs. 1 and 2.

At block 410, the first device 110 determines a transmission configuration related to at least one flow from the first device to a second device. The transmission configuration indicates allowance or disallowance of a small data transmission mode for the at least one flow. At block 420, the first device 110 determines whether data associated with a flow of the at least one flow is to be transmitted. If the first device 110 determines that data associated with a flow is to be transmitted, at block 430, the first device 110 determines, based on the transmission configuration, whether the small data transmission mode is allowed for the flow. The first device 110 may continue monitoring data arriving for at least one flow if it is determined that data associated with a flow of the at least one flow is to be transmitted. At block 440, the first device 110 transmits the data associated with the flow to the second device based on a result of the determination of whether the small data transmission mode is allowed for the flow.

In some example embodiments, the transmission configuration is specified in the first device or is indicated in configuration information received from the second device.

In some example embodiments, the transmission configuration indicates at least one of the following: a first identity of a first flow allowed for the small data transmission mode, a second identity of a second flow disallowed for the small data transmission mode, a first range of identities of flows allowed for the small data transmission mode, and a second range of identities of flows disallowed for the small data transmission mode.

In some example embodiments, the first and second flows identified by the first and second identities are mapped to a same first data radio bearer, and/or wherein the flows identified by the first and second ranges of identities are mapped to a same second data radio bearer.

In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: determining whether an identity of the flow matches the at least one of the first identity, the second identity, the first range of identities, and the second range of identities, and determining whether the small data transmission mode is allowed for the flow based on a match result of the identity with the at least one of the first identity, the second identity, the first range of identities, and the second range of identities.

In some example embodiments, the transmission configuration indicates that the small data transmission mode is allowed or disallowed for a new flow mapped to a default data radio bearer. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: determining whether there is a stored flow-to-data radio bearer mapping rule for the flow, and in accordance with a determination that there is no stored flow-to-data radio bearer mapping rule for the flow, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.

In some example embodiments, the transmission configuration indicates whether the small data transmission mode is allowed or disallowed for a session established between the first device and the second device. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: in accordance with a determination that the flow belongs to the session, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.

In some example embodiments, the transmission configuration indicates a restriction criterion for allowance of the small data transmission mode in a remapping of the at least one flow between data radio bearers. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: receiving, from the second device, information indicating that the flow is to be remapped from a first data radio bearer to a second data radio bearer for transmission, and determining whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer based on the restriction criterion.

In some example embodiments, the restriction criterion requires that the allowance of the small data transmission mode is restricted to at least one of a flow and a data radio bearer. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: determining, according to the restriction criterion, whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer by determining at least one of the following: whether the small data transmission mode is allowed for the flow when the flow is mapped to the first data radio bearer, and whether the small data transmission mode is allowed for transmission over the second data radio bearer.

In some example embodiments, the transmission configuration indicates at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: in accordance with a determination that a trigger condition of the at least one trigger condition specific to the flow is satisfied, determining that the small data transmission mode is allowed for the flow.

In some example embodiments, the at least one trigger condition comprises at least one data volume threshold specific to the at least one flow. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: determining whether a volume of the data associated with the flow is below a data volume threshold of the at least one data volume threshold specific to the flow, and in accordance with a determination that the volume of the data associated with the flow is below the data volume threshold, determining that the small data transmission mode is allowed for the flow.

In some example embodiments, the at least one trigger condition comprises at least one channel quality threshold specific to the at least one flow. In some example embodiments, determining whether the small data transmission mode is allowed for the flow comprises: determining whether a channel quality between the first device and the second device exceeds a channel quality threshold of the at least one channel quality threshold specific to the flow, and in accordance with a determination that the channel quality exceeds the channel quality threshold, determining that the small data transmission mode is allowed for the flow.

Fig. 5 shows a flowchart of an example method 500 implemented at a second device 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 device 120 with respect to Figs. 1 and 2.

At block 510, the second device 120 transmits, to a first device 110, configuration information indicating a transmission configuration related to at least one flow from the first device to the second device. The transmission configuration indicates allowance or disallowance of a small data transmission mode for the at least one flow. At block 520, the second device 120 receives data associated with a flow of the at least one flow from the first device. The data associated with the flow is received from the first device based on the transmission configuration.

In some example embodiments, the transmission configuration indicates at least one of the following: a first identity of a first flow allowed for the small data transmission mode, a second identity of a second flow disallowed from the small data transmission mode, a first range of identities of flows allowed for the small data transmission mode, a second range of identities of flows disallowed for the small data transmission mode, the small data transmission mode being allowed or disallowed for a new flow mapped to a default data radio bearer, whether the small data transmission mode is allowed or disallowed for a session established between the first device and the second device, a restriction criterion for allowance of the small data transmission mode in the remapping, and at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow.

In some example embodiments, the at least one trigger condition comprises at least one of the following: at least one data volume threshold specific to the at least one flow, and at least one channel quality threshold specific to the at least one flow.

In some example embodiments, a first apparatus capable of performing any of the method 400 (for example, the first device 110) 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 device 110.

In some example embodiments, the first apparatus comprises means for: determining a transmission configuration related to at least one flow from the first apparatus to a second apparatus (e.g., implemented as or included in the second device 120) , the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determining, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and transmitting the data associated with the flow to the second apparatus based on a result of the determination of whether the small data transmission mode is allowed for the flow.

In some example embodiments, the transmission configuration is specified in the first apparatus or is indicated in configuration information received from the second apparatus.

In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: determining whether an identity of the flow matches the at least one of the first identity, the second identity, the first range of identities, and the second range of identities, and determining whether the small data transmission mode is allowed for the flow based on a match result of the identity with the at least one of the first identity, the second identity, the first range of identities, and the second range of identities.

In some example embodiments, the transmission configuration indicates that the small data transmission mode is allowed or disallowed for a new flow mapped to a default data radio bearer. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: determining whether there is a stored flow-to-data radio bearer mapping rule for the flow, and in accordance with a determination that there is no stored flow-to-data radio bearer mapping rule for the flow, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.

In some example embodiments, the transmission configuration indicates whether the small data transmission mode is allowed or disallowed for a session established between the first apparatus and the second apparatus. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: in accordance with a determination that the flow belongs to the session, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.

In some example embodiments, the transmission configuration indicates a restriction criterion for allowance of the small data transmission mode in a remapping of the at least one flow between data radio bearers. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: receiving, from the second apparatus, information indicating that the flow is to be remapped from a first data radio bearer to a second data radio bearer for transmission, and determining whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer based on the restriction criterion.

In some example embodiments, the restriction criterion requires that the allowance of the small data transmission mode is restricted to at least one of a flow and a data radio bearer. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: determining, according to the restriction criterion, whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer by determining at least one of the following: whether the small data transmission mode is allowed for the flow when the flow is mapped to the first data radio bearer, and whether the small data transmission mode is allowed for transmission over the second data radio bearer.

In some example embodiments, the transmission configuration indicates at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: in accordance with a determination that a trigger condition of the at least one trigger condition specific to the flow is satisfied, determining that the small data transmission mode is allowed for the flow.

In some example embodiments, the at least one trigger condition comprises at least one data volume threshold specific to the at least one flow. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: determining whether a volume of the data associated with the flow is below a data volume threshold of the at least one data volume threshold specific to the flow, and in accordance with a determination that the volume of the data associated with the flow is below the data volume threshold, determining that the small data transmission mode is allowed for the flow.

In some example embodiments, the at least one trigger condition comprises at least one channel quality threshold specific to the at least one flow. In some example embodiments, the means for determining whether the small data transmission mode is allowed for the flow comprises means for: determining whether a channel quality between the first apparatus and the second apparatus exceeds a channel quality threshold of the at least one channel quality threshold specific to the flow, and in accordance with a determination that the channel quality exceeds the channel quality threshold, determining that the small data transmission mode is allowed for the flow.

In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 400. In some example embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with 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 device 120) 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 device 120.

In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus (implemented as or included in the first device 110) , configuration information indicating a transmission configuration related to at least one flow from the first apparatus to the second apparatus, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and receiving data associated with a flow of the at least one flow from the first apparatus, the data associated with the flow being received from the first apparatus based on the transmission configuration.

In some example embodiments, the transmission configuration indicates at least one of the following: a first identity of a first flow allowed for the small data transmission mode, a second identity of a second flow disallowed from the small data transmission mode, a first range of identities of flows allowed for the small data transmission mode, a second range of identities of flows disallowed for the small data transmission mode, the small data transmission mode being allowed or disallowed for a new flow mapped to a default data radio bearer, whether the small data transmission mode is allowed or disallowed for a session established between the first apparatus and the second apparatus, a restriction criterion for allowance of the small data transmission mode in the remapping, and at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow.

In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 500. In some example embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with 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 device 110 or the second device 120 as shown in Fig. 1 and Fig. 2. 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.

A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in the memory, e.g., 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 Figs. 3 to 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. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. 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 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, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While 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.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a physical or virtual processor, to carry out any of the methods as described above with reference to Figs. 3 to 6. 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. These program codes 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 codes, 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, while 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, while 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. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple 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 device comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to:

determine a transmission configuration related to at least one flow from the first device to a second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow;

in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determine, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and

transmit the data associated with the flow to the second device based on a result of the determination of whether the small data transmission mode is allowed for the flow.
The first device of claim 1, wherein the transmission configuration is specified in the first device or is indicated in configuration information received from the second device.
The first device of claim 1, wherein the transmission configuration indicates at least one of the following:

a first identity of a first flow allowed for the small data transmission mode,

a second identity of a second flow disallowed for the small data transmission mode,

a first range of identities of flows allowed for the small data transmission mode, and

a second range of identities of flows disallowed for the small data transmission mode.
The first device of claim 3, wherein the first and second flows identified by the first and second identities are mapped to a same first data radio bearer, and/or

wherein the flows identified by the first and second ranges of identities are mapped to a same second data radio bearer.
The first device of claim 3, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

determining whether an identity of the flow matches the at least one of the first identity, the second identity, the first range of identities, and the second range of identities, and

determining whether the small data transmission mode is allowed for the flow based on a match result of the identity with the at least one of the first identity, the second identity, the first range of identities, and the second range of identities.
The first device of claim 1, wherein the transmission configuration indicates that the small data transmission mode is allowed or disallowed for a new flow mapped to a default data radio bearer; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

determining whether there is a stored flow-to-data radio bearer mapping rule for the flow, and

in accordance with a determination that there is no stored flow-to-data radio bearer mapping rule for the flow, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.
The first device of claim 1, wherein the transmission configuration indicates whether the small data transmission mode is allowed or disallowed for a session established between the first device and the second device; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

in accordance with a determination that the flow belongs to the session, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.
The first device of claim 1, wherein the transmission configuration indicates a restriction criterion for allowance of the small data transmission mode in a remapping of the at least one flow between data radio bearers; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

receiving, from the second device, information indicating that the flow is to be remapped from a first data radio bearer to a second data radio bearer for transmission, and

determining whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer based on the restriction criterion.
The first device of claim 8, wherein the restriction criterion requires that the allowance of the small data transmission mode is restricted to at least one of a flow and a data radio bearer; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

determining, according to the restriction criterion, whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer by determining at least one of the following:

whether the small data transmission mode is allowed for the flow when the flow is mapped to the first data radio bearer, and

whether the small data transmission mode is allowed for transmission over the second data radio bearer.
The first device of claim 1, wherein the transmission configuration indicates at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

in accordance with a determination that a trigger condition of the at least one trigger condition specific to the flow is satisfied, determining that the small data transmission mode is allowed for the flow.
The first device of claim 10, wherein the at least one trigger condition comprises at least one data volume threshold specific to the at least one flow; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

determining whether a volume of the data associated with the flow is below a data volume threshold of the at least one data volume threshold specific to the flow, and

in accordance with a determination that the volume of the data associated with the flow is below the data volume threshold, determining that the small data transmission mode is allowed for the flow.
The first device of claim 10, wherein the at least one trigger condition comprises at least one channel quality threshold specific to the at least one flow; and

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to determine whether the small data transmission mode is allowed for the flow by:

determining whether a channel quality between the first device and the second device exceeds a channel quality threshold of the at least one channel quality threshold specific to the flow, and

in accordance with a determination that the channel quality exceeds the channel quality threshold, determining that the small data transmission mode is allowed for the flow.
The first device of claim 1, wherein the first device comprises a terminal device, and the second device comprises a network device, and

wherein the at least one flow comprises at least one quality of service flow.
A second device comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to:

transmit, to a first device, configuration information indicating a transmission configuration related to at least one flow from the first device to the second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and

receive data associated with a flow of the at least one flow from the first device, the data associated with the flow being received from the first device based on the transmission configuration.
The second device of claim 14, wherein the transmission configuration indicates at least one of the following:

a first identity of a first flow allowed for the small data transmission mode,

a second identity of a second flow disallowed from the small data transmission mode,

a first range of identities of flows allowed for the small data transmission mode,

a second range of identities of flows disallowed for the small data transmission mode,

the small data transmission mode being disallowed for a new flow mapped to a default data radio bearer,

whether the small data transmission mode is allowed or disallowed for a session established between the first device and the second device,

a restriction criterion for allowance of the small data transmission mode in the remapping, and

at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow.
The second device of claim 15, wherein when the transmission configuration indicates the at least one trigger condition, the at least one trigger condition comprises at least one of the following:

at least one data volume threshold specific to the at least one flow, and

at least one channel quality threshold specific to the at least one flow.
A method comprising:

determining a transmission configuration related to at least one flow from a first device to a second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow;

in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determining, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and

transmitting the data associated with the flow to the second device based on a result of the determination of whether the small data transmission mode is allowed for the flow.
The method of claim 17, wherein the transmission configuration is specified in the first device or is indicated in configuration information received from the second device.
The method of claim 17, wherein the transmission configuration indicates at least one of the following:

a first identity of a first flow allowed for the small data transmission mode,

a second identity of a second flow disallowed for the small data transmission mode,

a first range of identities of flows allowed for the small data transmission mode, and

a second range of identities of flows disallowed for the small data transmission mode.
The method of claim 17, wherein the transmission configuration indicates that the small data transmission mode is allowed or disallowed for a new flow mapped to a default data radio bearer; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

determining whether there is a stored flow-to-data radio bearer mapping rule for the flow, and

in accordance with a determination that there is no stored flow-to-data radio bearer mapping rule for the flow, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.
The method of claim 17, wherein the transmission configuration indicates whether the small data transmission mode is allowed or disallowed for a session established between the first device and the second device; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

in accordance with a determination that the flow belongs to the session, determining, based on the transmission configuration, whether the small data transmission mode is allowed or disallowed for the flow.
The method of claim 17, wherein the transmission configuration indicates a restriction criterion for allowance of the small data transmission mode in a remapping of the at least one flow between data radio bearers; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

receiving, from the second device, information indicating that the flow is to be remapped from a first data radio bearer to a second data radio bearer for transmission, and

determining whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer based on the restriction criterion.
The method of claim 22, wherein the restriction criterion requires that the allowance of the small data transmission mode is restricted to at least one of a flow and a data radio bearer; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

determining, according to the restriction criterion, whether the small data transmission mode is allowed for the flow after the flow is remapped to the second data radio bearer by determining at least one of the following:

whether the small data transmission mode is allowed for the flow when the flow is mapped to the first data radio bearer, and

whether the small data transmission mode is allowed for transmission over the second data radio bearer.
The method of claim 17, wherein the transmission configuration indicates at least one trigger condition for triggering the small data transmission mode for the at least one flow, each respective one of the at least one trigger condition being specific to one of the at least one flow; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

in accordance with a determination that a trigger condition of the at least one trigger condition specific to the flow is satisfied, determining that the small data transmission mode is allowed for the flow.
The method of claim 24, wherein the at least one trigger condition comprises at least one data volume threshold specific to the at least one flow; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

determining whether a volume of the data associated with the flow is below a data volume threshold of the at least one data volume threshold specific to the flow, and

in accordance with a determination that the volume of the data associated with the flow is below the data volume threshold, determining that the small data transmission mode is allowed for the flow.
The method of claim 24, wherein the at least one trigger condition comprises at least one channel quality threshold specific to the at least one flow; and

wherein determining whether the small data transmission mode is allowed for the flow comprises:

determining whether a channel quality between the first device and the second device exceeds a channel quality threshold of the at least one channel quality threshold specific to the flow, and

in accordance with a determination that the channel quality exceeds the channel quality threshold, determining that the small data transmission mode is allowed for the flow.
A method comprising:

transmitting, to a first device, configuration information indicating a transmission configuration related to at least one flow from the first device to a second device, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and

receiving data associated with a flow of the at least one flow from the first device, the data associated with the flow being received from the first device based on the transmission configuration.
A first apparatus comprising means for:

determining a transmission configuration related to at least one flow from the first apparatus to a second apparatus, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow;

in accordance with a determination that data associated with a flow of the at least one flow is to be transmitted, determining, based on the transmission configuration, whether the small data transmission mode is allowed for the flow; and

transmitting the data associated with the flow to the second apparatus based on a result of the determination of whether the small data transmission mode is allowed for the flow.
A second apparatus comprising means for:

transmitting, to a first apparatus, configuration information indicating a transmission configuration related to at least one flow from the first apparatus to the second apparatus, the transmission configuration indicating allowance or disallowance of a small data transmission mode for the at least one flow; and

receiving data associated with a flow of the at least one flow from the first apparatus, the data associated with the flow being received from the first apparatus based on the transmission configuration.
A computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 17 to 26, or the method of claim 27.