Method and apparatus for small data transmission

Abstract

Embodiments of the present application relate to methods and apparatus for small data transmission for a user equipment (UE) in an RRC_IDLE state or an RRC_INACTIVE state. According to embodiments of the present application, a method can include maintaining a priority variable for each logical channel of at least one logical channel, determining a value of the priority variable for each logical channel after performing a first logical channel prioritization (LCP) procedure, receiving a message indicating a MAC reset, and after receiving the message, using the value as an initial value of the priority variable for each logical channel of the at least one logical channel in a second LCP procedure after the first LCP procedure. Embodiments of the present application can meet QoS requirements and fairness of traffic transmitted in the logical channels in an NR system.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application generally relate to wireless communication technology, and more particularly, to methods and devices for small data transmission of a user equipment (UE) in an RRC_IDLE state or an RRC_INACTIVE state. BACKGROUND

[0002] In long term evolution (LTE), in a case where a UE wants to transmit data, it can trigger an early data transmission (EDT) procedure. The EDT procedure can include an EDT procedure for control plane (CP) cellular internet of things (CIoT) evolved packet system (EPS) optimization and an EDT procedure for user plane (UP) CIoT EPS optimization. In the EDT procedure for CP CIoT EPS optimization, data can be transmitted through a radio resource control (RRC) early data request message. In the EDT procedure for UP CIoT EPS optimization, data can be transmitted through an RRC connection resume request message.

[0003] New radio (NR) supports an RRC_INACTIVE state. In a case where a UE wants to transmit data in the RRC_INACTIVE state, a work item in NR states that data can be transmitted through a random access channel (RACH)-based scheme (e.g., a 2-step RACH scheme or a 4-step RACH scheme) via preconfigured physical uplink shared channel (PUSCH) resources.

[0004] All of the above-mentioned schemes for transmitting data in an RRC_IDLE state or in an RRC_INACTIVE state can involve a medium access control (MAC) reset operation after transmitting data. However, the MAC reset operation can affect the fairness of traffic in some logical channels (e.g., logical channels with low priority). In addition, for data transmission using the EDT procedure for CP CIoT EPS optimization, another issue is how to manage quality of service (QoS).

[0005] Therefore, there is a need in the industry for improved techniques for small data transmission in order to meet the QoS requirements and fairness of traffic transmitted in logical channels in an NR system. SUMMARY

[0006] Some embodiments of the present application at least provide a technical solution for small data transmission of a UE.

[0007] According to some embodiments of the present application, a method can include maintaining a priority variable for each logical channel of at least one logical channel; determining a value of the priority variable for each logical channel after performing a first logical channel prioritization (LCP) procedure; receiving a message indicating a MAC reset; and after receiving the message, using the value as an initial value of the priority variable for each logical channel of the at least one logical channel in a second LCP procedure after the first LCP procedure.

[0008] In an embodiment of the present application, the message indicating the MAC reset can be one of: an RRC release message including a suspend configuration information element (IE); an RRC early data complete message; and a MAC reset message after a small data transmission.

[0009] In another embodiment of the present application, the at least one logical channel can be for a small data transmission, and wherein the at least one logical channel can be determined based on configuration information from a base station (BS) and / or a logical channel selection procedure for an uplink (UL) grant.

[0010] Some embodiments of the present application also provide an apparatus including at least one non-transitory computer-readable medium having computer-executable instructions stored therein; at least one receiver; at least one transmitter; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiver, and the at least one transmitter. The computer-executable instructions are programmed to implement any of the methods described above with the at least one receiver, the at least one transmitter, and the at least one processor.

[0011] Embodiments of the present application provide technical solutions for small data transmission for a UE, e.g., the UE is not in an RRC CONNECTED state. For example, the UE can be in an RRC IDLE state or an RRC INACTIVE state. Thus, embodiments of the present application can meet the QoS requirement and fairness of traffic transmitted in logical channels in an NR system. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to describe the manner in which the advantages and features of the present application can be obtained, a description of the present application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These figures are not limiting of the present application, but are intended to be illustrative only.

[0013] Figure 1 is a schematic diagram illustrating an exemplary wireless communication system 100 according to some embodiments of the present application;

[0014] Figure 2FIG. 1 is a flow diagram illustrating a method for small data transmission according to some other embodiments of the present application; and

[0015] Figure 3 FIG. 2 is a flow diagram illustrating a method for small data transmission according to some embodiments of the present application;

[0016] Figure 4 FIG. 3 is a flow diagram illustrating a method for small data transmission according to some other embodiments of the present application; and

[0017] Figure 5 FIG. 4 is a simplified block diagram of a device 500 for small data transmission according to some embodiments of the present application. DETAILED DESCRIPTION

[0018] The detailed description set forth below, in connection with the appended drawings and embodiments of the application, is intended as a description of the

[0019] Reference will now be made to some embodiments of the application, examples of which are illustrated in the accompanying drawings.

[0020] Figure 1 FIG. 1 is a schematic diagram illustrating an exemplary wireless communication system 100 according to embodiments of the present application.

[0021] As shown in FIG. 1, the wireless communication system 100 can include at least one base station (BS) 101 and at least one UE 103. While Figure 1 a particular number of BSs 101 and UEs 103 are depicted in FIG. 1, e.g., only one BS 101 and only one UE 103, it will be understood by those skilled in the art that any number of BSs 101 and UEs 103 can be included in the wireless communication system 100. Figure 1

[0022] The BSs 101 can be dispersed throughout the geographic region, and typically, each BS will be located near the center of the area it is designed to cover. The BSs 101 will also typically be multiple-access, multiple- input, multiple-output (MEMO) systems, using technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or orthogonal frequency divisional multiple access (OFDMA), or some other multiple access technologies.

[0023] ​The UE 103 can be a legacy UE (or regular UE) that is compatible with existing technology or a normal NR UE. For example, the UE 103 can be a computing device such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart television (e.g., a television connected to the Internet), a set-top box, a game console, a security system (including security cameras), a vehicle computer, a network device (such as a router, switch, and modem), or the like. According to embodiments of the present application, the UE 103 can be a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identity module, a personal computer, a selective call receiver, or any other device capable of sending and receiving communication signals on a wireless network. In some embodiments of the present application, the UE 103 can be a wearable device such as a smart watch, a fitness band, an optical head-mounted display, or the like. Further, the UE 103 can be referred to as a subscriber unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.

[0024] The UE 103 can be a reduced-capability UE such as a Narrow Band Internet of Things (NB-IoT) UE or an enhanced Machine Type Communication (eMTC) UE. The reduced-capability UE can be an industrial wireless sensor, a video surveillance device, a wearable device, or another device with reduced-capability UE characteristics. Compared to a legacy UE, the reduced capability can have a smaller bandwidth to achieve several Kbps to several Mbps throughput; and achieve lower power consumption to achieve longer UE battery life, cost reduction, flexible latency requirement, flexible UE processing time, and flexible UE processing capability, etc.

[0025] In Long Term Evolution (LTE), in a case where a UE wants to transmit uplink data, it can trigger an EDT procedure.

[0026] According to some embodiments of the present application, the EDT procedure can include an EDT procedure for CP CIoT EPS optimization. In this procedure, the uplink data can be included in a Non-Access Stratum (NAS) message, the UE can transmit a RRC early data request message including the NAS message to the BS. In response to the RRC early data request message, the BS can transmit a RRC early data complete message. After receiving the RRC early data complete message, the UE can reset the MAC and release the MAC configuration. In embodiments of the present application, an uplink (UL) grant for transmitting the uplink data can be indicated in a random access response message. In embodiments of the present application, the UL grant for transmitting the uplink data can be a preconfigured uplink resource (PUR).

[0027] According to some other embodiments of the present application, the EDT procedure can include an EDT procedure for UP CIoT EPS optimization. In this procedure, the UE can transmit an RRC connection resume request message including uplink data to the BS. In response to the RRC connection resume request message, the BS can transmit an RRC connection release message including a suspend configuration IE to the UE to keep the UE in RRC_IDLE state. After receiving the RRC connection release message, the UE can reset the MAC. In embodiments of the present application, an uplink (UL) grant for transmitting the uplink data can be indicated in a random access response message. In embodiments of the present application, the UL grant for transmitting the uplink data can be a preconfigured uplink resource (PUR).

[0028] NR supports RRC_INACTIVE state. RRC_INACTIVE state does not support data transmission until Rel-16. Thus, in case a UE in RRC_INACTIVE state has data to be transmitted, it has to resume the connection (i.e., move to RRC_CONNECTED state) for any downlink and uplink data transmission. RRC connection setup and subsequent release to RRC_INACTIVE state occurs for each data transmission, which results in unnecessary power consumption and signaling overhead. To enable data transmission in RRC_INACTIVE state, a work item in NR states that small data transmission in RRC_INACTIVE state can be implemented through a random access channel (RACH)-based scheme (e.g., 2-step RACH scheme or 4-step RACH scheme, as specified in 3GPP standard documents) without changing the RRC state of the UE to RRC_CONNECTED state. For example, small data can be transmitted using MSGA in 2-step RACH scheme or using MSG3 in 4-step RACH scheme. In these schemes, small data can be transmitted via preconfigured PUSCH resources (e.g., reuse of configured grant type 1 as specified in 3GPP standard documents). After transmitting the small data, the UE can receive a MAC reset message. If the reset of the MAC entity is requested by an upper layer of the UE, the MAC entity can initialize the priority variables (e.g., Bj as specified in 3GPP standard documents) of each logical channel to zero.

[0029] Small data can include small and infrequent data traffic. Specific examples of small and infrequent data traffic include the following use cases: 1) smartphone applications; and 2) non-smartphone applications. Smartphone applications can include traffic from instant messaging services (WhatsApp, QQ, WeChat, etc.); heart-beat / keep-alive traffic from instant messaging (IM) / email clients and other applications; and push notifications from various applications. Non-smartphone applications can include traffic from wearable devices (e.g., periodic location information, etc.), sensors (e.g., industrial wireless sensor networks that transmit temperature, pressure readings periodically or event-triggered, etc.), and smart meters and smart meter networks that send periodic meter readings. Those skilled in the art will appreciate that the above use cases are for illustrative purposes only, and that the same data can include data with the same amount and infrequent transmission in other use cases according to some other embodiments.

[0030] When uplink data transmission is performed, a logical channel prioritization (LCP) procedure can be applied. In the LCP procedure, the RRC controls the scheduling of uplink data through signaling for each logical channel per MAC entity: priority, where an increasing priority value indicates a lower priority level; prioritized bit rate (PBR); and bucket size duration (BSD). The UE can maintain a priority variable (e.g., Bj) for each logical channel j. The UE’s MAC entity can initialize Bj for a logical channel to zero when the logical channel is established. For each logical channel j, the UE’s MAC entity can increment Bj by PBR x T before each instance of the LCP procedure, where T is the time elapsed since Bj was last incremented; if the increment would cause the value of Bj to exceed the bucket size (i.e., PBR x BSD), the UE can set Bj to the bucket size. Logical channels with Bj > 0 are allocated resources in decreasing priority order. After the LCP procedure, the UE can decrement Bj by the total size of MAC service data units (SDUs) for logical channel j in the LCP procedure.

[0031] For example, Figure 2 An LCP procedure in NR according to some embodiments of the present application is described. Referring to Figure 2 , assume that the UE has two logical channels, e.g., LCH 1 and LCH 2. The priority of LCH 1 is higher than LCH 2. The UE can maintain a priority variable (e.g., Bj) for each logical channel j. For example, the UE can maintain a priority variable B1 for LCH 1 and maintain a priority variable B2 for LCH 2. The bucket size of LCH 1 is PBR1 x BSD1. The bucket size of LCH 2 is PBR2 x BSD2.

[0032] At time tO, the UE's MAC entity can initialize both B1 and B2 to zero. Thereafter, the UE's MAC entity can increment Bj by the product of PBR and T prior to each instance of the LCP procedure, where T is the time elapsed since Bj was last incremented. At time period TP1, UL grant 1 can be available to the UE for transmission of uplink user data, and thus the UE can allocate UL grant to data in logical channels with Bj > 0 in decreasing priority order.

[0033] As shown in Figure 2 , assuming that the total time elapsed from time tO to the time of UL grant 1 is N x T, B1 for LCH 1 can be PBR1 x N x T and B2 for LCH 2 can be PBR2 x N x T. Since the priority of LCH 1 is higher than LCH 2, data in LCH 1 should be allocated the resources of the first granted UL. As shown in Figure 2 , not all data in LCH 1 can be transmitted in UL grant 1, only a fraction 1 of data in LCH 1 is included in MAC SDU 1 for transmission in UL grant 1.

[0034] After MAC SDU 1 is formed, the UE's MAC entity can decrement B1 by the size of MAC SDU 1, and the value of B1 can be (PBR1 x N x T) - size of MAC SDU 1, which is negative, as shown in Figure 2 . On the other hand, data in LCH 2 is not transmitted, and thus the UE's MAC entity does not perform a subtraction on B2.

[0035] Thereafter, at time period TP2, UL grant 2 can be available to the UE for transmission of uplink user data. The UE can allocate UL grant to data in logical channels with Bj > 0 in decreasing priority order. Both B1 and B2 are incremented from the time MAC SDU 1 is transmitted until UL grant 2 occurs. However, at the time of UL grant 2, B1 is still negative, and thus data in CH2 should be allocated the resources of UL grant 2. As shown in Figure 2 , all data in LCH 2 is included in MAC SDU 2 for transmission in UL grant 2. After MAC SDU 2 is formed, the UE's MAC entity can decrement B2 by the size of MAC SDU 2. B2 can be zero, as shown in Figure 2 .

[0036] Thereafter, at time period TP3, UL grant 3 is available for the UE to transmit uplink user data. The UE can allocate the UL grant to data in logical channels with Bj > 0 in decreasing priority order. Both B1 and B2 are incremented from the time MAC SDU 2 is transmitted until UL grant 3 occurs. At the time UL grant 2 occurs, B1 is positive, and thus data in LCH 1 should be allocated the resources of UL grant 3 first. As Figure 2 demonstrated in FIG. 3B, part 2 of data in LCH 1 is included in MAC SDU 3 for transmission in UL grant 3. After MAC SDU 3 is formed, the MAC entity of the UE can decrement B1 by the size of MAC SDU 3. The above procedure is continuously performed over time. It is understood by one of ordinary skill in the art that two logical channels are used for illustrative purposes only, and according to some other embodiments, the UE can include one or more logical channels and the procedure is similar to that described above.

[0037] Figure 2 The LCP procedure in FIG. 2 ensures the fairness of data transmission in different logical channels, especially for logical channels with low priority. However, the LCP procedure in small data transmission for a UE in RRC IDLE state or RRC INACTIVE state can cause some problems. For example, Figure 3 An LCP procedure for small data transmission according to some embodiments of the present application is described.

[0038] Reference is made to Figure 3 Each of UL grant 1, UL grant 2, and UL grant 3 can be obtained based on the EDT procedure, can be obtained based on the RACH procedure, can be configured grant type 1 resources, or can be resources obtained for small data transmission from any other procedure. For example, UL grant 1 can be obtained based on the RACH procedure, while UL grant 2 and UL grant 3 can be similar to or can reuse the configured grant type 1 resources specified in 3GPP standard documents. The operations before transmitting MAC SDU 1 are the same as those described in Figure 2 FIG. 2. The difference is that Figure 3 small data transmission for a UE in RRC IDLE state or RRC INACTIVE state is involved. That is, after transmitting MAC SDU 1 in UL grant 1, at time t1, the UE can receive an RRC release message including a suspend configuration IE, an RRC early data complete message, or a MAC reset message after small data transmission. All of these messages can indicate that the MAC is to be reset. In view of this, although B1 is negative after transmitting MAC SDU 1, it will be initialized to zero after receiving the message indicating that the MAC is to be reset.

[0039] Thereafter, at time period TP2, UL grant 2 is available for the UE to transmit uplink user data. The UE can allocate the UL grant to data in logical channels with Bj > 0 in decreasing priority order. Both B1 and B2 are incremented from the time of transmission of MAC SDU 1 until the occurrence of UL grant 2. At the occurrence of UL grant 2, B1 is incremented to a positive value and thus data in LCH 1 should be transmitted first in UL grant 2. As Figure 3 As shown in the middle, part 2 of data in LCH 1 and part 1 of data in LCH 2 are multiplexed into MAC SDU 2 for transmission in UL grant 2. MAC SDU 2 can include MAC SDU 2 and at least one subheader. MAC SDU 2 can include part 2 of data in LCH 1 and part 1 of data in LCH 2. After MAC SDU 2 is formed, the values of B1 and B2 are updated according to the size of the MAC SDU, which can be positive or negative. However, both B1 and B2 can be initialized to zero after receiving a message indicating that the MAC is reset at time t2.

[0040] In view of the above, from Figure 3 It can be seen that the priority of logical channels determines the order for assembling data in UL grants and Bj has no impact. This is not fair to logical channels with low priority because data in logical channels with high priority is always transmitted first. For example, part 2 of data in LCH 2, which should be transmitted in UL grant 2, has to wait for UL grant 3 for transmission.

[0041] In addition, for EDT procedures for CP CIoT EPS optimization, uplink user data can be encapsulated in an uplink RRC message as a NAS protocol data unit (PDU). The UE can transmit a RRC early data request message concatenating uplink user data. There is no QoS related procedure in the access stratum (AS) layer. However, all traffic in NR can already be configured with QoS parameters. Therefore, a technical solution to meet QoS in procedures for CP optimization is necessary.

[0042] Thus, embodiments of the present application can maintain fairness of data in all logical channels when data is transmitted as small data transmission and manage QoS when uplink user data is transmitted using CP solution (e.g., uplink user data concatenated in a NAS message in a RRC message). More details regarding embodiments of the present application will be explained in the following text in conjunction with the attached drawings.

[0043] Figure 4 is a flowchart illustrating a method for small data transmission according to some embodiments of the present application. The method can be performed by a UE as Figure 1The UE 103 in RRC_IDLE state or in RRC-INACTIVE state as shown in FIG. 1 performs.

[0044] As Figure 4 As shown in FIG. 4, in step 402, the UE 103 can maintain a priority variable for each of the at least one logical channel. The at least one logical channel can be used by the UE 103 for small data transmission.

[0045] According to some embodiments of the present application, the at least one logical channel can be all logical channels of the UE. In these embodiments, the UE can consider that all logical channels can be used for small data transmission.

[0046] According to some embodiments of the present application, the at least one logical channel can be determined based on configuration information from the BS and / or logical channel selection procedure for UL grant. For example, assuming that the UE has five logical channels numbered 0, 1, 2, 3 and 4, in an embodiment of the present application, the configuration information from the BS can indicate that logical channels 0, 1, 2 can be used for small data transmission, then the at least one logical channel can be logical channels 0, 1, 2. In another embodiment of the present application, the at least one logical channel can be logical channels 1, 2, 3 determined by the logical channel selection procedure as specified in 3GPP standard documents. In yet another embodiment of the present application, the configuration information from the BS can indicate that logical channels 1, 2, 3, 4 can be used for small data transmission, and the UE can perform the logical channel selection procedure as specified in 3GPP standard documents to select logical channels 1, 2, 3 for small data transmission. In this case, the at least one logical channel can be logical channels 1, 2 and 3 determined based on the configuration information from the BS and the logical channel selection procedure.

[0047] According to some embodiments of the present application, the small data transmission can include UP-based small data transmission and CP-based small data transmission. The UP-based small data transmission can include transmission of small data multiplexed with RRC message. The CP-based small data transmission can include transmission of small data in a NAS message concatenated in a RRC message.

[0048] According to some embodiments of the present application, the UE 103 can transmit the small data through a RACH-based scheme, e.g., a 2-step RACH scheme or a 4-step RACH scheme as specified in 3GPP standard documents. For example, the small data can be transmitted using MSGA in a 2-step RACH scheme or using MSG3 in a 4-step RACH scheme. In an embodiment of the present application, the BS 101 can transmit a broadcast message indicating that the network supports small data transmission.

[0049] According to some embodiments of the present application, the UL grant for transmission of small data can be a preconfigured resource (e.g., a configured grant Type 1 resource as specified in 3GPP standard documents). In embodiments of the present application, the preconfigured resource can be configured with a release message for small data transmission when the network releases the UE to RRC INACTIVE state.

[0050] According to some embodiments of the present application, the UE can support UP-based small data transmission. In these embodiments of the present application, the priority variable maintained for each logical channel in the at least one logical channel can be Bj as specified in 3GPP standard documents. For example, assume that the at least one logical channel for small data transmission is logical channel 1, 2, 3, and 4, and thus the UE can maintain B1, B2, B3, and B4 for logical channel 1, 2, 3, and 4, respectively.

[0051] The initialization procedure for Bj can be the same as the procedure specified in 3GPP standard documents. For example, when a logical channel is established, the MAC entity of the UE 103 can initialize Bj of the logical channel to zero.

[0052] For each logical channel j, the MAC entity of the UE can increment Bj by PBRxT before each instance of the LCP procedure to determine a first value, where T is the time elapsed since Bj was last incremented; if the first value is greater than the bucket size for logical channel j (i.e., PBRxBSD), the UE 103 can set Bj to the bucket size.

[0053] When performing the first small data transmission, a first LCP procedure can be applied. In the first LCP procedure, the MAC entity of the UE 103 can allocate resources to the at least one logical channel as follows: all allowed logical channels in the at least one logical channel where Bj > 0 are allocated resources in decreasing priority order. It will be appreciated by one of ordinary skill in the art that the first small data transmission can refer to the initial small data transmission after the initialization procedure or any other small data transmission after the initial small data transmission. Similarly, the first LCP procedure can refer to the initial LCP procedure after the initialization procedure or any other LCP procedure after the initial LCP procedure.

[0054] After performing the first LCP procedure, in step 404, the MAC entity of the UE 103 can determine the value of Bj for each logical channel j in the at least one logical channel. Determining the value of Bj for each logical channel j can include decrementing Bj of each logical channel by the total size of the MAC SDU(s) for logical channel j, where the value of Bj before performing the decrementing can be determined based on the incrementing procedure as described above.

[0055] In step 406, the UE 103 can receive a message indicating a MAC reset. According to some embodiments of the present application, the message indicating a MAC reset can include one of: an RRC release message including a suspend configuration IE; an RRC early data complete message; and a MAC reset message after a small data transmission.

[0056] In step 408, after receiving the message, the UE can use the value of Bj determined after the first LCP procedure as the initial value of Bj for each logical channel j in the at least one logical channel in a second LCP procedure after the first LCP procedure. In these embodiments, step 408 can be implemented by the following procedure. For example, in response to receiving the message, the UE 103 can store the value of Bj for each logical channel determined after the first LCP procedure as a temporary value Bj_temp for each logical channel in the RRC layer or the MAC layer. In embodiments of the present application, the UE 103 can store the value of Bj for each logical channel as a temporary value Bj_temp for each logical channel in the RRC layer or the MAC layer at the time of receiving the message or upon receiving the message. After the MAC is reset, the UE 103 can set the temporary value Bj_temp as the initial value of Bj for each logical channel or configured logical channel configured to allow small data transmission (e.g., set Bj = Bj_temp), and thus Bj can be used in the second LCP procedure for a second small data transmission thereafter. In embodiments of the present application, the exact time(s) at which the UE updates Bj between LCP procedures depends on the UE implementation as long as Bj is up-to-date at the time the grant is processed through the LCP procedure or after the MAC is reset.

[0057] According to some other embodiments of the present application, the UE can support UP-based small data transmission. In these embodiments of the present application, the priority variable maintained for each logical channel in the at least one logical channel can be a new priority variable (e.g., Bj_smalldata) different from Bj as specified in the 3GPP standard document. The new priority variable (e.g., Bj_smalldata) is not affected by the MAC reset operation. The new priority variable can be configured or predefined for small data transmission, such as CP-based small data transmission and / or UP-based small data transmission. In one embodiment of this embodiment of the present application, the 3GPP standard document can define the new priority variable for small data transmission. In one embodiment of this embodiment of the present application, the new priority variable can be a MAC parameter.

[0058] For example, assume that the at least one logical channel for small data transmission is logical channel 1, 2, 3, and 4, and thus the UE can maintain B1_smalldata, B2_smalldata, B3_smalldata, and B4_smalldata for logical channel 1, 2, 3, and 4, respectively.

[0059] When the UE 103 initiates a small data transmission or when the UE 103 is released to the INACTIVE state with configuration for small data transmission or when a logical channel is established, the MAC entity of the UE 103 can initialize Bj_smalldata for the logical channel to zero.

[0060] For each logical channel j, the MAC entity of the UE can increment Bj_smalldata by PBR x T before each instance of the LCP procedure to determine a first value, where T is the time elapsed since Bj_smalldata was last incremented; if the first value is greater than the bucket size for the logical channel j (i.e., PBR x BSD), the UE 103 can set Bj_smalldata to the bucket size. In embodiments of the present application, the exact time(s) at which the UE updates Bj_smalldata between LCP procedures depends on the UE implementation, as long as Bj_smalldata is up-to-date when grants are processed through the LCP procedure or after the MAC is reset.

[0061] When performing the first small data transmission, a first LCP procedure can be applied. In the first LCP procedure, the MAC entity of the UE 103 can allocate resources to the at least one logical channel as follows: Step 1: All allowed logical channels in the at least one logical channel with Bj_smalldata > 0 are allocated resources in decreasing priority order. If the PBR of a logical channel is set to infinity, the MAC entity shall allocate resources for all data that can be transmitted on the logical channel before the PBR of lower priority logical channel(s) is met. It is understood by one of ordinary skill in the art that the first small data transmission can refer to the initial small data transmission after the initialization procedure or any other small data transmission after the initial small data transmission. Similarly, the first LCP procedure can refer to the initial LCP procedure after the initialization procedure or any other LCP procedure after the initial LCP procedure.

[0062] Step 2: After performing the first LCP procedure, the MAC entity of the UE 103 can determine the value of Bj_smalldata for each logical channel j in the at least one logical channel (i.e., as Figure 4The value of Bj_smalldata for each logical channel j can be determined by the UE 103 in step 404) as shown in Figure 4. Determining the value of Bj_smalldata for each logical channel j can include decrementing Bj_smalldata for each logical channel by the total size of the MAC SDU(s) for logical channel j, where the value of Bj_smalldata prior to performing the decrement can be determined based on the increment procedure as described above. Bj_smalldata can be negative after the first LCP procedure is performed.

[0063] Step 3: If any resources remain, serve all logical channels of the at least one logical channel in strict decreasing order of priority regardless of the value of Bj_smalldata until the data or UL grant for that logical channel is exhausted, whichever occurs first. Logical channels configured with equal priority should be served equally. According to some embodiments of the application, steps 1 and 2 can not be performed by the UE 103.

[0064] In step 406, the UE 103 can receive a message indicating a MAC reset. According to some embodiments of the application, the message indicating a MAC reset can include one of: an RRC release message including a suspend configuration IE; an RRC early data complete message; and a MAC reset message after a small data transmission.

[0065] In step 408, after receiving the message, in a second LCP procedure after the first LCP procedure, the UE can use the value of Bj_smalldata determined after the first LCP procedure as the initial value of Bj_smalldata for each logical channel j in the at least one logical channel in the second LCP procedure. As described above, Bj_smalldata is a new priority variable that is not affected by the MAC reset operation. That is, in response to receiving the message, the UE 103 can not initialize the priority variable Bj_smalldata for each logical channel j to zero, such that the value of Bj_smalldata determined after the first LCP procedure can be used in the second LCP procedure for a second small data transmission.

[0066] According to some embodiments of the application, the UE can support CP-based small data transmission. In embodiments of the application, according to the mapping rules of flows to DRBs and DRBs to logical channels, the AS layer can find the logical channel j corresponding to the NAS flow for which the NAS data is transmitted. In embodiments of the application, CP-based small data transmission can be limited to some flows configured by a mobility management entity (MME) or an access and mobility management function (AMF).

[0067] In these embodiments, the priority variable maintained for each of the at least one logical channel can be Bj as specified in the 3GPP standard documents. For example, assume that the at least one logical channel for small data transmission is logical channel 1, 2, 3, and 4, and thus the UE can maintain B1, B2, B3, and B4 for logical channel 1, 2, 3, and 4, respectively.

[0068] The initialization procedure for Bj can be the same as the procedure specified in the 3GPP standard documents. For example, when a logical channel is established, the MAC entity of the UE 103 can initialize Bj of the logical channel to zero.

[0069] For each logical channel j, the MAC entity of the UE can increment Bj by PBRxT before each instance of the LCP procedure to determine a second value, where T is the time elapsed since Bj was last incremented; if the second value is greater than the bucket size for logical channel j (i.e., PBRxBSD), the UE 103 can set Bj to the bucket size.

[0070] When performing the first small data transmission, the first LCP procedure can be applied. In a CP-based small data transmission, the first small data can be contained in a NAS message concatenated in an RRC message for transmission via the logical channel(s). In the first LCP procedure, the MAC entity of the UE 103 can allocate resources to the logical channel(s) for small data transmission. It is understood by one skilled in the art that the first small data transmission can refer to the initial small data transmission after the initialization procedure or any other small data transmission after the initial small data transmission. Similarly, the first LCP procedure can refer to the initial LCP procedure after the initialization procedure or any other LCP procedure after the initial LCP procedure.

[0071] After performing the first LCP procedure, in step 404, the MAC entity of the UE 103 can determine the value of Bj for each logical channel j of the at least one logical channel. Before determining the value of Bj, the lower layer of the UE 103 can retrieve from the higher layer the size of the data transmitted by the higher layer for each logical channel. In embodiments of the present application, the lower layer can be an AS layer. The AS layer can include one or more of the following: a RRC layer, a MAC layer, a packet data convergence protocol (PDCP), a radio link control (RLC) layer, and a physical (PHY) layer. In embodiments of the present application, the higher layer can be a NAS layer.

[0072] Thereafter, the UE 103 can determine the total size of the MAC SDUs for each logical channel based on at least one of: the size of data transmitted by the higher layer for the logical channel; the size of the PDCP header; the size of the RLC header; and the size of the service data adaptation protocol (SDAP) header. For example, in the case that the SDAP layer is configured for the UE, the total size of the MAC SDUs for each logical channel is equal to the sum of the size of data transmitted by the higher layer, the size of the PDCP header, the size of the RLC header, and the size of the SDAP header. Then, the UE can determine the value of the priority variable Bj for each logical channel based on the total size of the MAC SDUs for each logical channel. For example, determining the value of Bj for each logical channel j can include decrementing Bj for each logical channel by the total size of the MAC SDU(s) for logical channel j, where the value of Bj before performing the decrementing can be determined based on the incrementing procedure as described above.

[0073] In embodiments of the present application, in response to the value of the priority variable Bj being negative, the lower layer of the UE 103 can transmit a first indication to the higher layer to suspend small data transmission. After some time instances, the UE 103 can transmit a second indication to the higher layer to allow small data transmission when Bj > 0.

[0074] In another embodiment of the present application, in response to the value of the priority variable Bj being positive, the lower layer of the UE 103 can transmit a second indication to the higher layer to allow small data transmission.

[0075] In step 406, the UE 103 can receive a message indicating MAC reset. According to some embodiments of the present application, the message indicating MAC reset can be one of: an RRC release message including a suspend configuration IE; an RRC early data complete message; and a MAC reset message after small data transmission.

[0076] In step 408, after receiving the message, in a second LCP procedure after the first LCP procedure, the UE can use the value of Bj determined after the first LCP procedure as the initial value of Bj for each logical channel j in the at least one logical channel. In these embodiments, step 408 can be implemented by the following procedure. For example, in response to receiving the message, the UE 103 can store the value of Bj for each logical channel determined after the first LCP procedure as a temporary value Bj_temp in the RRC layer or the MAC layer. After the MAC reset, the UE 103 can set the temporary value Bj_temp as the initial value of Bj for each logical channel (e.g., set Bj = Bj_temp), and thus Bj can be used in the second LCP procedure thereafter for the second small data transmission.

[0077] According to some other embodiments of the present application, the UE can support CP-based small data transmission. In embodiments of the present application, the AS layer can find the logical channel j corresponding to the NAS flow for which the NAS data is transmitted according to the mapping rules of the flows to logical channels. In embodiments of the present application, CP-based small data transmission can be limited to some flows configured by a mobility management entity (MME) or an access and mobility management function (AMF).

[0078] In these embodiments of the present application, the priority variable maintained for each of the at least one logical channel can be a new priority variable (e.g., Bj_smalldata) different from Bj as specified in the 3GPP standard documents. The new priority variable (e.g., Bj_smalldata) is not affected by the MAC reset operation. The new priority variable can be configured or predefined for small data transmission, such as CP-based small data transmission and / or UP-based small data transmission. In one embodiment of this embodiment of the present application, the 3GPP standard documents can define the new priority variable for small data transmission. In one embodiment of this embodiment of the present application, the new priority variable can be a MAC parameter.

[0079] For example, assume that the at least one logical channel for small data transmission is logical channel 1, 2, 3, and 4, and thus the UE can maintain B1_smalldata, B2_smalldata, B3_smalldata, and B4_smalldata for logical channel 1, 2, 3, and 4, respectively.

[0080] The MAC entity of the UE 103 can initialize Bj_smalldata of a logical channel to zero when the UE 103 initiates small data transmission or when the UE 103 is released to INACTIVE state with configuration of small data transmission or when the logical channel is established.

[0081] For each logical channel j, the MAC entity of the UE can increment Bj_smalldata by PBR x T before each instance of the LCP procedure to determine a second value, where T is the time elapsed since Bj_smalldata was last incremented; if the second value is greater than the bucket size (i.e., PBR x BSD) for the logical channel j, the UE 103 can set Bj_smalldata to the bucket size. In embodiments of the present application, the exact time(s) at which the UE updates Bj_smalldata between LCP procedures depends on the UE implementation as long as Bj_smalldata is up-to-date when the grant is processed through the LCP procedure or after the MAC is reset.

[0082] When performing the first small data transmission, a first LCP procedure can be applied. In the CP-based small data transmission, the first small data can be contained in a NAS message concatenated in an RRC message for transmission via the logical channel(s). In the first LCP procedure, the MAC entity of the UE 103 can allocate resources to the logical channel(s) for the small data transmission. It is understood by those skilled in the art that the first small data transmission can refer to the initial small data transmission after the initialization procedure or any other small data transmission after the initial small data transmission. Similarly, the first LCP procedure can refer to the initial LCP procedure after the initialization procedure or any other LCP procedure after the initial LCP procedure.

[0083] After performing the first LCP procedure, in step 404, the MAC entity of the UE 103 can determine the value of Bj_smalldata for each logical channel j in the at least one logical channel. Before determining the value of Bj_smalldata, the lower layer of the UE 103 can retrieve from the higher layer the size of the data transmitted by the higher layer for each logical channel. In embodiments of the present application, the lower layer can be an AS layer. The AS layer can include one or more of the following: RRC layer, MAC layer, PDCP, RLC layer, and PHY layer. In embodiments of the present application, the higher layer can be a NAS layer.

[0084] Thereafter, the UE 103 can determine the total size of the MAC SDU for each logical channel based on at least one of the following: the size of the data transmitted by the higher layer for the logical channel; the size of the PDCP header; the size of the RLC header; and the size of the SDAP header. For example, in the case where the SDAP layer is configured for the UE, the total size of the MAC SDU for each logical channel is equal to the sum of the size of the data transmitted by the higher layer, the size of the PDCP header, the size of the RLC header, and the size of the SDAP header. Then, the UE can determine the value of the priority variable Bj_smalldata based on the total size of the MAC SDU for each logical channel. For example, determining the value of Bj_smalldata for each logical channel j can include decrementing Bj_smalldata for each logical channel by the total size of the MAC SDU(s) for the logical channel j, where the value of Bj_smalldata before performing the decrementing can be determined based on the incrementing procedure as described above.

[0085] In embodiments of the present application, in response to the value of the priority variable Bj_smalldata being negative, the lower layer of the UE 103 can transmit a first indication of suspending the small data transmission to the higher layer. After some time instance, the UE 103 can transmit a second indication of allowing the small data transmission when Bj_smalldata > 0 to the higher layer.

[0086] In another embodiment of the present application, in response to the value of the priority variable Bj_smalldata being positive, the lower layers of the UE 103 can transmit a second indication to the higher layers that small data transmission is allowed.

[0087] If any resources remain, all logical channels of the at least one logical channel are served in strict decreasing priority order, regardless of the value of Bj_smalldata, until the data or UL grant of that logical channel is exhausted, whichever occurs first. Logical channels configured with equal priority should be served equally.

[0088] In step 406, the UE 103 can receive a message indicating a MAC reset. According to some embodiments of the present application, the message indicating a MAC reset can be one of: an RRC release message including a suspend configuration IE; an RRC early data complete message; and a MAC reset message after small data transmission.

[0089] In step 408, after receiving the message, in a second LCP procedure after the first LCP procedure, the UE can use the value of Bj_smalldata determined after the first LCP procedure as the initial value of Bj_smalldata for each logical channel j in the at least one logical channel in the second LCP procedure. As described above, Bj_smalldata is a new priority variable that is not affected by the MAC reset operation. That is, in response to receiving the message, the UE 103 can not initialize the priority variable Bj_smalldata for each logical channel j to zero, such that the value of Bj_smalldata determined after the first LCP procedure can be used in the second LCP procedure that follows for a second small data transmission.

[0090] Figure 5 A simplified block diagram of an apparatus 500 for small data transmission according to some embodiments of the present application is illustrated. The apparatus 500 can be Figure 1 the UE 103 shown in FIG. 1.

[0091] Reference is made to Figure 5, the device 500 can include at least one non-transitory computer-readable medium 502, at least one receiving circuitry 504, at least one transmitting circuitry 506, and at least one processor 508. In some embodiments of the present application, the at least one receiving circuitry 504 and the at least one transmitting circuitry 506 can be integrated as at least one transceiver. The at least one non-transitory computer-readable medium 502 can have computer-executable instructions stored therein. The at least one processor 508 can be coupled to the at least one non-transitory computer-readable medium 502, the at least one receiving circuitry 504, and the at least one transmitting circuitry 506. The computer-executable instructions can be programmed to implement a method with the at least one receiving circuitry 504, the at least one transmitting circuitry 506, and the at least one processor 508. The method can be a method according to embodiments of the present application, such as the method shown in Figure 4 .

[0092] Methods according to embodiments of the present application can also be implemented on a programmed processor. However, controllers, flow diagrams, and modules can also be implemented on general purpose or special purpose computers, programmed microprocessors or microcontrollers and peripheral integrated circuit elements, integrated circuits, hardware electronic or logic circuits, such as a discrete element circuit, a programmable logic device, or the like. In general, any device on which finite state machines, when enabled to perform the flow diagrams shown in the Figures, can be implemented. For example, embodiments of the present application provide a device for emotion recognition from speech, comprising a processor and a memory. Computer programmable instructions for implementing a method of emotion recognition from speech are stored in the memory, and the processor is configured to execute the computer programmable instructions to implement the method of emotion recognition from speech. The method can be the method described above or other methods according to embodiments of the present application.

[0093] Alternative embodiments preferably implement methods according to embodiments of the present application in a non-transitory computer-readable storage medium storing computer programmable instructions. The instructions are preferably executed by a computer executable component, preferably integrated with a network security system. The non-transitory computer-readable storage medium can be stored on any suitable computer readable media, such as RAM, ROM, flash memory, EEPROM, optical storage (CD or DVD), hard disk, floppy disk, or any suitable device. The computer executable component is preferably a processor, but the instructions can alternatively or additionally be executed by any suitable dedicated hardware device. For example, embodiments of the present application provide a non-transitory computer-readable storage medium having computer programmable instructions stored therein. The computer programmable instructions are configured to implement the method of emotion recognition from speech described above or other methods according to embodiments of the present application.

[0094] While the application has been described with reference to particular embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. For example, various components of the embodiments can be interchanged, added, or removed in other embodiments. Also, all elements of each figure are not necessary for the operation of the disclosed embodiments. For example, one of ordinary skill in the art of the field of the disclosed embodiments will be able to make and use the teachings of this application by simply employing the elements of the independent claims. Accordingly, the embodiments of the application set forth herein are intended to be illustrative, not limiting. Various changes can be made without departing from the spirit and scope of the application.

Claims

1. A user equipment (UE) for wireless communication, the UE comprising: a processor; and a memory coupled to the processor, the processor configured to cause the UE to: perform a small data transmission while the UE is in a radio resource control idle (RRC IDLE) state or a radio resource control inactive (RRC INACTIVE) state; apply an initial logical channel prioritization (LCP) procedure for the small data transmission on one or more uplink (UL) grant resources; receive a message indicating a medium access control (MAC) reset; and reset the MAC prior to transmitting a second small data transmission.

2. The UE of claim 1, wherein the processor is configured to cause the UE to apply one or more other LCP procedures after the initial LCP procedure for the small data transmission.

3. The UE of claim 1, wherein the processor is configured to cause the UE to apply the initial LCP procedure for the small data transmission by allocating resources to at least one logical channel according to an initial value of a priority variable configured for a logical channel of the small data transmission.

4. The UE of claim 1, wherein the processor is configured to cause the UE to transmit the small data transmission by a random access channel (RACH)-based scheme.

5. The UE of claim 1, wherein the processor is configured to cause the UE to transmit the small data transmission using UL grant resources, the UL grant resources being preconfigured resources.

6. The UE of claim 1, wherein the processor is configured to cause the UE to at least one of: transmit the small data transmission by transmitting the small data multiplexed with a radio resource control (RRC) message; or transmit the small data transmission in a non-access stratum (NAS) message concatenated in a RRC message.

7. The UE of claim 1, wherein the message indicating the MAC reset comprises at least one of: a RRC release message including a suspend configuration information element (IE); a RRC early data complete message; or a MAC reset message following the small data transmission.

8. The UE of claim 1, wherein the processor is configured to cause the UE to use a pre-defined value as an initial value of a priority variable configured for a logical channel of the small data transmission.

9. A processor for wireless communication, the processor comprising: at least one controller coupled to at least one memory and configured to cause the processor to: perform a small data transmission while in a radio resource control idle (RRC IDLE) state or a radio resource control inactive (RRC INACTIVE) state; apply an initial logical channel prioritization (LCP) procedure for the small data transmission on one or more uplink (UL) grant resources; receive a message indicating a medium access control (MAC) reset; and reset the MAC prior to transmitting a second small data transmission. ​ 10. A method performed by a user equipment (UE), the method comprising: performing a small data transmission while the UE is in a radio resource control idle (RRC_IDLE) state or a radio resource control inactive (RRC_INACTIVE) state; applying an initial logical channel prioritization (LCP) procedure for the small data transmission on one or more uplink (UL) grant resources; receiving a message indicating a medium access control (MAC) reset; and resetting the MAC prior to transmission of a second small data transmission.

11. The method of claim 10, further comprising applying one or more other LCP procedures after the initial LCP procedure for the small data transmission.

12. The method of claim 10, wherein applying the initial LCP procedure for the small data transmission comprises allocating resources to at least one logical channel according to an initial value of a priority variable of a logical channel configured for the small data transmission.

13. The method of claim 10, wherein the small data transmission is transmitted through a random access channel (RACH)-based scheme.

14. The method of claim 10, wherein the small data transmission is transmitted using UL grant resources, the UL grant resources being preconfigured resources.

15. The user equipment of claim 10, wherein transmitting the small data transmission comprises transmitting the small data multiplexed with a radio resource control (RRC) message or transmitting the small data in a non-access stratum (NAS) message concatenated in a RRC message.

16. The method of claim 10, wherein the message indicating the MAC reset comprises at least one of: a RRC release message including a suspend configuration information element (IE); a RRC early data complete message; or a MAC reset message following the small data transmission.

17. The method of claim 10, further comprising using a predefined value as the initial value of the priority variable of the logical channel configured for the small data transmission.

Images