Triggering mechanism for wireless power headroom reporting during small data transmission

Abstract

The present disclosure relates generally to power headroom report (PHR) management in wireless communication systems, and more particularly to improving timely triggering and transmission of PHR from a wireless terminal device to a base station during small data transmission (SDT) during radio resource control (RRC) inactive states. The present disclosure includes an example process for handling triggering of a PHR in a wireless terminal device to avoid potential pre-cancel of the PHR triggering during an SDT process under certain SDT conditions, and correspondingly instances where the PHR cannot be transmitted, and enhance the timeliness of the PHR triggering function, which would otherwise be obstructed under some other SDT conditions.

Description

Technical Field

[0001] The present disclosure generally relates to Power Headroom Report (PHR) management in a wireless communication system, and more particularly to improving the timely triggering and transmission of PHR from a wireless terminal device to a base station during a Small Data Transmission (SDT) process in a Radio Resource Control (RRC) Inactive state. Background Art

[0002] A key aspect of network management in a radio access network is radio frequency (RF) transmission power control. The operation of a mobile wireless terminal is typically limited by its battery life. Therefore, the RF power for transmitting data or control signals from the mobile wireless terminal to the base station should be carefully managed to save energy while maintaining the integrity of signal transmission and reception. The Power Headroom Report (PHR) of a wireless terminal contains important information items that inform the base station of the comparison between the power capability of the wireless terminal and the nominal uplink power signal level estimated to maintain the integrity of specific data reception at the base station. The base station can rely on these information items contained in the PHR to adaptively determine frequency, time, and coding resource allocations as well as other network configuration parameters. Therefore, the timely triggering of the PHR and the timely transmission of the triggered PHR to the base station are crucial for the performance of a wireless access communication network. Summary of the Invention

[0003] The present disclosure generally relates to PHR management in a wireless communication system, and more particularly to improving the timely triggering of PHR from a wireless terminal device to a base station and the transmission of the triggered PHR during an SDT process in an RRC Inactive state.

[0004] In some example embodiments, a method for a wireless terminal device to transmit a data payload during an SDT process is disclosed. The method may include: determining that the wireless transmission resources allocated by a wireless base station for the SDT process are sufficient to transmit the data payload but insufficient to additionally send a Power Headroom Report (PHR) to the wireless base station. The method may further include: in response to the determination, using the wireless transmission resources to transmit the data payload to the wireless base station without any PHR; canceling all triggered PHRs; and activating at least one predetermined process to facilitate PHR triggering.

[0005] In the above example embodiment, the at least one predetermined process includes starting or restarting a predetermined timer, where the predetermined timer is configured to trigger a PHR upon its expiration.

[0006] In any of the above exemplary embodiments, the at least one predetermined process includes treating the transmission of the data payload as a PHR transmission.

[0007] In any of the above exemplary embodiments, the at least one predetermined process may include: starting or restarting a predetermined timer, where the predetermined timer is configured to trigger a PHR upon its expiration; and treating the transmission of the data payload as a PHR transmission.

[0008] In any of the above exemplary embodiments, the method may further include modifying at least one state of the wireless terminal device to reflect that a most recent PHR transmission has effectively occurred when transmitting the data payload.

[0009] In any of the above exemplary embodiments, no previous PHR was sent during the SDT process; and no new PHR is triggered without activating the at least one predetermined process.

[0010] In any of the above exemplary embodiments, at least one previous PHR has been sent during the SDT process; and the probability of an untimely PHR transmission is reduced compared to when the at least one predetermined process is not activated.

[0011] In some other exemplary embodiments, a wireless terminal device including a processor and a memory is disclosed. The processor may be configured to read computer code from the memory to implement any of the above methods.

[0012] In still some other exemplary embodiments, a computer program product is disclosed, which includes a non-transitory computer-readable program medium having computer code stored thereon. The computer code, when executed by a processor of a wireless terminal device, may cause the wireless terminal device to implement any of the above methods.

[0013] The above embodiments and other aspects and alternatives of their implementation are described in more detail in the following drawings, description, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 An exemplary wireless communication network including a radio access network, a core network, and a data network is shown.

[0015] Figure 2 An exemplary radio access network including a plurality of wireless terminal devices or user equipment (UE) and radio access network nodes communicating with each other via an over-the-air wireless communication interface is shown.

[0016] Figure 3 Shows a first scenario in the SDT process, where the triggering of the PHR may potentially be irreversibly cancelled.

[0017] Figure 4 Shows a second scenario in the SDT process, where the triggering of the PHR may be hindered.

[0018] Figure 5 Shows an implementation scenario of an example embodiment of the present disclosure for restoring the PHR trigger that was potentially permanently cancelled during the SDT process.

[0019] Figure 6 Shows another implementation scenario of an example embodiment of the present disclosure for reducing the potential hindrance of the PHR trigger during the SDT process.

[0020] Figure 7 Shows yet another implementation scenario of an example embodiment of the present disclosure for reducing the potential hindrance of the PHR trigger during the SDT process. Detailed implementation

[0021] The techniques and examples of the embodiments and / or examples described in the present disclosure can be used to improve PHR management in wireless terminal devices. The term "exemplary / example" is used to mean "an instance of", and unless otherwise stated, does not imply an ideal or preferred instance, embodiment or example. In this disclosure document, subsection headings are used for ease of understanding the disclosed embodiments, rather than limiting the disclosed technology to the subsections corresponding to the parts. The disclosed embodiments can be further embodied in various different forms. Therefore, the scope of the present disclosure or the claimed subject matter is intended to be construed as not limited to any of the following embodiments. The various embodiments can be embodied as methods, devices, components, systems or non-transitory computer-readable media. Therefore, the embodiments of the present disclosure may take the form of hardware, software, firmware or any combination thereof.

[0022] The present disclosure generally relates to power headroom report (PHR) management in a wireless communication system, and particularly to improving the timely triggering and transmission of PHR from a wireless terminal device to a base station during small data transmission (SDT) in a radio resource control (RRC) inactive state. The following disclosure includes example processes for handling the triggering of PHR in a wireless terminal device to avoid potential premature cancellation of PHR triggering during the SDT process under certain SDT conditions and the corresponding situation of not being able to transmit the PHR, and to enhance the timeliness of the PHR triggering function, which would otherwise be hindered under some other SDT conditions.

[0023] Overview of Wireless Network

[0024] Figure 1An example wireless communication network 100 as shown may include wireless terminal devices or user equipment (UE) 110, 111, and 112, a carrier network 102, various service applications 140, and other data networks 150. For example, the carrier network 102 may include access networks 120 and 121, and a core network 130. The carrier network 110 can be configured to transmit voice, data, and other information (collectively referred to as data traffic) between the UEs 110, 111, and 112, between the UEs 110, 111, and 112 and the service applications 140, or between the UEs 110, 111, and 112 and other data networks 150. The access networks 120 and 121 can be configured as various wireless access network nodes (Wireless Access Network Node, WANN, also referred to as base stations), interacting with the UEs 110, 111, and 112 on one side of a communication session and with the core network 130 on the other side. The core network 130 can include various network nodes that are configured to control communication sessions and perform network access management and data traffic routing. The service applications 140 can be hosted by various application servers deployed outside but connected to the core network 130. Similarly, the other data networks 150 can also be connected to the core network 130.

[0025] In Figure 1 In the wireless communication network 100 as shown, the UEs 110, 111, and 112 can communicate with each other via the wireless access network. For example, UEs 110 and 112 may be connected to the same access network 120 and communicate through it. The UEs 110, 111, and 112 can also communicate with each other through the access network and the core network. For example, UE 110 may be connected to access network 120, while UE 111 may be connected to access network 121. Therefore, UE 110 and UE 111 can communicate with each other through access networks 120 and 121 and the core network 130. The UEs 110, 111, and 112 can also communicate further with the service applications 140 and the data networks 150 through the core network 130. In addition, the UEs 110, 111, and 112 can communicate directly with each other through sidelink communication, as shown as 113 in the figure.

[0026] Figure 2Further shows an example system diagram of the radio access network 120, which includes a WANN 202 that provides services to UEs 110 and 112 via the air interface 204. The term air interface can be interchangeably referred to as the air interface or radio interface, etc. The radio transmission resources of the air interface 204 include a combination of frequency, time, space, and / or coding resources. Each of UEs 110 and 112 may be a mobile or fixed terminal device equipped with a mobile access unit (such as a Subscriber Identity Module (SIM) / Universal Subscriber Identity Module (USIM) module) for accessing the wireless communication network 100. UEs 110 and 112 can be respectively implemented as terminal devices capable of wireless communication, including but not limited to mobile phones, smartphones, tablets, laptops, in-vehicle communication devices, roadside communication devices, sensor devices, smart home appliances (such as TVs, refrigerators, and ovens), etc. As Figure 2 shown, each UE (such as UE 112) may include a transceiver circuit 206 coupled to one or more antennas 208 to enable wireless communication with the WANN 120 or another UE (such as UE 110). The transceiver circuit 206 may also be coupled to a processor 210, which may also be coupled to a memory 212 or other storage devices. The memory 212 may be transient or non-transient and may store computer instructions or code that, when read and executed by the processor 210, cause the processor 210 to implement the various methods described herein.

[0027] Similarly, the WANN 120 may include a base station or a wireless network access point, capable of wirelessly communicating with one or more UEs via an air interface 204 and capable of communicating with the core network 130. For example, the WANN 120 may be implemented as, but not limited to, a second-generation (2G) base station, a third-generation (3G) Node B (NB), a Long Term Evolution (LTE) evolved Node B (eNB), a fourth-generation (4G) LTE base station, a fifth-generation (5G) New Radio (NR) base station, a 5G Central-Unit (CU) base station, or a 5G Distributed-Unit (DU) base station. Each type of these WANNs may be configured to perform a corresponding set of wireless network functions. The WANN 202 may include a transceiver circuit 214 connected to one or more antennas 216, and these antennas may include various forms of antenna towers 218 to enable wireless communication with the UEs 110 and 112. The transceiver circuit 214 may be connected to one or more processors 220, and these processors may be further connected to a memory 222 or other storage devices. The memory 222 may be transient or non-transient, and may store therein, when read and executed by one or more processors 220, causing one or more processors 220 to implement the various functions of the WANN 120 described in this document.

[0028] In a wireless access network as Figure 2 described, data packets may be transmitted as Protocol Data Units (PDUs). The data contained in the data packets may be packed as PDUs at different network layers and wrapped with nested and / or hierarchical protocol headers. Once a connection (e.g., an RRC connection) is established between a sending device or a transmitter (these two terms may be used interchangeably) and a receiving device or a receiver (these two terms may also be used interchangeably), the PDUs may communicate between them. Any one of the sending device or the receiving device may be a wireless terminal device, such as Figure 2 the devices 110 and 120, or a wireless access network node, such as Figure 2 the node 202. Each device may be both a sending device and a receiving device for two-way communication.

[0029] To effectively manage the various communication resources for carrying data and control information between the UE and the base station, such as Figure 1 and Figure 2Various information items related to device capabilities and network channel conditions may be exchanged between the UE and the base station in []. For example, a UE in the form of a mobile radio terminal device is typically powered by a battery and is thus subject to operational limitations of battery life. For example, the mobile terminal device may be associated with one or more maximum uplink transmission power levels according to the device capabilities of the mobile terminal device. On the other hand, in order to maintain an acceptable reception quality of data or control signals at the base station, a nominal power level may be required on a specific uplink (UL) channel or sounding reference signal (SRS) for the mobile terminal device and the base station. The nominal power level, for example, may be closely related to the corresponding radio channel conditions, including but not limited to path loss and interference from other channels. In some embodiments, the radio terminal device may be configured to inform the base station on different occasions of the comparison between the power capabilities of the radio terminal device and the nominal transmission power level in the target radio channel.

[0030] For example, the radio terminal device may transmit a power headroom report (PHR) to the base station periodically or under other triggering conditions. The PHR may contain information related to the power headroom of the radio terminal device. The power headroom, for example, may be represented by the difference between the maximum power capability level of the radio terminal device and the nominal power level of the UL channel or SRS. A positive power headroom indicates that the terminal device is capable of increasing the transmission power of the radio frequency signal above the nominal power level of the corresponding radio communication channel, while a negative power headroom indicates that the terminal device cannot reach the nominal power level of the corresponding radio communication channel. Once the base station learns the power headroom information, it may adjust the radio resource allocation and other network parameters for communicating with the radio terminal device according to the reported power headroom.

[0031] In some embodiments, the radio terminal device may be configured to transmit the PHR only when the PHR is triggered. Once triggered, the PHR may be prepared and transmitted under certain circumstances described in more detail below. Thus, triggering the PHR may put the radio terminal device in a state where it can transmit the triggered PHR to the base station when needed. The conditions for triggering the PHR and the conditions for transmitting the triggered PHR may be different, and they may be dependent or related to each other, or they may be independent or unrelated. The PHR may be triggered in various different ways. The triggering of the PHR or the triggered PHR may be cancelled before transmission. The cancelled PHR will not be transmitted until it is re-triggered. When all triggered PHRs are cancelled, no PHR can be transmitted without re-triggering.

[0032] In some embodiments, when the PHR is triggered, the actual transmission of the PHR may be carried out as an auxiliary to the transmission of data (or in some cases, control information). In other words, the PHR may be transmitted to the base station together with some data (or control) information, rather than being transmitted separately, using the radio resources allocated for the transmission of this data (or control information) when transmitting the PHR. Therefore, the transmission of the PHR may depend on two factors: (1) the PHR has been triggered (and not cancelled after being triggered); and (2) there is data (or control information) to be transmitted. In some embodiments, the PHR is only allowed to be transmitted together with a new data transmission. The term "new transmission" is used to refer to a data transmission that is not a retransmission required due to a previous transmission failure or non - confirmation.

[0033] In some embodiments, the triggering of the PHR may follow a set of predefined rules and be controlled by one or more PHR parameters. These PHR parameters may be configured by the network through the base station. For example, these parameters may be configured or controlled by an RRC entity at a higher layer, such as the RRC layer.

[0034] In some exemplary embodiments, the RRC layer may control the triggering and transmission of the PHR by configuring a set of PHR parameters, which may include but are not limited to: the PHR periodic timer (phr - PeriodicTimer), the PHR prohibit timer (phr - ProhibitTimer), and the PHR transmission power factor change (phr - Tx - PowerFactorChange). These exemplary configured parameters may control the triggering of the PHR on the wireless terminal device in various ways. As explained in more detail below, the parameter phr - PeriodicTimer represents a periodic timer that facilitates the triggering of the PHR without unduly prolonging the untriggered or cancelled time period. The parameter phr - Tx - PowerFactorChange may be used as a threshold level for path loss or power back - off change to control the PHR triggering that may be required when there is a large enough change / variation in the wireless communication channel conditions. The parameter phr - ProhibitTimer may be used in combination with the parameter phr - Tx - PowerFactorChange so as to effectively act as a low - pass filter to avoid overly frequent PHR triggering due to rapid fluctuations in the channel conditions.

[0035] For example, the PHR may be triggered when the following series of optional / alternative events related to the above - mentioned PHR parameters occur:

[0036] A. When the phr-ProhibitTimer expires or has expired, and the path loss of the corresponding radio communication channel has changed by more than phr-Tx-PowerFactorChange dB since the last PHR transmission. In addition, the following conditions are also required to be met: for example, the Media Access Control (MAC) entity of the wireless terminal device has UL resources for new data transmission (instead of retransmission). In order for this optional / alternative trigger condition to be effective, there must have been an actual previous PHR transmission as a reference in the current communication session or process, so as to compare the path loss to determine whether the change in path loss exceeds the threshold specified by the phr-Tx-PowerFactorChange parameter.

[0037] B. When the phr-PeriodicTimer expires, the purpose is that the PHR should not remain untriggered or disabled for a long time. This timer may be started to limit the length of time the PHR remains untriggered.

[0038] C. By upper layer configuration or reconfiguration of the power headroom reporting function, and this configuration or reconfiguration is not used to disable the PHR function. In other words, the configuration of the PHR function by the upper layer (e.g., the RRC layer) may automatically trigger the corresponding PHR for subsequent transmission.

[0039] D. When the phr-ProhibitTimer expires or has expired, and the MAC entity has UL resources for new transmission, and the power back-off required due to power management has changed by more than phr-Tx-PowerFactorChange dB since the last PHR transmission. In order for this optional / alternative trigger condition to be effective, there must have been an actual previous PHR transmission as a reference in the current communication session or process, so as to compare the power back-off to determine whether the change in power back-off exceeds the threshold specified by the phr-Tx-PowerFactorChange parameter. The term "power back-off" may refer to the required power headroom. This required power headroom may change. For example, the required power back-off may change from 3 dB to 5 dB. When such a change in power back-off exceeds the threshold factor specified by the phr-Tx-PowerFactorChange parameter, this condition provides an optional / alternative for PHR triggering.

[0040] As described above, triggering the PHR through the above various optional / alternative methods only allows the wireless terminal device to prepare the PHR for transmission. The actual transmission of the triggered PHR may be carried out together with new data transmission (as opposed to retransmission), and may be subject to other conditions or restrictions in order for the PHR transmission to actually occur.

[0041] In some example embodiments, when the MAC entity of a wireless terminal device obtains UL resources / grant allocated for performing new data transmission, the MAC entity may determine whether a triggered PHR should be appended or tagged to the data to be transmitted for transmission to the base station together. For example, the MAC entity may perform the following example procedures:

[0042] - The MAC entity determines whether the current data transmission is the first new data transmission on the allocated UL resources / grant since the last MAC reset. The UL resources / grant for small data transmission (SDT) may be allocated based on random access (RA) or configured grant (CG). If the MAC entity makes such a determination (i.e., the data transmission in the current SDT procedure is the first new data transmission), then:

[0043] * The MAC entity may start the phr-PeriodicTimer.

[0044] - The MAC entity further determines, according to its PHR procedure, whether at least one PHR has been triggered and not cancelled, and whether the allocated UL resources / grant can accommodate the PHR MAC control element (CE) + its sub-header. If the answers to both determinations are affirmative, then:

[0045] * The MAC entity may obtain the value of the power headroom from the physical layer;

[0046] * The MAC entity may obtain the value of the maximum transmission power from the physical layer;

[0047] * The MAC entity may instruct the multiplexing and assembly procedure to generate and transmit a PHR MAC CE based on the values reported by the physical layer.

[0048] * The MAC entity may start or restart the phr-PeriodicTimer;

[0049] * The MAC entity may start or restart the phr-ProhibitTimer;

[0050] * The MAC entity may cancel all triggered PHRs.

[0051] - The PHR can be transmitted in various formats. For example, the PHR can be transmitted as a MAC CE. Such a MAC CE can be referred to as a PHR MAC CE.

[0052] PHR under RRC State, Small Data Transmission (SDT) and RRC - Inactive State

[0053] under PHR

[0054] In Figure 2 the example wireless access system shown, the wireless connection between the UE and the base station may be configured at the RRC layer. Accordingly, the connection state between the UE and the base station may include, for example, the RRC connected (RRC_CONNECTED) state, the RRC inactive (RRC_INACTIVE) state, and the RRC idle (RRC_IDLE) state, with their overall nominal radio interface operating power consumption decreasing in sequence. The RRC_CONNECTED state represents an active communication state established through the RRC connection procedure, where the UE and the base station are engaged in active communication. In the RRC_IDLE state, the UE has no RRC connection with the base station, and in order to establish a communication session with the base station, an RRC connection must first be activated and established. Therefore, transitioning from the RRC_IDLE state to the RRC_CONNECTED state will require going through the full RRC connection procedure, which typically takes a relatively long time. The RRC_INACTIVE state may be introduced as an intermediate state between the RRC_IDLE state and the RRC_CONNECTED state to reduce the control plane latency from this intermediate state to the RRC_CONNECTED state. Specifically, the UE may have no or very little data to transmit in the RRC_INACTIVE state and may suddenly encounter significant data transmission requirements. The purpose of the RRC_INACTIVE state is to allow the UE to maintain a relatively low power consumption in the RRC_INACTIVE state but be able to quickly transition to the RRC_CONNECTED state when needed.

[0055] In some example embodiments of the RRC_INACTIVE state, infrequent (periodic and / or aperiodic) small data transmissions may be allowed without transitioning the UE from the RRC_INACTIVE state to the RRC_CONNECTED state. Such data transmissions may be referred to as small data transmissions (SDT) and may be handled by the SDT procedure in the RRC_INACTIVE state. Through SDT, the UE can save power consumption and signaling overhead while still being able to transmit a certain amount of data, although the amount of data may be limited.

[0056] The SDT procedure may be based on random access, called RA-SDT. The SDT procedure may also be based on configured grant, called CG-SDT. In either case, one or more uplink grants (UL grants) (either through dynamic scheduling or through configured grant) may be provided for SDT to perform uplink transmissions during the SDT procedure.

[0057] For SDT, even if data transmission may be infrequent, PHR transmission may still be supported in some example embodiments. However, since PHR transmission is typically auxiliary to data transmission and the UL transmission resources / grants allocated for SDT may be limited, there may not always be sufficient UL resources / grants to accommodate the transmission of both the scheduled small data and the triggered PHR MAC CE. For example, the UL resources / grants allocated for a particular new transmission may only be able to accommodate the transmission of 100 bytes of information. If the actual data (plus its sub - header) is close to this amount, e.g., 98 bytes, and the triggered PHR MAC CE plus its sub - header contains 3 bytes of information, then the allocated resources / grants will not be able to transmit both the data and the 101 bytes occupied by the PHR MAC CE and its sub - header at the same time.

[0058] A set of transmission priority rules can be preset to handle this situation. For example, in a certain example embodiment, if the UE determines (e.g., at the MAC layer) that an SDT process is in progress and the UL grant can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub - header, then the UE may decide to cancel all the triggered PHRs. In other words, in this case, the PHR trigger will be cancelled and only the data will be transmitted without any PHR MAC CE. Another example is that if the UE determines that an SDT process is in progress and the UL grant cannot accommodate all the pending data to be transmitted but is sufficient to accommodate the PHR MAC CE and its sub - header, then the UE may decide to transmit the triggered PHR MAC CE together with some part of the data or no data. In other words, the UE may decide to transmit at least one of the PHR MAC CE or the data completely.

[0059] Accidental Permanent Cancellation or Partial Prohibition of PHR Function in SDT

[0060] The general PHR trigger process described above, when applied in combination with the above - mentioned SDT process, may lead to potential untimely PHRs, including but not limited to the permanent de - triggering or cancellation of PHR transmission in some cases during the SDT process, or the partial hindrance / reduction of the PHR trigger function in some other cases. Such permanent de - triggering or partial hindrance of the PHR trigger function may not occur during normal data transmission in the RRC_CONNECTED state.

[0061] An example scenario, referred to as Scenario I, may lead to potential permanent de - triggering or cancellation of PHR trigger under the above - mentioned PHR and SDT processes, as Figure 3 shown. Specifically, Figure 3 shows a specific sequence of events / steps in SDT based on the above - described PHR and SDT processes, in which permanent de - triggering or cancellation of PHR trigger may occur in the above - mentioned PHR and SDT processes:

[0062] Step 1: The SDT is configured and started, and because the above trigger condition C is met (when the power headroom reporting function is configured or reconfigured by the upper layer and triggers the PHR, and this PHR trigger is not used to disable the PHR function), the PHR is triggered when the SDT process starts.

[0063] Step 2: The UE starts the phr-PeriodicTimer when sending the first new SDT transmission after the last MAC reset. In this scenario, it is assumed that the uplink grant(s) is only sufficient to transmit data and not sufficient to transmit both data and the triggered PHR MAC CE and its sub-header at the same time. According to the above SDT / PHR process, the triggered PHR MAC CE is therefore not transmitted and is cancelled.

[0064] Step 3: The timer phr-PeriodicTimer expires, and the PHR is triggered according to the above PHR trigger condition B.

[0065] Step 4: Another new transmission (referred to as new transmission 1) is scheduled for transmission. In this scenario, it is again assumed that the uplink grant(s) is only sufficient to transmit the data of new transmission 1 and not sufficient to transmit both data and the triggered PHR MAC CE and its sub-header at the same time. According to the above SDT / PHR process, the triggered PHR MAC CE is not transmitted and is cancelled.

[0066] Step 5: In a subsequent new SDT transmission ( Figure 3 referred to as new transmission 2 herein), there is no other triggering mechanism among the above PHR trigger conditions A - D that can re-trigger the PHR for transmission. Therefore, the PHR will be permanently de-triggered (in other words, the PHR trigger is permanently cancelled), and even if the uplink grant(s) is sufficient to transmit new data and the PHR MAC CE and its sub-header, the PHR is not allowed to be transmitted together with new transmission 2 in the SDT process.

[0067] For the above step 5, the PHR transmission cannot be re-triggered because none of the above-described PHR trigger conditions A - D can take effect. For example, because there is no actual PHR transmission in scenario I, even if there is a large enough change in path loss or power back-off compared to the phr-Tx-PowerFactorChange parameter, the PHR trigger conditions A and D cannot take effect because there is no reference PHR transmission for comparison of path loss or power back-off. The inability to trigger the PHR in the case of large path loss or power back-off changes may result in wasted or insufficient transmission power for the SDT. In addition, since the phr-PeriodicTimer is not restarted, the PHR transmission trigger condition B will not take effect. Moreover, because inFigure 3 After the first new transmission without MAC reset or (re)configuration of PHR, the above trigger condition C will not be triggered either.

[0068] Figure 4 Another example scenario is further presented, which will not cause the permanent de - triggering of PHR, but may cause local obstruction or reduction of the PHR triggering function under the above PHR and SDT processes. Figure 4 The scenario is called Scenario II. Specifically, Figure 4 Shows a specific event / step sequence in SDT based on the above - described PHR and SDT processes, in which the triggering and transmission of PHR may be obstructed:

[0069] Step 1: In the first new transmission (referred to as new transmission 1), assume that the uplink grant(s) is sufficient to transmit data and the PHR MAC CE and its sub - header. Therefore, data and the PHR MAC CE are transmitted simultaneously during new transmission 1. According to the above PHR and SDT processes, when a new transmission of data and the PHR MAC CE is sent, the phr - PeriodicTimer and phr - ProhibitTimer are also started.

[0070] Step 2: The timer phr - ProhibitTimer expires.

[0071] Step 3: The timer phr - PeriodicTimer expires, and the PHR is triggered when the phr - PeriodicTimer expires according to the above PHR trigger condition B.

[0072] Step 4: Another data transmission (referred to as new transmission 2) is scheduled. In this scenario, assume that the uplink grant(s) is only sufficient to transmit the data of new transmission 2 and not sufficient to transmit the data and the triggered PHR MAC CE and its sub - header simultaneously. Therefore, according to the above PHR and SDT processes, all triggered PHRs are cancelled.

[0073] Step 5: After step 4, although it is still possible to trigger the PHR based on the above PHR trigger condition A or D, the PHR trigger under PHR trigger condition B is temporarily impossible. Therefore, the PHR trigger function may be obstructed. For example, the path loss or power back - off may remain stable, so the PHR trigger under PHR trigger condition A or D does not occur. However, there may be other reasons to trigger and transmit the PHR. But since the PHR trigger condition B may not occur, the PHR will not be triggered in a timely manner. The obstructed or untimely PHR trigger may lead to waste or insufficiency of the transmission power during the SDT process.

[0074] The main difference between the above-mentioned Scenario I and Scenario II is that in Scenario I, there is no actual PHR transmission. Therefore, the above-mentioned PHR trigger conditions A and D will not take effect, resulting in the PHR being possibly permanently disabled when the phr-PeriodicTimer has no chance to start or restart. While in Scenario II, there has been actual PHR transmission. Therefore, PHR trigger conditions A and D may still occur, but due to the phr-PeriodicTimer not being able to start or restart in time, the PHR function is hindered.

[0075] The above scenarios showing potential permanent PHR non-triggering or partial PHR triggering hindrance are just examples. When following the above PHR and SDT procedures, other scenarios may occur, in which the PHR trigger function may be completely or partially impaired.

[0076] Embodiments for Improving PHR Trigger Function

[0077] In the following further disclosure, in order to improve the PHR trigger function and timeliness in the SDT process in the above various scenarios, several embodiments are provided. The basic principles of these embodiments are applicable to improving the PHR trigger function in other scenarios where PHR trigger and transmission are completely or partially blocked. These embodiments and basic principles are applicable to the RA-SDT process or the CG-SDT process.

[0078] Embodiment 1 (Starting or restarting the phr-PeriodicTimer when canceling all triggered PHRs in the SDT process)

[0079] In this exemplary embodiment, when in the SDT process, because the uplink grant(s) can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, all triggered PHRs are canceled, and the MAC entity shall start or restart the phr-PeriodicTimer.

[0080] Described in another way, when there is an ongoing SDT process and the uplink grant(s) can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, all triggered PHRs shall be canceled, and the MAC entity shall start or restart the phr-PeriodicTimer.

[0081] Described in yet another way, when there is an ongoing SDT process and the uplink grant(s) can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, all triggered PHRs shall be canceled, and the phr-PeriodicTimer shall be started or restarted.

[0082] The term "start" refers to activating the phr-PeriodicTimer when it has expired and is not running before the phr-PeriodicTimer. The term "restart" refers to refreshing the phr-PeriodicTimer when it is still running and has not expired, causing it to count down from its full preset time value.

[0083] By forcing the start or restart of the phr-PeriodicTimer when the uplink grant(s) can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, the phr-PeriodicTimer can re-trigger the PHR transmission in Scenario I above when it expires (even if there has been no actual PHR transmission before). Additionally, the blockage caused by the inability of the phr-PeriodicTimer to trigger the PHR in Scenario II above may also be eliminated due to the forced start / restart of the phr-PeriodicTimer.

[0084] Figure 6 Figures 6 to 8 show several examples in which the above embodiments are applied to an event / step sequence to avoid potential permanent disabling or partial blockage of the PHR triggering function.

[0085] In Figure 5 the example of, Embodiment 1 is applied to Scenario I above. Specifically, during a new SDT transmission, when all triggered PHRs are cancelled because the UL grant is not sufficient to additionally accommodate any triggered PHR MAC CE, the MAC entity may start or restart the phr-PeriodicTimer. The following steps can be taken to avoid potential permanent de-triggering of the PHR:

[0086] Step 1: Configure and start the SDT process, and when the SDT process starts, trigger one or more PHRs because the above PHR triggering condition C is met (triggering the PHR when the power headroom reporting function is configured or reconfigured by the upper layer, and this PHR triggering is not used to disable the PHR function).

[0087] Step 2: The UE starts the phr-PeriodicTimer when transmitting the first new SDT transmission after the last MAC reset. In this scenario, it is assumed that the uplink grant(s) is only sufficient to transmit data and not sufficient to transmit both data and the triggered PHR MAC CE and its sub-header simultaneously. According to the above SDT / PHR procedure, all triggered PHR MAC CEs are not transmitted and are cancelled. Additionally, according to Embodiment 1, the MAC entity restarts the phr-PeriodicTimer (since the phr-PeriodicTimer was just started and is still running before the PHR was cancelled).

[0088] Step 3: The timer phr-PeriodicTimer expires, and a PHR is triggered according to the above PHR trigger condition B.

[0089] Step 4: Another new transmission (referred to as new transmission 1) is scheduled for transmission. In this scenario, it is again assumed that the uplink grant(s) is only sufficient to transmit the data of new transmission 1 and not sufficient to transmit both data and the triggered PHR MAC CE and its sub-header simultaneously. According to the above SDT / PHR procedure, all triggered PHR MAC CEs are not transmitted and are cancelled. Additionally, according to Embodiment 1, the MAC entity starts the phr-PeriodicTimer (since the phr-PeriodicTimer expired in Step 3 and the PHR triggered by this expiration was cancelled due to insufficient uplink grant).

[0090] Step 5: The timer phr-PeriodicTimer expires, and the PHR is re-triggered according to the above PHR trigger condition B.

[0091] Step 6: Another new transmission (referred to as new transmission 2) is scheduled for transmission. Now it is assumed that the uplink grant(s) is sufficient to transmit the data of new transmission 2 and the triggered PHR MAC CE and its sub-header. Since the PHR was triggered in Step 5 when the forcibly started phr-ProhibitTimer expired in Step 4, the UE is now allowed to transmit the triggered PHR MAC CE. According to the above SDT and PHR procedures, the UE also starts the phr-PeriodicTimer and the phr-ProhibitTimer when transmitting the new SDT transmission 2 with the PHR transmission.

[0092] At Figure 6In the example of , Embodiment 1 is applied to Scenario II. Particularly during a new SDT transmission, when all triggered PHRs are cancelled because the uplink grant is not sufficient to additionally accommodate any triggered PHR MAC CE, the MAC entity may start the phr-PeriodicTimer. The following steps can be taken to eliminate the PHR triggering obstacle caused by the lack of a running phr-PeriodicTimer:

[0093] Step 1: In the first new transmission (referred to as new transmission 1), assume that the uplink grant(s) is sufficient to transmit data and the PHR MAC CE and its sub-header. Therefore, data and the PHR MAC CE are transmitted simultaneously during new transmission 1. According to the above PHR and SDT procedures, when sending the data and the PHR MAC CE for the new transmission, the phr-PeriodicTimer and the phr-ProhibitTimer are also started.

[0094] Step 2: The timer phr-ProhibitTimer expires.

[0095] Step 3: The timer phr-PeriodicTimer expires, and a PHR is triggered when the phr-PeriodicTimer expires according to PHR triggering condition B above.

[0096] Step 4: Another data transmission (referred to as new transmission 2) is scheduled. In this scenario, assume that the uplink grant(s) is only sufficient to transmit the data for new transmission 2 and not sufficient to transmit the data and the triggered PHR MAC CE and its sub-header simultaneously. Therefore, according to the above PHR and SDT procedures, all triggered PHRs are cancelled. Additionally, according to Embodiment 1, the MAC entity starts the phr-PeriodicTimer (because the phr-PeriodicTimer has expired in Step 3 and the PHR triggered by the expiration of the phr-PeriodicTimer is cancelled due to insufficient uplink grant).

[0097] Step 5: The timer phr-PeriodicTimer expires, and the PHR is re-triggered according to PHR triggering condition B above.

[0098] Step 6: Another new transmission (referred to as new transmission 3) is scheduled for transmission. Now assume that the uplink grant(s) is sufficient to transmit the data of new transmission 3 and the triggered PHR MAC CE and its sub-header. Since the phr-ProhibitTimer that was forcibly started in Step 4 has expired, the PHR was triggered in Step 5, and the UE is now allowed to transmit the triggered PHR MAC CE. According to the above SDT and PHR procedures, when the UE sends new SDT transmission 3 with PHR transmission, it also starts the phr-PeriodicTimer and phr-ProhibitTimer.

[0099] In Figure 7 the example of, Embodiment 1 is also applied to Scenario II. In particular, during SDT transmission, when all PHRs are cancelled because the uplink grant is not sufficient to additionally accommodate any triggered PHR MAC CE, the MAC entity may restart the phr-PeriodicTimer. The following steps can be taken to eliminate the obstacle to PHR triggering caused by the lack of a running phr-PeriodicTimer:

[0100] Step 1: In the first new transmission (referred to as new transmission 1), assume that the uplink grant(s) is sufficient to transmit the data and the PHR MAC CE and its sub-header. Therefore, both the data and the PHR MAC CE are transmitted during new transmission 1. According to the above PHR and SDT procedures, when sending the data and PHR MAC CE of new transmission, the phr-PeriodicTimer and phr-ProhibitTimer are also started.

[0101] Step 2: The timer phr-ProhibitTimer expires, but the timer phr-PeriodicTimer is still running.

[0102] Step 3: Another data transmission (referred to as new transmission 2) is scheduled. Assume that since the last PHR transmission (which occurred in Step 1), the path loss or power back-off has changed by more than phr-Tx-PowerFactorChange dB. Therefore, at this time, the PHR may be triggered according to the above PHR trigger condition A or D. Also assume that the uplink grant(s) is only sufficient to transmit the data of new transmission 2 and not sufficient to transmit both the data and the triggered PHR MAC CE and its sub-header at the same time. Therefore, all triggered PHRs are cancelled according to the above PHR and SDT procedures. However, under Embodiment 1, the MAC entity may additionally restart the phr-PeriodicTimer (this is a restart rather than a start because the phr-PeriodicTimer is still running and has not expired).

[0103] Step 4: The timer phr-PeriodicTimer expires and triggers a PHR when phr-PeriodicTimer expires according to the above PHR triggering condition B.

[0104] Step 5: Another new transmission (referred to as new transmission 3) is scheduled for transmission. Now assume that the uplink grant(s) is sufficient to transmit the data of new transmission 3 and the triggered PHR MAC CE and its sub-header. Since the PHR was triggered in Step 4 due to the expiration of the phr-ProhibitTimer that was forcibly restarted in Step 3, the UE is now allowed to transmit the triggered PHR MAC CE. According to the above SDT and PHR procedures, when the UE sends a new SDT transmission 3 with a PHR transmission, it also starts the phr-PeriodicTimer and the phr-ProhibitTimer.

[0105] Embodiment 2 (Regarding an SDT transmission without a PHR transmission as a PHR transmission)

[0106] In this exemplary embodiment, during the SDT process, when all triggered PHRs are cancelled because the uplink grant is sufficient to accommodate all the pending data to be transmitted but not sufficient to additionally accommodate the triggered PHR MAC CE and its sub-header, the current transmission is regarded as a PHR transmission by the UE (e.g., the MAC entity of the UE).

[0107] Described in another way, when there is an ongoing SDT process and the uplink grant can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, all triggered PHRs should be cancelled and the current transmission is regarded as a PHR transmission.

[0108] In some exemplary embodiments, regarding an SDT transmission with a cancelled PHR as a PHR transmission may involve several operations of the UE. For example, the UE may calculate the current path loss, power back-off, or both during the SDT transmission and store the results as values corresponding to the current transmission, thereby creating a reference for comparing the path loss or power back-off during the next SDT transmission to evaluate whether to trigger a PHR according to the above PHR triggering condition A or D.

[0109] The above Embodiment 2 helps to prevent Figure 3The PHR for Medium Scenario I is permanently de-triggered or cancelled because it effectively creates a PHR transmission even when there isn't one in reality, as in the case of Scenario I. The consequence of this consideration is to provide a potential PHR trigger based on the above PHR trigger conditions A or D. In particular, since SDT data transmissions without a PHR are considered PHR transmissions, when the phr-ProhibitTimer expires or has expired, the PHR trigger condition based on a change in path loss or power back-off exceeding the threshold may still occur, thus avoiding the situation of permanent PHR de-triggering or cancellation.

[0110] The above Embodiment 2 also helps to improve Figure 4 the PHR trigger for Medium Scenario II. Specifically, referring to Figure 4 , the new SDT transmission 2 without a PHR is considered a PHR transmission, then the "previous" PHR transmission is effectively updated from the earlier actual PHR transmission together with the new transmission 1 to the new transmission 2, thus providing a more relevant and up-to-date comparison of path loss or power back-off for future determination of PHR triggers based on the above PHR trigger conditions A or D.

[0111] To specifically illustrate this improvement in Scenario II, assume that Figure 4 the path loss of the new transmission 1 is 100 dB, then it changes to 105 dB at the new transmission 2, and then changes back to 100 dB at the new transmission 3. If such a consideration is not made according to Embodiment 2, then when determining the path loss change at the new transmission 3, it will be compared with the path loss of the actual PHR transmission in the new transmission 1. In this specific example, the change is small or there is no change (both are 100 dB). Therefore, this change will be less than the threshold phr-Tx-PowerFactorChange. Thus, even when the phr-ProhibitTimer expires or has expired, no PHR will be triggered at the new transmission 3. In other words, when the most recently updated path loss condition requires a PHR transmission to be triggered (a 5 dB change between the new transmission 2 and the new transmission 3), an implementation that does not handle it according to Embodiment 2 may unfavorably prevent the PHR from being triggered in some cases.

[0112] To provide another specific example of PHR trigger improvement, assume that Figure 4The path loss of the new transmission 1 is 105 dB, then the path loss becomes 100 dB during the new transmission 2, and remains 100 dB unchanged during the new transmission 3. If there is no Example 2, then during the new transmission 3, it is determined that the path loss change will be compared with the path loss of the actual PHR transmission in the new transmission 1. In this specific example, the change is 5 dB. Assuming that this change is greater than the threshold phr-Tx-PowerFactorChange, if the phr-ProhibitTimer expires or has expired, the UE will decide to trigger a PHR according to the PHR trigger condition A during the new transmission 3. However, such a PHR trigger may be unnecessary because the path loss does not change from the new transmission 2 to the new transmission 3. Instead, implementing according to the method of Example 2 will advantageously regard the new transmission 2 as a PHR transmission and use it as a reference for the path loss, thus obtaining a more appropriate judgment that no PHR is triggered.

[0113] Example 3 (combining Example 1 and Example 2)

[0114] In Example 3, the processes in Example 1 and Example 2 may be carried out simultaneously. Specifically, during the SDT process, when all triggered PHRs are cancelled because the uplink grant can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, the current transmission should be regarded as a PHR transmission, and the MAC entity should start or restart the phr-PeriodicTimer.

[0115] Described in another way, when there is an ongoing SDT process and the uplink grant can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, all triggered PHRs should be cancelled, the current transmission should be regarded as a PHR transmission, and at the same time, the phr-PeriodicTimer should be started or restarted.

[0116] Described in yet another way, when there is an ongoing SDT process and the uplink grant can accommodate all the pending data to be transmitted but is not sufficient to additionally accommodate the PHR MAC CE and its sub-header, all triggered PHRs should be cancelled, the current transmission should be regarded as a PHR transmission, and the MAC entity should start or restart the phr-PeriodicTimer.

[0117] In some exemplary embodiments, regarding the SDT transmission where the PHR is cancelled as a PHR transmission may involve several operations of the UE. For example, the UE may calculate the current path loss, power back-off, or both during the SDT transmission and store the results as values corresponding to the current transmission, so as to create a reference for comparing the path loss or power back-off during the next SDT transmission to evaluate whether to trigger a PHR according to the above PHR trigger conditions A or D.

[0118] Embodiment 3 essentially provides the benefits of improving the timeliness of PHR triggering and transmission in a wider range of scenarios during the SDT process, and these benefits are derived from Embodiment 1 and Embodiment 2.

[0119] As a summary of the above disclosure, the various embodiments disclosed herein essentially relate to activating some example UE actions or processes when, during the execution of an SDT transmission, the uplink grant is sufficient to transmit the SDT but not sufficient to additionally transmit any PHR. For example, these UE actions or processes may involve starting / restarting a timer (which, when it expires, configures the triggering of a PHR), or treating the SDT transmission as a PHR transmission, or both. Such a process helps prevent potential permanent de-triggering or cancellation of the PHR as in Scenario I of Figure 3 or reduce the potential hindrance to PHR triggering as in Scenario II of Figure 4 or improve the timeliness of PHR triggering and transmission in other scenarios.

[0120] The above description and the accompanying drawings provide specific example embodiments and implementations. However, the described subject matter may be embodied in various different forms, and thus, the subject matter covered or claimed is intended to be construed as not limited to any of the example embodiments set forth herein. A reasonably broad scope of the subject matter claimed or covered is contemplated. Among other things, for example, the subject matter may be implemented as a method, apparatus, component, system, or non-transitory computer-readable medium for storing computer code. Thus, the embodiments may take, for example, the form of hardware, software, firmware, a storage medium, or any combination thereof. For example, the method embodiments described above may be implemented by a component, device, or system including a memory and a processor by executing computer code stored in the memory.

[0121] Throughout the specification and claims, terms may have nuances that are implied or implicit in the context, beyond the explicit meaning stated. Similarly, the phrase "in one embodiment / implementation" used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment / implementation" does not necessarily refer to a different embodiment. For example, the claimed subject matter is intended to include combinations of example embodiments, whether in whole or in part.

[0122] Generally, terms can be understood, at least in part, from their use in context. For example, terms such as "and", "or", and "and / or" used herein may have a variety of meanings that depend, at least in part, on the context in which they are used. Generally, if "or" is used to associate a list, such as A, B, or C, it is intended to mean A, B, and C, here used in an inclusive sense, as well as A, B, or C, here used in an exclusive sense. Additionally, the term "one or more" used herein can, at least in part, depending on the context, be used to describe a singular sense of any feature, structure, or characteristic, or to describe a plural sense of a combination of features, structures, or characteristics. Similarly, terms such as "a", "an", or "the" can be understood, at least in part, depending on the context, to convey a singular use or to convey a plural use. Further, the term "based on" may be understood to not necessarily intend to convey an exclusive set of factors, but may allow for the existence of additional factors that are not necessarily expressly described, again, at least in part, depending on the context.

[0123] Features, advantages, or similar language mentioned throughout the specification do not preclude that all features and advantages of the current solution that may be realized should be included in any single embodiment. On the contrary, language referring to features and advantages is understood to mean that a particular feature, advantage, or characteristic described as being associated with a certain embodiment is included in at least one embodiment of the current solution. Thus, the discussion of features and advantages throughout the specification and similar language may, but does not necessarily, refer to the same embodiment.

[0124] Moreover, the described features, advantages, and characteristics of the current solution can be combined in any suitable manner in one or more embodiments. Those of ordinary skill in the relevant art will recognize, based on the description herein, that the current solution can be practiced without one or more particular features or advantages of a particular embodiment. In other instances, additional features and advantages may be identified in certain embodiments that may not be present in all embodiments of the current solution.

Claims

1. A method for a wireless terminal device to transmit a data payload during a small data transfer (SDT) process, comprising: Determining that the wireless transmission resources allocated by a wireless base station for the SDT process are sufficient to transmit the data payload, but insufficient to additionally send a power headroom report (PHR) to the wireless base station; And In response to the determination: Transmitting the data payload to the wireless base station using the wireless transmission resources without any PHR; Canceling all triggered PHRs; And Activating at least one predetermined process to facilitate PHR triggering.

2. The method according to claim 1, wherein The at least one predetermined process includes starting or restarting a predetermined timer, wherein the predetermined timer is configured to trigger a PHR upon its expiration.

3. The method according to claim 2, wherein: No previous PHR has been sent during the SDT process; and No new PHR will be triggered without activating the at least one predetermined process.

4. The method according to claim 2, wherein: At least one previous PHR has been sent during the SDT process; And The probability of untimely PHR transmission is reduced compared to when the at least one predetermined process is not activated.

5. The method according to claim 1, wherein The at least one predetermined process includes treating the transmission of the data payload as a PHR transmission.

6. The method according to claim 5, further comprising: Modifying at least one state of the wireless terminal device to reflect that the most recent PHR transmission has effectively occurred during the transmission of the data payload.

7. The method according to claim 1, wherein The at least one predetermined process includes: Starting or restarting a predetermined timer, wherein the predetermined timer is configured to trigger a PHR upon its expiration; and Treating the transmission of the data payload as a PHR transmission.

8. The method according to claim 7 further comprises: Modifying at least one state of the wireless terminal device to reflect that the most recent PHR transmission has effectively occurred during the transmission of the data payload.

9. The method according to claim 7, wherein: No previous PHR has been sent during the SDT process; and No new PHR will be triggered without activating the at least one predetermined process.

10. The method according to claim 7, wherein: At least one previous PHR has been sent during the SDT process; And The probability of untimely PHR transmission is reduced compared to when the at least one predetermined process is not activated.

11. A wireless terminal device, comprising a memory for storing instructions and a processor configured to execute the instructions to cause the wireless terminal device to perform the following operations: Determine that the radio transmission resources allocated by the radio base station for the small data transmission SDT procedure are sufficient to transmit the data payload, but not sufficient to additionally send a power headroom report PHR to the radio base station; And In response to the determination: Transmitting the data payload to the wireless base station using the wireless transmission resources without any PHR; Canceling all triggered PHRs; And Activating at least one predetermined process to facilitate PHR triggering.

12. The wireless terminal device according to claim 11, wherein, The at least one predetermined process includes starting or restarting a predetermined timer, wherein the predetermined timer is configured to trigger a PHR upon its expiration.

13. The wireless terminal device according to claim 12, wherein: No previous PHR has been sent during the SDT process; and No new PHR will be triggered without activating the at least one predetermined process.

14. The wireless terminal device according to claim 12, wherein: At least one previous PHR has been sent during the SDT process; and The probability of untimely PHR transmission is reduced compared to when the at least one predetermined process is not activated.

15. The wireless terminal device according to claim 11, wherein, The at least one predetermined process includes treating the transmission of the data payload as a PHR transmission.

16. The wireless terminal device according to claim 15, wherein, The processor is configured to execute the instructions to cause the wireless terminal device to modify at least one state of the wireless terminal device to reflect that a most recent PHR transmission has effectively occurred when transmitting the data payload.

17. The wireless terminal device according to claim 11, wherein, The at least one predetermined process includes: Starting or restarting a predetermined timer, where the predetermined timer is configured to trigger a PHR upon its expiration; and Treating the transmission of the data payload as a PHR transmission.

18. The wireless terminal device according to claim 17, wherein, The processor is configured to execute the instructions to cause the wireless terminal device to modify at least one state of the wireless terminal device to reflect that a most recent PHR transmission has effectively occurred when transmitting the data payload.

19. The wireless terminal device according to claim 17, wherein: No previous PHR has been sent during the SDT process; and Without activating the at least one predetermined process, no new PHR is triggered.

20. The wireless terminal device according to claim 17, wherein: At least one previous PHR has been sent during the SDT process; and The probability of untimely PHR transmission is reduced compared to when the at least one predetermined process is not activated.

21. A computer-readable non-transitory medium for storing computer instructions, the computer instructions when executed by a processor of a wireless terminal device cause the wireless terminal device to: Determine that the radio transmission resources allocated by the radio base station for the small data transmission SDT process are sufficient to transmit the data payload, but not sufficient to additionally send a power headroom report PHR to the radio base station; and In response to the determination: Transmit the data payload to the wireless base station using the wireless transmission resources without any PHR; Cancel all triggered PHRs; and Activate at least one predetermined process to facilitate PHR triggering.

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