WO2020211040A1

WO2020211040A1 - Method for communication, terminal device, and computer readable medium

Info

Publication number: WO2020211040A1
Application number: PCT/CN2019/083237
Authority: WO
Inventors: Zhaobang MIAO; Gang Wang
Original assignee: Nec Corporation
Priority date: 2019-04-18
Filing date: 2019-04-18
Publication date: 2020-10-22
Also published as: JP2023110023A; JP2022532484A

Abstract

Embodiments of the present disclosure provide a solution for allocating transmission power for simultaneous transmissions. In a method for communication, a terminal device selects a first transmission or a second transmission as a secondary transmission with a lower transmission requirement. The first transmission is to be performed in a first period and the second transmission is to be performed in a second period overlapping with the first period. The terminal device adjusts transmission power of the secondary transmission in an overlapped portion between the first and second periods, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device. The embodiments of the present disclosure provide a feasible and reasonable solution for power allocation for simultaneous transmissions.

Description

METHOD FOR COMMUNICATION, TERMINAL DEVICE, AND COMPUTER READABLE MEDIUM

FIELD

Embodiments of the present disclosure generally relate to the field of communication, and in particular, to allocation of transmission power for simultaneous transmissions of a terminal device in a wireless communication.

BACKGROUND

The latest developments of the 3GPP standards are referred to as Long Term Evolution (LTE) of Evolved Packet Core (EPC) network and Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) , also commonly termed as ‘4G. ’ In addition, the term ‘5G New Radio (NR) ’ refers to an evolving communication technology that is expected to support a variety of applications and services. The 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (for example, with Internet of Things) , and other requirements. Some aspects of the 5G NR may be based on the 4G Long Term Evolution (LTE) standards.

In many communication scenarios in a 5G NR system, a terminal device may need to perform a plurality of transmissions simultaneously. However, total available transmission power of the terminal device for performing these transmissions at the same time is limited. Therefore, there is a need for a feasible and reasonable solution of allocating transmission power among different simultaneous transmissions.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for allocating transmission power for simultaneous transmissions.

In a first aspect, there is provided a method for communication. The method comprises selecting, at a terminal device, a first transmission or a second transmission as a secondary transmission with a lower transmission requirement. The first transmission is to be performed in a first period and the second transmission is to be performed in a second period overlapping with the first period. The method also comprises adjusting transmission power of the secondary transmission in an overlapped portion between the first and second periods, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device.

In a second aspect, there is provided a method for communication. The method comprises selecting, at a terminal device, a first sidelink transmission or a second sidelink transmission as a secondary sidelink transmission with a lower transmission requirement. The first sidelink transmission is to be performed in a first period and the second sidelink transmission is to be performed in a second period. The method also comprises selecting the secondary sidelink transmission or an uplink transmission as a target transmission with a lower transmission requirement. The uplink transmission is to be performed in a third period. The first, second and third periods have an overlapped portion. The method further comprises adjusting transmission power of the target transmission in the overlapped portion, such that total transmission power of the first and second sidelink transmissions and the uplink transmission is below available transmission power of the terminal device.

In a third aspect, there is provided a method for communication. The method comprises determining, at a terminal device, a first transmission to be performed in a first period and a second transmission to be performed in a second period overlapping with the first period. The method also comprises determining that the first period has an earlier start time than the second period. The method further comprises maintaining transmission power of the first transmission unchanged in the first period.

In a fourth aspect, there is provided a terminal device. The terminal device comprises a processor and a memory storing instructions. The memory and the instructions are configured, with the processor, to cause the terminal device to select a first transmission or a second transmission as a secondary transmission with a lower transmission requirement. The first transmission is to be performed in a first period and the second transmission is to be performed in a second period overlapping with the first period. The memory and the instructions are also configured, with the processor, to cause the terminal device to adjust transmission power of the secondary transmission in an overlapped portion between the first and second periods, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device.

In a fifth aspect, there is provided a terminal device. The terminal device comprises a processor and a memory storing instructions. The memory and the instructions are configured, with the processor, to cause the terminal device to select a first sidelink transmission or a second sidelink transmission as a secondary sidelink transmission with a lower transmission requirement. The first sidelink transmission is to be performed in a first period and the second sidelink transmission is to be performed in a second period. The memory and the instructions are also configured, with the processor, to cause the terminal device to select the secondary sidelink transmission or an uplink transmission as a target transmission with a lower transmission requirement. The uplink transmission is to be performed in a third period. The first, second and third periods have an overlapped portion. The memory and the instructions are further configured, with the processor, to cause the terminal device to adjust transmission power of the target transmission in the overlapped portion, such that total transmission power of the first and second sidelink transmissions and the uplink transmission is below available transmission power of the terminal device.

In a sixth aspect, there is provided a terminal device. The terminal device comprises a processor and a memory storing instructions. The memory and the instructions are configured, with the processor, to cause the terminal device to determine a first transmission to be performed in a first period and a second transmission to be performed in a second period overlapping with the first period. The memory and the instructions are also configured, with the processor, to cause the terminal device to determine that the first period has an earlier start time than the second period. The memory and the instructions are further configured, with the processor, to cause the terminal device to maintain transmission power of the first transmission unchanged in the first period.

In a seventh aspect, there is provided a computer readable medium having instructions stored thereon. The instructions, when executed on at least one processor of a device, cause the device to carry out the method according to the first, second, or third aspect.

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

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

Fig. 1 is a schematic diagram of a communication environment in which some embodiments of the present disclosure can be implemented;

Fig. 2 shows a flowchart of an example method in accordance with some embodiments of the present disclosure;

Fig. 3 shows a flowchart of an example process in accordance with some embodiments of the present disclosure;

Fig. 4 shows a flowchart of another example process in accordance with some embodiments of the present disclosure;

Fig. 5 shows a flowchart of another example method in accordance with some embodiments of the present disclosure;

Fig. 6 shows a schematic diagram of different subframes for different transmissions with different durations in accordance with some embodiments of the present disclosure;

Fig. 7 shows a flowchart of another example method in accordance with some embodiments of the present disclosure; and

Fig. 8 is a simplified block diagram of a device that is suitable for implementing some embodiments of the present disclosure.

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

DETAILED DESCRIPTION OF EMBODIMENTS

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

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

As used herein, the term “network device” or “base station” (BS) refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an Evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNB) , an infrastructure device for a V2X (vehicle-to-everything) communication, a Transmission/Reception Point (TRP) , a Remote Radio Unit (RRU) , a radio head (RH) , a remote radio head (RRH) , a low power node such as a femto node, a pico node, and the like.

As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of the terminal device include, but not limited to, user equipment (UE) , vehicle-mounted terminal devices, devices of pedestrians, roadside units, personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, image capture devices such as digital cameras, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like. For the purpose of discussion, in the following, some embodiments will be described with reference to UEs as examples of terminal devices and the terms “terminal device” and “user equipment” (UE) may be used interchangeably in the context of the present disclosure.

As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.

In some examples, values, procedures, or apparatus are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

Fig. 1 is a schematic diagram of a communication environment 100 in which some embodiments of the present disclosure can be implemented. As shown in Fig. 1, the communication environment 100 may include a first network device 110 and a second network device 120, which provide wireless connections for a plurality of

terminal devices

130, 140, and 150 within their coverage. Although a common coverage of the first network device 110 and the second network device 120 is depicted in Fig. 1, it is understood that the first network device 110 and the second network device 120 may have their respective serving cells, which are not shown in Fig. 1.

In some embodiments, the first network device 110 may be a gNB which is operated with the 5G NR technology, and the second network device 120 may be an eNB which is operated with the LTE technology. In some other embodiments, the first network device 110 and the second network device 120 may be any network devices using a same radio access technology (RAT) or different RATs. As shown in Fig. 1, the

terminal devices

130, 140, and 150 are schematically depicted as mobile phones. However, it is understood that this depiction is only for example without suggesting any limitation. In other embodiments, the

terminal devices

130, 140, and 150 may be any other wireless communication devices, for example, vehicle-mounted terminal devices.

The terminal device 130 may communicate with the network device 110 via wireless transmissions 115, 117, and 119. As used herein, the transmission 115 from the terminal device 130 to the network device 110 may be referred to as an uplink transmission 115, whereas the transmission 117 from the network device 110 to the terminal device 130 may alternatively be referred to as a downlink transmission 117.

In addition, while the terminal device 130 is performing the uplink transmission 115 to the network device 110, the terminal device 130 may simultaneously perform another uplink transmission 119 to the network device 110. In other words, the uplink transmissions 115 and 119 are overlapping with each other in time domain. In some embodiments, the uplink transmission 115 may include an Ultra-Reliable Low Latency Communication (URLLC) uplink transmission and the uplink transmission 119 may include a common uplink transmission, namely, does not include a URLLC uplink transmission.

Likewise, the transmission 125 from the terminal devices 130 to the network device 120 may be referred to as an uplink transmission 125, whereas the transmission 127 from the network device 120 to the terminal device 130 may alternatively be referred to as a downlink transmission 127. In a similar manner, each of the

terminal devices

140 and 150 may have wireless links (not shown) with one or both of the

network devices

110 and 120.

In addition to the communications via the

network devices

110 and 120, the terminal device 130 may communicate with the

terminal devices

140 and 150 via device-to-device (D2D)

transmissions

135 and 145, respectively. In some embodiments, the D2D transmission 135 and the D2D transmission 145 may use a same RAT, such as, the 5G NR technology. In some other embodiments, the D2D transmission 135 and the D2D transmission 145 may use different RATs. For example, the D2D transmission 135 uses the 5G NR technology, namely it is an NR sidelink transmission, whereas the D2D transmission 145 uses the LTE technology, namely it is an LTE sidelink transmission.

Although not shown in Fig. 1, there may also be D2D communications among the

terminal devices

140 and 150 as well as other terminal devices. As used herein, D2D communication links for D2D communications among the

terminal devices

130, 140, and 150 as well as other terminal devices not shown may also be referred to as sidelinks. As a result, the

D2D transmissions

135 and 145 may also be referred to as

sidelink transmissions

135 and 145. In case that the

terminal devices

130, 140, and 150 are vehicle-mounted terminal devices, the communications relate to the

terminal devices

130, 140, and 150 may be referred to as V2X communications. More generally, although not shown in Fig. 1, a V2X communication related to the

terminal device

130, 140, or 150 may comprise a communication between the

terminal device

130, 140, or 150 and any other communication device, including but not limited to an infrastructure device, another vehicle-mounted terminal device, a device of a pedestrian, a roadside unit, or the like.

It is to be understood that the number of network devices and the number of terminal devices as shown in Fig. 1 are only for the purpose of illustration without suggesting any limitations. The communication environment 100 may include any suitable number of network devices and any suitable number of terminal devices adapted for implementing embodiments of the present disclosure. In addition, it would be appreciated that there may be various wireless communications as well as wireline communications (if needed) among these additional network devices and additional terminal devices.

The communications in the communication environment 100 may conform to any suitable standards including, but not limited to, Global System for Mobile Communications (GSM) , Extended Coverage Global System for Mobile Internet of Things (EC-GSM-IoT) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , GSM EDGE Radio Access Network (GERAN) , and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols.

As mentioned above, total available transmission power of a terminal device for performing a plurality of transmissions at the same time is limited. In general, the total available transmission power of a terminal device is the maximum transmission power of the terminal device. Therefore, according to current protocols, if a sidelink transmission to be performed by a terminal device on a carrier overlaps in time domain with other sidelink transmission (s) or an uplink transmission to be performed on other carder (s) , and total transmission power of these transmissions exceeds the maximum transmission power of the terminal device, then the terminal device shall adjust transmission power of at least one of the transmissions, such that their total transmission power does not exceed the maximum transmission power of the terminal device.

In the meanwhile, different from a LTE system, a 5G NR uplink supports URLLC traffic which has extremely strict reliability and latency requirements. Thus, degradation of performance of the URLLC transmission may need to be avoided. On the other hand, sidelink transmissions (for example, V2X) in a 5G NR system can also support some important packet types. Further, NR V2Xs, as well as NR uplinks, can support various types of numerology. In other words, these transmissions may have subframes with different durations. In view of these technical natures and requirements, there are some issues in traditional communication systems.

In traditional solutions, when a terminal device determines whether a sidelink transmission has priority over an uplink transmission, a “priority” comparison is done between a priority of the sidelink transmission and a threshold priority pre-configured for sidelink transmissions, without considering Uu (User Equipment to the UMTS Terrestrial Radio Access Network) uplink, that is, the comparison is made inside the sidelink function itself. However, the NR Uu supports URLLC traffic whose performance may need not to be degraded by reducing transmission power. For example, if an NR sidelink transmission (with a priority value less than a predefined threshold value, which means that the NR sidelink transmission has a high priority) overlaps with an NR URLLC uplink transmission, the performance of the NR URLLC traffic would be degraded after reducing the transmission power of the uplink transmission according to the existing prioritization rule.

In addition, existing power scaling is done in any overlapped portion of the subframes for the simultaneous transmissions, but a subframe boundary of carriers for performing different transmissions may not be aligned, due to timing error and/or different types of numerology, for example. As a result, a power transition within a subframe (or a time slot) may be possible and need to be considered, for example, to be avoided. Further, in the case that there are multiple sidelink transmissions overlapping with an uplink transmission, according to the existing prioritization rule, a terminal device cannot determine whether to compare the multiple sidelink transmissions or compare one of the sidelink transmissions with the uplink transmission to scale the total transmission power down.

In order to solve the above technical problems and potentially other technical problems in conventional solutions, embodiments of the present disclosure provide a solution for allocating transmission power for simultaneous transmissions. In particular, some embodiments define a proper prioritization rule among various transmissions, including between a sidelink transmission and an uplink transmission, between multiple sidelink transmissions, and between other transmissions with different types and/or different RATs.

In some embodiments, the proposed rule may be based on a multi-stage comparison approach between different transmissions. In some embodiments, an indication may be provided for an important uplink transmission, such as a URLLC uplink transmission. Alternatively, the important uplink transmission can be identified by a terminal device from a set of transmission parameters. In some embodiments, a power control behavior in advance may be defined to avoid a power transition in a subframe. Embodiments of the present disclosure provide a feasible and reasonable solution for power allocation among simultaneous transmissions, which is well worked between various transmissions, such as an NR sidelink transmission and an NR Uu uplink transmission. Principles and implementations of the present disclosure will be described in detail below with reference to the figures.

Fig. 2 shows a flowchart of an example method 200 in accordance with some embodiments of the present disclosure. The method 200 can be implemented at a terminal device, such as the terminal device 130 as shown in Fig. 1. Additionally or alternatively, the method 200 can also be implemented at the

terminal devices

140 and 150, as well as other terminal devices not shown in Fig. 1. For the purpose of discussion, the method 200 will be described with reference to Fig. 1 as performed by the terminal device 130 without loss of generality.

As mentioned above, in various communication scenarios, the terminal device 130 may need to perform a plurality of transmissions overlapped in time domain. For example, the terminal device 130 is to perform a first transmission in a first period and is to perform a second transmission in a second period overlapping with the first period. In such communication scenarios, the terminal device 130 may need to ensure total transmission power of the first and second transmissions does not exceed available transmission power of the terminal device 130. Otherwise, both the first and second transmissions may not be performed properly by the terminal device 130. In some embodiments, the available transmission power of the terminal device 130 may be the maximum transmission power of the terminal device 130. In some other embodiments, the available transmission power of the terminal device 130 may be particular transmission power specified by applicable regulations or configurations of the terminal device 130.

However, first transmission power of the first transmission and second transmission power of the second transmission may be calculated by the terminal device 130 separately according to different transmission power control functions. In other words, a sum of the separately calculated first transmission power and second transmission power can exceed the available transmission power of the terminal device 130. Thus, the terminal device 130 may need to adjust the transmission power of at least one of the first and second transmissions, such that the total transmission power of the first and second transmissions does not exceed the available transmission power of the terminal device 130.

Typically, the terminal device 130 adjusts the transmission power of one transmission, and thus performance of the other transmission may not be degraded. In general, the terminal device 130 may adjust the transmission power of the secondary one of the first and second transmissions, namely, the transmission with less importance. In other words, the performance of the more important transmission would not be impacted.

Accordingly, at block 210, the terminal device 130 selects the first transmission or the second transmission as a secondary transmission with a lower transmission requirement. The lower transmission requirement can indicate that the secondary transmission is less important than the other transmission. That is, the terminal device 130 determines which transmission of the first and second transmissions is less important than the other transmission. Then, the terminal device 130 may adjust the transmission power of the less important transmission, so as to prevent the performance of the more important transmission from being degraded. This is reasonable since the more important transmission takes precedence over the secondary transmission.

In different communication scenarios, the first transmission may comprise various transmissions with respective types or RATs, the second transmission may also comprise various transmissions with respective types or RATs, the first and second transmissions may have a same type and/or RAT, or they can have different types and/or RATs. In the following, some embodiments will be detailed with respect to these different scenarios.

In a first scenario, the first transmission may comprise a sidelink transmission, such as the sidelink transmission 135 from the terminal device 130 to the terminal device 140 as depicted in Fig. 1, which is to be performed according to the 5G NR technology, or the sidelink transmission 145 from the terminal device 130 to the terminal device 150 as depicted in Fig. 1, which is to be performed according to the LTE technology. More generally, the first transmission may include a sidelink transmission of any RAT.

Further, in the first scenario, the second transmission may comprise an uplink transmission, such as the uplink transmission 115 from the terminal device 130 to the network device 110 as depicted in Fig. 1, which is to be performed according to the 5G NR technology, or the uplink transmission 125 from the terminal device 130 to the network device 120 as depicted in Fig. 1, which is to be performed according to the LTE technology. Similar to the first transmission, the second transmission may include an uplink transmission of any RAT more generally.

A specific example of the first scenario may be that, in the NR sidelink transmission mode 1 or 2 (as specified in 3GPP specifications) , the sidelink transmission 135 of the terminal device 130 in a subframe overlaps in time domain with its uplink transmission (s) 115 and/or 125 occurring on serving cell (s) where the sidelink transmission does not occur. The following description takes the sidelink transmission 135 as the first transmission and the uplink transmission 115 as the second transmission without loss of generality.

In such a first scenario, the terminal device 130 may determine whether the sidelink transmission 135 is more important than the uplink transmission 115 by comparing a transmission requirement of the sidelink transmission 135 with a predetermined threshold. In some embodiments, the transmission requirement may include a reliability requirement, a latency requirement, or the like. For example, if the reliability requirement of the sidelink transmission 135 exceeds threshold reliability (which may be referred to as thresSL-TxReliability) , meaning that the sidelink transmission 135 has a high reliability requirement, then the terminal device 130 can determine the uplink transmission 115 as the secondary transmission.

Alternatively or additionally, if the latency requirement of the sidelink transmission 135 is below threshold latency (which may be referred to as thresSL-TxLatency) , meaning that the sidelink transmission 135 has a strict latency requirement, the terminal device 130 can determine the uplink transmission 115 as the secondary transmission. In some embodiments, the threshold reliability and the threshold latency could be configured through radio resource control (RRC) signaling (for example, a system information block, SIB) or could be pre-configured. By comparing the reliability requirement and/or the latency requirement of the sidelink transmission 135 with the threshold reliability and/or the threshold latency, it can be ensured that an important uplink transmission, such as a URLLC uplink transmission, would only be impacted by an extremely important sidelink transmission.

As used herein and defined in 3GPP specification TS 22.186, End-to-end latency (latency for short) may refer to the time taken to transfer a given piece of information from a source to a destination, measured at the application level, from the moment it is transmitted by the source to the moment it is received at the destination. As used herein and defined in 3GPP specification TS 22.186, reliability (which may be a percentage) may refer to the success probability of transmitting X bytes (X refers to a natural number) within a certain delay, which is the time taken to deliver a small data packet from the radio protocol layer 2/3 service data unit (SDU) ingress point to the radio protocol layer 2/3 SDU egress point of the radio interface. In some embodiments, the reliability requirement and the latency requirement of the sidelink transmission 135 may be specified in a “reliability” field and a “latency” field in sidelink control information (SCI) of the sidelink transmission 135.

In addition to the reliability and latency requirements, the transmission requirement of the sidelink transmission 135 may also include a priority, which may be the priority as defined in the 3GPP specification TS 23.285 and/or TS 23.303 and which may be specified in a “priority” field in the SCI of the sidelink transmission 135. That is, besides the reliability and latency requirements, the priority of the sidelink transmission 135 may also be used as a consideration in determining whether the sidelink transmission 135 is more important than the uplink transmission 115. This will be detailed as below with reference to Fig. 3.

Fig. 3 shows a flowchart of . an example process 300 in accordance with some embodiments of the present disclosure. The process 300 may be considered as an example embodiment of the block 210 of the method 200. At block 302, the terminal device 130 determines whether the reliability requirement of the sidelink transmission 135 exceeds the threshold reliability. If the reliability requirement of the sidelink transmission 135 exceeds the threshold reliability, meaning that the sidelink transmission 135 has a high reliability requirement, then the process 300 proceeds to block 304. Otherwise, the process 300 proceeds to block 310, where the terminal device 130 determines the sidelink transmission 135 as the secondary transmission, since the sidelink transmission 135 does not have a high reliability requirement.

At block 304, the terminal device 130 determines whether the latency requirement of the sidelink transmission 135 is below the threshold latency. If the latency requirement of the sidelink transmission 135 is below the threshold latency, meaning that the sidelink transmission 135 has a strict latency requirement, then the process 300 proceeds to block 306. Otherwise, the process 300 proceeds to block 310, where the terminal device 130 determines the sidelink transmission as the secondary transmission, since the sidelink transmission 135 does not have a strict latency requirement. In some embodiments, the order of the block 302 and the block 304 may be reversed, namely, the block 304 may be performed before the block 302. In both orders, the threshold reliability may be set to a relatively high value, and the threshold latency may be set to a relatively small value, so as to filter out most of sidelink transmissions in determining the uplink transmission 115 as the secondary transmission, and thus ensure the performance of a potential URLLC uplink transmission.

At block 306, the terminal device 130 determines whether the priority of the sidelink transmission 135 exceeds a threshold priority. In practice, the priority of the sidelink transmission 135 may be indicated by a priority value and a smaller priority value may correspond to a higher priority. For example, as defined in the 3GPP specification TS 23.285, a predefined number (such as, three) of bits can be used to indicate such a priority value. As another example, the priority value may be a ProSe Per-Packet Priority (PPPP) defined in the 3GPP specification TS 23.303. However, it is understood that the priority value indicating the priority of the sidelink transmission 135 may also be designed such that a greater priority value corresponds to a higher priority.

Similarly, the threshold priority can be represented by a threshold priority value (which may be referred to as thresSL-TxPrioritization) . In case a smaller priority value indicates a higher priority, if the priority value of the sidelink transmission 135 is less than or equal to the threshold priority value, the sidelink transmission 135 may be considered to have a high priority. In some embodiments, the threshold priority could be configured through RRC signaling (such as, a SIB) or could be pre-configured. It is assumed that the terminal device 130, at block 306, determines the priority of the sidelink transmission 135 exceeding the threshold priority, for example, the priority value of the sidelink transmission 135 being less than or equal to the threshold priority value if a smaller priority value indicates a higher priority. This means that the sidelink transmission 135 has a high priority, then the process 300 proceeds to block 308.

At block 308, since the sidelink transmission 135 is important in reliability, latency and priority, the terminal device 130 determines the uplink transmission 115 as the secondary transmission. Otherwise, the process 300 proceeds to block 310, where the terminal device 130 determines the sidelink transmission 135 as the secondary transmission, since the sidelink transmission 135 does not have a high priority. With the multi-stage comparison approach as shown in Fig. 3, in determining the uplink transmission 115 as the secondary transmission, most sidelink transmissions can be filtered out and thus only sidelink transmissions with a high reliability requirement, a low latency requirement, and a high priority can take precedence over the uplink transmission 115, which may be a URLLC uplink transmission.

In some embodiments, instead of using the reliability requirement, the latency requirement, and the priority of the sidelink transmission 135 one by one, the terminal device 130 can use a combined requirement of the sidelink transmission 135 to determine whether it is more important than the uplink transmission 115. The combined requirement combines the reliability requirement, the latency requirement, the priority, and any other transmission requirements, or the like. For example, if the combined requirement of the sidelink transmission 135 exceeds a combined threshold, the terminal device 130 may determine the uplink transmission 115 as the secondary transmission. Otherwise, the terminal device 130 may determine the sidelink transmission 135 as the secondary transmission.

As an example, the combined requirement may include “5QI. ” As used herein, 5QI may refer to 5G QoS indication as defined in the 3GPP specification TS 23.501. Standardized 5QI values have one-to-one mapping to a standardized combination of 5G QoS characteristics as specified in the 3GPP specification TS 23.501. By using such a combined requirement, a plurality of comparisons can be avoided, while the reliability requirement, the latency requirement, and the priority of the secondary transmission 135 are taken into account comprehensively. In addition, in performing various comparisons as described above, a value indicating a requirement or a priority may be equal to a predefined threshold value. The terminal device 130 may either consider such an equality case as the threshold value being exceeded or alternatively consider such an equality case as the threshold value being not exceeded. Further, this configuration of the equality case may be varied for different comparisons of different requirements or priorities. The configuration can be pre-configured according to specific technical environments and design requirements.

The above description illustrates some embodiments in which a multi-stage comparison approach is used to select the secondary transmission. In some other embodiments, in order to guarantee the performance of an important uplink transmission, such as a URLLC transmission which has extremely strict reliability and latency requirements, the terminal device 130 may first determine whether the uplink transmission 115 is an important uplink transmission, such as a URLLC uplink transmission. These embodiments will be detailed below with reference to Fig. 4.

Fig. 4 shows a flowchart of another example process 400 in accordance with some embodiments of the present disclosure. The process 400 can be considered as another example embodiment of the block 210 of the method 200. At block 402, the terminal device 130 determines whether the uplink transmission 115 has a predefined transmission requirement higher than a specified threshold, namely, an important uplink transmission. For example, the terminal device 130 may determine whether the uplink transmission 115 is a URLLC uplink transmission, which has a predefined transmission requirement as specified in 3GPP specifications. There may be various manners for the terminal device 130 to determine whether the uplink transmission 115 has the predefined transmission requirement.

For example, the terminal device 130 may obtain, from control information of the sidelink transmission 135, an indication indicating whether the uplink transmission 115 has the predefined transmission requirement. For instance, in NR sidelink transmission mode 1 or 2 (as defined in the 3GPP specifications) , if the sidelink transmission 135 of the terminal device 130 in a subframe overlaps in time domain with its uplink transmission (s) 115 and/or 125 occurring on serving cell (s) where the sidelink transmission 135 does not occur. It is assumed that a higher layer of the sidelink knows whether there is a URLLC transmission or not in an uplink carrier. The higher layer of the sidelink may use a parameter “URLLC_exist” to indicate whether the uplink is transmitting URLLC traffic. In some embodiments, the parameter “URLLC_exist” may be a field in the SCI or information element (IE) from the sidelink higher layer. With the indication of the important uplink transmission, the terminal device 130 may be explicitly informed that the uplink transmission 115 is an important uplink transmission, such as a URLLC uplink transmission.

As another example of determining whether the uplink transmission 115 has the predefined transmission requirement, the terminal device 130 may determine from a set of uplink transmission parameters, at least one period for a scheduled uplink transmission with the predefined transmission requirement, that is, a scheduled important uplink transmission. For instance, in the case where configured grant Type 1 (as defined in the 3GPP specifications) is configured in the uplink cartier, the potential URLLC in time domain may be determined by a combination of the following higher layer parameters: cs-RNTI, which refers to the CS-RNTI for retransmission; periodicity, which refers to the periodicity of the configured grant Type 1; timeDomainOffset, which refers to an offset of a resource with respect to SFN=0 in time domain; timeDomainAllocation, which refers to allocation of configured uplink grant in time domain which contains startSymbolAndLength; and nrofHARQ-Processes, which refers to the number of HARQ processes for configured grant.

Alternatively, in the case where configured grant Type 2 (as defined in the 3GPP specifications) is configured in the uplink carder, the potential URLLC in time domain may be determined by a combination of the following higher layer parameters derived from a higher layer and a UL grant received on the DCI: cs-RNTI, which refers to the CS-RNTI for activation, deactivation, and retransmission; periodicity, which refers to the periodicity of the configured grant Type 2; and nrofHARQ-Processes, which refers to the number of HARQ processes for configured grant.

If the at least one period for a scheduled important uplink transmission includes the second period of the uplink transmission 115, the terminal device 130 may determine that the uplink transmission 115 has the predefined transmission requirement. In this way, an important uplink transmission can be determined by using existing uplink transmission parameters without increasing a signaling overhead.

As shown in Fig. 4, if the uplink transmission 115 has the predefined transmission requirement, meaning that the uplink transmission 115 is an important uplink transmission, then the process 400 may proceed to block 408, where the terminal device 130 determines the sidelink transmission 135 as the secondary transmission. Otherwise, if the uplink transmission 115 does not have the predefined transmission requirement, in other words, ifthe transmission requirement of the uplink transmission 115 is different from the predefined transmission requirement, meaning that the uplink transmission 115 is not an important uplink transmission, then the process 400 can proceed to block 404. At block 404, the terminal device 130 determines whether the transmission requirement of the sidelink transmission 135 is higher than a predefined threshold requirement, for example, so as to determine whether the sidelink transmission 135 is an important sidelink transmission.

In particular, similar to the comparisons described with respect to the first scenario, the terminal device 130 may compare the reliability requirement of the sidelink transmission 135 with the threshold reliability. Alternatively or additionally, the terminal device 130 may compare the latency requirement of the sidelink transmission 135 with the latency reliability. Alternatively or additionally, the terminal device 130 may compare the priority of the sidelink transmission 135 with the threshold priority. Alternatively or additionally, the terminal device 130 may compare the “5QI” of the sidelink transmission 135 with a threshold 5QI. In this way, the reliability requirement, the latency requirement, the priority of the secondary transmission are taken into account comprehensively.

If the transmission requirement of the sidelink transmission 135 is higher than the threshold requirement, meaning that the sidelink transmission 135 is an important sidelink transmission, then the process 400 can proceed to block 406, where the terminal device 130 determines the uplink transmission 115 as the secondary transmission. Otherwise, if the transmission requirement of the sidelink transmission 135 is lower than the threshold requirement, meaning that the sidelink transmission 135 is not an important sidelink transmission, then the process 400 can proceed to block 408, where the terminal device 130 determines the sidelink transmission 135 as the secondary transmission.

The above description illustrates some embodiments under the first scenario in which the first transmission may be a sidelink transmission and the second transmission may be an uplink transmission. In the following, some other embodiments under a second scenario will be described. In the second scenario, the first and second transmissions may both comprise a sidelink transmission.

In particular, with reference to Fig. 1, the first transmission may comprise a first sidelink transmission 135 from the terminal device 130 to the terminal device 140. In some embodiments, the first sidelink transmission 135 is to be performed according to the 5G NR or the LTE technologies. The second transmission may comprise a second sidelink transmission 145 from the terminal device 130 to the terminal device 150. In some embodiments, the second sidelink transmission 145 is to be performed according to the 5G NR or the LTE technologies.

In such a second scenario, the first sidelink transmission 135 and the second sidelink transmission 145 may be of a same RAT, for example, both are to be performed according to the 5G NR technology. As an example, in NR sidelink transmission mode 1 or 2 (as defined in the 3GPP specifications) , the NR sidelink transmission 135 of the terminal device 130 on a carrier overlaps in time domain with another NR sidelink transmission 145 on other carrier (s) . In this event, the terminal device 130 may select the secondary transmission by directly comparing respective transmission requirements of the two

NR sidelink transmissions

135 and 145.

For example, the terminal device 130 may compare the reliability requirements of the first sidelink transmission 135 and second sidelink transmission 145. Alternatively or additionally, the terminal device 130 may compare the latency requirements of the first sidelink transmission 135 and second sidelink transmission 145. Alternatively or additionally, the terminal device 130 may compare the priorities of the first sidelink transmission 135 and second sidelink transmission 145. In this way, it is guaranteed that the transmission requirements of the two transmissions are directly comparable when they are of the same RAT, and the reliability requirement, the latency requirement, and the priority of the secondary transmission are taken into account comprehensively.

In some embodiments, instead of comparing the reliability requirements, the latency requirements, and the priorities one by one, the terminal device 130 can compare a combined requirement of the first sidelink transmission 135 and the combined requirement of the second sidelink transmission 145. As described above, the combined requirement combines the reliability requirement, the latency requirement, the priority, or the like. In this way, a plurality of comparisons can be avoided, while the reliability requirement, the latency requirement, and the priority of the secondary transmission 135 are taken into account comprehensively.

On the other hand, the first sidelink transmission 135 and second sidelink transmission 145 may be of different RATs, for example, the first sidelink transmission 135 is to be performed according to the 5G NR technology, and the second sidelink transmission 145 is to be performed according to the LTE technology. For example, in NR sidelink transmission mode 1 or 2 (as defined in the 3GPP specifications) , the NR sidelink transmission 135 of the terminal device 130 on a carrier overlaps in time domain with the LTE sidelink transmission 145 of mode 3 or 4 (as defined in the 3GPP specifications) on other carrier (s) . Then, the transmission requirements of the two

sidelink transmissions

135 and 145 may not be directly comparable, because their transmission requirements may not be specified according to a same set of rules.

In this event, for selecting the secondary transmission from the two

sidelink transmissions

135 and 145, the terminal device 130 may map a first value indicating the first transmission requirement of the first sidelink transmission 135 to a mapped value, and then compare the mapped value with a second value indicating a second transmission requirement of the second sidelink transmission 145. In some embodiments, the first value may be derived from a “5QI” field in the sidelink control information of the first sidelink transmission 135 of the 5G NR, and the second value may be the “priority” field in the sidelink control information of the second sidelink transmission 145 of the LTE. In this way, the transmission requirements of the two

sidelink transmissions

135 and 145 of different RATs may be reasonably compared.

In some other embodiments, although the first sidelink transmission 135 and the second sidelink transmission 145 are of different RATs, they may still have a common field indicating a common transmission requirement. For example, the first sidelink transmission 135 of the 5G NR may also have a “priority” field, similar to the second sidelink transmission 145 of the LTE. In this event, the terminal device 130 can compare the priorities of the first sidelink transmission 135 and the second sidelink transmission 145, to select a sidelink transmission with a lower priority as the secondary transmission.

The above description illustrates some embodiments under the second scenario in which the first transmission may be a first sidelink transmission and the second transmission may be a second sidelink transmission. In the following, some other embodiments under a third scenario will be described. In the third scenario, the first transmission may comprise a sidelink transmission of a first RAT, and the second transmission may comprise an uplink transmission of a second RAT.

In particular, with reference to Fig. 1, the first transmission may be the sidelink transmission 135 from the terminal device 130 to the terminal device 140, which is to be performed according to the 5G NR technology. The second transmission may be the uplink transmission 125 from the terminal device 130 to the network device 120, which is to be performed according to the LTE technology.

In such a third scenario, it is assumed that the terminal device 130 is configured with a reference time division duplex (TDD) configuration for the LTE Uu, for example. When selecting the secondary transmission, the terminal device 130 may determine whether the transmission requirement of the sidelink transmission 135 exceeds a predetermined threshold. If the transmission requirement of the sidelink transmission 135 exceeds the predetermined threshold, meaning that the sidelink transmission 135 is an important sidelink transmission, then the terminal device 130 may determine the uplink transmission 125 as the secondary transmission, because the uplink transmission 125 of the LTE technology does not include an important uplink transmission, such as a URLLC uplink transmission as specified in the 5G NR.

Otherwise, if the transmission requirement of the sidelink transmission 135 is below the predetermined threshold, meaning that the sidelink transmission 135 is not an important sidelink transmission, then the terminal device 130 may determine the sidelink transmission 135 as the secondary transmission. In this way, the sidelink transmission 135 can take precedence over the uplink transmission 125 as long as it has a relatively higher priority. Compared with the previous scenarios, in this third scenario, more sidelink transmissions can be determined as a more important transmission, since the uplink transmission 125 of the LTE does not include an important uplink transmission, such as a URLLC uplink transmission.

The above description illustrates some embodiments under the third scenario in which the first transmission may comprise a sidelink transmission of a first RAT and the second transmission may comprise an uplink transmission of a second RAT. In the following, some other embodiments under a fourth scenario will be described. In the fourth scenario, the first transmission may comprise a first uplink transmission of a first RAT. The second transmission may comprise a second uplink transmission of the first RAT without a predefined transmission requirement higher than a specified threshold, an uplink transmission of a second RAT, or a sidelink transmission of the second RAT.

In particular, with reference to Fig. 1, the first transmission may be the uplink transmission 115 from the terminal device 130 to the network device 110, which is to be performed according to the 5G NR technology. The second transmission may be the uplink transmission 119 from the terminal device 130 to the network device 110, which is to be performed according to the 5G NR technology and which is not an important uplink transmission, such as a URLLC uplink transmission. Alternatively, the second transmission may be the uplink transmission 125 from the terminal device 130 to the network device 120, which is to be performed according to the LTE technology. Alternatively, the second transmission may be a sidelink transmission 145 from the terminal device 130 to the terminal device 150, which is to be performed according to the LTE technology.

In such a fourth scenario, the terminal device 130 may determine whether the first uplink transmission 115 has the predefined transmission requirement, namely an important uplink transmission, such as, a URLLC uplink transmission. In case there is an indication for the important uplink transmission 115, as described with respect to the first scenario, the terminal device 130 can know the NR URLLC uplink time duration via an indication field in the SCI/DCI or an RRC indication. Alternatively, the terminal device 130 may determine the potential URLLC time duration fi`om a set of uplink transmission parameters, as described also with respect to the first scenario. In this way, it is ensured that an important uplink transmission, such as a URLLC uplink requirement, would not be affected by other less important transmissions without the predefined transmission requirement.

If the first uplink transmission 115 has the predefined transmission requirement, meaning that the first uplink transmission 115 is an important uplink transmission, then the terminal device 130 may determine the second transmission as the secondary transmission. For example, if the terminal device 130 determines that the first uplink transmission 115 is a URLLC uplink transmission, the terminal device 130 can directly determine the second transmission as the secondary transmission, so as to ensure the performance of the URLLC uplink transmission.

Referring back to Fig. 2, at block 220, the terminal device 130 adjusts the transmission power of the secondary transmission in an overlapped portion between the first and second periods, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device 130. For example, in the various communication scenarios as described above, the transmission power of the determined secondary transmission can be reduced for the overlapped duration between the first and second periods. In other words, the performance of the more important transmission can be guaranteed at the cost of degradation of the performance of the less important transmission.

In some embodiments, if an adjusted amount of the transmission power of the secondary transmission exceeds a threshold amount, meaning that the secondary transmission would probably fail to be received properly by a receiving device due to a lowered transmission power, then the terminal device 130 may cease the secondary transmission. In this way, the power of the terminal device 130 may be saved.

It is to be understood that all the embodiments described above are under a precondition that the terminal device 130 has a capability for dynamic power sharing between different simultaneous transmissions. However, in some embodiments, the terminal device 130 may be incapable of dynamic power sharing between different transmissions. In this event, the terminal device 130 may cease or drop the first transmission or the second transmission, for example, according to which transmission is ahead in time domain. In this way, the operation of selecting the secondary transmission can be advantageously avoided. Alternatively, the terminal device 130 may cease or drop the secondary transmission, such that the more important transmission is guaranteed.

For example, in connection with the third scenario as described above, it is assumed that the terminal device 130 is configured with a reference TDD configuration for the LTE Uu. Ifthe terminal device 130 does not have a capability for dynamic power sharing between a Uu uplink and an NR sidelink, the terminal device 130 may follow the following procedures, when a corresponding subframe on the LTE Uu is an UL subframe in the reference TDD configuration. The terminal device 130 may drop the NR sidelink transmission 135, if a transmission requirement (such as a “priority” field in the SCI) is higher than or equal to a threshold (such as a “priority_threshold” configured by a higher layer. On the other hand, the terminal device 130 may drop the LTE uplink transmission 125, if the transmission requirement (such as the “priority” field in the SCI) is lower than the threshold (such as the “priority_threshold” configured by the higher layer.

As described, in case that the first and second transmissions have different types of numerology, the first and second periods for performing the first and second transmissions may have different durations. In this event, a possible power transition in the first or second period for performing the secondary transmission may need to be avoided. Accordingly, if the first and second periods have different start times or end times, meaning that they have different durations, the terminal device 130 may perform the secondary transmission with the adjusted transmission power in a non-overlapped portion of the first period or the second period. In other words, the terminal device 130 may use the adjusted transmission power to perform the secondary transmission in the entire first or second period. In this manner, a possible power transition in the first or second period can be effectively avoided.

The above description illustrates some embodiments in which the terminal device 130 have two simultaneous transmissions to perform, and the transmission power of the secondary transmission is adjusted if the total transmission power exceeds the available transmission power of the terminal device 130. In the following, some other embodiments will be described in which the terminal device 130 have more than two simultaneous transmissions to perform. In general, if all the simultaneous transmissions have a same type, then a secondary transmission can be selected by directly comparing their transmission requirements. However, if the simultaneous transmissions have different types, there may be a need for a clear and definite rule to select the secondary transmission from these transmissions of different types. This will be detailed below with reference to Fig. 5.

Fig. 5 shows a flowchart of another example method 500 in accordance with some embodiments of the present disclosure. The method 500 can be implemented at a terminal device, such as the terminal device 130 as shown in Fig. 1. Additionally or alternatively, the method 500 can also be implemented at the

terminal devices

140 and 150, as well as other terminal devices not shown in Fig. 1. For the purpose of discussion, the method 500 will be described with reference to Fig. 1 as performed by the terminal device 130 without loss of generality.

In the example embodiment of Fig. 5, it is assumed that the terminal device 130 have three simultaneous transmissions to perform. The first transmission may comprise the first sidelink transmission 135 from the terminal device 130 to the terminal device 140, which is to be performed in a first period. The second transmission may comprise the second sidelink transmission 145 from the terminal device 130 to the terminal device 150, which is to be performed in a second period. The third transmission may comprise the uplink transmission 115 from the terminal device 130 to the network device 110 or the uplink transmission 125 from the terminal device 130 to the network device 120, which is to be performed in a third period. The first, second, and third period have an overlapped portion. In the following, the uplink transmission 115 will be taken as an example of the third transmission without loss of generality.

At block 502, the terminal device 130 selects the first sidelink transmission 135 or the second sidelink transmission 145 as a secondary sidelink transmission with a lower transmission requirement. For example, the terminal device 130 may use a same or similar approach as described in connection with the above second scenario, to determine which sidelink transmission has a lower transmission requirement. Alternatively or additionally, the terminal device 130 may employ any suitable manner as described with reference to Figs. 2 to 4 to select the secondary sidelink transmission. The details for the selection will not be repeated here.

At block 504, the terminal device 130 selects the secondary sidelink transmission or the uplink transmission 115 as a target transmission with a lower transmission requirement. In other words, the sidelink transmission with a lower transmission requirement among the first and second sidelink transmissions is compared with the uplink transmission, to select the transmission of the least importance. More generally, ifthere are three or more simultaneous sidelink transmissions, the sidelink transmission of the least importance may be firstly determined, and then this least important sidelink transmission can be compared with the uplink transmission. The terminal device 130 may employ any suitable manner as described with reference to Figs. 2 to 4 to select the target transmission. The details for the selection will not be repeated here.

At block 504, the terminal device 130 adjusts the transmission power of the target transmission in the overlapped portion, such that total transmission power of the first and second sidelink transmissions and the uplink transmission is below available transmission power of the terminal device. It is noted that all the details as explained with respect to Figs. 2 to 4 are equally applicable to the method 500 of Fig. 5. For example, if an adjusted amount of the transmission power of the target transmission exceeds a threshold amount, then the terminal device 130 may cease the target transmission. Also, if the terminal device 130 is incapable of dynamic power sharing between different transmissions, the terminal device 130 may cease or drop any one of the first sidelink transmission, the second sidelink transmission and the uplink transmission.

As indicated, different simultaneous transmissions of the terminal device 130 may have different types of numerology. For example, both sidelink transmissions and uplink transmissions of the 5G NR can support different types of numerology, and these numerology types can be different from that of the sidelink transmissions and uplink transmissions of the LTE. As a result, in all the embodiments as described above, the first period (such as a first subframe) of the first transmission and the second period (such as a second subframe) of the second transmission may have different start times or end times.

Fig. 6 shows a schematic diagram of

different subframes

612, 622 for different transmissions with different durations in accordance with some embodiments of the present disclosure. As shown in Fig. 6, a set of subframes 610 includes a subframe 612 which is scheduled to perform the first transmission, and a set of subframes 620 includes a subframe 622 which is scheduled to perform the second transmission. In the example embodiment ot Fig. 6, the subframe 612 and the subframe 622 have different start times but the same end time, and thus have different durations.

It is appreciated that this depiction is only for example without suggesting any limitation. In other embodiments, a first subframe of the first transmission and a second subframe of the second transmission may have different end times and the same start time, or both different start times and different end times. In the scenarios where the first and second periods (subframes) have different start times or end times, it is advantageous to avoid a possible power change within one period (subframe) due to a transmission power adjustment. This is detailed below with reference to Fig. 7.

Fig. 7 shows a flowchart of another example method 700 in accordance with some embodiments of the present disclosure. The method 700 can be implemented at a terminal device, such as the terminal device 130 as shown in Fig. 1. Additionally or alternatively, the method 700 can also be implemented at the

terminal devices

140 and 150, as well as other terminal devices not shown in Fig. 1. For the purpose of discussion, the method 700 will be described with reference to Fig. 1 as performed by the terminal device 130 without loss of generality.

At block 702, the terminal device 130 determines a first transmission to be performed in a first period and a second transmission to be performed in a second period overlapping with the first period. The first and second transmissions can be transmissions of any type and any RAT as described above in connection with various scenarios. The details of these scenarios will not be repeated here.

At block 704, the terminal device 130 determines that the first period has an earlier start time than the second period. In other words, the first period is prior to the second period. In the following, the first transmission may also be referred to as an earlier transmission, the first period may also be referred to as an earlier period, the second transmission may also be referred to as a later transmission, and the second period may also be referred to as a later period. In some embodiments, the first and second periods may be subframes for performing the first and second transmission. For example, with reference to Fig. 6, the first subframe 612 has an earlier start time than the second subframe 622.

At block 706, the terminal device 130 maintains the transmission power of the first transmission unchanged in the first period. In other words, the terminal device 130 prevents the transmission power of the earlier transmission in the earlier period from changing within the whole earlier period, so that a possible power transition in the first period can be advantageously avoided. There may be various manners for the terminal device 130 to maintain the transmission power of the first transmission unchanged in the first period.

For example, the terminal device 130 may adjust the transmission power of the second transmission in the second period, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device 130 in an overlapped portion between the first and second periods. With reference to the embodiment of Fig. 6, for the first transmission in the first subframe 612, the terminal device 130 may use the transmission power calculated according to a transmission power control function for the first transmission. If total transmission power of the first and second transmissions will exceed the available transmission power of the terminal device 130 during the subframe 622, the terminal device 130 can reduce the transmission power of the second later transmission in the later subframe, regardless of respective transmission requirements of the first and second transmissions.

As another example of maintaining the transmission power of the first transmission unchanged in the first period, if total transmission power of the first and second transmissions exceeds the available transmission power of the terminal device 130 in the overlapped portion between the first and second periods, the terminal device 130 may cease the first transmission or the second transmission in the overlapped portion. In connection with the embodiment of Fig. 6, the terminal device 130 may use the transmission power calculated according to the transmission power control function for the first transmission in the non-overlapped portion of the first subframe 612, and may cease the first transmission in the overlapped portion of the first subframe 612. Alternatively, the terminal device 130 can stop the second transmission in the overlapped portion of the second subframe 622. In some embodiments, the terminal device 130 may drop the less important transmission with a lower transmission requirement in the overlapped portion.

Fig. 8 is a simplified block diagram of a device 800 that is suitable for implementing some embodiments of the present disclosure. The device 800 can be considered as a further example embodiment of the

network devices

110 and 120 as well as the

terminal devices

130, 140, and 150 as shown in Fig. 1. Accordingly, the device 800 can be implemented at or as at least a part of the

network devices

110, 120 and the

terminal devices

130, 140, 150.

As shown, the device 800 includes a processor 810, a memory 820 coupled to the processor 810, a suitable transmitter (TX) and receiver (RX) 840 coupled to the processor 810, and a communication interface coupled to the TX/RX 840. The memory 820 stores at least a part of a program 830. The TX/RX 840 is for bidirectional communications. The TX/RX 840 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between gNBs or eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the gNB or eNB, Un interface for communication between the gNB or eNB and a relay node (RN) , or Uu interface for communication between the gNB or eNB and a terminal device.

The program 830 is assumed to include program instructions that, when executed by the associated processor 810, enable the device 800 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Figs. 2 to 5 and 7. The embodiments herein may be implemented by computer software executable by the processor 810 of the device 800, or by hardware, or by a combination of software and hardware. The processor 810 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 810 and memory 820 may form processing means 850 adapted to implement various embodiments of the present disclosure.

The memory 820 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 820 is shown in the device 800, there may be several physically distinct memory modules in the device 800. The processor 810 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 800 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The components included in the apparatuses and/or devices of the present disclosure may be implemented in various manners, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more units may be implemented using software and/or firmware, for example, machine-executable instructions stored on the storage meditate. In addition to or instead of machine-executable instructions, parts or all of the units in the apparatuses and/or devices may be implemented, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs) , Application-specific Integrated Circuits (ASICs) , Application-specific Standard Products (ASSPs) , System-on-a-chip systems (SOCs) , Complex Programmable Logic Devices (CPLDs) , and the like.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to any of Figs. 2 to 5 and 7. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

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

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

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

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

Claims

A method for communication, comprising:

selecting, at a terminal device, a first transmission or a second transmission as a secondary transmission with a lower transmission requirement, wherein the first transmission is to be performed in a first period and the second transmission is to be performed in a second period overlapping with the first period; and

adjusting transmission power of the secondary transmission in an overlapped portion between the first and second periods, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device.
The method of claim 1, wherein the first transmission comprises a sidelink transmission and the second transmission comprises an uplink transmission, and wherein selecting the secondary transmission comprises determining the uplink transmission as the secondary transmission if:

a reliability requirement of the sidelink transmission exceeds threshold reliability; and/or

a latency requirement of the sidelink transmission is below threshold latency.
The method of claim 2, wherein determining the uplink transmission as the secondary transmission comprises:

determining the reliability requirement of the sidelink transmission exceeding the threshold reliability;

determining the latency requirement of the sidelink transmission being below the threshold latency; and

determining a priority of the sidelink transmission exceeding a threshold priority.
The method of claim 1, wherein the first transmission comprises a sidelink transmission and the second transmission comprises an uplink transmission, and wherein selecting the secondary transmission comprises:

in response to determining a combined requirement of the sidelink transmission exceeding a combined threshold, determining the uplink transmission as the secondary transmission, the combined requirement combining a reliability requirement, a latency requirement, and a priority.
The method of claim 1, wherein the first transmission comprises a sidelink transmission and the second transmission comprises an uplink transmission, and wherein selecting the secondary transmission comprises:

determining whether the uplink transmission has a predefined transmission requirement higher than a specified threshold; and

in response to the uplink transmission having the predefined transmission requirement, determining the sidelink transmission as the secondary transmission.
The method of claim 5, wherein determining whether the uplink transmission has the predefined transmission requirement comprises:

obtaining, from control information of the sidelink transmission, an indication indicating whether the uplink transmission has the predefined transmission requirement.
The method of claim 5, wherein determining whether the uplink transmission has the predefined transmission requirement comprises:

determining, from a set of uplink transmission parameters, at least one period for a scheduled uplink transmission with the predefined transmission requirement; and

in response to the at least one period including the second period, determining that the uplink transmission has the predefined transmission requirement.
The method of claim 5, further comprising:

in response to a transmission requirement of the uplink transmission being different from the predefined transmission requirement, determining the uplink transmission as the secondary transmission if:

a reliability requirement of the sidelink transmission exceeds threshold reliability; and/or

a latency requirement of the sidelink transmission is below threshold latency; and/or

a priority of the sidelink transmission exceeds a threshold priority.
The method of claim 1, wherein the first transmission comprises a first sidelink transmission and the second transmission comprises a second sidelink transmission, and wherein selecting the secondary transmission comprises:

determining whether the first sidelink transmission and the second sidelink transmission are of a same radio access technology (RAT) ; and

in response to the first and second sidelink transmissions being of the same RAT, selecting the secondary transmission by at least one of:

comparing reliability requirements of the first and second sidelink transmissions;

comparing latency requirements of the first and second sidelink transmissions; and

comparing priorities of the first and second sidelink transmissions.
The method of claim 9, wherein selecting the secondary transmission further comprises:

in response to the first and second sidelink transmissions being of different RATs,

mapping a first value indicating a first transmission requirement of the first sidelink transmission to a mapped value; and

comparing the mapped value with a second value indicating a second transmission requirement of the second sidelink transmission.
The method of claim 1, wherein the first transmission comprises a sidelink transmission of a first RAT and the second transmission comprises an uplink transmission of a second RAT, and wherein selecting the secondary transmission comprises:

determining whether a transmission requirement of the sidelink transmission exceeds a predetermined threshold;

in response to the transmission requirement exceeding the predetermined threshold, determining the uplink transmission as the secondary transmission; and

in response to the transmission requirement being below the predetermined threshold, determining the sidelink transmission as the secondary transmission.
The method of claim 1, wherein the first transmission comprises a first uplink transmission of a first RAT,

wherein the second transmission comprises a second uplink transmission of the first RAT without a predefined transmission requirement higher than a specified threshold, an uplink transmission of a second RAT, or a sidelink transmission of the second RAT, and

wherein selecting the secondary transmission comprises:

determining whether the first uplink transmission has the predefined transmission requirement; and

in response to the first uplink transmission having the predefined transmission requirement, determining the second transmission as the secondary transmission.
The method of claim 1, further comprising:

in response to the first and second periods having different start times or end times, performing the secondary transmission with the adjusted transmission power in a non-overlapped portion of the first period or the second period.
The method of claim 1, further comprising:

in response to the terminal device being incapable of dynamic power sharing between different transmissions, ceasing the first transmission or the second transmission.
The method of claim 1, further comprising:

in response to an adjusted amount of the transmission power of the secondary transmission exceeding a threshold amount, ceasing the secondary transmission.
A method for communication, comprising:

selecting, at a terminal device, a first sidelink transmission or a second sidelink transmission as a secondary sidelink transmission with a lower transmission requirement, wherein the first sidelink transmission is to be performed in a first period and the second sidelink transmission is to be performed in a second period;

selecting the secondary sidelink transmission or an uplink transmission as a target transmission with a lower transmission requirement, wherein the uplink transmission is to be performed in a third period, the first, second and third periods having an overlapped portion; and

adjusting transmission power of the target transmission in the overlapped portion, such that total transmission power of the first and second sidelink transmissions and the uplink transmission is below available transmission power of the terminal device.
The method of claim 16, wherein a transmission requirement of the first and second sidelink transmissions and the uplink transmission comprises at least one of a reliability requirement, a latency requirement, and a priority.
A method for communication, comprising:

determining, at a terminal device, a first transmission to be performed in a first period and a second transmission to be performed in a second period overlapping with the first period;

determining that the first period has an earlier start time than the second period; and

maintaining transmission power of the first transmission unchanged in the first period.
The method of claim 18, wherein maintaining the transmission power unchanged comprises:

adjusting transmission power of the second transmission in the second period, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device in an overlapped portion between the first and second periods.
The method of claim 18, wherein maintaining the transmission power unchanged comprises:

in response to total transmission power of the first and second transmissions exceeding available transmission power of the terminal device in an overlapped portion between the first and second periods, ceasing the first transmission or the second transmission in the overlapped portion.
A terminal device, comprising:

a processor; and

a memory storing instructions,

the memory and the instructions being configured, with the processor, to cause the terminal device to:

select a first transmission or a second transmission as a secondary transmission with a lower transmission requirement, wherein the first transmission is to be performed in a first period and the second transmission is to be performed in a second period overlapping with the first period; and

adjust transmission power of the secondary transmission in an overlapped portion between the first and second periods, such that total transmission power of the first and second transmissions is below available transmission power of the terminal device.
A terminal device, comprising:

a processor; and

a memory storing instructions,

the memory and the instructions being configured, with the processor, to cause the terminal device to:

select a first sidelink transmission or a second sidelink transmission as a secondary sidelink transmission with a lower transmission requirement, wherein the first sidelink transmission is to be performed in a first period and the second sidelink transmission is to be performed in a second period;

select the secondary sidelink transmission or an uplink transmission as a target transmission with a lower transmission requirement, wherein the uplink transmission is to be performed in a third period, the first, second and third periods having an overlapped portion; and

adjust transmission power of the target transmission in the overlapped portion, such that total transmission power of the first and second sidelink transmissions and the uplink transmission is below available transmission power of the terminal device.
A terminal device, comprising:

a processor; and

a memory storing instructions,

the memory and the instructions being configured, with the processor, to cause the terminal device to:

determine a first transmission to be performed in a first period and a second transmission to be performed in a second period overlapping with the first period;

determine that the first period has an earlier start time than the second period; and

maintain transmission power of the first transmission unchanged in the first period.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor of a device, causing the device to carry out the method according to any of claims 1 to 15, claims 16 to 17, and claims 18 to 20.