WO2024098338A1

WO2024098338A1 - Power control for carrier aggregation

Info

Publication number: WO2024098338A1
Application number: PCT/CN2022/131186
Authority: WO
Inventors: Sheng Lin SHI; Georg-Raffael Janczyk; Alfredo Rocchetti; Jian Hua Wu; Li Fan ZHANG
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy
Priority date: 2022-11-10
Filing date: 2022-11-10
Publication date: 2024-05-16

Abstract

Embodiments of the present disclosure relate to power control for CA. A second device determines that a measurement for a cell in a PCell and a set of SCells satisfies a predetermined condition, and transmits, to a first device, an indication indicating update of transmission power for the PCell. Based on the indication, the first device updates the transmission power and performs, based on the updated transmission power, a transmission via the PCell and the set of SCells. In this way, power split between a PCell and a SCell may be adjusted, and better UL CA performance may be achieved.

Description

POWER CONTROL FOR CARRIER AGGREGATION

FIELD

Various example embodiments relate to the field of telecommunication and in particular, to a method, device, apparatus and computer readable storage medium of communication in power control for carrier aggregation (CA) .

BACKGROUND

For a radio access network, user equipment (UE) uplink (UL) power is always a critical factor which will impact UL performance. With UL CA support, UL power may be shared by all UL carriers. Transmission power of a primary cell (PCell) may always be secured based on UL grant, and remaining power may be scheduled for a secondary cell (SCell) . Thus, a carrier of a SCell may be easy to run into an under-power state.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of power control for CA.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first device at least to: receive, from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells; update the transmission power based on the indication; and perform, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second device at least to: determine that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and transmit, to a first device, an indication indicating update of transmission power for the primary cell.

In a third aspect, there is provided a method for communication. The method comprises: receiving, at a first device and from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells; updating the transmission power based on the indication; and performing, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.

In a fourth aspect, there is provided a method for communication. The method comprises: determining, at a second device, that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and transmitting, to a first device, an indication indicating update of transmission power for the primary cell.

In a fifth aspect, there is provided an apparatus for communication. The apparatus comprises: means for receiving, at a first device and from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells; means for updating the transmission power based on the indication; and means for performing, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.

In a sixth aspect, there is provided an apparatus for communication. The apparatus comprises: means for determining, at a second device, that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and means for transmitting, to a first device, an indication indicating update of transmission power for the primary cell.

In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method according to the third or fourth aspect.

In an eighth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus to perform at least the method according to the third or fourth aspect.

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

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1 illustrates an example communication environment in which embodiments of the present disclosure may be implemented;

Fig. 2 illustrates a diagram illustrating an example comparison between static power split and dynamic power sharing between PCell and SCell;

Fig. 3 illustrates a diagram illustrating a process of communication according to some embodiments of the present disclosure;

Fig. 4 illustrates a diagram illustrating an example process of power control with both p0-AlphaSets reconfiguration during a SCell addition and a TPC command according to some embodiments of the present disclosure;

Fig. 5 illustrates a diagram illustrating an example process of p0-AlphaSets reconfiguration during a SCell release according to some embodiments of the present disclosure;

Fig. 6 illustrates a diagram illustrating an example performance simulation of a solution according to some embodiments of the present disclosure;

Fig. 7 illustrates a flowchart of an example method implemented at a first device according to some embodiments of the present disclosure;

Fig. 8 illustrates a flowchart of an example method implemented at a second device according to some embodiments of the present disclosure;

Fig. 9 illustrates a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure; and

Fig. 10 illustrates a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

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

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. 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.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , the future sixth generation (6G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a new radio (NR) next generation NodeB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. An RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY) .

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IoT device or fixed IoT device) . This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node (s) , as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

Principles and implementations of the present disclosure will be described in detail below with reference to the figures.

Fig. 1 illustrates a schematic diagram of an example 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 device 110, a second device 120 and a third device 130. The second device 120 may provide a group of cells (e.g.,

cells

121 and 122 are shown) to serve one or more devices. The third device 130 may also provide a group of cells (for convenience, only one cell 131 is shown) to serve one or more devices.

In some embodiments, the first device 110 may be located in the cell 121 and served by the second device 120. The first device 110 may be configured with CA. The first device 110 may be served by the second device 120 and may be connected with both the

cells

121 and 122 of the second device 120. As an example, the cell 121 may serve as a primary cell (PCell) , and the cell 122 may serve as a SCell.

Assuming that the cell 131 is configured to the first device 110 as a candidate cell. In some embodiments, the second device 120 and the third device 130 are the same device. In some embodiments, the second device 120 and the third device 130 are different devices.

In some scenarios, as the first device 110 moves, when a condition for a candidate cell (for example, the cell 131) is fulfilled, the cell 131 may be added as a SCell. Accordingly, the first device 110 may be caused to establish a connection with the

cells

121, 122 and 131. These scenarios may be called as SCell addition or SCell change or SCell swap.

In some scenarios, as the first device 110 moves, when a condition for SCell release is fulfilled, the first device 110 may be caused to release the

cell

122 or 131. These scenarios may be called as SCell release.

It is to be understood that the number of devices and cells in Fig. 1 is given for the purpose of illustration without suggesting any limitations to the present disclosure. The communication environment 100 may include any suitable number of first devices and/or second devices and/or third devices and/or cells adapted for implementing implementations of the present disclosure. In some embodiments, the first device 110 may be a terminal device, and the second and

third devices

120 and 130 may be network devices.

Merely for illustration purposes and without suggesting any limitations as to the scope of the present disclosure, some embodiments will be described in the context where the first device 110 is a terminal device and the second and

third devices

120 and 130 are network devices. It is to be understood that, in other embodiments, the first device 110 may be a network device and any of the second and

third devices

120 and 130 may be a terminal device. In other words, the principles and spirit of the present disclosure may be applied to both uplink and downlink transmissions.

As shown in Fig. 1, the first device 110 and any of the second device 120 and the third device 130 may communicate with each other via a wireless communication channel. The communications within the network 100 may conform to any suitable standard including, but not limited to, LTE, LTE-evolution, LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , code division multiple access (CDMA) and global system for mobile communications (GSM) 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) or the sixth generation (6G) communication protocols.

As mentioned above, for a radio access network, UE UL power is always a critical factor which will impact UL performance. With UL CA support, UL power may be shared by all UL carriers and thus each UL carrier may be easy to run into an under-power state.

Conventionally, if total UE transmit power for a physical uplink shared channel (PUSCH) or physical uplink control channel (PUCCH) or physical random access channel (PRACH) or sounding reference signal (SRS) transmission in a respective transmission occasion i would exceed a maximum transmission power

for single cell operation with two uplink carriers or for operation with CA, UE may allocate power to PUSCH/PUCCH/PRACH/SRS transmissions according to a priority order so that the total UE transmit power is smaller than or equal to

in every symbol of transmission occasion i. In case of the same priority order and for operation with CA, the UE prioritizes power allocation for transmissions on a PCell of a master cell group (MCG) or a secondary cell group (SCG) over transmissions on a SCell and prioritizes power allocation for transmissions on a PCell over transmissions on a primary secondary cell (PSCell) .

Thus, with UL CA support, UE may always secure transmission power of a PCell based on UL grant, and remaining power may be scheduled for SCell. In some scenarios, the maximum transmission power may be reconfigured so that the maximum transmission power may be split between PCell and SCells statically. In this case, even better performance may be obtained per Shannon Theory. Fig. 2 illustrates a diagram 200 illustrating an example comparison between static power split and dynamic power sharing between PCell and SCell. As shown in Fig. 2, curve 210 denotes single UE throughout versus path loss in static power split, and curve 220 denotes single UE throughout versus path loss in dynamic power sharing. It can be known from Fig. 2 that reserving more power for a SCell in case more available physical resource blocks (PRBs) over a SCell will get a higher UL CA throughput gain.

However, the maximum transmission power of PCell may only be reconfigured through a synchronous reconfiguration (e.g., reconfigurationWithSync) so that the maximum transmission power may be statically split over PCell and SCell carriers, while a random access procedure may be triggered due to the synchronous reconfiguration. Considering a traffic model in live network, SCell addition and release may happen with high frequency to match the traffic need. Thus, the runtime random access procedure together with SCell addition and release may be unacceptable to achieve the UL CA throughput gain.

Currently, a simple solution is to configure the maximum transmission power for UE per UE capability. The configured maximum transmission power P _CMAX per each carrier may be set within the following bounds:

P _{CMAX_L} ≤ P _CMAX ≤ P _{CMAX_H}

where

- P _{CMAX_L} = MIN {10 log ₁₀ ∑ p _EMAX, c -ΔT _C , P _EMAX, CA, P _PowerClass –MAX (MAX (MPR, A-MPR) + ΔT _IB, c + ΔT _C + ΔT _RxSRS, P-MPR _c) }

- P _{CMAX_H} = MIN {10 log ₁₀ ∑ p _EMAX, c , P _EMAX, CA , P _PowerClass}

- p _EMAX, c is the linear value of P _EMAX, c which is given by IE P-Max for serving cell c;

- P _PowerClass is the maximum UE power without taking into account the tolerance.

UE may follow a pre-defined priority for PCell and SCell transmission power reduction. Thus, UE may still always secure PCell UL transmission power, and a carrier of a SCell may be easy to run into an under-power state.

In view of this, embodiments of the present disclosure provide a solution of communication to overcome the above and other potential issues. In the solution, a measurement for a cell (e.g., each cell) in PCell and a set of SCells is considered, such as in terms of a load of PRBs, pathloss or other measurements. When the measurement for the cell satisfies a predetermined condition, update of transmission power for a PCell is indicated.

In one aspect, if the measurement satisfies a predetermined condition, a power control parameter associated with a terminal device (e.g., p0-AlphaSets) may be reconfigured during SCell addition. In this way, transmission power of a PCell may be reconfigured. High bandwidth gain may be achieved based on Shannon Theory. More UL transmission power may be reserved for a SCell and better UL performance may be obtained for UL CA support.

In some embodiments, the power control parameter associated with the terminal device (e.g., p0-AlphaSets) may be reconfigured back (i.e., recovered) during SCell release. In this way, better PCell UL gain may be achieved.

In another aspect, if the measurement satisfies a predetermined condition, DCI comprising a TPC command may be transmitted to indicate power variation of transmission power of a PCell. In this way, transmission power of a PCell may be dynamically adjusted in closed loop power control (CLPC) , and thus better UL performance may be obtained for UL CA support.

In some embodiments, different frame structures for a PCell and a SCell may be considered, and power variations are determined differently for overlapping and non-overlapping slots of a PCell and a SCell. In this way, finer power control may be achieved, and UL performance may be further enhanced for UL CA support.

In some embodiments, upon SCell release, CLPC may return to a single component carrier (CC) behavior. In this way, efficient power control may be achieved.

For illustration, detailed description on the solution will be given in connection with Fig. 3 below. Fig. 3 illustrates a flowchart illustrating a diagram illustrating a process 300 of communication according to some embodiments of the present disclosure. For the purpose of discussion, the process 300 will be described with reference to Fig. 1. The process 300 may involve the first device 110 and the second device 120 as illustrated in Fig. 1. It is assumed that the first device 110 is served by the second device 120.

As shown in Fig. 3, the second device 120 may perform 310 a measurement for a cell (e.g., each cell) in a group of cells comprising a PCell and a set of SCells. In some embodiments, the second device 120 may measure a load of PRBs for the cell. For example, the second device 120 may measure a load of UL PRBs for the cell.

In some embodiments, the second device 120 may determine a reference load (for convenience, also referred to as a first load herein) of PRBs for the cell in a current transmission time interval (TTI) (for convenience, also referred to as a first TTI herein) , and determine the load of PRBs for the cell in the current TTI based on the reference load and a load of PRBs for the cell in a previous TTI (for convenience, also referred to as a second TTI herein) .

In some embodiments, the second device 120 may determine the reference load based on a number (for convenience, also referred to as a first number herein) of PRBs allocated in the current TTI and a number (for convenience, also referred to as a second number herein) of PRBs available for scheduling in the current TTI. For example, the second device 120 may determine the reference load based on equation (1) below.

where ulPRBLoad (t) denotes the reference load, numPRBAllocated (t) denotes the number of PRBs allocated in the current TTI, and totalPRBAvailable (t) denotes the number of PRBs available for scheduling in the current TTI. It is to be noted that equation (1) is merely an example and any other suitable forms are also feasible.

In some embodiments, the second device 120 may determine, as the load of PRBs for the cell in the current TTI, an average load of PRBs for the cell in the current TTI based on the reference load and an average load of PRBs for the cell in the previous TTI. For example, the second device 120 may determine the load of PRBs for the cell in the current TTI based on equation (2) below.

avgUlPRBLoad (t) =α*ulPRBLoad (t) + (1-α) *avgUlPRBLoad (t-1) (2)

where avgUlPRBLoad (t) denotes an average load of PRBs for the cell in the current TTI, ulPRBLoad (t) denotes the reference load, avgUlPRBLoad (t-1) denotes an average load of PRBs for the cell in the previous TTI, and α denotes a factor of a filter. It is to be noted that equation (2) is merely an example and any other suitable forms are also feasible.

In some embodiments, an initial value (e.g., avgUlPRBLoad (0) ) of an average load of PRBs for the cell may be set to a predetermined value during setup of the cell. For example, the initial value of the average load of PRBs for the cell may be set to 0. It is to be noted that any other suitable values are also feasible.

Besides the load of PRBs for the cell, any other suitable measurements are also feasible. In some embodiments, the second device 120 may measure a pathloss for the cell. For example, the second device 120 may measure an UL pathloss for the cell. It is to be understood that any combination of these measurements may also be feasible, and the present disclosure does not limit this aspect.

Continue to refer to Fig. 3, the second device 120 may determine 320 whether the measurement satisfies a predetermined condition. In some embodiments, if the load of PRBs for the cell is below (e.g., lower than or equal to) a threshold load, the second device 120 may determine that the measurement satisfies the predetermined condition. In some embodiments, if the pathloss for the cell is below (e.g., lower than or equal to) a threshold pathloss, the second device 120 may determine that the measurement satisfies the predetermined condition. It is to be understood that the predetermined condition may adopt any other suitable forms, and the present disclosure does not limit this aspect.

Upon determination that the measurement satisfies the predetermined condition, the second device 120 may transmit, to the first device 110, an indication indicating update of transmission power for a PCell. In this way, respective transmission power for a PCell and a SCell may be adjusted based on a condition of a cell, and thus power control for CA may be well supported.

With reference to Fig. 3, in some embodiments, the second device 120 may transmit 330 such indication during a SCell addition or a SCell release for the first device 110. As shown in Fig. 3, the second device 120 may decide 331 to perform a SCell addition for the first device 110. In some embodiments, if a condition for the SCell addition is satisfied, the second device 120 may decide to perform the SCell addition. The present disclosure does not limit the condition for the SCell addition.

The second device 120 may transmit 332, to the first device 110, a message (for convenience, also referred to as a first message herein) indicating a SCell addition. The message comprises an indication (for convenience, also referred to as a first indication herein) indicating that a configuration for a power control parameter associated with the first device 110 is changed from an original configuration (for convenience, also referred to as a first configuration herein) to an updated configuration (for convenience, also referred to as a second configuration herein) . It is to be understood that the first message may be carried out by any suitable messages existing or to be developed in future.

In some embodiments, the power control parameter associated with the first device 110 may be p0-AlphaSets. It is to be understood that any other suitable forms may also be feasible. In other words, a configuration for p0-AlphaSets may be updated during a SCell addition when the load of PRBs for the cell is low. In some embodiments, the message indicating the SCell addition may comprise the updated configuration for p0-AlphaSets.

Continue to refer to Fig. 3, in some embodiments, if the measurement does not satisfy the predetermined condition, e.g., if the load of PRBs for the cell is above (e.g., higher than or equal to) the threshold load, or if the pathloss for the cell is above (e.g., higher than or equal to) the threshold pathloss, the second device 120 may determine 333 that the configuration for the power control parameter is unchanged. In this case, the second device 120 may transmit 334, to the first device 110, a message (for convenience, also referred to as a third message herein) indicating the SCell addition that does not comprise the configuration for the power control parameter. In some embodiments, the third message may not comprise the first indication. In some embodiments, the third message may comprise an indication indicating unchanging of the configuration for the power control parameter.

In some embodiments, the second device 120 may decide 335 to perform a SCell release for the first device 110. In some embodiments, if a condition for the SCell release is satisfied, the second device 120 may decide to perform the SCell release. The present disclosure does not limit the condition for the SCell release.

In this case, the second device 120 may transmit 336, to the first device 110, a message (for convenience, also referred to as a second message herein) indicating the secondary cell release, the second message comprising an indication (for convenience, also referred to as a second indication herein) indicating that the configuration for the power control parameter associated with the first device 110 is changed from the updated configuration to the original configuration. In other words, the configuration for the power control parameter is reconfigured back to the original configuration. It is to be understood that the second message may be carried out by any suitable messages existing or to be developed in future. In some embodiments, the second device 120 may transmit the second message if all the set of SCells are released for the first device 110.

With this mechanism, more triggers may be judged for power control parameter reconfiguration. Thus, power split between PCell and SCell may be adjusted, and better UL CA performance may be achieved.

In particular, each carrier may be configured with Pmax, c and P0 and so on. A terminal device may follow such configuration to perform an UL transmission over each carrier. If there is enough power, the terminal device may use transmission power based on pathloss measurement, so a network device may achieve receiving power P0, until its transmission power reaches Pmax, c.

In the mechanism of the present disclosure, reconfiguration of P0 through p0-AlphaSets may be performed based on measurements for a SCell to change the P0 of a PCell, and thus UL transmission power over PCell may be changed as UE will use the UL transmission power to a PCell based on P0 and the remaining power will be used by a SCell.

The above power control parameter reconfiguration during SCell addition or SCell release is a static way to reconfigure one or more power control parameters and achieve better UL performance. However, after SCell addition, the measurement for a cell such as a SCell load may vary dynamically. In this case, a PCell may use more UL transmission power to get better performance. In view of this, embodiments of the present disclosure also provide a solution of dynamic power control for CA. This solution is also described with reference to Fig. 3.

As shown in Fig. 3, in some alternative or additional embodiments, the second device 120 may transmit 340, in downlink control information (DCI) , the indication indicating the update of the transmission power of the PCell. For example, the DCI may be used for UL data scheduling. The second device 120 may transmit, in the DCI, a TPC command indicating a power variation of the transmission power for the PCell.

In some embodiments, the second device 120 may determine 341 a reference power variation for a TTI associated with the measurement. In some embodiments, the reference power variation may be determined based on closed loop power control (CLPC) . It is to be understood that the reference power variation may be determined in any suitable ways, and the present disclosure does not limit this aspect.

The second device 120 may further determine 342 the power variation for the TTI based on at least one of the reference power variation or an offset value in a set of offset values corresponding to the predetermined condition.

In some embodiments, the second device 120 may determine the power variation for the TTI based on the reference power variation and the offset value in a set of offset values corresponding to the predetermined condition. In other words, a set of predetermined conditions may be defined for comparison with the measurement, and the set of predetermined conditions are associated with a set of offset values. Whenever the measurement satisfies a predetermined condition in the set of predetermined conditions, the second device 120 may decide to adjust the transmission power of the PCell by an offset value in the set of offset values corresponding to the predetermined condition.

For example, the power variation may be determined based on equation (3) below.

TPC (t) =f _TPC (legacy _TPC _(t) + deltaTPCofScellLoad (ulPRBLoad (t) ) ) (3)

where TPC (t) denotes a power variation to be applied in a current TTI, legacy _TPC _(t) denotes a reference power variation, deltaTPCofScellLoad (ulPRBLoad (t) ) denotes an offset value corresponding to a current predetermined condition satisfied by a current measurement, and f _TPC (x) denotes an interpolation function finding a TPC with power adjustment nearest to the argument x from an allowed TPC command set. It is to be noted that equation (3) is merely an example and any other suitable forms are also feasible.

In this way, transmission power of a PCell may be continuously adjusted by a TPC command.

In some scenarios, different cells may support different frame structures, and thus part of slots among cells will not be overlapped. For example, for CA involving a PCell with frequency division duplex (FDD) and a SCell with time division duplex (TDD) , update for transmission power of a PCell may be beneficial in an overlapping slot. However, in a non-overlapping slot, it is better to keep transmission power optimized for a non-CA case, as only the PCell is transmitting there.

In some embodiments, if a TTI is an overlapping slot for the PCell and the set of SCells, the second device 120 may determine the power variation for the TTI based on the reference power variation and the offset value. For example, the second device 120 may determine the power variation based on the above equation (3) .

In some embodiments, if a TTI is a non-overlapping slot for the PCell and the set of SCells, the second device 120 may determine the power variation for the TTI based on the reference power variation. For example, the second device 120 may determine the power variation based on equation (4) below.

TPC (t) =legacy_TPC (t) (4)

where TPC (t) denotes a power variation to be applied in a current TTI, legacy _TPC _(t) denotes a reference power variation. It is to be noted that equation (4) is merely an example and any other suitable forms are also feasible.

In some embodiments, if the set of SCells are released, the second device 120 may also determine the power variation for the TTI based on the reference power variation. In other words, upon SCell release, CLPC may return to a single CC behavior. In this way, efficient power control may be achieved.

Then the second device 120 may transmit 343, in DCI e.g., for UL data scheduling, a TPC command indicating the power variation.

Conventionally, only a limited set of TPC values are allowed. For instance, with enabled TPC accumulation, the biggest positive power adjustment step is +3dB, the only negative power adjustment step is -1dB, the last one fortunately having a positive counterpart of +1dB. That means, this variant allows only adjustments of +/-1dB with TPC accumulation enabled. However, according to embodiments of the present disclosure, an absolute TPC may be used for power control for an overlapping or non-overlapping slot. For example, a restricted range of adjustments of {+/-1dB; +/-4dB} may be achieved.

Continue to refer to Fig. 3, upon reception of the indication indicating the update of the transmission power for the PCell, the first device 110 may update 350 the transmission power (e.g., UL transmission power) for the PCell based on the indication.

In some embodiments, upon reception of the first message indicating the SCell addition with the first indication, the first device 110 may update the transmission power of the PCell at least based on the updated configuration for the power control parameter. In other words, the first device 110 may change the transmission power of the PCell from original transmission power (for convenience, also referred to as first transmission power herein) to updated transmission power (for convenience, also referred to as second transmission power herein) . The transmission power of the PCell may be determined from the configuration for the power control parameter (e.g., p0-AlphaSets) and any other configurations, and the present disclosure does not limit this aspect.

In some embodiments, upon reception of the third message indicating the SCell addition without the first indication, the first device 110 does not need to change the transmission power for the PCell and the set of SCells.

In some embodiments, upon reception of the second message indicating the SCell release with the second indication, the first device 110 may update the transmission power of the PCell at least based on the original configuration for the power control parameter. In other words, the first device 110 may change the transmission power from the updated transmission power to the original transmission power. The transmission power may be determined from the configuration for the power control parameter (e.g., p0-AlphaSets) and any other configurations, and the present disclosure does not limit this aspect.

That is, during SCell release procedure, a power control parameter (e.g., p0-AlphaSets) configuration may be recovered. In this way, better PCell UL gain may be achieved.

After updating of the transmission power of the PCell, the first device 110 may update transmission power of the set of SCells. In other words, the first device 110 may perform power split between a PCell and a SCell. The power split may be carried out in any suitable ways existing or to be developed in future and the present disclosure does not limit this aspect.

Based on the updated transmission power for the PCell and the set of SCells, the first device 110 may perform 360 a transmission (e.g., UL transmission) via the PCell and the set of SCells. In some embodiments where a SCell release is performed, the first device 110 may perform a transmission via the PCell only.

It is to be understood that static power control with power control parameter reconfiguration during a SCell addition or a SCell release and dynamic power control with a TPC command may be carried out separately or in any combination.

For illustration, some example embodiments will be described below in connection with Figs. 4 and 5. Fig. 4 illustrates a diagram illustrating an example process 400 of power control with both p0-AlphaSets reconfiguration during a SCell addition and a TPC command according to some embodiments of the present disclosure. For the purpose of discussion, the process 400 will be described with reference to Fig. 1. The process 400 may involve the first device 110 and the second device 120 as illustrated in Fig. 1. It is assumed that the first device 110 is served by the second device 120. The second device 120 comprises a gNB-CU and a gNB-DU.

As shown in Fig. 4, the gNB-CU may decide 401 to perform a SCell addition for the terminal device 110. In this case, the gNB-CU may transmit 402, to the gNB-DU serving the terminal device 110, a UE context modification request indicating the SCell addition.

The gNB-DU may measure 403 PRB load for each cell (i.e., per carrier load measurement) . Upon reception of the UE context modification request from the gNB-CU, the gNB-DU may determine 404 updated p0-AlphaSets configuration for UL CA UE. The gNB-DU may transmit 405, to the gNB-CU, a UE context modification response comprising the updated p0-AlphaSets configuration for UL CA UE.

Then the gNB-CU may transmit 406 a DL RRC message (e.g., RRC reconfiguration message) to the terminal device 110. The DL RRC message may comprise the updated p0-AlphaSets configuration for UL CA UE.

Upon reception of the DL RRC message, the terminal device 110 may apply 407 the updated p0-AlphaSets configuration, and transmit 408 a UL RRC message (e.g., RRC reconfiguration complete message) to the gNB-CU.

The gNB-CU may transmit 409, to the gNB-DU, another UE context modification request indicating that the updated p0-AlphaSets configuration is applied. The gNB-DU may transmit 410 a UE context modification response to the gNB-CU. Then the gNB-DU may apply 411 the updated p0-AlphaSets configuration for UL scheduling.

After applying the updated p0-AlphaSets configuration, the gNB-DU may apply dynamic PCell power adjustment in UL DCI. In this example, the gNB-DU may compare 412 a measured PRB load for each cell with a set of threshold loads. If the measured PRB load is below a threshold load in the set of threshold loads, the gNB-DU may generate 413 a TPC command, e.g., based on equation (3) or (4) . Then the gNB-DU may transmit 414, to the first device 110, DCI comprising the TPC command. The first device 110 may adjust transmission power accordingly.

In this way, during SCell addition procedure, a network may decide to reconfigure p0-AlphaSets based on SCell load so as to achieve Shannon gain for UL scheduling of UL CA UE. With a TPC command in DCI, power split between a PCell and a SCell may be further adjusted in a dynamic way. Thus, better UL performance may be achieved for UL CA UE.

Fig. 5 illustrates a diagram illustrating an example process 500 of p0-AlphaSets reconfiguration during a SCell release according to some embodiments of the present disclosure. For the purpose of discussion, the process 500 will be described with reference to Fig. 1. The process 500 may involve the first device 110 and the second device 120 as illustrated in Fig. 1. It is assumed that the first device 110 is served by the second device 120. The second device 120 comprises a gNB-CU and a gNB-DU.

As shown in Fig. 5, the gNB-CU may decide 501 to perform a SCell release for the terminal device 110. In this case, the gNB-CU may transmit 502, to the gNB-DU serving the terminal device 110, a UE context modification request indicating the SCell release.

Upon reception of the UE context modification request from the gNB-CU, the gNB-DU may recover 503 the updated p0-AlphaSets configuration for UL CA UE to original p0-AlphaSets configuration. The gNB-DU may transmit 504, to the gNB-CU, a UE context modification response comprising the original p0-AlphaSets configuration for UL CA UE.

Then the gNB-CU may transmit 505 a DL RRC message (e.g., RRC reconfiguration message) to the terminal device 110. The DL RRC message may comprise the original p0-AlphaSets configuration for UL CA UE.

Upon reception of the DL RRC message, the terminal device 110 may apply 506 the original p0-AlphaSets configuration, and transmit 507 a UL RRC message (e.g., RRC reconfiguration complete message) to the gNB-CU.

The gNB-CU may transmit 508, to the gNB-DU, another UE context modification request indicating that the original p0-AlphaSets configuration is applied. The gNB-DU may transmit 509 a UE context modification response to the gNB-CU. Then the gNB-DU may apply 510 the original p0-AlphaSets configuration for UL scheduling.

In this way, during SCell release procedure, a network may recover the original p0-AlphaSets configuration so as to achieve better PCell UL gain.

Other details of the processes of Figs. 4 and 5 are similar to that described in Fig. 3, and thus are omitted for conciseness. It is to be noted that the above processes as shown in Figs. 3 to 5 are merely examples, and may have additional or less operations. Further, the order of the steps is not limited to that as shown. In addition, although gNB-CU and gNB-DU are shown as being implemented by the same device or entity in examples of Figs. 4 and 5, gNB-CU and gNB-DU may also be implemented in separate devices or entities.

Fig. 6 illustrates a diagram 600 illustrating an example performance simulation of a solution according to some embodiments of the present disclosure. In this example, single UE throughout with different p0-AlphaSets configurations is shown. As shown in Fig. 6, curve 610 denotes single UE throughout with p0-Nominal of -80dBm, curve 620 denotes single UE throughout with p0-Nominal of -85dBm, curve 630 denotes single UE throughout with p0-Nominal of -90dBm, curve 640 denotes single UE throughout with p0-Nominal of -93dBm, and curve 650 denotes single UE throughout with p0-Nominal of -96dBm.

It can be known from Fig. 6 that, UE secures PCell UL transmission power while lower p0-Nominal will reserve more power for SCell UL scheduling. Thus, SCell may achieve higher performance based on Shannon Theory when SCell UL PRB usage is not very high.

Corresponding to the above processes, example embodiments of the present disclosure also provide methods of communication. Fig. 7 illustrates a flowchart of an example method 700 implemented at a first device according to some embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described with reference to Fig. 1.

At block 710, the first device 110 receives, from the second device 120, an indication indicating update of transmission power for a PCell.

In some embodiments, the first device 110 may receive, as the indication, a first message indicating a SCell addition. The first message comprises a first indication indicating that a configuration for a power control parameter associated with the first device 110 is changed from a first configuration to a second configuration.

In some embodiments, the first device 110 may receive, as the indication, DCI comprising a TPC command. The TPC command indicates a power variation of the transmission power for the PCell.

At block 720, the first device 110 updates the transmission power based on the indication.

In some embodiments where the first message is received, the first device 110 may update, at least based on the second configuration for the power control parameter, the transmission power for the PCell from first transmission power to second transmission power.

In some embodiments where the TPC command is received, the first device 110 may update the transmission power for the PCell based on the power variation in the TPC command.

At block 730, the first device 110 performs, based on the updated transmission power, a transmission via the PCell and a set of SCells.

In some embodiments, the first device 110 may further receive, from the second device 120, a second message indicating a SCell release. The second message comprises a second indication indicating that the configuration for the power control parameter associated with the first device is changed from the second configuration to the first configuration. In these embodiments, the first device 110 may update the transmission power from the second transmission power to the first transmission power at least based on the first configuration for the power control parameter, and perform, based on the first transmission power, the transmission via the PCell.

With the method 700, power split between a PCell and a SCell may be adjusted and better UL CA performance may be achieved.

Fig. 8 illustrates a flowchart of an example method 800 implemented at a second device according to some embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described with reference to Fig. 1.

At block 810, the second device 120 determines that a measurement for a cell satisfies a predetermined condition. The cell is one of a group of cells comprising a PCell and a set of SCells.

In some embodiments, the second device 120 may determine a load of PRBs for the cell. In some embodiments, the second device 120 may determine a first load of PRBs for the cell in a first TTI. In some embodiments, the second device 120 may determine the first load based on a first number of PRBs allocated in the first TTI and a second number of PRBs available for scheduling in the first TTI. Based on the first load and an average load of PRBs for the cell in a second TTI earlier than the first TTI, the second device 120 may determine, as the load of PRBs, an average load of PRBs for the cell in the first TTI. In some embodiments, the second device 120 may set an initial value of an average load of PRBs for the cell to a predetermined value during setup of the cell.

If the load of PRBs is below a threshold load, the second device 120 may determine that the measurement satisfies the predetermined condition. If the load of PRBs is above the threshold load, the second device 120 may determine that the measurement does not satisfy the predetermined condition.

If the measurement satisfies the predetermined condition, the method 800 proceeds to block 820. At block 820, the second device 120 transmits, to the first device 110, an indication indicating update of transmission power of the PCell.

In some embodiments, the second device 120 may transmit, as the indication, a first message indicating a SCell addition. The first message comprises a first indication indicating that a configuration for a power control parameter associated with the first device 110 is changed from a first configuration to a second configuration.

In some embodiments, if the set of SCells are to be released, the second device 120 may transmit, to the first device 110, a second message indicating a SCell release. The second message comprises a second indication indicating that the configuration for the power control parameter associated with the first device 110 is changed from the second configuration to the first configuration.

In some embodiments, if the measurement for the cell does not satisfy the predetermined condition, the second device 120 may determine that the configuration for the power control parameter is unchanged, and transmit, to the first device 110, a third message indicating a SCell addition. The third message does not comprise the configuration for the power control parameter.

In some embodiments, the second device 120 may transmit, as the indication, DCI comprising a TPC command. The TPC command indicates a power variation of the transmission power for the PCell.

In some embodiments, the predetermined condition is one of a set of predetermined conditions, and the set of predetermined conditions are associated with a set of offset values. In these embodiments, the second device may determine a reference power variation for a TTI associated with the measurement, and determine the power variation for the TTI based on at least one of the reference power variation or an offset value in the set of offset values corresponding to the predetermined condition.

In some embodiments, if the TTI is an overlapping slot for the PCell and the set of SCells, the second device 120 may determine the power variation for the TTI based on the reference power variation and the offset value. If the TTI is a non-overlapping slot for the PCell and the set of SCells, the second device 120 may determine the power variation for the TTI based on the reference power variation. In some embodiments, if the set of SCells are released, the second device 120 may determine the power variation for the TTI based on the reference power variation.

With the method 800, power split between a PCell and a SCell may be adjusted, and better UL CA performance may be achieved.

It is to be noted that the operations of the methods 700 to 800 correspond to that described in connection with Figs. 3 to 5, and thus other details are not repeated here for conciseness.

Example embodiments of the present disclosure also provide the corresponding apparatus. In some embodiments, an apparatus (for example, the first device 110) capable of performing the method 700 may comprise means for performing the respective steps of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the apparatus comprises: means for receiving, at a first device and from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells; means for updating the transmission power based on the indication; and means for performing, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.

In some embodiments, the means for receiving the indication may comprise means for receiving, as the indication, a first message indicating a secondary cell addition, the first message comprising a first indication indicating that a configuration for a power control parameter associated with the first device is changed from a first configuration to a second configuration. In these embodiments, the means for updating the transmission power may comprise means for updating, at least based on the second configuration for the power control parameter, the transmission power for the primary cell from first transmission power to second transmission power.

In some embodiments, the apparatus may further comprise: means for receiving, from the second device, a second message indicating a secondary cell release, the second message comprising a second indication indicating that the configuration for the power control parameter associated with the first device is changed from the second configuration to the first configuration; means for updating the transmission power for the primary cell from the second transmission power to the first transmission power at least based on the first configuration for the power control parameter; and means for performing, based on the first transmission power, a transmission via the primary cell.

In some embodiments, the means for receiving the indication may comprise means for receiving, as the indication, downlink control information comprising a transmission power control command, the transmission power control command indicating power variation of the transmission power for the primary cell. In these embodiments, the means for updating the transmission power may comprise means for updating the transmission power for the primary cell based on the power variation.

In some embodiments, an apparatus (for example, the second device 120) capable of performing the method 800 may comprise means for performing the respective steps of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the apparatus comprises: means for determining, at a second device, that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and means for transmitting, to a first device, an indication indicating update of transmission power for the primary cell.

In some embodiments, the means for transmitting the indication may comprise: means for transmitting, as the indication, a first message indicating a secondary cell addition, the first message comprising a first indication indicating that a configuration for a power control parameter associated with a first device is changed from a first configuration to a second configuration.

In some embodiments, the apparatus may further comprise: means for, in accordance with a determination that the set of secondary cells are to be released, transmitting, to the first device, a second message indicating a secondary cell release, the second message comprising a second indication indicating that the configuration for the power control parameter associated with the first device is changed from the second configuration to the first configuration.

In some embodiments, the apparatus may further comprise: means for, in accordance with a determination that the measurement for the cell does not satisfy the predetermined condition, determining that the configuration for the power control parameter is unchanged; and means for transmitting, to the first device, a third message indicating the secondary cell addition, the third message comprising no configuration for the power control parameter.

In some embodiments, the means for transmitting the indication may comprise: means for transmitting, as the indication, downlink control information comprising a transmission power control command, the transmission power control command indicating a power variation of the transmission power for the primary cell.

In some embodiments, the predetermined condition is one of a set of predetermined conditions, and the set of predetermined conditions are associated with a set of offset values. In these embodiments, the apparatus may further comprise means for determining the power variation. The means for determining the power variation may comprise: means for determining a reference power variation for a transmission time interval associated with the measurement; and means for determining the power variation for the transmission time interval based on at least one of the reference power variation or an offset value in the set of offset values corresponding to the predetermined condition.

In some embodiments, the means for determining the power variation may comprise: means for, in accordance with a determination that the transmission time interval is an overlapping slot for the primary cell and the set of secondary cells, determining the power variation for the transmission time interval based on the reference power variation and the offset value; or means for, in accordance with a determination that the transmission time interval is a non-overlapping slot for the primary cell and the set of secondary cells, determining the power variation for the transmission time interval based on the reference power variation. In some embodiments, the means for determining the power variation may comprise: means for, in accordance with a determination that the set of secondary cells are released, determining the power variation for the transmission time interval based on the reference power variation.

In some embodiments, the means for determining that the measurement satisfies the predetermined condition may comprise: means for determining that a load of physical resource blocks for the cell is below a threshold load.

In some embodiments, the apparatus may further comprise means for determining the load. The means for determining the load may comprise means for determining a first load of physical resource blocks for the cell in a first transmission time interval; and means for determining, as the load, an average load of physical resource blocks for the cell in the first transmission time interval based on the first load and an average load of physical resource blocks for the cell in a second transmission time interval, the second transmission time interval being earlier than the first transmission time interval.

In some embodiments, the means for determining the first load may comprise: means for determining the first load based on a first number of physical resource blocks allocated in the first transmission time interval and a second number of physical resource blocks available for scheduling in the first transmission time interval.

In some embodiments, the apparatus may further comprise: means for setting an initial value of an average load of physical resource blocks for the cell to a predetermined value during setup of the cell.

Fig. 9 is a simplified block diagram of a device 900 that is suitable for implementing embodiments of the present disclosure. The device 900 may be provided to implement the communication device, for example the first device 110, the second device 120 or the third device 130 as shown in Fig. 1. As shown, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

The communication module 940 is for bidirectional communications. The communication module 940 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 910 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 900 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 924, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 922 and other volatile memories that will not last in the power-down duration.

A computer program 930 includes computer executable instructions that are executed by the associated processor 910. The program 930 may be stored in the ROM 920. The processor 910 may perform any suitable actions and processing by loading the program 930 into the RAM 920.

The embodiments of the present disclosure may be implemented by means of the program 930 so that the device 900 may perform any process of the disclosure as discussed with reference to Figs. 3 to 7. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 930 may be tangibly contained in a computer readable medium which may be included in the device 900 (such as in the memory 920) or other storage devices that are accessible by the device 900. The device 900 may load the program 930 from the computer readable medium to the RAM 922 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. Fig. 10 shows an example of the computer readable medium 1000 in form of CD or DVD. The computer readable medium has the program 930 stored thereon.

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

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the

method

700 or 800 as described above with reference to Figs. 7 to 8. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

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

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

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

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

Claims

A first device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the first device at least to:

receive, from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells;

update the transmission power based on the indication; and

perform, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.
The first device of claim 1, wherein the first device is caused to receive the indication by: receiving, as the indication, a first message indicating a secondary cell addition, the first message comprising a first indication indicating that a configuration for a power control parameter associated with the first device is changed from a first configuration to a second configuration, and

wherein the first device is caused to update the transmission power by: updating, at least based on the second configuration for the power control parameter, the transmission power for the primary cell from first transmission power to second transmission power.
The first device of claim 2, wherein the first device is further caused to:

receive, from the second device, a second message indicating a secondary cell release, the second message comprising a second indication indicating that the configuration for the power control parameter associated with the first device is changed from the second configuration to the first configuration;

update the transmission power for the primary cell from the second transmission power to the first transmission power at least based on the first configuration for the power control parameter; and

perform, based on the first transmission power, a transmission via the primary cell.
The first device of any of claims 1-3, wherein the first device is caused to receive the indication by: receiving, as the indication, downlink control information comprising a transmission power control command, the transmission power control command indicating power variation of the transmission power for the primary cell, and

wherein the first device is caused to update the transmission power by: updating the transmission power for the primary cell based on the power variation.
A second device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second device at least to:

determine that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and

transmit, to a first device, an indication indicating update of transmission power for the primary cell.
The second device of claim 5, wherein the second device is caused to transmit the indication by:

transmitting, as the indication, a first message indicating a secondary cell addition, the first message comprising a first indication indicating that a configuration for a power control parameter associated with a first device is changed from a first configuration to a second configuration.
The second device of claim 6, wherein the second device is further caused to:

in accordance with a determination that the set of secondary cells are to be released, transmit, to the first device, a second message indicating a secondary cell release, the second message comprising a second indication indicating that the configuration for the power control parameter associated with the first device is changed from the second configuration to the first configuration.
The second device of any of claims 5 to 7, wherein the second device is further caused to:

in accordance with a determination that the measurement for the cell does not satisfy the predetermined condition, determine that the configuration for the power control parameter is unchanged; and

transmit, to the first device, a third message indicating the secondary cell addition, the third message comprising no configuration for the power control parameter.
The second device of any of claims 5 to 8, wherein the second device is caused to transmit the indication by:

transmitting, as the indication, downlink control information comprising a transmission power control command, the transmission power control command indicating a power variation of the transmission power for the primary cell.
The second device of claim 9, wherein the predetermined condition is one of a set of predetermined conditions, and the set of predetermined conditions are associated with a set of offset values, and wherein the second device is further caused to determine the power variation by:

determining a reference power variation for a transmission time interval associated with the measurement; and

determining the power variation for the transmission time interval based on at least one of the reference power variation or an offset value in the set of offset values corresponding to the predetermined condition.
The second device of claim 10, wherein the second device is caused to determine the power variation by:

in accordance with a determination that the transmission time interval is an overlapping slot for the primary cell and the set of secondary cells, determining the power variation for the transmission time interval based on the reference power variation and the offset value; or

in accordance with a determination that the transmission time interval is a non-overlapping slot for the primary cell and the set of secondary cells, determining the power variation for the transmission time interval based on the reference power variation; or

in accordance with a determination that the set of secondary cells are released, determining the power variation for the transmission time interval based on the reference power variation.
The second device of any of claims 5 to 11, wherein the second device is caused to determine that the measurement satisfies the predetermined condition by:

determining that a load of physical resource blocks for the cell is below a threshold load.
The second device of claim 12, wherein the second device is further caused to determine the load by:

determining a first load of physical resource blocks for the cell in a first transmission time interval; and

determining, as the load, an average load of physical resource blocks for the cell in the first transmission time interval based on the first load and an average load of physical resource blocks for the cell in a second transmission time interval, the second transmission time interval being earlier than the first transmission time interval.
The second device of claim 13, wherein the second device is caused to determine the first load by:

determining the first load based on a first number of physical resource blocks allocated in the first transmission time interval and a second number of physical resource blocks available for scheduling in the first transmission time interval.
The second device of claim 13 or 14, wherein the second device is further caused to:

set an initial value of an average load of physical resource blocks for the cell to a predetermined value during setup of the cell.
A method of communication comprising:

receiving, at a first device and from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells;

updating the transmission power based on the indication; and

performing, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.
A method of communication comprising:

determining, at a second device, that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and

transmitting, to a first device, an indication indicating update of transmission power for the primary cell.
An apparatus of communication comprising:

means for receiving, at a first device and from a second device, an indication indicating update of transmission power for a primary cell, the update being determined based on a measurement for a cell satisfying a predetermined condition, the cell being one of a group of cells comprising the primary cell and a set of secondary cells;

means for updating the transmission power based on the indication; and

means for performing, based on the updated transmission power, a transmission via the primary cell and the set of secondary cells.
An apparatus of communication comprising:

means for determining, at a second device, that a measurement for a cell satisfies a predetermined condition, the cell being one of a group of cells comprising a primary cell and a set of secondary cells; and

means for transmitting, to a first device, an indication indicating update of transmission power for the primary cell.
A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method according to claim 16 or 17.