Method and apparatus for supporting power backoff reporting during power headroom reporting in a wireless communication system

Abstract

A method and apparatus for reporting transmit power headroom of a terminal in a wireless communication system is provided. [Solution] The present invention relates to a communication technique and system for converging a 5G communication system with IoT technology to support a higher data transmission rate than that of the 4G system. The present invention is applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, smart retail, security and safety services, etc.) based on 5G communication technology and IoT-related technology. A method and apparatus are provided for receiving a PHR setting including a prohibition timer and a threshold from a base station. It is determined whether the PHR is triggered based on the PHR setting. If the PHR is triggered, the PHR is transmitted to the base station. The PHR includes a bit field indicating a power backoff to be applied based on power management when the P field is set to 1.

Description

[Technical Field]

[0001] The present invention relates generally to terminal and base station operation in a wireless communication system, and more particularly to a method and apparatus for reporting transmit power headroom of a terminal in a wireless communication system. [Background technology]

[0002] Efforts are underway to develop improved 5G or pre-5G communication systems to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems. For this reason, 5G or pre-5G communication systems are referred to as beyond-4G network (Beyond 4G Network) or post-LTE (Post-LTE) systems. To achieve high data transmission rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., the 60 GHz band). To mitigate propagation path loss and increase transmission distance in ultra-high frequency bands, beamforming, massive multiple-input multiple-output (MM-MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antenna technologies are being discussed for 5G communication systems. Furthermore, to improve the system's network, technological developments are being made in the 5G communication system, such as advanced small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D communication), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and receive interference cancellation.Other advanced coding modulation (ACM) methods being developed for 5G systems include Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), as well as advanced connection technologies such as Filter Bank Multi Carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA).

[0003] Meanwhile, the Internet is evolving into the Internet of Things (IoT), a network that exchanges and processes information among distributed components such as objects. IoE (Internet of Everything) technology, which combines big data processing technology through connections to cloud servers and other technologies, is also emerging. To realize IoT, technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. In recent years, research has focused on sensor networks, M2M (Machine to Machine), and MTC (Machine Type Communication) for connecting objects. In an IoT environment, intelligent IT (Internet Technology) services are provided that create new value in human life by collecting and analyzing data generated between connected objects. Through the convergence and integration of existing IT (information technology) technologies with various industries, IoT is being applied to areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0004] As a result, various attempts are being made to apply 5G communication systems to IoT networks. For example, 5G communication technologies such as sensor networks, M2M (Machine to Machine), and MTC (Machine Type Communication) are being implemented using techniques such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN) as the aforementioned big data processing technology is also seen as an example of the convergence of 5G and IoT technologies. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned conventional technology, and an object of the present invention is to provide a method and apparatus for notifying a base station that power backoff has been performed when a terminal in a wireless communication system reports a transmission power headroom (hereinafter referred to as power headroom or PH). [Means for solving the problem]

[0006] In order to achieve the above object, according to one aspect of the present invention, a method performed by a terminal in a communication system includes the steps of receiving a power headroom reporting (PHR) setting from a base station, the PHR setting including a prohibition timer and a threshold for power management based on maximum power saving; checking whether the PHR is triggered based on the PHR setting; and transmitting the PHR to the base station if the PHR is triggered, wherein the PHR includes a bit field indicating a power backoff to be applied based on the power management when a P field is set to 1.

[0007] In order to achieve the above object, according to one aspect of the present invention, a method performed by a base station in a communication system includes the steps of: transmitting a power headroom reporting (PHR) setting to a terminal, the PHR setting including a prohibition timer and a threshold for power management based on maximum power saving; and receiving the PHR from the terminal when the PHR is triggered, wherein the PHR is triggered based on the PHR setting, and the PHR includes a bit field indicating a power backoff to be applied based on the power management when a P field is set to 1.

[0008] In order to achieve the above object, a terminal in a communication system according to one aspect of the present invention comprises a transceiver unit and a control unit connected to the transceiver unit, wherein the control unit is configured to receive a power headroom reporting (PHR) setting from a base station, the PHR setting including a prohibition timer and a threshold for power management based on maximum power saving, check whether a PHR is triggered based on the PHR setting, and if the PHR is triggered, transmit the PHR to the base station, and the PHR includes a bit field indicating a power backoff to be applied based on the power management when a P field is set to 1.

[0009] In order to achieve the above object, according to one aspect of the present invention, a base station in a communication system includes a transceiver unit and a control unit connected to the transceiver unit, wherein the control unit is configured to transmit a power headroom reporting (PHR) setting to a terminal, the PHR setting including a prohibition timer and a threshold for power management based on maximum power saving, and to receive the PHR from the terminal when the PHR is triggered, wherein the PHR is triggered based on the PHR setting, and the PHR includes a bit field indicating a power backoff to be applied based on the power management when a P field is set to 1. [Effects of the Invention]

[0010] According to the present invention, the terminal can separately adjust the power headroom report due to the occurrence of power backoff, and when the situation occurs, the base station is immediately notified of the fact, and scheduling can be performed according to the terminal's transmission power.

[0011] Other aspects, features, and advantages of the present invention will become more apparent from the following description taken in conjunction with the drawings. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a configuration of an LTE system according to one embodiment. [Figure 2] FIG. 1 is a diagram illustrating a configuration of a radio protocol in an LTE system according to one embodiment. [Figure 3] FIG. 10 is a diagram for explaining carrier aggregation in a terminal according to an embodiment. [Figure 4] FIG. 1 is a diagram illustrating the concept of multiple connections in LTE and NR according to one embodiment. [Figure 5A] FIG. 1 illustrates an uplink transmission method according to one embodiment. [Figure 5B] FIG. 1 illustrates a Multiple Entry PHR MAC CE format according to one embodiment. [Figure 5C] FIG. 10 is another diagram illustrating a Multiple Entry PHR MAC CE format according to one embodiment. [Figure 6] 10 is a diagram illustrating an operation procedure of a terminal according to a method for reporting a PHR when a power backoff for power control occurs according to an embodiment. [Figure 7] FIG. 2 is a diagram illustrating a block configuration of a terminal in a wireless communication system according to an embodiment. [Figure 8] FIG. 1 is a diagram illustrating a configuration of a base station according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, specific examples of embodiments of the present invention will be described in detail with reference to the drawings. Although the same or similar components are shown in different drawings, they are denoted by the same or similar reference numerals. Detailed descriptions of known structures or processes that may obscure the gist of the present invention will be omitted.

[0014] The terms explained below are defined in consideration of the functions of the present invention, and may differ depending on the user, the user's intention, or customs. Therefore, the definition of the terms should be based on the contents of the entire specification.

[0015] In the following description, terms for identifying connection nodes, terms for designating network entities, terms for designating messages, terms for designating interfaces between network objects, terms for designating various identification information, etc. are provided as examples for the convenience of description. Therefore, the present invention is not limited to the terms described below, and other terms for designating objects having equivalent technical meanings may be used.

[0016] For ease of explanation, the present invention will use terms and names defined in the 3GPP (registered trademark) LTE (The 3rd Generation Partnership Project Long Term Evolution) standard, which is the latest standard among existing communication standards. However, the present invention is not limited by the terms and names and is similarly applicable to systems based on other standards. In particular, the present invention is applied to 3GPP (registered trademark) NR (New Radio: fifth generation mobile communication standard).

[0017] FIG. 1 is a diagram illustrating a configuration of an LTE system according to an embodiment.

[0018] 1, the wireless communication system includes multiple base stations (105, 110, 115, 120), a mobility management entity (MME) 125, and a serving gateway (S-GW) 130. A user equipment (UE or terminal) 135 is connected to an external network via the base stations (105, 110, 115, 120) and the S-GW 130.

[0019] The base stations (105, 110, 115, 120) are access nodes of the cellular network and provide wireless connections to terminals connected to the network. That is, to service user traffic, the base stations (105, 110, 115, 120) collect status information such as terminal buffer status, available transmit power status, and channel status, and perform scheduling to support the connection between the terminal and the core network (CN). The MME 125 is a device that handles various control functions, including mobility management for terminals, and is connected to multiple base stations. The S-GW 130 is a device that provides data bearers. In addition, the MME 125 and S-GW 130 also perform authentication and bearer management for terminals connected to the network, and process packets received from the base stations (105, 110, 115, 120) or packets to be transmitted to the base stations (105, 110, 115, 120).

[0020] 2 is a diagram illustrating a radio protocol configuration in an LTE system according to an embodiment. The NR system also has substantially the same protocol structure as the LTE system.

[0021] Referring to Figure 2, the LTE system's radio protocol consists of PDCP (packet data convergence protocol) (205, 240), RLC (radio link control) (210, 235), and MAC (medium access control) (215, 230) in the UE and ENB, respectively. PDCP (205, 240) is responsible for operations such as IP header compression / decompression, and RLC (210, 235) reassembles PDCP PDUs (packet data units) into appropriate sizes.

[0022] The MAC (215, 230) is connected to multiple RLC layer devices configured in one terminal and performs operations of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The physical layer (PHY layer) (220, 225) channel codes and modulates higher layer data, generates OFDM symbols, and transmits them over a wireless channel, or demodulates and channel-decodes OFDM symbols received over a wireless channel and transmits them to a higher layer. The physical layer also uses hybrid ARQ (HARQ) for additional error correction, and a receiving terminal transmits one bit indicating whether it has received a packet transmitted from a transmitting terminal. This is called HARQ ACK / NACK information. Downlink HARQ ACK / NACK information for uplink transmission is transmitted via a physical hybrid-ARQ indicator channel (PHICH) physical channel, and uplink HARQ ACK / NACK information for downlink transmission is transmitted via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) physical channel.

[0023] Above the PDCP layer of the UE and the base station, there exists a radio resource control (RRC) layer, and the RRC layer transmits and receives configuration control messages related to connection and measurement for radio resource control.

[0024] The PHY layer consists of one or more frequencies / carriers, and the technology of simultaneously configuring and using multiple frequencies in one base station is called carrier aggregation (CA). CA technology refers to a technology that uses only one carrier for communication between a terminal and a base station (E-UTRAN NodeB, eNB) and additionally uses a primary carrier and one or more secondary carriers. CA technology can dramatically increase the transmission rate by the number of secondary carriers. In LTE and NR systems, the cell in a base station that uses the primary carrier is called a PCell (primary cell), and the secondary carrier is called an SCell (secondary cell). The technology of extending the above CA function to two base stations is called dual connectivity (DC).

[0025] In DC technology, a terminal is simultaneously connected to a primary base station (master E-UTRAN NodeB (MeNB)) and a secondary base station (secondary E-UTRAN NodeB (SeNB)). Cells belonging to the primary base station are called the master cell group (MCG), and cells belonging to the secondary base station are called the secondary cell group (SCG). Each cell group has a representative cell. The representative cell of the MCG is called the PCell, and the representative cell of the SCG is called the primary secondary cell (PSCell). When using the above-mentioned NR, the MCG is used with LTE technology (i.e., an LTE base station is used as the base station corresponding to the MCG) and the SCG is used with NR (i.e., an NR base station is used as the base station corresponding to the SCG), allowing the terminal to use LTE and NR simultaneously. Alternatively, an NR base station can be used as the base station corresponding to the MCG and an LTE base station can be used as the base station corresponding to the SCG, or both NR and NR base stations can be used for both the MCG and the SCG. The scenario in which different RATs are connected by DC as described above is commonly called MR-DC (Multi-RAT DC), and DC between NRs is called NR-DC.

[0026] Meanwhile, in LTE and NR systems, a terminal reports PHR to a base station according to predetermined conditions. Power headroom information refers to the difference between the maximum transmit power set in the terminal and the transmit power estimated by the terminal. The transmit power estimated by the terminal is calculated based on the value used when the terminal actually transmits an uplink (the calculated value is called a real value at this time). However, when the terminal does not actually transmit, it is calculated based on a predetermined formula defined in the standard (the calculated value is called a virtual value at this time). By reporting the power headroom information, the base station can determine the maximum transmit power of the terminal. Meanwhile, in CA situations, power headroom information is transmitted for each subcarrier.

[0027] FIG. 3 is a diagram illustrating a carrier aggregation technique in a terminal according to an embodiment.

[0028] Referring to Figure 3, a base station typically transmits and receives multiple carriers across multiple frequency bands. For example, when a base station 305 transmits a carrier 315 with a center frequency of f1 and a carrier 310 with a center frequency of f3, a terminal conventionally transmits and receives data using one of the two carriers. However, a terminal capable of carrier aggregation can simultaneously transmit and receive data using multiple carriers. The base station 305 can increase the transmission speed of a terminal 330 capable of carrier aggregation by allocating more carriers to the terminal 330, depending on the situation.

[0029] In the traditional sense, when one forward carrier and one reverse carrier transmitted from and received by one base station constitute one cell, carrier aggregation is understood as a terminal transmitting and receiving data through multiple cells simultaneously, whereby the maximum transmission speed increases in proportion to the number of aggregated carriers.

[0030] Hereinafter, when a terminal receives data via any forward carrier or transmits data via any reverse carrier, this means transmitting and receiving data using a control channel and a data channel provided in a cell corresponding to a center frequency and frequency band that characterize the carrier. In addition, in the following embodiments of the present invention, for convenience of explanation, an LTE system and an NR system will be described, but the present invention can be applied to various wireless communication systems that support carrier aggregation.

[0031] Whether CA is performed or not, reverse transmission (i.e., from the terminal to the base station) causes interference in the reverse direction of other cells, so the reverse transmission power must be maintained at an appropriate level. To this end, when performing reverse transmission, the terminal calculates the reverse transmission power using a predetermined function and performs the reverse transmission with the calculated reverse transmission power. For example, the terminal calculates a required reverse transmission power value by inputting input values ​​that can estimate the amount of allocated transmission resources, scheduling information such as an applied modulation coding scheme (MCS) level, and channel conditions such as a path loss value into a predetermined function, and performs the reverse transmission by applying the calculated required reverse transmission power value.

[0032] The reverse transmission power value that the terminal can apply is limited by the terminal's maximum transmission value. If the calculated required transmission power value exceeds the terminal's maximum transmission value, the terminal applies the maximum transmission value to perform reverse transmission. In this case, sufficient reverse transmission power cannot be applied, resulting in degradation of reverse transmission quality. It is desirable for the base station to perform scheduling so that the required transmission power does not exceed the maximum transmission power. However, since the base station cannot grasp some parameters such as path loss, the terminal transmits a PHR when necessary to report the terminal's transmission power headroom or available transmission power status to the base station.

[0033] Factors that affect the available transmit power include 1) the amount of allocated transmission resources, 2) the MCS used for reverse transmission, 3) the path loss of the associated forward carrier, and 4) the accumulated value of the power adjustment command. Among these, the path loss (PL) and accumulated power adjustment command value differ for each reverse carrier. Therefore, when multiple reverse carriers are aggregated in one UE, it is reasonable to configure whether to transmit a PHR for each reverse carrier. However, for efficient PHR transmission, it is also possible to report PHs for multiple reverse carriers on one reverse carrier. Depending on the operation strategy, PHs for carriers on which PUSCH transmission is not actually performed may be required. Therefore, in such cases, it is more efficient to report PHs for multiple reverse carriers on one reverse carrier. To achieve this, the existing PHR must be extended. Multiple PHs included in one PHR are configured according to a predetermined procedure.

[0034] A PHR is usually triggered when the path loss of the connected forward carrier changes to a predetermined reference value or more, when the prohibit PHR timer expires, or when a predetermined period of time has passed since the PHR was generated. Even when a PHR is triggered, the UE does not immediately transmit the PHR, but waits until reverse transmission is possible, for example, until reverse transmission resources are allocated. This is because the PHR is not information that should be processed quickly.

[0035] FIG. 4 is a diagram illustrating dual connectivity according to an embodiment.

[0036] When dual connectivity (DC) technology is used, a terminal is simultaneously connected to two base stations, and in this example drawing, a case is shown in which a terminal 405 is simultaneously connected to a macro base station 400 using LTE technology and a small cell base station 410 using NR technology to transmit and receive data. This is called EN-DC (E-UTRAN-NR dual connectivity).

[0037] In this situation, the macro base station 400 is called an MeNB, and the small cell base station is called a secondary 5G NodeB (SgNB). Multiple small cells exist within the service area of ​​the MeNB, and the MeNB is connected to the SgNB via a wired backhaul network 415. A group of serving cells provided by the MeNB is called an MCG 420, and one serving cell in the MCG is a PCell 425 that has all the functions performed by existing cells, such as connection establishment, connection re-establishment, and handover. In addition, the PCell has a PUCCH as an uplink control channel. Serving cells other than the PCell are called SCells 430.

[0038] 4 illustrates a scenario in which an MeNB provides one SCell and an SgNB provides three SCells. A group of serving cells provided by the SgNB is referred to as an SCG 440.

[0039] When a UE transmits or receives data from two base stations, the MeNB transmits a command to the SgNB to add, modify, or remove a serving cell provided by the SgNB. To transmit such a command, the MeNB configures the UE to measure the serving cell and neighboring cells. The UE reports the measurement results to the MeNB according to the configuration information. In order for the SgNB to efficiently transmit and receive data to the UE, a serving cell that plays a role similar to the PCell of the MCG is required, and this is referred to as a PSCell 435 in the present invention. The PSCell is configured as one of the serving cells of the SCG and is characterized by having a PUCCH, which is an uplink control channel. The PUCCH is used by the UE to transmit HARQ ACK / NACK information, channel status information (CSI), scheduling request (SR), etc. to the base station.

[0040] In a DC scenario, the MCG and SCG each have an independent MAC entity, i.e., there are two MAC entities in DC, and various MAC functions (e.g., PHR reporting) are performed independently for each base station.

[0041] FIG. 5A illustrates an uplink transmission method according to one embodiment.

[0042] In FIG. 5A, example 1 is a diagram illustrating a scenario in which a terminal performs uplink transmission according to the scheduling of a base station after two serving cells, i.e., a PCell 501 and one SCell 503, are configured. In this scenario, the terminal is unable to simultaneously transmit PUCCH and PUSCH in one serving cell due to restrictions on the transmission method and RF architecture. Accordingly, the terminal transmits PUCCH information embedded in the PUSCH transmission (505). The terminal transmits PUCCH information via the PCell, or, if there is no PUSCH to transmit via the PCell, transmits via an SCell with a lower index among the SCells. The above-mentioned PHR message is transmitted via a portion of the PUSCH, and therefore, in this scenario, the terminal controls the maximum transmission power (P CMAX,c ) minus the transmission power consumed in PUSCH transmission (505, 507). This is called Type 1 power headroom.

[0043] Example 2 is also a diagram illustrating a scenario in which a terminal performs uplink transmission according to the scheduling of a base station after two serving cells, i.e., a PCell 511 and one SCell 513, are configured. In this scenario, the terminal has the capability to simultaneously transmit PUCCH and PUSCH in one serving cell, or transmits PUCCH and PUSCH separately using an uplink transmission technology that allows simultaneous transmission. In this case, in the case of the PCell (or the SCell if PUCCH can be transmitted via the SCell), the terminal transmits the maximum transmission power (P CMAX,f,cIt is necessary to report a power headroom value obtained by subtracting both the transmission power values ​​for the PUSCH transmission and the PUCCH transmission from the power headroom value (517, 519) in consideration of the transmission power consumed not only for the PUSCH transmission (517, 519) but also for the PUCCH transmission (515). This is called Type 2 power headroom.

[0044] When reporting Type 1 or Type 2 power headroom, the terminal reports using a MAC control element (CE), which is a control message of the MAC layer, and more specifically, reports using a single list PHR (Single Entry PHR) MAC CE format 521 or a multiple list PHR (Multiple Entry PHR) MAC CE format 531. When only a single carrier is used, the terminal uses the Single Entry PHR format, and when dual connectivity is set (or CA is set), the terminal uses the Multiple Entry PHR MAC CE format.

[0045] When the Single Entry PHR MAC CE format is used, the terminal determines the power headroom 523 for the serving cell and the maximum transmission power P CMAX,f,c Send 525.

[0046] The power headroom value is used to indicate one of a range between -32 dB and 38 dB as shown in the table below, which indicates the available transmit power of the terminal.

[0047] [Table 1]

[0048] The terminal calculates the available transmit power using the following equation (1) or an equivalent equation:

[0049]

number

[0050] That is, in Equation (1), PH(i) when PUSCH transmission is performed at time i in serving cell c (frequency f) is the maximum reverse transmission power P CMAX,f,c (i) The number of resource blocks, M PUSC HRB,b,f,c (i) Power offset Δ induced by MCS TF、c (i), Path loss PL c, It is calculated by fc(i) (accumulated TPC commands). In Equation (1), PLc indicates the path loss of a cell configured to provide path loss to serving cell c. The path loss used to determine the reverse transmission power of a serving cell is the path loss of the forward channel of the cell or the path loss of the forward channel of another cell. The base station selects which path loss to use and notifies the terminal via a message in the RRC layer.

[0051] When a terminal uses multiple beams in one cell, the terminal is notified of which beam or reference signal to select for measurement and calculation. c (i) denotes the cumulative value of the transmission power control command of the serving cell c. O_PUSCH,C is set as a parameter of a higher layer as the sum of a cell-specific and a UE-specific value.

[0052] In general, P O_PUSCH,C Various values ​​are applied to α depending on the type of PUSCH transmission, such as semi-persistent scheduling, dynamic scheduling, and random access response. cis a 3-bit cell-specific value provided by a higher layer, and the value applied is limited depending on the PUSCH transmission type via a weighting factor applied to the path loss when calculating the reverse transmission power (i.e., the higher this value, the more the path loss affects the reverse transmission power). The value j is used to indicate the type of PUSCH. When j=0, it indicates semi-persistent scheduling, when j=1, it indicates dynamic scheduling, and when j=2, it indicates random access response. In equation (1), when there is no PUSCH transmission in a specific serving cell, M PUSCH and Δ TF cannot be applied to the above equation (1) according to the definition.

[0053] On the other hand, the maximum transmission power of the terminal in serving cell c (frequency f) is P CMAX,f,c is expressed as P CMAX_L,f,c and P CMAX_H,f,c or an equivalent mathematical formula.

[0054]

number

[0055] In the above formula (2), P CMAX,f,c The maximum value of P CMAX_H,f,c is the P that the base station can directly transmit. EMAX,c It is determined by value and frequency band. TIFF0007731352000004.tif10128 is determined by the minimum value of the values. CMAX,f,c The minimum value of P CMAX_L,f,c is determined by the value reduced by the additional factor in each maximum value. For example, P EMAX,c By value, by band condition TIFF0007731352000005.tif10128 is reduced and specified by frequency band. The TIFF0007731352000006.tif10128 value takes into consideration the MPRc (maximum power reduction) determined by the terminal's transmission modulation and transmission bandwidth, the A-MPRc value (additional maximum power reduction, or also called network signaling (NS) value) determined by the signaling that the base station additionally transmits to the terminal to reduce interference in surrounding bands, and the P-MPRc (power management maximum power reduction) value used to reduce the transmission power to meet the required value for electromagnetic wave energy absorption by the human body, and reduces the minimum value of the terminal's maximum transmission power based on the larger of these values.

[0056] For example, in a system that operates at a high frequency such as an NR system, a terminal may transmit at high power, but since high power transmission may be harmful to the human body, the maximum transmission value is adjusted according to a required value that regulates this. The case where the actual transmission power is adjusted by lowering the minimum value of the maximum transmission power according to the P-MPRc value as described above is called power backoff that occurs for power management.

[0057] FIG. 5B is a diagram illustrating a Multiple Entry PHR MAC CE format according to one embodiment.

[0058] Referring to FIG. 5B, when the Multiple Entry PHR MAC CE format is used, the terminal notifies which serving cells the power headroom is to be reported for using a bitmap 533, and the power headroom is configured as (541, 551, 561) for the serving cells that have notified the report through the bitmap and the serving cells that are unconditionally reported. Also, if reporting is required, the terminal uses the corresponding P CMAX,f,cThe values ​​are reported together (543, 553, 563). When the terminal reports the power headroom, it reports using a field having a length of 6 bits as shown, and in LTE, it has values ​​as shown in Table 2 below.

[0059] [Table 2]

[0060] On the other hand, in NR, the frequency range in which the base station operates can be broadly divided into two frequency ranges as shown in Table 3 below.

[0061] [Table 3]

[0062] The transmission power required for a terminal to operate in a base station operating in FR1 and a base station operating in FR2 is significantly different. Therefore, a separate table different from Table 2 in LTE is defined for each frequency range (i.e., for FR1 and FR2, respectively).

[0063] For example, the following Table 4 is used for PHR reporting for a base station operating in FR1 among NR base stations. (Table 4 is not significantly different from the frequency range in which LTE operates, and for convenience, it is illustrated as the same table as Table 2, but other values ​​may be used.)

[0064] [Table 4]

[0065] Also, for example, the following Table 5 is used for PHR reporting for base stations operating in FR1 among NR base stations.

[0066] [Table 5]

[0067] In the case of a Multiple Entry PHR MAC CE, a P bit 535 and a V bit 537 are additionally included.

[0068] The P bit indicates information indicating power backoff generated for power management. That is, if the maximum transmission power value of the serving cell becomes lower than the original value due to power backoff, the P bit is set to 1 and reported to the base station. CMAX,f,c The base station is notified that the value of has been adjusted for the above reason.

[0069] The V bit indicates information indicating whether or not an actual uplink transmission is performed according to scheduling information for each serving cell when the UE reports Multiple Entry PHR MAC CE. When reporting Multiple Entry PHR MAC CE, the UE may or may not actually transmit uplink data for each serving cell according to scheduling information. If actual transmission is performed, the V bit is set to 0, and the PH value is calculated and reported according to the actual transmission. However, if no uplink data is transmitted, the V bit is set to 1, and a value calculated assuming that a predetermined virtual transmission is performed is reported as PH. The virtual transmission is called a PUSCH reference format.

[0070] The values ​​of the P and V bits can be set in various ways: setting the P bit to 0 indicates that the maximum transmission power value is lower than the original value, and setting the V bit to 1 indicates that the PH value is a value calculated by actual transmission.

[0071] Therefore, when the terminal reports a PHR for each cell that the current base station has configured and activated for the terminal, even if the same PH report field is used in the Multiple Entry PHR format according to the RAT and operating frequency of the serving cell, the terminal generates a value using a table according to the serving cell type and reports it to the base station.

[0072] Even when the above-mentioned Single Entry PHR MAC CE is used, the P CMAX,f,c Therefore, even in the case of Single Entry PHR MAC CE, the P bit 557 is included and a method for notifying this is considered.

[0073] Additionally, the power backoff described above is caused by the power backoff due to power management. CMAX,f,c If a case arises where the value of must be reduced, the power headroom is transmitted using a format such as that of FIG. 5C for more detailed reporting instead of the format described in FIG. 5B.

[0074] FIG. 5C illustrates a Multiple Entry PHR MAC CE format according to one embodiment.

[0075] When the base station explicitly configures the terminal to use a new format, the terminal reports using the format shown in this example. For example, if a new field such as reportPMPRenabled is introduced and the base station configures reportPMPRenabled in the terminal, both the Single Entry PHR MAC CE and Multiple Entry PHR MAC CE use the format for reporting the P bit and P-MPRc.

[0076] That is, compared to Figure 5B, P-MPRc fields (5c-07), (5c-71), (5c-75) and Dynamic duty cycle fields (5c-09), (5c-77) have been added to both the Single Entry PHR MAC CE (5c-51) and Multiple Entry PHR MAC CE formats (5c-31) shown in Figure 5C. Therefore, the remaining reference numerals in Figure 5C are the same as those in Figure 5B.

[0077] More specifically, when the terminal sets the P bit to 1, it explicitly indicates to the cell (c) the P-MPRc value to be used to reduce the transmission power described above using the P-MPRc field (5c-07), (5c-71), (5c-75).

[0078] In order to maximize reuse of the existing format, two reserved bits of the existing format are recycled, resulting in a maximum of four P-MPRc values ​​that can be reported. The four values ​​represent specific values ​​or ranges of values. For example, bit 00 indicates a value between 1 dB and 5 dB, bit 01 indicates a value between 6 dB and 10 dB, bit 10 indicates a value between 11 dB and 15 dB, and bit 11 indicates a value of 16 dB or more. However, the above content is merely one embodiment of the present invention, and the scope of the present invention is not limited thereto. That is, the P-MPRc values ​​or ranges indicated by the bits may be variously set.

[0079] If the P bit is set to 0, the reserved bit is used instead of this P-MPRc field as before, or the base station ignores the content of the P-MPRc field even if it receives it. In particular, when using Multiple Entry PHR MAC CE, the P bit is set to 0 or 1 for each serving cell, and the reserved bit is used for the serving cell set to 0 as before (5c-73), or the base station ignores the content of the P-MPRc field even if it receives it.

[0080] In addition, the Dynamic duty cycle field (5c-09) (5c-77) is included if at least one P field in the format is set to 1, and indicates the length of time that the terminal can maintain this power backoff.

[0081] Whether or not the Dynamic duty cycle field is present is determined by a method of including the Dynamic duty cycle field when at least one P field is set to 1, when the base station configures the new format as shown in Figure 5C via a separate indicator. Alternatively, even when the base station configures the new format as shown in Figure 5C via a separate indicator, a method of indicating whether or not the Dynamic duty cycle field is included via a separate indicator is also considered.

[0082] It is also possible to define a new format such as that shown in Figure 5C by adding only the P-MPRc fields (5c-07), (5c-71), and (5c-75) and omitting the Dynamic duty cycle fields (5c-09) and (5c-77). This allows the base station to obtain only information about how much power the terminal reduced when transmitting.

[0083] The base station can accurately identify the amount of transmission power reduced by the terminal and the length of time for which the transmission power has been reduced, and perform operations such as releasing the serving cell (especially in the case of an SCell) for that period of time or performing a handover to another cell.

[0084] Conditions are defined for when to send a PHR to a base station (i.e., when to trigger a report), and the following conditions are defined for LTE and NR systems:

[0085] Condition 1: When prohibitPHR-Timer has expired, the change in downlink reception strength of a serving cell belonging to any MAC entity configured in the terminal is greater than or equal to phr-Tx-PowerFactorChange dB.

[0086] That is, according to the above conditions, even if a change in signal strength occurs in one of the serving cells of the SCG in the DC scenario, the MCG will report a PHR.

[0087] Condition 2: When the phr-PeriodicTimer (of the MAC entity) expires.

[0088] Condition 3: PHR reporting is set up first.

[0089] Condition 4: An SCell including an uplink corresponding to any MAC entity is activated.

[0090] Condition 5: When using dual connectivity technology, a PSCell of an SCG is added or changed.

[0091] Condition 6: When the prohibitPHR-Timer has expired and there are resources to transmit in the uplink of a serving cell corresponding to any MAC entity configured in the terminal, the amount by which the transmit power should be reduced due to the power backoff generated for the above-mentioned power control is greater than the value previously reported by the PHR MAC CE. If necessary.

[0092] On the other hand, in the case of condition 6, when there is no P bit, such as in the Single Entry PHR MAC CE illustrated in 521 of Figure 5A, even when the base station receives the PHR MAC CE, it may be difficult for the base station to know whether power backoff has occurred in the terminal for power control. For this reason, condition 6 is modified to condition 6-1 as follows.

[0093] Condition 6-1: When the prohibitPHR-Timer has expired and there are resources to transmit on the uplink of the serving cell corresponding to any MAC entity configured in the terminal, multiple PHR MAC CE is used, or when multiple PHR MAC CE is not used (i.e., Single Entry MAC CE is used), the base station configures the Single Entry PHR MAC CE to include the P bit and transmit it as in the 551 format of Figure 5B.

[0094] If the size of the amount by which the transmit power should be reduced due to the power backoff generated for the above-mentioned power control is greater than or equal to phr-Tx-PowerFactorChange compared to the value previously reported by the PHR MAC CE.

[0095] In addition, although the same prohibitPHR-Timer value and phr-Tx-PowerFactorChange value are used in Condition 1 and Condition 6 (or Condition 6-1) in the above conditions, the base station can set the values ​​for Condition 6 and Condition 6-1 separately to separately control the occurrence of power backoff. For example, the base station sets the phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit values ​​separately for Condition 6 and Condition 6-1, and uses the additionally set values ​​instead of the prohibitPHR-Timer and phr-Tx-PowerFactorChange values ​​for Condition 6 and Condition 6-1. The additionally set values ​​are transmitted to the terminal, for example, via an RRC message. This applies to both when using an (updated) Single Entry PHR MAC CE and a Multiple Entry PHR MAC CE.

[0096] If the above PHR triggering conditions occur in each base station depending on the conditions, the terminal generates and reports a PHR in the base station. However, if the above-mentioned dynamic power sharing is not supported, if a PHR is triggered by an event occurring in a MAC entity other than its own MAC entity, the terminal may report a PHR but not report the power headroom value of the serving cell corresponding to the MAC entity, which may result in only the PHR value belonging to its own MAC entity being transmitted unnecessarily.

[0097] FIG. 6 is a diagram illustrating an operation procedure of a terminal according to a method for reporting a PHR when a power backoff for power control occurs according to an embodiment.

[0098] The method starts in step 601. A terminal in an idle state (IDLE) searches for and selects a suitable NR base station (or cell) and connects to the base station in step 603. To this end, the terminal transmits an RRC Request message of the RRC layer to the base station, thereby receiving an RRC Setup message from the base station, and then transmits an RRC Setup Complete message to the base station to complete the connection procedure.

[0099] If the terminal has never previously connected to the operator's network or if the core network does not have capability information to accommodate the terminal due to movement, the base station instructs the terminal to report the terminal's capability information using a UECapabilityEnquiry message of the RRC layer.

[0100] Accordingly, the UE reports its capability information to the base station using a UECapabilityInformation message of the RRC layer. The UE transmits to the base station a bit (e.g., singleEntryPbit) indicating whether or not it supports a format including a P bit in the Single Entry PHR MAC CE in step 605. Also, if the base station has the capability information of the UE, the step of transmitting the UECapabilityInformation message is omitted.

[0101] Thereafter, the terminal receives an RRC Reconfiguration message of the RRC layer from the base station in step 607. The RRC Reconfiguration message includes configuration information.

[0102] The configuration information includes settings related to PHR reporting. The settings related to PHR reporting are included in a phr-Config information element (IE) in an RRCReconfiguration message and transmitted to the terminal.

[0103] The phr-Config IE includes at least one of values ​​such as whether to use multiple PHR, phr-ProhibitTimer, phr-PeriodicTimer, and phr-Tx-PowerFactorChange. Furthermore, if the base station sets multiple PHR to false according to the capability of the terminal (i.e., if the use of Single Entry PHR MAC CE is configured), the base station additionally configures the Single Entry PHR MAC CE to use a format including the P bit described above. For example, whether the P bit is included in the Single Entry PHR MAC CE is indicated using a bit such as singleEntryPbitEnabled (e.g., an indicator of whether the P bit for single PHR is used).

[0104] Meanwhile, the configuration information included in the above-mentioned RRC message is merely one embodiment of the present invention, and the scope of the present invention is not limited thereto. For example, some of the above information may not be included, or only some of the information may be included.

[0105] In addition, if the base station wishes to separately control the PHR triggered when a power backoff occurs due to the above-mentioned power management, the base station additionally sets new parameters phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit corresponding to the existing phr-ProhibitTimer and phr-Tx-PowerFactorChange.

[0106] If the phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit are not signaled, the terminal determines whether to trigger PHR using the phr-ProhibitTimer and phr-Tx-PowerFactorChange in the PHR triggering condition of Condition 6 above.

[0107] However, if phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit are signaled, condition 6 of the conditions for triggering PHR is used to determine whether to trigger PHR using phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit.

[0108] Furthermore, the field names such as phr-ProhibitTimer and phr-ProhibitTimerPbit are used for convenience of explanation and may be replaced with terms such as first prohibition timer and second prohibition timer. Furthermore, phr-Tx-PowerFactorChange and phr-Tx-PowerFactorChangePbit may be replaced with information on change in strength of the first received signal, information on change in strength of the second received signal, etc.

[0109] Alternatively, the UE may determine whether to trigger PHR using condition 6-1 instead of condition 6. That is, when the prohibitPHR-Timer has expired and there are resources to transmit in the uplink of a serving cell corresponding to any MAC entity configured in the UE, if multiple PHR MAC CEs are used, or when multiple PHR MAC CEs are not used (i.e., Single Entry MAC CEs are used) and the base station is configured to include and transmit P bits in Single Entry PHR MAC CEs as in the 551 format, PHR is triggered if the amount by which the transmission power should be reduced due to the power backoff generated for the above-mentioned power control is greater than or equal to phr-Tx-PowerFactorChange compared to the value previously reported for PHR MAC CE. Additionally, if the phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit are set, the terminal replaces phr-ProhibitTimer and phr-Tx-PowerFactorChange with phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit in condition 6-1. If the base station sets separate parameters for the power backoff case as described above, triggering is determined by the separate parameters when a power backoff situation for the corresponding power control occurs, and the base station can report the situation more quickly or more freely depending on the set value.

[0110] Upon receiving the configuration information, the terminal transmits a confirmation message in response to the configuration information. The confirmation message is an RRCReconfigurationComplete message.

[0111] Thereafter, the terminal determines whether the following PHR report triggering conditions occur according to the parameters set in the base station as described above.

[0112] Condition 1: When prohibitPHR-Timer has expired, the change in downlink reception strength of a serving cell belonging to any MAC entity configured in the terminal is greater than or equal to phr-Tx-PowerFactorChange dB.

[0113] Condition 2: When the phr-PeriodicTimer (of the MAC entity) expires.

[0114] Condition 3: PHR reporting is set up first.

[0115] Condition 4: An SCell including an uplink corresponding to any MAC entity is activated.

[0116] Condition 5: When using dual connectivity technology, the primary cell (PSCell) of the SCG is added or changed.

[0117] Condition 6: When prohibitPHR-Timer expires, the amount of transmission power reduction required (due to transmission power regulation, etc.) is greater than or equal to phr-Tx-PowerFactorChange when transmitting on the uplink of a serving cell corresponding to any MAC entity configured in the terminal; or

[0118] Condition 6-1: When the prohibitPHR-Timer has expired and multiple PHR MAC CE is used when there are resources to transmit on the uplink of a serving cell corresponding to any MAC entity configured in the terminal, or when multiple PHR MAC CE is not used (i.e., Single Entry MAC CE is used) and the base station is configured to transmit Single Entry PHR MAC CE including a P bit as in the 551 format of Figure 5B (singleEntryPbitEnabled), or when the size of the amount by which the transmit power should be reduced due to the power backoff generated for the above-mentioned power control is required to be greater than phr-Tx-PowerFactorChange compared to the value previously reported for the PHR MAC CE.

[0119] If phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit are additionally set, in conditions 6 and 6-1, the terminal replaces phr-ProhibitTimer and phr-Tx-PowerFactorChange with phr-ProhibitTimerPbit and phr-Tx-PowerFactorChangePbit.

[0120] When condition 6-1 is used, if singleEntryPbitEnabled is not set, PHR is not triggered.

[0121] In the embodiment of Fig. 6, it is assumed that a PHR report is triggered when power backoff occurs in the terminal due to power control, whereby the terminal assumes that condition 6 or condition 6-1 is satisfied.

[0122] Accordingly, in step 611, the terminal determines the format of the MAC CE to be reported to the PHR depending on whether the multiplePHR setting information and singleEntryPbitEnable are set from the base station.

[0123] If multiple PHR is set to true (i.e., the base station sets CA or DC to the terminal), in step 613, the P bit included in the MAC CE for the serving cell (carrier) where power backoff occurs is set to 1 (or 0 depending on the setting) using Multiple Entry PHR MAC CE, and the P bit of the serving cell is set to 1 (or 0 depending on the setting). CMAX,f,c Set the PHR MAC CE to a value adjusted by power backoff.

[0124] If multiplePHR is set to false (i.e., the base station does not configure CA or DC for the terminal and uses only a single serving cell), and singleEntryPbitEnabled is not set, the terminal generates a PHR MAC CE using the existing Single Entry PHR MAC CE 521 (see FIG. 5A) without a P bit in step 617. In one embodiment of FIG. 6, assuming that PHR is triggered, if condition 6-1 is used as described above, PHR itself is not triggered if singleEntryPbitEnabled is not set.

[0125] If multiplePHR is set to false (i.e., the base station does not set CA or DC for the terminal and uses only a single serving cell), and singleEntryPbitEnabled is set, the terminal generates a PHR MAC CE using a Single Entry PHR MAC CE including a P bit as shown in 551 of FIG. 5B in step 615. That is, the P bit is set to 1 in the current MAC CE, and the P bit of the corresponding serving cell is set to 1. CMAX,f,c Set the PHR MAC CE to a value adjusted by power backoff.

[0126] Thereafter, the terminal reports the generated PHR to the base station and notifies the base station of the terminal's power headroom in step 619. The method ends in step 621. The base station then determines the terminal's current power headroom and schedules the terminal accordingly.

[0127] FIG. 7 is a diagram showing a block configuration of a terminal in a wireless communication system according to an embodiment.

[0128] Referring to FIG. 7, the terminal includes an RF (Radio Frequency) processing unit 710, a baseband processing unit 720, a storage unit 730, and a control unit 740.

[0129] The RF processor 710 performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processor 710 up-converts a baseband signal provided from the baseband processor 720 to an RF band signal and transmits the signal via an antenna, and down-converts an RF band signal received via an antenna back to a baseband signal. For example, the RF processor 710 includes a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Although FIG. 7 illustrates only one antenna, a terminal may have multiple antennas. The RF processor 710 also includes multiple RF chains. The RF processor 710 also performs beamforming. For beamforming, the RF processor 710 adjusts the phase and magnitude of each signal transmitted and received via multiple antennas or antenna elements.

[0130] The baseband processor 720 performs conversion between a baseband signal and a bit stream in accordance with the system's physical layer standard. For example, during data transmission, the baseband processor 720 generates complex symbols by encoding and modulating a transmission bit stream. During data reception, the baseband processor 720 demodulates and decodes the baseband signal provided by the RF processor 710 to restore a received bit stream. For example, in the case of orthogonal frequency division multiplexing (OFDM), during data transmission, the baseband processor 720 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and constructs OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. During data reception, the baseband processor 720 divides the baseband signal provided by the RF processor 710 into OFDM symbols, restores the signals mapped to the subcarriers through fast Fourier transform (FFT), and restores the received bit stream through demodulation and decoding.

[0131] The baseband processor 720 and the RF processor 710 transmit and receive signals as described above. Therefore, the baseband processor 720 and the RF processor 710 are referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processor 720 and the RF processor 710 includes multiple communication modules to support multiple different wireless access technologies. Furthermore, at least one of the baseband processor 720 and the RF processor 710 includes different communication modules to process signals in different frequency bands. For example, different wireless access technologies include wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. Furthermore, different frequency bands include super high frequency (SHF) bands (e.g., 2.5 GHz, 5 GHz) and millimeter wave (mm wave) bands (e.g., 60 GHz).

[0132] The memory unit 730 stores data such as basic programs, applications, and setting information for the operation of the terminal. In particular, the memory unit 730 stores information about wireless LAN nodes that perform wireless communication using wireless LAN connection technology. The memory unit 730 then provides the stored data in response to a request from the control unit 740.

[0133] The controller 740 controls the overall operation of the terminal. For example, the controller 740 transmits and receives signals via the baseband processor 720 and the RF processor 710. The controller 740 also writes and reads data to and from the memory unit 740. To this end, the controller 740 includes at least one processor. For example, the controller 740 includes a communication processor (CP) that controls communications and an application processor (AP) that controls higher layers such as application programs. According to one embodiment, the controller 740 includes a multiple connection processor 742 that performs processing for operating in a multiple connection mode. For example, the controller 740 controls the terminal to perform the procedures shown in the terminal operation illustrated in FIG. 5.

[0134] In one embodiment, the control unit 740 determines whether to set the P bit even when Single Entry PHR MAC CE is used based on the terminal's capability and configuration information received from the base station, and if it is determined that a PHR report should be made, instructs the terminal to generate and transmit the PHR report to the base station.

[0135] FIG. 8 is a diagram illustrating a configuration of a base station according to an embodiment.

[0136] 8, the terminal includes a transceiver unit 810, a controller 820, and a memory unit 830. In the present invention, the controller is defined as a circuit, an application-specific integrated circuit, or at least one processor.

[0137] The transceiver 810 transmits and receives signals to and from other network entities, for example, receives capabilities of the terminal and transmits configuration information to the terminal.

[0138] The controller 820 controls the overall operation of the base station according to the exemplary embodiment of the present invention. For example, the controller 820 controls the signal flow between each block to perform the operations according to the above-described flowchart. For example, the controller 820 receives the PHR determined by the above-described method from the terminal, and controls the transmission power accordingly to transmit data.

[0139] The storage unit 830 stores at least one of information transmitted and received via the transmission / reception unit 810 and information generated via the control unit 820 .

[0140] The methods according to the embodiments claimed or described in the specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0141] In the case of a software implementation, a computer-readable storage medium is provided that stores one or more programs (software modules). The one or more programs stored on the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform a method according to an embodiment of the present invention as claimed or described in the specification.

[0142] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), other forms of optical storage, magnetic cassette, or in memory configured as a combination of some or all of these. Furthermore, multiple copies of each type of memory may be included.

[0143] The program may also be stored in an attachable storage device that can be accessed via a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), or a storage area network (SAN), or a combination thereof. Such a storage device is connected to an apparatus that implements an embodiment of the present invention through an external port. Alternatively, a separate storage device on the communication network may be connected to an apparatus that implements an embodiment of the present invention.

[0144] In the specific embodiments of the present invention described above, elements included in the present invention are expressed as singular or plural in accordance with the specific embodiments presented. However, the expressions singular or plural are selected to fit the presented situation for the convenience of explanation, and the present invention is not limited to singular or plural elements, and elements expressed as plural may be composed of singular elements, and elements expressed as singular may be composed of plural elements.

[0145] While the detailed description of the present invention has been given with reference to specific embodiments, it is understood that various modifications are possible within the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the claims and their equivalents. [Explanation of symbols]

[0146] 105, 110, 115, 120, 305 base station 125 MME(mobility management entity) 130 S-GW (Serving Gateway) 135, 330, 405 UE (user equipment) or terminal 205, 240 PDCP (packet data convergence protocol) 210, 235 RLC (radio link control) 215, 230 MAC (medium access control) 220, 225 Physical layer (PHY layer) 310 Carrier with center frequency f3 315 Carrier with center frequency f1 400 Macro Base Stations (MeNB: Main Base Station) 410 Small cell base station (SeNB: auxiliary base station) 415 wired backhaul network 420 Serving cell group provided by MeNB (MCG: cells belonging to the primary base station) 425 PCell (MCG representative cell) 430 Serving cell (SCell) other than PCell 435 PSCell (SCG representative cell) 440 Serving cell group provided by SgNB (SCG: cells belonging to auxiliary base station) 501, 511 PCell (Primary Cell) 503, 513 SCell (Secondary Cell) 505 PUSCH (+PUCCH) transmission 507, 517, 519 PUSCH transmission 515 PUCCH transmission 521 Single Entry PHR (MAC CE format) 523, 541, 551, 561 Power Headroom 525 Maximum Transmit Power (P CMAX,f,c ) 531 Multiple Entry PHR (MAC CE format) 533 bitmap 535, 557 P-bit 537 V-bit 710 RF Processing Unit 720 Baseband Processing Unit 730, 830 Storage section 740, 820 Control unit 742 Multiplex Connection Processing Unit 810 Transmitter / Receiver

Claims

1. 1. A method performed by a terminal in a communication system, comprising: receiving configuration information from a base station, the configuration information including a first power headroom reporting (PHR) configuration including a first prohibit timer (ProhibitTimer) and a second PHR configuration including a threshold and a second prohibit timer; determining whether a power management maximum power reduction (P-MPR) associated with a power management maximum power reduction (PHR) applied to meet the required value is triggered based on the setting information; transmitting a PHR associated with the P-MPR to the base station when the P-MPR value is equal to or greater than the threshold value and the second inhibit timer is not running; If the P field included in the PHR associated with the P-MPR is set to 1, the field included in the PHR associated with the P-MPR indicates the P-MPR value; The method of claim 1, wherein the length of the field is 2 bits.

2. The field indicates a range of the P-MPR value, 2. The method of claim 1, wherein the field is used as a reserved field if the P field is set to 0.

3. and starting the second inhibit timer when a PHR associated with the P-MPR is triggered; 2. The method of claim 1, wherein the PHR associated with the P-MPR comprises a single entry PHR or a multiple entry PHR.

4. 1. A method performed by a base station in a communication system, comprising: transmitting configuration information to the terminal, the configuration information including a first power headroom reporting (PHR) configuration including a first prohibit timer (ProhibitTimer) and a second PHR configuration including a threshold value and a second prohibit timer; receiving a power management maximum power reduction (P-MPR)-related PHR from the terminal when the PHR is triggered, the PHR being related to the P-MPR applied to satisfy the required value; a PHR associated with the P-MPR is triggered when the P-MPR value is equal to or greater than the threshold value and the second inhibit timer is not running; If the P field included in the PHR associated with the P-MPR is set to 1, the field included in the PHR associated with the P-MPR indicates the P-MPR value; The method of claim 1, wherein the length of the field is 2 bits.

5. The field indicates a range of the P-MPR value, 5. The method of claim 4, wherein the field is used as a reserved field if the P field is set to 0.

6. When a PHR associated with the P-MPR is triggered, the second inhibit timer is started; 5. The method of claim 4, wherein the PHR associated with the P-MPR comprises a single entry PHR or a multiple entry PHR.

7. A terminal in a communication system, a transmitter / receiver; a control unit connected to the transceiver unit, The control unit receiving configuration information from a base station, the configuration information including a first power headroom reporting (PHR) configuration including a first prohibit timer (ProhibitTimer) and a second PHR configuration including a threshold and a second prohibit timer; Based on the configuration information, determining whether a PHR related to a power management maximum power reduction (P-MPR) to be applied to meet the required value is triggered; configured to transmit a PHR associated with the P-MPR to the base station when the P-MPR value is equal to or greater than the threshold value and the second prohibit timer is not running; If the P field included in the PHR associated with the P-MPR is set to 1, the field included in the PHR associated with the P-MPR indicates the P-MPR value; A terminal characterized in that the length of the field is 2 bits.

8. The field indicates a range of the P-MPR value, 8. The terminal of claim 7, wherein the field is used as a reserved field if the P field is set to 0.

9. the control unit is further configured to start the second inhibit timer when a PHR associated with the P-MPR is triggered; 8. The terminal of claim 7, wherein the PHR associated with the P-MPR includes a single entry PHR or a multiple entry PHR.

10. A base station in a communication system, comprising: a transmitter / receiver; a control unit connected to the transceiver unit, The control unit Sending configuration information to the terminal, the configuration information including a first power headroom reporting (PHR) configuration including a first prohibit timer (ProhibitTimer) and a second PHR configuration including a threshold value and a second prohibit timer; When a PHR related to a maximum power reduction (P-MPR) of power management applied to satisfy a required value is triggered, the PHR is configured to receive a PHR related to the P-MPR from the terminal; a PHR associated with the P-MPR is triggered when the P-MPR value is equal to or greater than the threshold value and the second inhibit timer is not running; If the P field included in the PHR associated with the P-MPR is set to 1, the field included in the PHR associated with the P-MPR indicates the P-MPR value; The base station is characterized in that the length of the field is 2 bits.

11. The field indicates a range of the P-MPR value, The field is used as a reserved field if the P field is set to 0; When a PHR associated with the P-MPR is triggered, the second inhibit timer is started; The base station of claim 10, wherein the PHR associated with the P-MPR includes a single entry PHR or multiple entry PHR.

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