Method and apparatus for establishing and signaling maximum transmission power in wireless communication system

A user equipment (UE) dually connected to a first base station and a second base station and establishing maximum output power, the UE comprising:

• a receiving unit receiving a radio resource control (RRC) message including a UE-specific maximum transmission power value established in the first base station as mPEMAX or the second base station as sPEMAX, the first and the second base stations being connected through a backhaul;
• a control unit reestablishing maximum output power based on the received UE-specific maximum transmission power value by establishing PCMAX;
• and
• a transmitting unit simultaneously transmitting an uplink to the first base station and the second base station within the reestablished maximum output power PCMAX,
• wherein the UE-specific maximum transmission power value is established for each of the first base station and the second base station, and
• wherein:
• PPCMAX_L_DU≤PCMAX≤PCMAX_H_DU (equation 12)
• PCMAX_L_DU=MIN(10 log10ΣkpEMAX,c−ΔTC,PPOWERCLASS−MAX(MPR+A−MPR,P−MPR)−ΔTC) (equation 13)
• PCMAX_H_DU=MIN(10 log10ΣkpEMAX,c,PPOWERCLASS) (equation 14)
• wherein PPOWERCLASS is a parameter indicating the capability of the UE,
• MPR represents a power reduction value established in a range to satisfy requirements established by considering a corresponding band and modulation in the UE,
• A-MPR is a value established by the UE in a range indicated by the first or second base station,
• P-MPR represents maximum output power reduction permitted by considering a case in which a non-LTE system is used,
• ΔTc represents a fixed power offset value and a function of a transmission bandwidth for a component carrier,
• kPEMAX is a value transmitted to the UE through the RRC dedicated signaling for each serving cell of the UE, with 1≤k≤n and n represents a number of serving base stations,
• kpEMAX is a linear value of kPEMAX, and
• dP-Max is a value allocated to the UE and a value transmitted to the UE through the RRC dedicated signaling for each cell.

A method for establishing maximum transmission power of a user equipment (UE) which is dually connected to a first base station and a second base station, the method comprising:

• calculating power headroom for the second base station, the first and the second base stations being connected through a backhaul;
• transmitting a report of the power headroom to the first base station;
• and
• receiving from the first base station upper layer signaling indicating a change of a UE-specific maximum transmission power value for a serving cell group (CG) provided by at least one of the first base station and the second base station,
• wherein the report of the power headroom indicates power headroom value for all serving cells that belong to the CG, and
• a change of the UE-specific maximum transmission power value is determined based on the power headroom, and
• further comprising establishing or reestablishing maximum output power (PCMAX) configured in UE based on the upper layer signaling indicating the change of the UE-specific maximum transmission power value, wherein:
• PPCMAX_L_DU≤PCMAX≤PCMAX_H_DU (equation 12)
• PCMAX_L_DU=MIN(10 log10ΣkpEMAX,c−ΔTC,PPOWERCLASS−MAX(MPR+A−MPR,P−MPR)−ΔTC) (equation 13)
• PCMAX_H_DU=MIN(10 log10ΣkpEMAX,c,PPOWERCLASS) (equation 14)
• wherein PPOWERCLASS is a parameter indicating the capability of the UE,
• MPR represents a power reduction value established in a range to satisfy requirements established by considering a corresponding band and modulation in the UE,
• A-MPR is a value established by the UE in a range indicated by the first or second base station,
• P-MPR represents maximum output power reduction permitted by considering a case in which a non-LTE system is used,
• ΔTc represents a fixed power offset value and a function of a transmission bandwidth for a component carrier,
• kPEMAX is a value transmitted to the UE through a radio resource control RRC dedicated signaling for each serving cell of the UE, with 1≤k≤n and n represents a number of serving base stations,
• kpEMAX is a linear value of kPEMAX, and
• dP-Max is a value allocated to the UE and a value transmitted to the UE through the RRC dedicated signaling for each cell.

A user equipment (UE) dually connected to a first base station and a second base and establishing maximum transmission power, the UE comprising:

• a control unit calculating power headroom for the second base station, the first and the second base stations being connected through a backhaul;
• a transmitting unit transmitting a report of the power headroom to the first base station;
• and
• a receiving unit receiving from the first base station upper layer signaling indicating a change of a UE-specific maximum transmission power value for a serving cell group (CG) provided by at least one of the first base station and the second base station,
• wherein the report of the power headroom indicates power headroom value for all serving cells that belong to the CG, and
• a change of the UE-specific maximum transmission power value is determined based on the power headroom,
• and further comprising establishing or reestablishing maximum output power (PCMAX) configured in UE based on the upper layer signaling indicating the change of the UE-specific maximum transmission power value,
• wherein:
• PCMAX_L_DU≤PCMAX≤PCMAX_H_DU (equation 12)
• PCMAX_L_DU=MIN(10 log10ΣkpEMAX,c−ΔTC,PPOWERCLASS−MAX(MPR+A−MPR,P−MPR)−ΔTC) (equation 13)
• PCMAX_H_DU=MIN(10 log10ΣkpEMAX,c,PPOWERCLASS) (equation 14)
• wherein PPOWERCLASS is a parameter indicating the capability of the UE,
• MPR represents a power reduction value established in a range to satisfy requirements established by considering a corresponding band and modulation in the UE,
• A-MPR is a value established by the UE in a range indicated by the first or second base station,
• P-MPR represents maximum output power reduction permitted by considering a case in which a non-LTE system is used,
• ΔTc represents a fixed power offset value and a function of a transmission bandwidth for a component carrier,
• kPEMAX is a value transmitted to the UE through a radio resource control (RRC) dedicated signaling for each serving cell of the UE, with 1≤k≤n and n represents a number of serving base stations,
• kpEMAX is a linear value of kPEMAX, and
• dP-Max is a value allocated to the UE and a value transmitted to the UE through the RRC dedicated signaling for each cell.