Power headroom reporting for in-device coexistence interference avoidance

A mobile terminal for reporting a maximum output power level (PCMAX) in a mobile communication system including a base station and a wireless communication device, the mobile terminal having a predetermined nominal mobile terminal power (PPowerClass) and being configured with a maximum allowed mobile terminal output power (PEMAX) for communication with the base station via one radio technology and being configured for communication with the wireless communication device via another radio technology, the mobile terminal comprises:

• a processor configured to calculate a power management related power backoff value (P-MPR) for the one radio technology so as to avoid in-device interference between the one and the other radio technology, by referring to a reception quality level set for communication via the other radio technology;
• wherein the processor is further configured to calculate lower and upper bounds of a maximum output power level (PCMAX—L;PCMAX—H)for the one radio technology based on the calculated power management related power backoff value (P-MPR), where the lower bound (PCMAX—L) and the upper bound (PCMAX—H) are defined by:
• PCMAX—L=min{PEMAX−ΔTc,PPowerClass−max(MPR+A-MPR,P-MPR)−ΔTc}
• PCMAX—H=min{PEMAX,PPowerClass}
• wherein the processor is further configured to set a maximum output power level (PCMAX) for communication on the one radio technology, where the configured maximum output power level (PCMAX) is set within the determined lower and upper bounds to meets the condition:
• PCMAX—L≦PCMAX≦PCMAX—H;
• and
• a transmitter configured to report the set maximum output power level (PCMAX) using an in-device coexistence, IDC, problem indication message for the one radio technology to the base station;
• wherein the lower bound (PCMAX—L) is calculated using MPR=0 dB, A-MPR=0 dB and either an allowed operating band edge transmission power relaxation value (ΔTc) or ΔTc=0 dB.

A method for reporting a maximum output power level (PCMAX) by a mobile terminal in a mobile communication system including a base station and a wireless communication device, the mobile terminal having a predetermined nominal mobile terminal power (PPowerClass) and being configured with a maximum allowed mobile terminal output power (PEMAX) for communication with the base station via one radio technology and being configured for communication with the wireless communication device via another radio technology, the method comprising the steps of:

• calculating, by the mobile terminal, a power management related power backoff value (P-MPR) for the one radio technology by referring to a reception quality level set for communication via the other radio technology;
• determining, by the mobile terminal, whether or not the calculated power management related power backoff value (P-MPR) for the one radio technology exceeds a predefined power backoff threshold value;
• and
• calculating, by the mobile terminal, lower and upper bounds of a maximum output power level (PCMAX—L;PCMAX—H)for the one radio technology based on the calculated power management related power backoff value (P-MPR), where the lower bound (PCMAX—L) and the upper bound (PCMAX—H) are defined by:
• PCMAX—L=min{PEMAX−ΔTc,PPowerClass−max(MPR+A-MPR,P-MPR)−ΔTc}
• PCMAX—H=min{PEMAX,PPowerClass}
• setting, by the mobile terminal, the maximum output power level (PCMAX) for communication on the one radio technology, where the maximum output power level (PCMAX) is set within the determined lower and upper bounds to meets the condition:
• PCMAX—L≦PCMAX≦PCMAX—H;
• reporting, by the mobile terminal, the set maximum output power level (PCMAX) using an extended power headroom report (ePHR) for the one radio technology to the base station;
• and wherein
• in case the calculated power management related power backoff value (P-MPR) exceeds the predefined power backoff threshold value, the lower bound (PCMAX—L) is calculated using MPR=0 dB, A-MPR=0 dB, and either an allowed operating band edge transmission power relaxation value (ΔTc) or ΔTc=0 dB ;
• and
• in case the calculated power management related power backoff value (P-MPR) does not exceed the predefined power backoff threshold value, the lower and upper bounds (PCMAX—L;PCMAX—H) are calculated using a mobile terminal specific allowed maximum power reduction value (MPR), a mobile terminal specific additional maximum power reduction value (A-MPR), and an allowed operating band edge transmission power relaxation value (ΔTc).