5. Average monthly revenue per unit (ARPU) Average monthly revenue per unit, or ARPU, is used to measure average monthly operating revenues attributable to designated services on a per user basis. In the case of our fixed line business, ARPU is calculated by dividing revenue items in the operating revenues of our Regional Communications Business, that is, subscriber lines services and ISDN and B FLET's, by the No. of active subscribers to the relevant services. In the case of our cellular business, ARPU is calculated by dividing revenue items included in the operating revenues from our Mobile Cummunications Business, such as revenues from Cellular (mova) services and revenues from Cellular (FOMA) services, which are incurred consistently each month (i.e., monthly charges and voice/packet transmission charges), by the No. of active subscribers to the relevant services (the calculation of these figures excludes revenues that are not representative of monthly average usage such as equipment sales and activation fees). We believe that our ARPU figures calculated in this way provide useful information regarding the monthly average usage of our subscribers. The revenue items included in the numerators of our ARPU figures are based on our financial results comprising our U.S. GAAP results of operations. Notes : 1 We separately compute the following 4 categories ARPU for the fixed line business conducted by each of NTT East and NTT West, using the following measures.     - Aggregate Fixed Line ARPU (Telephone Subscriber Lines + ISDN Subscriber Lines): Caluculated based on revenue from monthly charges and call charges for Telephone Subscriber Lines and ISDN Subscriber Lines, which are included in operating revenues from Voice Transmission Services (excluding IP Services), and revenues from FLET'S ADSL and FLET'S ISDN, which are included in operating revenues from IP Services. - Telephone Subscriber Lines ARPU: Calculated based on revenues from monthly charges and call charges for Telephone Subscriber Lines, and revenues from FLET'S ADSL. - ISDN Subscriber Lines ARPU: Calculated based on revenues from monthly charges and call charges for ISDN Subscriber Lines and revenues from FLET'S ISDN. - B FLET'S ARPU: Calculated based on revenues from B FLET'S, which are included in operating revenues from IP services, and revenues from monthly charges, call charges and connection device charges for Hikari Phone. - B FLET'S includes FLET'S Hikari Premium provided by NTT West.   2 Revenues from interconnection charges are excluded from the calculation of Aggregate Fixed Line ARPU (Telephone Subscriber Lines +ISDN Subscriber Lines), Telephone Subscriber Lines ARPU, ISDN Subscriber Lines ARPU, and B FLET's ARPU.   3 For purposes of calculating Telephone Subscriber Lines ARPU abd ISDN Subscriber Lines ARPU, number of subscribers is determined using the number of lines for each service.   4 In terms of No. of channels, transmission rate, and line use rate (base rate), INS-Net 1500 is in all cases roughly ten times greater than INS-Net 64. For this reason, one INS-Net 1500 subscription is calculated as ten INS-Net 64 subscriptions.   5 For purposes of calculating B FLET's ARPU, number of subscribers is determined based on the number of B FLET's subscribers.   6 We compute ARPU for our cellular business using three aggregate measures.     - Cellular Aggregate ARPU (FOMA+mova) = Voice ARPU (FOMA+mova) + Packet ARPU (FOMA+mova).   - Our Voice ARPU (FOMA+mova) is based on operating revenues related to voice services, such as monthly charges and voice transmission charges, attributable to our third generation FOMA and conventional mova services, and our Packet ARPU (FOMA+mova) is based on operating revenues related to packet communication services, such as monthly charges and packet transmission charges, attributable to our third generation FOMA services and based on operating revenues related to i-mode services, such as monthly charges and packet transmission charges, to our conventional mova services. We also separately compute i-mode ARPU (FOMA+mova), as a subcomponent of Packet ARPU (FOMA+mova). In particular, i-mode ARPU (FOMA+mova) is based on operating revenues from monthly charges and packet transmission charges to our i-mode-related FOMA and mova services. - Cellular Aggregate ARPU (FOMA) = Voice ARPU (FOMA) + Packet ARPU (FOMA).   - Our Voice ARPU (FOMA) is based on operating revenues related to voice services, such as monthly charges and voice transmission charges, and our Packet ARPU (FOMA) is based on operating revenues related to packet communication services, such as monthly charges and packet transmission charges, in each case attributable to our third generation FOMA services. We also separately compute i-mode ARPU (FOMA), as a subcomponent of Packet ARPU (FOMA). In particular, i-mode ARPU (FOMA) is based on operating revenues from monthly charges and packet transmission charges attributable to our i-mode-related FOMA services. - Cellular Aggregate ARPU (mova) = Cellular Voice ARPU (mova) + i-mode ARPU (mova).   - Our Voice ARPU (mova) is based on operating revenues related to voice services, such as monthly charges and voice transmission charges, and our i-mode ARPU (mova) is based on operating revenues related to i-mode services, such as monthly charges and packet transmission charges, in each case attributable to our conventional mova services.   7 We show ARPU for our i-mode using two aggregate measures.     - i-mode ARPU is based on the No. of all subscribers who have active cellular phones, regardless of whether the i-mode service is activated. - ARPU generated purely from i-mode is based on the No. of active subscribers to the i-mode service only.   8 Considering the increaseing international services of cellular services, revenues from international services are included in Cellular Aggregate ARPU (FOMA+mova), Cellular Aggregate ARPU (FOMA), and Cellular Aggregate ARPU (mova) from Year Ended March 31, 2006 and the figures are as follows.   9 Communications module service subscribers and the revenues thereof are not included in the calculations of cellular ARPU.   10 No. of active subscribers used in ARPU calculation are as below.     - FY Results & Forecast: Sum of No. of active subscribers**(as defined below) for each month from Apr. to Mar. - 1Q Results: Sum of No. of active subscribers**(as defined below) for each month from Apr. to Jun. - 2Q Results: Sum of No. of active subscribers**(as defined below) for each month from Jul. to Sept. - 3Q Results: Sum of No. of active subscribers**(as defined below) for each month from Oct. to Dec. - 4Q Results: Sum of No. of active subscribers**(as defined below) for each month from Jan. to Mar.   **active subscribers = (No. of subscribers at end of previous month + No. of subscriber at end of current month)/2 Copyright (c) 2006 Nippon telegraph and telephone corporation