Mobile Services  (1)  Includes monthly fees.  P AR T I 32 As of December 31, 2011, we had 17,973 cellular base stations (including both GSM base stations and 3G cellular base  stations) covering substantially all of Taiwan’s population. We use these base stations to support both our GSM network and 3G  networks. In 2011, we upgraded more than 8,113 3G cellular base stations with HSDPA capacity and 2,444 GSM base stations with  EDGE capacity in the larger metropolises of Taiwan. We will continue this process of implementing HSDPA and EDGE upgrades in  the major areas of Taiwan.  We offer digital mobile service through our dual band GSM network. We are one of the three national licensed providers of  GSM services. We have been allocated 15 MHz in the 900 MHz frequency band and 11.25 MHz in the 1800 MHz frequency band for  GSM services and general packet-switched radio services, or GPRS, and 15 MHz paired spectrum plus 5 MHz unpaired spectrum in  the 2 GHz frequency band for 3G mobile services. This is the largest frequency spectrum allocation to any mobile operator in Taiwan.  In February 2002, the Ministry of Transportation and Communications granted 3G mobile services concessions to five companies,  including us. In March 2002, we paid NT$10.2 billion to the government for our concession. Our 3G mobile services license is valid  until December 31, 2018. In July 2005, we launched our 3G mobile services using WCDMA technology. We also offer the largest  international roaming network among Taiwan mobile service providers. In particular, our 2G customers have access to 366 networks  in 188 countries through our GSM service roaming network and 277 networks in 134 countries through our GPRS roaming network.  In addition, our 3G service system includes 158 networks in 75 countries.  As the market for mobile services has continued to expand, we have experienced growth in our mobile customer base. We  are the largest mobile operator in Taiwan in terms of revenues and number of customers. We had 10.07 million mobile customers,  for a market share of approximately 34.9% of total mobile customers and approximately 32.6% of total mobile services revenues in  Taiwan, as of December 31, 2011.  We are Taiwan’s largest provider of mobile services in terms of both revenues and customers. In 2009, we generated revenues  of NT$71.4 billion, or 35.9% of our total revenues, from mobile services. In 2010, we generated revenues of NT$73.1 billion, or  36.1% of our total revenues, from mobile services. In 2011, we generated revenues of NT$70.9 billion (US$2.3 billion), or 32.6% of  our total revenues, from mobile services. The decrease of mobile services revenues in 2011 was primarily due to the NCC’s change  in policy for collecting the tariffs for fixed-to-mobile calls from mobile service providers to fixed communications service providers  since January 1, 2011. As a result, our fixed communications business now has the right to set and collect the tariffs for fixed line-to- mobile phone calls. However, the interconnection and transition fees paid by our fixed communication business and received by our  mobile segment deems as internal revenue and not recognized as external revenue of our mobile segment, while the aforementioned  fees received by the alternative mobile operators were recognized as external revenue. Year ended December 31, 2009 2010 2011 NT$ NT$ NT$ US$ (in billions) (in millions) Mobile services revenues: Usage (1) 54.4 53.0 45.6 1,505.5 Interconnection 7.0 7.2 7.5 249.1 Mobile data 8.4 11.1 15.2 502.9 Other 1.6 1.8 2.6 84.6 Total mobile services ................................................. 71.4 73.1 70.9 2,342.1