same fiber-optic lines and other infrastructure as the back- haul network connecting antennas and controllers in cellular base stations to mobile switching offices and the Internet. China maintains tight controls on the media. To limit contact with the outside world, access to many web sites such as YouTube and Facebook is restricted. Also, citizens are often not allowed access to e-commerce sites that compete with Chinese companies. However, some sophisticated users, particularly college students, have found ways to circumvent these restrictions. The three largest mobile providers in China, China Mobile, China Unicom, and China Telecom, are all owned by the Chinese government. (For more information about Chinese carriers, see Table 8-2.) These providers have other similarities. All of them offer subsidized handsets, enjoy spectacular growth in mobile subscriptions, operate both fixed-line and wireless networks, and currently have a low percentage of mobile subscribers on their 3G networks. However, the number of 3G subscribers is growing due in part to China's investment in 3G infrastructure. Providers are planning to increase the appeal of 3G by operating app stores, increasing the number of smart- phones available to customers, and lowering 3G fees. As of December 2011, China Unicom, which was initially the only carrier to offer Apple's iPhone, had the largest percentage of users on its 3G network. The Chinese government reorganized the structure of the mobile telecom sector by merging six mobile operators into the aforementioned three organizations in 2008. This was done SO that each would have nationwide coverage and provide competition to China Mobile. To streamline operations at China Unicom, which at that time oper- ated both Code-Division Multiple Access (CDMA) and Global System for Mobile Communications (GSM) networks, the government directed China Unicom to divest itself of the CDMA network and give it to China Telecom. China Telecom is now the only operator that uses CDMA technology in China. Each of 