the Cyberspace Administration of China is responsible for setting policy and the regulatory framework for user content generated in online social activities on Internet portals. Foreign participation Before China’s membership of the WTO in 2001, China protected its emerging national telecom industry which was and still is regarded as a national priority sector. Only foreign equipment vendors were allowed to invest in China. Authorization for the investments was conditioned on technology transfer. International telecom carriers were banned from accessing the market. As part of its commitments to the WTO, the Chinese government is gradually opening the carrier market to foreign investors. There are some geographical limits to this opening which will be progressively relaxed. In 2005, foreign investors were authorised to form joint ventures, investing up to 50% in Internet services in the whole country, up to 49% in the mobile sector in 17 major Chinese cities and up to 25% in fixed-line basic services in Beijing, Shanghai, and Guangzhou (Canton). Finding a Chinese partner to form a joint venture with, preferably a major carrier, is mandatory for a foreign company wishing to access the Chinese market. Foreign investments have come, in order of importance, from the United States, Canada, Sweden, Finland, Germany, France, Japan, and South Korea. Many companies from these countries have established one or more joint ventures, not all of which have been successful. Market overview As of March 2012, China has 284.3 million fixed-line subscribers and 1.01 billion mobile customers. Chinese telecom operators focus their effort on voice. Revenues from data only account 5%. New technologies are being deployed to provide differential services. These technologies include ADSL, wireless LAN technology, IP (Internet Protocol) telephony and services associated with mobile communications such as Short Messaging Service (SMS), Multimedia Messaging Service (MMS), ring tone download etc. Premium SMS connectivity is allowing entrepreneurs and established businesses to profit from revenue taken directly from users' monthly phone bills or pre-paid credit. One of the first companies to offer such Chinese Premium SMS connectivity to the world market and to advise on the regulations and requirements involved are mBILL. Chinese operators are often cautious in purchasing cutting-edge technologies. Mobile communication, especially Global System for Mobile (GSM) is the most profitable sub sector and reports 46% of all total revenues. Halfway between mobile and fixed, Xiaolingtong is a limited mobility service based on Personal Access System (PAS)/Personal Handy Phone System (PHS) technology.