Post and telecommunications are comparatively advanced. Computer-controlled telephone lines link Xining, and most prefectures and counties in the province to other parts of the country and to more than 160 foreign countries. Wireless telecom services have also developed rapidly. The transmission system has utilized cables, microwaves, and satellites. Among the city dwellers, there are 25.5 telephones for every 100 persons. Mobile phone users have reached 210,700. There are now 6,498 Internet users and the figure is increasingly rapidly.