There are a variety of cell phone companies around the USTB area. The most popular companies are China Mobile and China Unicom. Both companies offer coverage throughout China and if your plan allows for it, international coverage. Make sure you carefully read everything before you sign up for a particular plan; in particular, please be certain to ask specifically about international calling rates, messaging plans, 3G/4G network fees and capabilities (if applicable), contract agreements, and possible overage charges. Note that cell phone shops are unlikely to have English speakers, so bring a translator with you if possible.