The Personal Handy-phone System (PHS), also known as the Personal Communication Telephone (PCT) in Thailand, and the Personal Access System (PAS) and commercially branded as Xiaolingtong in China, was a mobile network system operating in the 1880–1930 MHz frequency band. In Japan, it was introduced as a low-cost wireless service with smaller coverage areas than standard cellular networks. Its affordability made it popular in China, Taiwan, and other parts of Asia, as both the handsets and network infrastructure were relatively inexpensive to maintain.