移动电话系统（Mobile Telephone Service，MTS）由美国贝尔电话实验室发展，支持半双工通信，是美国最早的公众移动通信系统（Public Mobile System）。1965年贝尔电话实验室再推出IMTS，支持全双工通信。

The Mobile Telephone Service (MTS) is a pre-cellular VHF radio system that links to the Public Switched Telephone Network (PSTN). MTS was the radiotelephone equivalent of land dial phone service. As of 2012, only rural and wilderness areas were still using the system.