The Improved Mobile Telephone Service (IMTS) was a pre-cellular VHF/UHF radio system which linked to the public telephone network. IMTS was the radiotelephone equivalent of land dial phone service.

2021年1月17日 · IMTS was the radiotelephone equivalent of land dial phone service. Introduced in 1964, it replaced Mobile Telephone Service (MTS) and improved on most MTS systems by offering direct-dial rather than connections through a live operator, and full-duplex operation so both parties could talk at the same time.

Parallel to Improved Mobile Telephone Service (IMTS) in the US until the rollout of cellular AMPS systems, a competing mobile telephone technology was called Radio Common Carrier (RCC). The service was provided from the 1960s until the 1980s when cellular AMPS systems made RCC equipment obsolete.

2024年10月2日 · 改进型移动电话系统（Improved Mobile Telephone Service，IMTS），美国贝尔实验室于1965年在MTS的基础上所发展的汽车公用无线电话。 同样属于 0G 的无线通信技术，相较于MTS只具备 半双工 ，IMTS具有 全双工 的通信能力。

The Mobile Telephone Service (MTS) was a pre-cellular VHF radio system that linked to the Public Switched Telephone Network (PSTN). MTS was the radiotelephone equivalent of land dial phone service. The Mobile Telephone Service was one of …

2021年1月17日 · 1969 年，美国推出了改进型的 MTS 车载电话系统，称为 IMTS（improved MTS）。 IMTS 支持全双工、自动拨号和自动频道搜索，可以提供了 11 个频道（后来为 12 个），相比 MTS 有了质的飞跃。

2020年3月13日 · A common IMTS phone, the 25 watt Motorola TLD-1100, had two roughly 8-inch square circuit boards to locate an idle channel and do other channel management via audio tones.

There are examples of the Cinderella head marked "Duplex" and "Dial," suggesting some were made for the "Dial" radio telephone system which pre-dated IMTS. The radio package resembled a Motorola "T-Power" transistor-powered mobile, and contained a maximum of five channels.

These pages are a history of the car telephone as used by the Bell System and its affiliates from the beginnings in 1946 through the end of IMTS telephone product production, although many IMTS car telephone radio systems continued on the air through the late 1990's and some are still on the air in Canada and Pennsylvania.

The Motorola MJ IMTS Radio. The MJ radiotelephone is a standard TLD1000 MTS radio, but with a change to the selective call decoder assembly. In the TLD1000, this was a simple MTS decoder only, located on a hinged bracket underneath the radio chassis.