J TACS

J TACs is an analog cellular system that was used in Japan at the start of cellular telephone.  The system in many ways was similar to other analog cellular systems around the world except for frequency.  Frequency bands for analog cellular did vary with the specific type of analog, but were all mostly in the 800 MHz and 900 MHz frequency range.  Other analog cellular systems were called AMPs (Americas), TACs (outside US) , and ETACs (Europe) , and later NAMPs (narrowband AMPs) and a few other varieties of narrowband analog systems.

J-TACS stands for Japan Total Access Communication System