> For the complete documentation index, see [llms.txt](https://yingshaoxo.gitbook.io/university-notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://yingshaoxo.gitbook.io/university-notes/cir.md).

# CIR

Let's be honest, if you ask a railway worker in China what is CIR. They'll probably tell you it is `机车综合无线通信设备`.

But that's not the end, the interesting part is, even they call that device `CIR` every day, they can still not be able to tell you the full name of `CIR`.

At the day I was writing this, I can not get the answer from Baidu.com

But I guess, CIR means `Car Integrated Radio` or `Cab Integrated Radio communication equipment`.