In order to realize subway mobile communication signal coverage, specialized radio communication system was established.

为了实现地铁移动通信信号的覆盖，建立了专用无线通信系统。

youdao

In order to realize subway mobile communication signal coverage, specialized radio communication system was established.

为了实现地铁移动通信信号的覆盖，建立了专用无线通信系统。

youdao