Channels are dynamically distributed using the control signaling. MSK modulated digital common signal is used as airsignal, characterized by its fast connecting.
由控制信道来动态分配信道，空中信令采用MSK调制的数字共路信令，具有接续速度快的特点。
2
There were 15 minutes between the first air raid alert and the sounding of the all-clear signal.
从第一个空袭警报到警报解除号音其间有15分钟。
《柯林斯英汉双解大词典》
3
The fighting starts when a signal such as an air horn or whistle blows, and can last anywhere from a few minutes to a few hours.