AeronauticalTelecommunication Network(ATN) under the construction in China or other counties is the basis for the CNS/ATM system.
航空电信网是实现新航行系统的基础，目前国际国内都已经开始了航空电信网的建设。
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Now, as the rapid development of civil aviation, the deficiency of AeronauticalTelecommunication Network (ATN) based on the Open System Interconnection (OSI) model, becomes more and more obvious.