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在国土辽阔的国家中,架空明线杆路的维护费用较贵,因此墨西哥Ndem铁路的整个通信网决定采用无线通信。它能提供120个话路的大容量微波接力通路,可解决铁路电话网的需要,并把计算机终端设备联接到中央处理机上,开放数据传输。甚高频无线通信能为地区电话网和行进中的车辆之间提供双向通信。另一个频段的甚高频无线通信在一定地面范围内可构成列车调度员和列车乘务员之间的通话回路。 1975年开始建造现代化通信设备。由日本电气公司供应微波设备,由美国马达罗拉公司供应甚高频移动无线通信设备。从Ndem铁路总局建筑物上的天线有7条主干微波接力通路通向各地。
In countries with vast territories, the cost of overhead overhead poles is more expensive to maintain, so the entire communications network in Mexico’s Ndem Railway has decided to adopt wireless communications. It can provide 120 channels of high-capacity microwave relay access, to solve the needs of the railway telephone network, and the computer terminal equipment connected to the central processing unit, open data transmission. Very high-frequency wireless communications provide two-way communication between regional telephone networks and moving vehicles. Another band of VHF wireless communication within a certain range of the ground can be formed between the train dispatcher and train crew call back circuit. Beginning in 1975 to build modern communications equipment. Microwave equipment supplied by Japan Electric Company, the supply of VHF mobile wireless communications equipment by the United States of America motorola company. From the antenna on the Ndem General Railway building there are seven main microwave relay access to all over.