窄带直接打印 meaning in English

nbd narrow band direct printing

Global maritime distress and safety system - part 6 : narrowband direct - printing telegraph equipment for the reception of navigational and meteorological warnings and urgent information to ships navtex - operational and performance requirements , methods of testing and required test results
海上呼救和安全装置.第6部分:船用船海,气象预报和应急信息接收窄带直接打印电报设备.操作和性能要求,试验方法和结果