A.MQTTB.485C.ModbusD.NB-IOT
A.GPRSB.寬帶物聯(lián)網(wǎng)C.北斗衛(wèi)星短報(bào)文D.NB-IOT
A.方格網(wǎng)法B.斷面法C.區(qū)域土方平衡D.三角網(wǎng)法