| 摘要 |
PURPOSE:To improve the data transmission efficiency by refering to an incoming call electric field value and a time so as to decide the propriety of data transmission with respect to the data line defect alarm circuit used for data transmission by using a narrow band mobile radio line. CONSTITUTION:When a detection section 12 detects it that a DC voltage sent from an incoming electric field monitor section 111 is a preset threshold level or below, the section 12 sends the result of detection to a measurement section 13. When the section 13 measures it that the result of detection is consecutive for a prescribed time or over, the measurement section 13 sends the result of measurement of a data line defect to a display section 14, in which the result is displayed. A preset data transmission propriety criterion is stored in a memory section 23. A deciding section 22 digitizes the DC voltage outputted from the incoming electric field monitor section 111 and compares it with the data transmission propriety criterion from the memory to decide the data transmission propriety. When the result of decision indicates the data transmission negation, the result of decision of data line defect is sent to the display section 14, in which the result is displayed. When the deciding section 22 decides the data transmission negation, a gate section 24 is turned off based on the result of decision to prevent a base band signal from being fed to a transmission section 21. |
