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Official Description

Cell Signal Monitor Pro is an advanced network monitor that helps you to watch the state of cellular network by gathering data about cell towers. The app supports GSM, UMTS and LTE networks.

The first tab contains the following information:
• Connection status (in service/emergency only/out of service/radio is off)
• Operator name and its MCC and MNC
• Network technology (GPRS/EDGE/UMTS/LTE)
• Current cell identity (CID)
• Current area identity (LAC/RNC/TAC)
• Signal strength (RSSI and RSRP for LTE networks)

Charts show the changes of strength level and speed of mobile connection. Log and Statistics display the data about cells which were used by a mobile device.

https://signalmonitoring.com/en/cell-signal-monitor-description