Series 3: What is the best way to determine the signal strength on a cellular modem through a CradlePoint router?

Beverly McRae

If you are unsure of CradlePoint Series or Model number, please click here.

This article was written based on Series 3 firmware version 5.0.0.


Low signal or high signal interference can cause a cellular modem to provide only intermittent connectivity or low connection speeds. This article describes how to check the signal strength and quality values for a cellular modem when used with a CradlePoint router.


  1. Plug your cellular modem into your CradlePoint router.
  2. Access the router’s administrative console. Click here if you are not sure how to do this.
  3. Click on the Status tab and select Internet Connections from the drop-down.  User-added image
  4. Select your cellular modem in the Device List by placing a check in the box next to its name. User-added image
  5. Scroll down to the Device Information section and look for the following values:
    • Service Display
    • Signal Strength or RSSI
    • Signal Quality – this value will be labelled differently, depending on the service display:
      • LTE: SINR
      • WiMAX: CINR
      • All other values: Ec/Io
  6. Monitor the numbers for 1 to 2 minutes to get an overview of the current signal characteristics.
  7. Compare your values with the Minimum Mobile Broadband Data Connection Signal Values.

Suggestions to Optimize Cellular Signal: If your signal strength values are below the required minimum values, you can try some of the suggestions listed below to improve your connection quality:

  • Switch the Modem Connection Mode between 4G and 3G to check which gives better values. Check this article for more information.
  • Move the router/modem to a side of the building that faces the carrier’s cellular tower.
  • Move the router/modem to a higher point in the building, second floor, on top of tall cabinets, etc.
  • Do not place the router/modem near any electrical devices, wiring, or radio devices.
  • Use a 6 to 10ft. good quality USB extension cable between the modem and router.
  • Use a passive cellular antenna plugged directly into the modem.

NOTE:  Cellular signal boosters do not improve cellular signal quality.  Use of a cellular signal booster may or may not improve the cellular signal characteristics although the signal level may report a -dBm that is within the modems allowable range.

NOTE:  Often a cellular modem’s connection may appear stable while it is plugged directly into a computer, even when the signal is actually marginal.  However, when the modem is used in the router this marginal signal may degrade slightly due to physical and electrical differences between the computer and router.  This small amount of signal degradation (~1 – 2dBm) can be enough to not allow the cellular modem to connect through the router.  Try the router/modem in other locations in your home or office.

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