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Troubleshooting Location Services

This page provides possible solutions to Location Services issues.

I cannot get a GNSS fix

Some older DKs might have difficulty getting a GNSS fix. Check that your device meets the prerequisites. If it does not have an internal GNSS antenna, attach an external antenna, or query the device location using cellular.

If your device has a newer nRF9160 SiP and you are still having trouble getting a GNSS fix, try the following:

  • Place the device near a window with a clear view of the sky.
  • Ensure that the device connection is stable.
  • Query the device location with an alternative method that does not require the GNSS receiver, such as cell location.

I cannot get cell location data

If your device is otherwise functioning normally, try the following to correct cellular issues:

  • If you have physical access to the device, open the LTE Link Monitor application of nRF Connect for Desktop to check the connection status:

    • Check that the correct COM port is selected.
    • Check which network the device is connected to and signal strength in the left panel.
    • There is occasionally a delay in establishing a connection after the device starts up or resets. See if the device functions as expected after two or three minutes. If it still does not connect, push the RESET button on the device.
  • Check with your cellular network provider to make sure there is coverage in your area.

  • If you are using an iBasis SIM, check that it still has data:
    1. Log in to the nRF Cloud portal.
    2. Select Device Management in the left navigation bar.
    3. Select SIM Cards.
    4. Buy more data for your SIM card if necessary.

The coordinates in the position response are not the actual coordinates of my device

The coordinates returned with a position response are the center point of a circle, the radius of which is represented in meters by the uncertainty value. There is a 1-sigma (68%) probability that your device's actual position falls within this circle. This does not mean your device is more likely to be near the center of the circle than near the outside.

The uncertainty value in my position response is higher than usual

The uncertainty value represents the estimated Horizontal Positioning Error (HPE), the radius in meters of an area around the returned coordinates, of which there is a 1-sigma (~68%) probability that the device's actual position falls within this area. This value increases the less certain the position estimate for a request is. This can be the result of a number of circumstances:

  • Low cell density, meaning the geographic area of each cell is larger, making the area of possible positions larger.
  • The specific ECI cannot be found, meaning the position estimate has fallen back to a less-precise method, like an area fallback based on the Tracking Area. To control this behavior, use the fallback query parameter.
  • The cells or access points sent have been measured in our database as being far away from one another. This can happen when a cell ID is reassigned within a PLMN, or an access point is moved to a new location.

The uncertainty or position value in my response does not change when using multiple cells (MCELL) instead of a single cell (SCELL)

There are two ways to submit a multicell (MCELL) request through nRF Cloud. The first method uses the nmr (Network Measurement Report) field, which includes signal strength measurements from neighboring cells. The second method sends data for multiple cells in the lte array. In either case, sending an MCELL request might not reduce the uncertainty value or change the result position coordinates.

In some cases, the geographical area of two cells may overlap so much that the neighboring cell does not change the position estimate. In other cases, the neighboring cell might not yet be in the nRF Cloud database, and the position estimate uses only the serving cell.

MCELL is recommended not only to obtain more accurate positioning data, but also to increase the chance of a valid result in cases where the serving cell is not yet known to nRF Cloud. In cases where you regularly do not see an increase in accuracy from multicell requests, consider using SCELL for power consumption and cost-saving reasons.

My Wi-Fi request returns the error MAC address "${MAC}" is a local MAC address

Locally administered MAC addresses cannot be used for positioning, because they are not unique outside of a local network. Universally administered addresses are set by the manufacturer and are universally unique (there is no other device with this MAC address, even between manufacturers).

To determine if a MAC address is locally administered, check whether the second-least-significant bit of the first octet of the address is set (assigned the value 1). For example, for the address "5A:00:00:00:00:00:00:00", the first octet "5A" is represented as "01011010" in binary. The second-least-significant bit (second bit from the end) is 1, so this is a locally administered address. For more information, see the Wikipedia entry for "MAC Address".

Can I make a Wi-Fi position request for a mobile hotspot?

Mobile hotspots can be sent in a position request, but are unlikely to return a reliable position. Because mobile hotspots can move (by definition), there is no way to accurately ascertain the "ground truth" position of such a device. While nRF Cloud does not ignore these devices in Wi-Fi positioning, it is recommended to filter them out of your requests to avoid inaccurate results.

I need to talk to customer support

If you need support with a specific issue that is not addressed here, see Support.