• State Verified Answer
  • +1 person also asked this people also asked this
  • Replies 6 replies
  • Subscribers 75 subscribers
  • Views 1470 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 255364
Options
This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

A-GPS SUPL library

pemar13

Hi!

I use ncs v1.3.0 and mfw 1.2.0 on a nRF9160 DK v0.8.5.

My app runs in PSM mode alternating between LTE and GPS following Jan-Tores suggestions in his response to my Ticket 254606.

1. Things work reasonably well, but I am surprised by the log output from supl_session (library nrf9160_libsupl-v0.6.0-aecb5b4) when using a SIM from Telia in Sweden:

MCC location info injected, MCC: 240
	Lat: 5851520 Lon: 780606
	Unc semiminor/semimajor: 119/119
	Confidence: 100
	Orientation: 0

I assume the location is generic, based on the MCC code. However, the MCC code 240 is for Sweden whereas the location is in Hornnes in Norway!

Do you have some explanation for this?

2. Also, when using your LTE Link Monitor, the serving station location is displayed as:

MccMnc:     24001
Operator:   Telia Sverige AB
CellID:     2568dddd
TAC:        ddd

which using LocationAPI is identified as the correct station that I am connected to.

Is it somehow possible to inject this location to the GPS?

3. At some occasions, the supl_session has timed out resulting in an error. In these cases, my app just hangs until the GPS-attempt times out.

Have you ever made similar observations, and if so, is there something I can do to let the code proceed without the A-GPS functionality?

Best regards,

Per

Parents
  • 0

    Hi Per,

    For your first question: I have wondered that earlier too. I was discussing about that with a Nordic employee and she told me how to calculate the coordinates from those values that SUPL returns.

    Lat: 5851520 Lon: 780606
    Latitude = 5851520 / (2^23/90) = 62.78
    Longitude = 780606 / (2^24/360) = 16.75

    So that location is the position the "center" of Sweden and this location is not a GPS location, but an input parameter from the SUPL client to the SUPL server.

    For another questions, I don't have any knowledge that would help.

Reply
  • 0

    Hi Per,

    For your first question: I have wondered that earlier too. I was discussing about that with a Nordic employee and she told me how to calculate the coordinates from those values that SUPL returns.

    Lat: 5851520 Lon: 780606
    Latitude = 5851520 / (2^23/90) = 62.78
    Longitude = 780606 / (2^24/360) = 16.75

    So that location is the position the "center" of Sweden and this location is not a GPS location, but an input parameter from the SUPL client to the SUPL server.

    For another questions, I don't have any knowledge that would help.

Children
Related
Terms of service