GCI search & multiple cell location

[barbiz]

Hello,

since location accuracy is not enough for us with single cell, we are trying to use multiple cell location.

We tries with %NCELLMEAS = 2 but we don't get multiple cells. Maybe the serving cell has good signal?

Then we tried with GCI search and fw 1.3.4.

%NCELLMEAS = 3,3

and we got those 3 cells (I added newlines for easiness of reading):

%NCELLMEAS: 0,

"0AAE62A2","22201","92B9",65535,0,6254,243,62,19,178936,0,0,

"0319AFA2","22201","92B8",65535,0,6254,295,62,18,178936,0,0,

"0094586F","22210","69D9",65535,0,6354,105,77,29,178973,0,0

so we tried to inject this data into the nrfCloud API:

{
  "lte": [
    {
      "mcc": 222,
      "mnc": 1,
      "eci": 179200674,
      "tac": 37561,
      "earfcn": 6254,
      "adv": 65535,
      "rsrp": -78,
      "rsrq": -10,
      "nmr": [
        {
          "earfcn": 6254,
          "pci": 295,
          "eci": 52015010,
          "rsrp": -78,
          "rsrq": -10.5
        },{
          "earfcn": 6354,
          "pci": 105,
          "eci": 9721967,
          "rsrp": -63,
          "rsrq": -5
        }
      ]
    }
  ]
}

and this is the response:

{
	"lat": 45.39999247,
	"lon": 11.90999508,
	"uncertainty": 2472,
	"fulfilledWith": "MCELL"
}

which does not give any improvement on the original location with SCELL.

Can you help us? Are we formatting the data the wrong way?

Marco

[AndrewKostka]

Hi, Marco: I've looked more into why my initial results were different from what I see now on nrfcloud. We have multiple data sources for some areas, and we continuously do performance evaluation in order to rank those data sources. The environment where I did my initial test had slightly outdated rankings. While these rankings in general improve our success rate, in very specific cases like this it can decrease accuracy.

This edge case has given our team some ideas for improvement of this ranking procedure, including checking SCELL vs. MCELL results for uncertainty decreases. I'm sorry if this isn't the answer you were hoping for, but these cases help us improve our service over time.

[barbiz]

Hello,

thanks.

At this point, we are stuck... do you have any idea on when this implementation can be improved?

Or perhaps can you tell us who the location provider is behind?

It's quite anoying to know that the solution is there but cannot access to it...

Marco

[AndrewKostka]

Hi, Marco: Unfortunately we're not able to give out the exact source of a specific data point. We're going to address this issue within the next couple of months, as part of a larger set of improvements to LTE Location Services.

However, I'd encourage you to test more than just this one data point, as you may get more accurate results from other towers when your device completes handover.