Google geolocation for LTE

IoT Modules LPWA Module
1

I am successfully getting geolocation using Google’s API for GPRS connections with the BG96. In this case I get the mnc, mcc, cell_id and lac from the AT+QENG command:

16/12/19 17:05:26.259 INFO: RX> "AT+QENG=“servingcell”"
16/12/19 17:05:26.267 INFO: RX> “+QENG: “servingcell”,“NOCONN”,“GSM”,234,30,822,81BF,49,850,0,-84,255,255,0,22,22,1,-,-,-,-,-,-,-,-,-,”-""

And then call the google API like this:

    		url = "https://www.googleapis.com/geolocation/v1/geolocate?key={}".format(key_dict['GMAK'])
    		cell_info_dict =     {
    								"radioType": radio_type,		# lte, gsm, cdma, and wcdma
    								"cellTowers": [
    												{
    												"cellId": cell_id,
    												"locationAreaCode": lac,
    												"mobileCountryCode": mcc,
    												"mobileNetworkCode": mnc
    												}
    								]
    							}
    		result = requests.post(url, json=cell_info_dict)

This works perfectly and gives and accurate location.

If instead I connect via NB1. The same AT command gives slightly different information:

13/12/19 15:15:38.072 INFO: RX> "AT+QENG=“servingcell”"
13/12/19 15:15:38.080 INFO: RX> "+QENG: “servingcell”,“NOCONN”,“CAT-NB”,“FDD”,234,15,19621F,122,6254,20,0,0,33F3,-86,-13,-73,10,-"

Again we get the mcc, mnc and cell_id, but now there is no lac and instead there is a tac. Does anyone know how to combine this information in the Google API call to get the correct result?

I have seen this SO post:

Which suggests that it is possible to use Google geolocation API for LTE, but I have tried lots of combinations to get a result and so far it has failed.

2

Hi Pdaj_mm,

you means that , if you set “locationAreaCode”: 0 under NB mode , It failed , right??

3

Hi Stephen,

Yes, that didn’t work unfortunately.

I found this issue tracker for Google’s geolocation API:
https://issuetracker.google.com/issues/139653740

So I’m suspicious that the API isn’t supporting NB1 yet.

Paul.

4

Ok ,

Pls check this issue from google side . thanks

5

A question about the same issue that I found on SO:

6

Hi pdaj_mm

Based on this phenomenon ， with some cellid ， google can locate it ，but with some others ，It does not work 。

General ， Google should be obtain location information data of cell ID from mobile operators.
.
Pls ask google , why some cell location is not synced timely

7

I’ve replied to https://issuetracker.google.com/issues/139653740 with what I believe is a workaround.

Note that some lte cells may not be indexed by Google as it’s a crowd-sourced database (gmaps?). Opcos may also be unwilling to share cellids as they sell their own location services.

Hope this helps,
Tad