[Xiaomi Redmi Note 7 Questions & Answers] Fehuvosu:
Hello.

Please tell me, on your current firmware (any) on redmi note 7, is A-GPS functionality supported?

I tried different firmware, A-GPS only works on android 9.

I test A-GPS through the GpsTest program:

GitHub - barbeau/gpstest: The #1 open-source Android GNSS/GPS test program

The #1 open-source Android GNSS/GPS test program. Contribute to barbeau/gpstest development by creating an account on GitHub.

github.com

GPSTest - Apps on Google Play

The open-source GNSS/GPS app on Android

play.google.com

GPSTest | F-Droid - Free and Open Source Android App Repository

An app for testing GPS and GNSS capabilities of a device

f-droid.org

http xtra requests are tracked through the NetGuard firewall:

GitHub - M66B/NetGuard: A simple way to block access to the internet per app

A simple way to block access to the internet per app - M66B/NetGuard

github.com

NetGuard - no-root firewall - Apps on Google Play

A simple way to block access to the internet per application

play.google.com

NetGuard | F-Droid - Free and Open Source Android App Repository

A simple way to block access to the internet per application

f-droid.org

If A-GPS works on your firmware and after the request to "enter PSDS data" you get an https request to XTRA servers or ephemeris and almanacs appear in the GpsTest program ("AE" flags), then A-GPS is working.

Then please tell here what kind of firmware you have.

If it does not work, then also let me know, I will be grateful. Thank you.

Before each test I:

1) turn off the Internet, gps

2) I clear a-gps data in GpsTest

3) reboot the smartphone

4) turn on the Internet, then GPS

5) run GpsTest

And so in every test.

I remind you

Almanacs are the approximate position of all satellites in the constellation for the coming weeks.

The ephemeris is the exact position of the satellite for the next few hours. Therefore, if you do not use GPS for several hours (especially at night), then the Ephemerides become rotten and here A-GPS comes to the rescue.

that after the correct XTRA (A-GPS) request, in the GpsTest program we should see the AE flags (Almanacs + Ephemerides).

If we see only Almanacs, then they either remained from the previous A-GPS request (when the Ephemeris went rotten) or most likely did not appear from A-GPS, but were downloaded directly from some one satellite.

Almanacs are transmitted by satellite to the entire group of satellites. Those. if at least 1 satellite managed to transmit almanacs, then the entire group of satellites will be with almanacs.

Ephemeris is transmitted by each satellite only to itself and without A-GPS, the transfer of all almanacs + ephemeris can take up to 30 minutes (for me).

I went out into an open field, stood there for half an hour, and only then did I get Ephemeris, and even then not on all satellites.

If we talk about a clean smartphone without almanacs and ephemeris, then the total transmission time of GPS almanacs (to all satellites) is 12.5 minutes, so A-GPS can be very helpful in such situations.

MIUI, Android 9, Official, Global Stable

miui_LAVENDERGlobal_V10.2.7.0.PFGMIXM_b4667cdac6_9.0.zip

a-gps seems to work, there are http requests, there are ephemeris. But there are no requests for http requests, only after rebooting and turning on gps. Those. ephemeris is cached somewhere in android. After what time the androyd will consider the ephemeris rotten, I don’t know.

This is the first firmware where I see that there are ephemeris for the entire group of GPS satellites at once.

https://disk.yandex.ru/d/R-po044EPeNJ_Q/miui-android9-global/1_gps-e.jpg - after http xtra request (a-gps). All GPS satellites have an E flag (ephemeris)

https://disk.yandex.ru/d/R-po044EPeNJ_Q/miui-android9-global/2_gps-ae.jpg - after http xtra request (a-gps). All GPS satellites have an E flag (ephemeris) and an A flag (Almanacs). As I understand it, this is the ideal work of A-GPS. When the entire group of satellites has the flag A + E.

https://disk.yandex.ru/d/R-po044EPeNJ_Q/miui-android9-global/gps-daemon.png - screen in NetGuard firewall with XTRA and NTP requests. (Time is down, don't mind)

https://disk.yandex.ru/d/R-po044EPe...al/Screenrecorder-2023-08-30-11-41-46-415.mp4 - video showing the appearance of Ephemeris after running Gpstest.

MIUI, Android 10, Official, Global Stable

miui_LAVENDERRUGlobal_V12.5.1.0.QFGRUXM_32f42d84aa_10.0.zip

a-gps not working, no http requests, no ephemeris

https://disk.yandex.ru/d/R-po044EPe...al/Screenrecorder-2023-08-31-11-50-07-834.mp4 - video demonstrating the absence of Ephemeris and the absence of http XTRA requests (a-gps)

MIUI, Android 10, Official, Russia Stable

miui_LAVENDERRUGlobal_V12.5.1.0.QFGRUXM_32f42d84aa_10.0.zip

a-gps not working, no http requests, no ephemeris

same behavior as Global android 10

MIUI, Android 10, Official, Europe Stable

miui_LAVENDEREEAGlobal_V12.5.1.0.QFGEUXM_39f6c7990f_10.0.zip

a-gps not working, no http requests, no ephemeris

same behavior as Global android 10