[Xperia X] [4.0.2.21] GPS: Lost position in flight mode

REPRODUCIBILITY (% or how often): 99%
BUILD ID = OS VERSION (Settings > About product): 4.2.0.21 Verla
HARDWARE (XA2, X10, X10 II, …): Xperia X
UI LANGUAGE: Swedish
REGRESSION: (compared to previous public release: Yes, No, ?): Yes

DESCRIPTION:

GPS position is immediately lost and never re-acquired when turning flight mode on.

PRECONDITIONS:

Actual location:

  • In a Swedish city

Settings for location services: Custom.

  • GPS: Enabled
  • Offline/Mozilla: Enabled
  • Online/Mozilla: Disabled

MLS packages installed from Jolla Store:

  • Northern Europe
  • Southern Europe

Radios:

  • GPS, mobile network: Enabled
  • WiFi, BT, NFC: Disabled

STEPS TO REPRODUCE:

  1. Go outside, wait for stable GPS fix
  2. Turn Flight mode on
  3. Observe result
  4. Wait
  5. Turn Flight mode off
  6. Observe result

EXPECTED RESULT:

Location to remain stable once a GPS fix is acquired, regardless of Flight mode state.

ACTUAL RESULT:

At step 1):

  • Location indicator at top of main screen (app grid) is steady
  • GPSInfo app shows 7/32 satellites used
  • Pure Maps has position lock with <20 meter precision

Enabling Flight mode:

  • Location is lost immediately
  • Location indicator at top of main screen (app grid) goes away
  • GPSInfo still shows 7/32 satellites used

Disabling Flight mode a few minutes after enabling it:

  • Precision location becomes available within minutes
  • Location indicator at top of main screen (app grid) blinks until location is available

Keeping Flight mode enabled:

  • Even waiting for hours, location is not acquired

ADDITIONAL INFORMATION:

I can’t remember ever getting a coarse location (radius of hundreds of meters) from MLS/cell towers. Rather, it appears to be nothing until I get a GPS fix (radius of tens of meters), which can take anything from minutes to hours.

It seems to me as if the Location services are permanently conditioned on the mobile network being available, not just as an initial aid to speed up GPS lock. In my opinion, this is a mistake.

In earlier versions of SFOS, I could track my position or use navigation while in Flight mode to save power. I’m not sure in which OS version this stopped working.

3 Likes

I can confirm this behaviour. Even when positioning is in “device only” mode. It is weird that position stops updating when flight mode is turn on, but starts again when positioning setting is changed (disabled and enabled again, fligt mode still on).