3 ms·

“All authorised phones must have this feature disabled”

by rusk 3y ago

joecool1029 3y ago
Like the US does with Beidou GNSS receivers. Know how pretty much every flagship phone advertises support for it? Can't use in the US, blocked by geofence set at firmware level. Take the device outside of the geofence and it'll see them.
- aftbit 3y ago
  Really? Why? What's the problem with using multiple GNSS constellations? They're receive-only. My phone definitely supports GLONASS but I hadn't checked Beidou.
  - joecool1029 3y ago
    (sorry for late response, maybe you'll still catch it) There's not a technical problem using multiple GNSS constellations. Officially the US had some treaty with Russia to allow use of GLONASS as a second constellation. Later on Galileo became the next constellation approved through a civil route, not a treaty. China's BeiDou would have to probably be approved through a treaty since it's run by their military, it's not going to happen. I've been told by someone who used to work at space force that beidou can be used to track users, but that's bullshit with how our receivers use it. Here's a US gov report on the matter, if it's receive only (no messaging component) tracking isn't going to happen https://www.uscc.gov/sites/default/files/Research/Staff%20Report_China%27s%20Alternative%20to%20GPS%20and%20Implications%20for%20the%20United%20States.pdf https://www.uscc.gov/sites/default/files/Research/Staff%20Re... Finally, the way at least Qualcomm receivers work is they will only lock to GPS first and then mix in the other constellations (at least while in CONUS).
    - aftbit 3y ago
      Thank you for the response anyway! I do review my comments every so often to catch these. How do you know so much about GPS and how can I learn more? :) Also, is there any hope for "authenticated GPS" to prevent spoofing? Is that even technically possible for non-secret codes like C/A or L5?
lxgr 3y ago
It's not a feature, though. It looks like a regular old 4G/5G network to the phone. I could see such a regulation be implemented for new phones (Apple's Globalstar functionality is already deactivated in software based on geolocation in non-supported countries and maybe even in hardware for models sold in some regions), but it won't help with existing devices. Another avenue would be restricting access to SIMs capable of logging on to these networks. SIMs have supported mutual authentication since (I believe) 3G, so it's not possible for a satellite 4G service to provide "unilateral roaming".
- rusk 3y ago
  Yes you are right actually, prohibition would need to be done at the SIM. Contraband much harder to detect.

“All authorised phones must have this feature disabled”

by rusk 3y ago

“All authorised phones must have this feature disabled”

Like the US does with Beidou GNSS receivers. Know how pretty much every flagship phone advertises support for it? Can't use in the US, blocked by geofence set at firmware level. Take the device outside of the geofence and it'll see them.

aftbit 3y ago
Really? Why? What's the problem with using multiple GNSS constellations? They're receive-only. My phone definitely supports GLONASS but I hadn't checked Beidou.
- joecool1029 3y ago
  (sorry for late response, maybe you'll still catch it) There's not a technical problem using multiple GNSS constellations. Officially the US had some treaty with Russia to allow use of GLONASS as a second constellation. Later on Galileo became the next constellation approved through a civil route, not a treaty. China's BeiDou would have to probably be approved through a treaty since it's run by their military, it's not going to happen. I've been told by someone who used to work at space force that beidou can be used to track users, but that's bullshit with how our receivers use it. Here's a US gov report on the matter, if it's receive only (no messaging component) tracking isn't going to happen https://www.uscc.gov/sites/default/files/Research/Staff%20Report_China%27s%20Alternative%20to%20GPS%20and%20Implications%20for%20the%20United%20States.pdf https://www.uscc.gov/sites/default/files/Research/Staff%20Re... Finally, the way at least Qualcomm receivers work is they will only lock to GPS first and then mix in the other constellations (at least while in CONUS).
  - aftbit 3y ago
    Thank you for the response anyway! I do review my comments every so often to catch these. How do you know so much about GPS and how can I learn more? :) Also, is there any hope for "authenticated GPS" to prevent spoofing? Is that even technically possible for non-secret codes like C/A or L5?

lxgr 3y ago

It's not a feature, though. It looks like a regular old 4G/5G network to the phone. I could see such a regulation be implemented for new phones (Apple's Globalstar functionality is already deactivated in software based on geolocation in non-supported countries and maybe even in hardware for models sold in some regions), but it won't help with existing devices. Another avenue would be restricting access to SIMs capable of logging on to these networks. SIMs have supported mutual authentication since (I believe) 3G, so it's not possible for a satellite 4G service to provide "unilateral roaming".

rusk 3y ago
Yes you are right actually, prohibition would need to be done at the SIM. Contraband much harder to detect.