4 ms·

"Theoretically, one positioning chip could be designed to incorporate all of these different systems, but that might run afoul of U.S. national security laws."

"Theoretically, one positioning chip could be designed to incorporate all of these different systems, but that might run afoul of U.S. national security laws." - the author mentions this speculatively but doesn't provide any citations. Does anyone know what they might be referring to and also what level of technology it would require to use multiple satellite networks at once or switch been them.

sftwds 8y ago
GPS+GLONASS chips have been available for a while now. Here’s an article about some new chips which support 4 constellations: https://www.gpsworld.com/quad-constellation-receiver-gps-glonass-galileo-beidou/ https://www.gpsworld.com/quad-constellation-receiver-gps-glo...
- _trampeltier 8y ago
  Since most smartphones today work at least with GPS and GLONASS, what does happen, if just one signal for ex. the GPS signal is spoofed / faked?
jlgaddis 8y ago
NFI. My iPhone 6s (a few years old) includes "Assisted GPS, GLONASS, Galileo, and QZSS" [0] and I suspect that most other modern mobile phones do as well. Besides, I would consider relying totally on any one country's GNSS (especially when several are available at very little additional cost) to be a rather poor decision. [0]: https://support.apple.com/kb/SP726?locale=en_US https://support.apple.com/kb/SP726?locale=en_US
- bjoli 8y ago
  I use a lower end phone (250ish dollars) that has (at least) both GPS and glonass.
metaphor 8y ago
I suspect it has something to do with the potential for a chip to be classified as USML Cat XII(d) under ITAR, more specifically, "specially designed for use with a null steering antenna, an electronically steerable antenna, or including a nullsteering antenna designed to reduce or avoid jamming signal"[1]. The actual USML[2] is a bit...verbose. [1] http://insidegnss.com/u-s-eases-export-regulations-for-gps-receivers/ http://insidegnss.com/u-s-eases-export-regulations-for-gps-r... [2] https://www.ecfr.gov/cgi-bin/text-idx?node=pt22.1.121#se22.1.121_11 https://www.ecfr.gov/cgi-bin/text-idx?node=pt22.1.121#se22.1...
jacknews 8y ago
Yes this seems strange, I can only assume that it means the devices will still function accurately despite any US GPS degradation (eg around military installations, sensitive events etc), ie they will no longer be under US control. But that would apply whether they are multi-system capable, or just that they can read the other systems, and are not entirely dependent on GPS.
omgtehlion 8y ago
That is bullshit. ~7 yeras ago I worked at a company, which designed and manufactured GNSS receivers capable of receiving gps,glonass,gallileo,qzss and blend the signals to get more accurate solution. Receivers started at $5000 a pop though. The company had no problems selling in the US abd Russia. And even had multiple competitors. Hence, expert/import laws are not a problem. At least for professional equipment.
- omgtehlion 8y ago
  P.S.: the tech was around at least a decade ago. Nowadays you can have at least alternating mode in cheap consumer devices.
- olex 8y ago
  Nowadays, combined GNSS receivers like you mention are available from various electronic retailers for around 20-50$ a piece. The uBlox Neo M8 is a popular chip, there are a few others too. They are widely used in UAVs (where I know them from) and a variety of other applications, and routinely use anywhere between 22-28 active satellites from multiple constellations (compared to typical 7-11 visible for GPS alone).
lozenge 8y ago
The national security laws prevent chips from working if you're above a certain height and over a certain speed. Although most chips implement an "or" instead of an "and". As for military receivers, apparently they are unclassified but plug into a separate system that works like a TPM and provides the decryption keys, which have to be refreshed at least once a year.

sftwds 8y ago

GPS+GLONASS chips have been available for a while now. Here’s an article about some new chips which support 4 constellations: https://www.gpsworld.com/quad-constellation-receiver-gps-glonass-galileo-beidou/ https://www.gpsworld.com/quad-constellation-receiver-gps-glo...

_trampeltier 8y ago
Since most smartphones today work at least with GPS and GLONASS, what does happen, if just one signal for ex. the GPS signal is spoofed / faked?

jlgaddis 8y ago

NFI. My iPhone 6s (a few years old) includes "Assisted GPS, GLONASS, Galileo, and QZSS" [0] and I suspect that most other modern mobile phones do as well. Besides, I would consider relying totally on any one country's GNSS (especially when several are available at very little additional cost) to be a rather poor decision. [0]: https://support.apple.com/kb/SP726?locale=en_US https://support.apple.com/kb/SP726?locale=en_US

bjoli 8y ago
I use a lower end phone (250ish dollars) that has (at least) both GPS and glonass.

metaphor 8y ago

I suspect it has something to do with the potential for a chip to be classified as USML Cat XII(d) under ITAR, more specifically, "specially designed for use with a null steering antenna, an electronically steerable antenna, or including a nullsteering antenna designed to reduce or avoid jamming signal"[1]. The actual USML[2] is a bit...verbose. [1] http://insidegnss.com/u-s-eases-export-regulations-for-gps-receivers/ http://insidegnss.com/u-s-eases-export-regulations-for-gps-r... [2] https://www.ecfr.gov/cgi-bin/text-idx?node=pt22.1.121#se22.1.121_11 https://www.ecfr.gov/cgi-bin/text-idx?node=pt22.1.121#se22.1...

jacknews 8y ago

Yes this seems strange, I can only assume that it means the devices will still function accurately despite any US GPS degradation (eg around military installations, sensitive events etc), ie they will no longer be under US control. But that would apply whether they are multi-system capable, or just that they can read the other systems, and are not entirely dependent on GPS.

omgtehlion 8y ago

That is bullshit. ~7 yeras ago I worked at a company, which designed and manufactured GNSS receivers capable of receiving gps,glonass,gallileo,qzss and blend the signals to get more accurate solution. Receivers started at $5000 a pop though. The company had no problems selling in the US abd Russia. And even had multiple competitors. Hence, expert/import laws are not a problem. At least for professional equipment.

omgtehlion 8y ago
P.S.: the tech was around at least a decade ago. Nowadays you can have at least alternating mode in cheap consumer devices.
olex 8y ago
Nowadays, combined GNSS receivers like you mention are available from various electronic retailers for around 20-50$ a piece. The uBlox Neo M8 is a popular chip, there are a few others too. They are widely used in UAVs (where I know them from) and a variety of other applications, and routinely use anywhere between 22-28 active satellites from multiple constellations (compared to typical 7-11 visible for GPS alone).

lozenge 8y ago

The national security laws prevent chips from working if you're above a certain height and over a certain speed. Although most chips implement an "or" instead of an "and". As for military receivers, apparently they are unclassified but plug into a separate system that works like a TPM and provides the decryption keys, which have to be refreshed at least once a year.