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Comment by avar | Hacker News Reader

Selective Availability was replaced by regional denial capabilities with the GPS III satellites, i.e. instead of fuzzing the signal the US can now turn off GPS for entire countries[1].

It's strategically foolish for the major economies like the EU, Russia & China to depend on the US's goodwill in maintaining a system that drives a huge part of their economy, GPS is used pervasively for everything, and that's only increasing.

Trump wants NATO countries to pay their fair share, how long until he gets the idea that all countries around the world should pay a GPS licensing fee least GPS regional denial be turned on?

Those are the sort of reasons for why it makes sense to develop a GPS alternative, even if you're only aiming for feature parity, or even less than that.

1. https://www.faa.gov/about/office_org/headquarters_offices/at...

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>>> It's strategically foolish for the major economies like the EU, Russia & China to depend on the US's goodwill in maintaining a system that drives a huge part of their economy, GPS is used pervasively for everything, and that's only increasing.

Exactly. For this same reason, India recently deployed its own satellite navigation system NAVIC[1][2].

[1] https://en.wikipedia.org/wiki/Indian_Regional_Navigation_Sat...

[2] http://www.isro.gov.in/irnss-programme

Indeed. In the India-Pakistan Kargil war of 1999, USA sided with Pak and turned off GPS for Indian troops. That led to the creation of NAVIC

http://timesofindia.indiatimes.com/home/science/How-Kargil-s...

seriously, WTF is wrong with US and their attitude towards India/Pakistan. India is democracy, never attacked anybody out of blue from 1947 when it was created (unlike its neighbors Pakistan and China who attacked it numerous times).

Yet US sides with dictatorship which doesn't even control its own secret service which creates its own terrorist organizations (laskar-e-taeba).

It's a political philosophy sometimes called 'realpolitik' that basically says never mind morality, just do what is in the interests of your own country. It has a certain emotional appeal, but when you take a cold and practical look at the history of decisions made on that basis, they tend to end up doing more harm than good to the interests of the country that made them, quite apart from everyone else.

India was part of the 'non-aligned' block and at various times has been keen on building ties with the Russians, buying lots of arms from them. In contrast, Pakistani leaders have been firmly in the US camp. Hence, in '71 it was a no-brainer for Nixon which side the US would support. It is bizarre the Nixon continued supporting Pakistan during the Bangladesh Genocide, but that's Nixon for you.

Also, India did invade and annex Goa in '62.

>> Also, India did invade and annex Goa in '62.

... because Goa is an historically Indian territory, and Republic of India just got it back from foreign invaders!?

Not just dictatorships. Islamist dictatorships (Pakistan, Saudi Arabia). A lot of western (not just US) diplomacy is horribly short sighted.

> never attacked anybody out of blue from 1947 when it was created

India "attacked" East Pakistan in the Bangladesh Liberation War [1]. Whether or not you or I feel it was justified is besides the point: it violated the sovereignty of another nation (similar to the U.S. in Iraq and Russia in Crimea).

[1] https://en.wikipedia.org/w/index.php?title=Bangladesh_Libera...

Your linked article reads

"India joined the war on 3 December 1971, after Pakistan launched preemptive air strikes on North India."

which doesn't sound out of the blue to me.

I think they're worried the Pakistani islamists will give nukes to the international jihadi islamists if we aren't somewhat supportive.

You must be new here. It's not about democracy, it's what's more convenient for the US interests. Welcome to HN.

Russia's GLONASS too, antennas for which have been built into iPhones since the 4S. https://en.wikipedia.org/wiki/GLONASS

Most smartphones designed in the past few years support GLONASS. Russian law requires GLONASS support to be sold there, so manufacturers have generally added it across their model lines since that's easier than producing different SKUs for sale in Russia.

I've never seen an authoritative reference for any area denial capability in block III. Can you provide one?

There is an enhanced footprint signal boost capability for the military but that's the opposite of what you describe.

I think the FAA is an authoritative reference, and I linked to their claims about GPS III regional denial in my original post.

Ah, I see where the misunderstanding arises. The reference to regional denial on that page is not a feature of any GPS satellite.

The military has airborne and surface-based electronic warfare platforms that can be used to jam GPS. That's what is referenced on that page.

The FAA is not considered an authority for GPS, with the exception of certifying that WAAS is in-service for aircraft when it is meeting FAA specifications. For civilian information purposes the appropriate agency is the US Coast Guard NAVCEN.

The Air Force Space Command is the holds primary developmental, specification, and operational responsibility.

Yes I'm pretty sure you're right. I wrote most of my comment from memory and just dug up a reference, knowing the FAA doesn't operate GPS, but figured their FAQ was summarizing the satellite features.

But I've searched around and can't find anything that indicates that this is a feature of the satellites themselves, rather it's just as you say, the US military has replaced SA with the general ability to jam local radio traffic, including GPS. E.g. [1] is another source for that.

So it does look like the US can't block GPS for entire countries anymore, I take that back.

I must say though, I think any public commentary about GPS capabilities should be taken with a huge grain of salt. It's a military system, they're very likely lying or not telling the full truth about what it's really capable of. E.g. I find the claim that the new generation can't do SA by design dubious, surely just fuzzing the signal by some offset is a rather trivial change.

1. https://web.archive.org/web/20050921115614/http://ngs.woc.no...

If SPACECOM can't tell the Navstar satellites to turn on selective availability for specific areas I will eat my hat. Much effort is being expended to provide over the air crypto re-key, increase anti-jam margin and improve signal authentication [1]. Would you really disable the SA feature when military consumer platforms now have the features to re-key, obviating the main drawback of SA?

[1] http://www.dote.osd.mil/pub/reports/fy2011/pdf/af/2011gps.pd...

It takes a fair amount of magical thinking to believe that GPS can do area denial from space. Consider how many satellites are above the horizon for a given location at any moment - somewhere around 8-12 at any moment, or more.

Each of those satellites in view would have to be implementing this scheme you suggest in order for it to be effective.

Since the satellites only have a single transmitter for each signal their entire receiving area would be affected by whatever modifications are made to implement SA. This means that to turn SA on for a single area more than half the globe would be getting a degraded signal from 1 or more satellites, which ones being undetectable.

I'm afraid SA is an all-or-nothing idea. Area denial (jamming) by surface and airborne transmitters is a much more workable approach. One could imagine jamming from space, but not using the GPS satellite vehicles.

Is it 'magical thinking' that the NSA would build a system with the capability to intercept every VPN session traversing the US, and spend ~$500 million to break the DH groups with the mother of all rainbow tables?

So, to GPS. In the original GPS SA it is certainly true that many satellites would have to be using degraded mode to guarantee degradation for a specific point. However, the newer satellites have an additional directional antenna. While primarily for transmitting M-code to a specific region, it could equally be used for transmitting a self-jamming signal.

Actually US can still jam Gallileo. US "asked" EU to patch it so that it can be controlled(turned off) by the US in case of war with Russia or China.

The "patch" was changing to a different frequency band, allowing anyone to block only one system without affecting the other [1]. This is very much different from being able to turn it off.

[1] https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)...

I think OP meant jam. I believe at some point in the discussions about the Galileo frequencies that the US threatened that they may need to use an ASAT weapon on Galileo spacecraft if they believe the system was being used against them. That would have been the only way to maintain GPS and stop Galileo. So Galileo switched to a different frequency than GPS.

>>Trump wants NATO countries to pay their fair share, how long until he gets the idea that all countries around the world should pay a GPS licensing fee least GPS regional denial be turned on?<<

Now now, do not insert political commentary into this discussions. I got yelled at for doing that. [1]

[1]https://news.ycombinator.com/item?id=13197536

I don't think this is unwarranted political comentary, the reasons to build the alternative to gps are largely political according to GP

I am largely with you, however the direct Trump referencing is unwarranted - it is the institution he will represent, not the man, which is involved in this political battleground.

EDIT: to wit, the institution is the most powerful military force, active across the globe https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...

He doesn't represent the administration, he leads it.

It seems perfectly fair and reasonable reason to mention the power the president has in the situation given some of the president elect's statements.

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