Pentagon official: FCC decision on 5G threatens GPS, national security • Hacker News Board

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#181

Post by upofadown » Thu, May 07, 2020, 9:19 PM UTC

thoraway1010 wrote: post #173

The history of lightsquared, the company involved, is horrendous. They bought spectrum with a SPECIFIC restriction on it to avoid GPS interference - then proceeded to get a proposal approved that violates that restriction. The amount of bad faith dealing by this company was eye opening. I thought Garmin / Trimble and basically every GPS company had sued them because of how terrible their proposals and behavior has be…

It's more or less the same process where a developer buys land cheap and then with the help of a corrupt government rezones that land to something more valuable.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#182

Post by strken » Thu, May 07, 2020, 9:33 PM UTC

nxc18 wrote: post #87

3pt14159 wrote: post #61

Earlier quoted context omitted.

Colour me skeptical. I've seen enough to know that MITM gives you enough information or threat vectors. That said, I agree with you about Huawei and non-5G. We shouldn't be talking about banning them on 5G, we should be talking about banning them (and anyone outside of the western alliance, really) from selling gear in our countries period. National security takes precedent. China doesn't even let reporters from the…

Should the Europeans ban American equipment? We know the NSA intercepts shipments and tampers with network equipment, on top of everything else they do. We also know a foreign agent (with considerable Chinese debt who was elected with the help of Russian intelligence) is now in the White House. I know it’s fashionable to shit on China (China China China), but it’s not like they’re doing something new and unique. How…

If European nations were worried about vulnerability to the US military they'd probably start by removing all those air bases and nuclear weapons and leaving NATO.

They aren't worried about the US, because the US isn't expansionist and generally only applies muscular diplomacy to nations that are small and poor. China has used military force to expand much more recently than the US, making it much more of a concern.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#183

Post by brendanmcd » Thu, May 07, 2020, 9:35 PM UTC

leetcrew wrote: post #141

takeda wrote: post #96

Earlier quoted context omitted.

> I want cellular that is competitive with cable internet. I want bandwidth available for IoT devices. It never will be though. Whatever frequencies you can do wirelessly you can do over a wire without the interference of other users using the same frequency at the same time. Also a lot of promises 5G offers only sound good on paper. The higher frequencies don't travel well through walls (that's why it uses lower fre…

>> I want cellular that is competitive with cable internet. I want bandwidth available for IoT devices. > It never will be though. Whatever frequencies you can do wirelessly you can do over a wire without the interference of other users using the same frequency at the same time. this is true in principle, but not necessarily in practice. I suspect it will hold for the near/medium future, but I can imagine a world whe…

agreed, the lower fixed costs of ripping up roads and driveways to install is key for understanding the benefits of 5G

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#184

Post by tamdar » Thu, May 07, 2020, 9:39 PM UTC

MR4D wrote: post #174

nxc18 wrote: post #87

Earlier quoted context omitted.

Should the Europeans ban American equipment? We know the NSA intercepts shipments and tampers with network equipment, on top of everything else they do. We also know a foreign agent (with considerable Chinese debt who was elected with the help of Russian intelligence) is now in the White House. I know it’s fashionable to shit on China (China China China), but it’s not like they’re doing something new and unique. How…

> Should the Europeans ban American equipment? That's up to them and their own risk assessment. One thing I know for sure is that if they did, the US would wage an economic war so fiercely on Europe, that Nokia & Ericsson would have a tough time doing anything in the US for years to come. Further, collateral damage would include all sorts of manufacturing, which would cripple Germany. Remember the imbalance here: Eur…

You are talking about US vs EU and compare US to Germany.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#185

Post by madengr » Thu, May 07, 2020, 9:39 PM UTC

andromeduck wrote: post #165

Rebelgecko wrote: post #135

Earlier quoted context omitted.

I'm not an RF person, but the way it was explained to me is that GNSS signals are in the neighborhood of 1560mhz-1610mhz. With the advent of GPSIII, even more of the important signals are getting pushed outwards towards the extremes of that range. Ligado/Lightsquared initially wanted permission to basically surround GPS (1526-1559mhz and 1610-1660mHz) After lots of complaints, they amended their request to leave a bu…

Why can't we just greatly improve the signal strength at source by an order of magnitude? Like I know the new satellites can use beam forming to increase power for some large area for military use but it looks like even so total power is about ~500W right now. What's stopping us from deploying 10KW sats?

Supplying the power to the satellite, and getting the heat out. The RF amps are at most 50 % efficient, so you are dissipating 1/2 the input power as heat.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#186

Post by joecool1029 » Thu, May 07, 2020, 9:56 PM UTC

andromeduck wrote: post #165

Rebelgecko wrote: post #135

Earlier quoted context omitted.

I'm not an RF person, but the way it was explained to me is that GNSS signals are in the neighborhood of 1560mhz-1610mhz. With the advent of GPSIII, even more of the important signals are getting pushed outwards towards the extremes of that range. Ligado/Lightsquared initially wanted permission to basically surround GPS (1526-1559mhz and 1610-1660mHz) After lots of complaints, they amended their request to leave a bu…

Why can't we just greatly improve the signal strength at source by an order of magnitude? Like I know the new satellites can use beam forming to increase power for some large area for military use but it looks like even so total power is about ~500W right now. What's stopping us from deploying 10KW sats?

> Like I know the new satellites can use beam forming to increase power for some large area for military use

No, what you think you 'know' is plain wrong. Usually when discussing satellites, we're talking about a directional antenna that focuses a spot or wide beam for broadcast. A spot beam allows you to target a particular region, DirecTV uses spot beams to provide local broadcasts to general regions of the US. The military uses M-code shit on GPS with a directional antenna for the same sort of use case.

Beam forming is a different concept where you get creative with multiple antennas broadcasting at once and exploit signal cancellation to improve the data rate by shifting the phase between them. It does increase your received signal but relies on the receiver transmitting information back to the satellite (which is not going to happen for GPS, at least not the vast majority of consumer equip). Beam forming discussed on HN just last month: https://news.ycombinator.com/item?id=22784132

> What's stopping us from deploying 10KW sats?

Sat power is around and above that already, it doesn't make sense to increase the spot transponder ERP too much or you end up with issues like interference with adjacent bands since RF gets trickier to filter the higher the power it gets. Keep in mind a comm satellite usually has lots of transponders using maybe 100-500W each, so it adds up to some geosynchronous ones being like 20kW total consumption. Smaller LEO ones obviously not going to be close to that.

GPS released a paper about interfering with itself: https://www.gps.gov/multimedia/presentations/2010/10/ICG/bet...

Communications history is littered with failure stories of people who wanted to throw power at the problem, when they only needed to find ways to listen better.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#187

Post by kelnos » Thu, May 07, 2020, 9:59 PM UTC

nxc18 wrote: post #80

_bxg1 wrote: post #45

I have yet to hear anyone who's not a telecom CEO or a politician say they actually want 5G

I want 5G. There, you heard it. I’m not a telecom CEO and I’m not a politician. Edit: I want fast, reliable telecommunications everywhere I go. I want ultra fast reliable telecom in crowded cities. I want cellular that is competitive with cable internet. I want bandwidth available for IoT devices.

> I want fast, reliable telecommunications everywhere I go. I want ultra fast reliable telecom in crowded cities. I want cellular that is competitive with cable internet. I want bandwidth available for IoT devices.

We don't have this today mainly because wireless carriers do the minimum required to compete with their minimal competition. It doesn't have that much to do with 4G vs. 5G or whatever. Even living in a city, I don't expect 5G to improve the situation all that much, unless carriers start really spending on their network.

The ubiquity, reliability, and bandwidth will only be there if carriers make huge investments in their networks, which I don't expect will happen.

You can certainly get what you want today, with 4G/LTE. You just have to go to a country with carriers that actually prioritize that, like Taiwan or Japan (and probably several other east/southeast Asian countries).

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#188

Post by kelnos » Thu, May 07, 2020, 10:03 PM UTC

mcguire wrote: post #155

asdff wrote: post #149

Earlier quoted context omitted.

Will it even be good in the city? I live in a city and 4G is pretty crap. Drops the connection all the time, speeds are poor, latency is high.

My understanding is that 5G is specifically designed to improve that situation, at the expense of things like range and building penetration.

The only way this works is if carriers invest in a ton more hardware, which means leasing more tower space, creating new tower space, getting creative with placing radios in areas where you can't really put towers, etc.

That's expensive. What's also expensive -- sometimes even more expensive -- is running wiring to all those places to connect those radios to the backhaul network.

I frankly do not expect US carriers to go to that expense, at least not universally.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#189

Post by gorkish » Thu, May 07, 2020, 10:11 PM UTC

michaelt wrote: post #113

josh2600 wrote: post #46

Earlier quoted context omitted.

When light squared was shut down for messing with gps frequencies in their satellite network, the military did not say that light^2 was actually broadcasting outside of the expected frequency band. The deal is that the military just doesn’t use filters on most of their broadcast and reception equipment so their operating frequency is actually way wider than they say publicly. This is because filters cost money and re…

> The deal is that the military just doesn’t use filters Do you have a citation for that? I would have thought the issue is not that GPS receivers don't use filters, but rather than no filter has a perfectly sharp cut-off and GPS signals are exceptionally faint. For example, if the GPS signal is 0.1 femtowatts at 1575MHz, even if you've got a filter that can remove 99.99999% of a noise signal at 1600MHz you can still…

There is also the insertion loss and physical size of the filter to consider. It's a four variable problem where you can only optimize for any two.

Re: Pentagon official: FCC decision on 5G threatens GPS, national security

#190

Post by izend » Thu, May 07, 2020, 10:16 PM UTC

ChuckMcM wrote: post #175

jrockway wrote: post #38

I don't think there's enough detail here to decide whether or not to be mad. The L band is huge, 1000MHz-2000MHz. GPS uses a few tiny slices of this band. Cell phones, amateur radio, weather radar (though not precipitation-detection radar), ADS-B, and a ton of other non-military things are in that band. Adding 5G may or may not have any negative effect on GPS. I doubt they are proposing to run their 5G network on top…

Your GPS receiver is not going to be able to "see" the current satellites. All of the other people who share this spectrum do so "horizontally" if you will, this frequency band isn't reflected by atmospheric effects so omni-directional emitters are not visible to antenna that are looking "up" to the sky. The problem with this proposal is that the company wants to broadcast DOWN from satellites which these antennas wi…

Chuck your comments are always filled with great information and humour. Thank you for your years of contribution to HN so that lurkers like myself can be informed and entertained.