Comment by int_19h
7 years ago
This makes a bit more sense:
"Every Volk phone has a SIM card slot and supports use on traditional LTE networks.
However, a SIM is not necessary and the phone will always prioritize the Volk network first.
The Volk network works as such: every Volk user gets a special router with their phone. The router acts as a wireless Qi charging pad also. The router connects to your existing internet via Ethernet or something similar.
The router is what connects phones to Volk and allows calls, texts, and data to go through.
If a router isn't nearby, the phone will try to find another Volk phone to use as a hop, until it finally reaches a router.
All Volk phones have strong radios and can go more than half a mile if terrain is clear.
If there are no routers or Volk phones nearby to hop to, you'll either not have service, have to use Wifi, or fallback to LTE if you have a SIM card installed and it has active service."
(https://www.reddit.com/r/Scams/comments/aq3hul/volk_fi_claim...)
So the backbone of the mesh network is their charging stations / routers, and phones can (?) mesh but not necessarily that far.
What I still don't like about this is that nowhere they talk about the frequencies on which they operate, not even in the "Specs" section of the website. This makes it very hard to verify any range claims they make.
The frequencies are what I was curious about as well. To have a half mile range at relatively low powers it would need to be a low frequency band.
I'm guessing they haven't bought licenses from the FCC, so my bet is that they're using the 900 MHz ISM band.
There's only 26 MHz of spectrum in that band, which isn't much, particularly for a mesh setup that won't be particularly spectrally efficient.
Even with a high 30 dB signal to noise ratio, the Shannon channel capacity in a 26 MHz band is 50 Mbps. MIMO helps a bit, but even in ideal real-world conditions you'll likely have at most 50 Mbps to share between all the users connected to a node. Spread that across a few users/mesh hops, throw in some packet retransmissions and noise, and it's not nearly enough to compete with LTE networks at any meaningful user density.
Incentivizing users to create as many nodes as possible is a good idea, as that allows lower power transmissions and better frequency reuse. It's still a huge struggle to get anywhere near commercial wireless speeds, particularly in areas where there are fewer nodes and a higher density of users.
I work with 900MHz radios and infrastructure, here's my thoughts:
> The frequencies are what I'm confused by as well. To have a half mile range at relatively low powers it would need to be a low frequency band.
> I'm guessing they haven't bought licenses from the FCC, so my bet is that they're using the 900 MHz ISM band.
Seems likely, and probably even works in controlled tests over relatively short distances. 900MHz meshing radios certainly exist, like this one (no affiliation with them, haven't used the product): https://www.rajant.com/products/breadcrumb-wireless-nodes/lx...
>Even with a high 30 dB signal to noise ratio, the Shannon channel capacity in a 26 MHz band is 50 Mbps.
Impossible in urban areas without highly directional antennas (which aren't small). The effective noise floor in most even semi-developed areas I've worked in is ~-100 to -80dBm - it can be a struggle even with expensive radios and fixed infrastructure. 30dB SNR just isn't going to happen over any appreciable amount of range on this sort of device (a high gain parabolic dish? sure). Using all 26MHz of the spectrum with an omni directional antenna (again, as would be required) also isn't going to happen except over relatively short distances.
900MHz is good technology, and can get robust, long distance links with the right infrastructure (I most work on 1-10mi links). The limitations on a pocket sized device with a pocket sized antenna mean this is unlikely to work @ 900MHz- especially in their fantasized scenarios of being in areas with no cell phone coverage (cell carriers have access to better bands, and far better infrastructure).
> cell carriers have access to better bands, and far better infrastructure
What would be the best band for this kind of infrastructure? ( Disregarding any existing FCC licenses )
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What if you used the noise as the carrier wave for the signal? Like, if in an urban area you have a "stable" probability distribution of noise, modulate that.
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They mention on Reddit that they are using 900 MHz.
https://www.reddit.com/r/VolkFi/comments/b1u7o3/spectrum/
My real world wifi experience. Domestic 2.4ghz wifi ap with a directional antenna plugged in, 600m direct line of sight across valley to neighbours netgear ap with stock antenna, assumed in his window. Internet achieved. Wifi ap, stock antenna in my house window, looking unobstructed over field, I get wifi internet on my phone about 200m out. Indoors in my stone walled house wifi is perhaps 10-15m. So half a mile range or 600m is almost true in a marketing sense though a bit dishonest in a real world usage sense.
> I'm guessing they haven't bought licenses from the FCC, so my bet is that they're using the 900 MHz ISM band.
No FCC filings for this device yet that I found. I guess we'll have to see.
If a router isn't nearby, the phone will try to find another Volk phone to use as a hop, until it finally reaches a router.
If my volkfi phone is acting as a relay for someone else's phone to hop to an available router isn't that going to run my phone's battery down? That's not going to be a nice experience if I'm unlucky enough to be a relay for a lot of people.
Better push for fast adoption.
> If there are no routers or Volk phones nearby to hop to, you'll either not have service, have to use Wifi, or fallback to LTE if you have a SIM card installed and it has active service.
That does make the "Global Coverage: Our network is everywhere our users are" claim a bit dodgy, no? Sure, you'll have coverage in the middle of the desert—if there happens to be a chain of Volk phones from there to the nearest point with actual regular coverage... which is highly unlikely.
It is hard to create coverage from nothing. So they made an hybrid form. "Bring your own coverage unless there is coverage". Something is better than nothing i guess. Even with this hybrid version i think chances are very slim one node will meet another and create a tiny chain by pure coincidence.
If it works as a drop-in replacement for the Pixel line on Fi, I'm pretty much sold.
Sounds like a genius idea to me. In theory at least.
Practicality is an issue though. Mostly because of our current regulation, must be said.
s/because/thanks
Our current legislation gave us a relatively "clean" frequency space. Would be so much worse without it
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If government regulates away personal sovereignty, you just tell a hundred million people they have personal sovereignty, and watch them decide if it's worth it to impede.
Ok, I have the following idea: instead of having to do house chores ourselves, our phones do them. How? Well, at night they transform, like in Transformers, into household robots and do all the cleaning, maintenance and food prepping. Then when you wake up it transforms back into a simple phone.
Genius right?