Facebook reveals 'SuperCell' tower to increase connectivity in rural areas
engineering.fb.com
engineering.fb.com
>The test location had a rocky desert topology with minimal foliage, and tests were conducted using LTE Band 41 (2,500 MHz).
T-Mobile/Sprint use this band. I have a lot of experience with it because I am located in a semi-rural and hilly area and I use LTE exclusively for internet access.
For B41, I have one tower that's approx 2 miles away and 600ft or so down from me in a valley, close to line-of-sight. This signal is only usable if I install an antenna outdoors or use next to a window facing the tower. My real-world speedtests are around 75mbit down, and 2mbit up on a good day. Indoors not in front of a window I cannot force any of the devices I own to connect to this band.
I'm also going to mention: Uplink/transmit power on most cellular devices is limited to 200mW (class 1) unless you use a device that supports Sprint's Class 2 High Performance User Equipment (HPUE) at 400mW or you have a router/device that does class 3 High Power User Equipment (also HPUE) at 1.25W. Only class 3 devices have a shot in hell at communicating back to this tower if there's even a small number of trees or a single wall between you and it.
Finally, this B41 TD-LTE tends to work worse the further you get outside the cell, since it relies on precise timing of all equipment inside it. Installing cell relay equipment works poorly outside of a mile or so of the transmitting antenna, again due to precise timing issues. (personal experience with a Sprint Magic Box).
Ignoring all the other social/anticompetitive issues there is with Facebook proposing this, it stinks like a scam to get a tax writeoff or jump onto the same sort of FCC rural internet grant money Starlink is bilking taxpayers out of. You can't scale a midband macro like this even using a dumb amount of spectrum. Oh totally forgot, there's an 'educational' use case for use of BRS (2500mhz) spectrum that I'll bet Facebook will also try to get their hands on.
EDIT: Note on power class, you have certify through the FCC initially to use higher classes, can't just enable it later on without recertification. Also, higher transmit power = less battery life. This is why in urban areas it usually makes more sense to use cell network to save battery (better scheduling/sleep modes, low transmit power) than it does in rural areas where the cell radio is cranked up to its limits and it makes more sense to use a low power radio like wifi broadcasting all the time.
GPS has the advantage of seeing multiple satellites and working with that by design since its one way. Despite that, Japan launched its own satellite to supplement GPS because it had so many issues. I think we’re spoiled by our phones that supplement GPS with cellular signals, wifi and inertial references.
Existing systems also supplement GPS network data with russia's GLONASS, as well as sometimes WAAS if the satellite gets picked up (WAAS is GEO system to provide for additional accuracy, since it's further and requires a path facing south, it's not often picked up on phones)
Can we really do inertial reference with current phone hardware? I would imagine our usecases don't really even give inertial reference a nice playing field.
My old Garmin wouldn’t realize I did a u-turn until I have half way back down the street.
Yes, check the specs for any recent (past 3 years) qualcomm chipset, initia sensors will be included. You can play around with this sensor (and others) using the Phyphox app for ios and android.
Look at the graph on "population and satellite density per degree" in [0] to see why SpaceX has most likely chosen the inclination that they use.
[0] https://caseyhandmer.wordpress.com/2019/11/02/starlink-is-a-...
One way to make a system like this work is heavily proxy and strip rich media out of the network (Globalstar sells a device called the SatFi that does this for their MEO constellation, Opera Mini used to do it for featurephones), so you can support quality of service in a remote population.
There's a financial incentive for Facebook to provide access to a specially crafted 'walled garden' that's designed for lower bandwidth scenarios. Facebook has tried this shit before in India without touting special network hardware and it was not well received: https://www.cnet.com/news/facebooks-free-basics-internet-ser...
Is it very clear that this pessimism/cynicism is warranted?
Yes, read some of my earlier comments regarding Starlink, DISH, and general telecom schemes. I'm not coming out of nowhere with this criticism.
With that being said I fully understand where their system is better than current MEO/GEO systems for low-latency rural deploys. I'm just not in the cult of Elon, physics/money/practicality have their limits.
I'd honestly be more excited with Starlink if they were primarily using it as a replacement for satellite backhaul on very remote cell sites. That way you don't need residential roof antennas and a ton of power to communicate with the network, just need your main power at the cell site. That's more practical for poor rural countries but isn't as big of a writeoff, doesn't look as sexy.
Starlink may as well take the money on the table if the constellation will fly overhead anyway.
https://www.canwisp.ca/resources/Conference%202020/Presentat...
Hmm. Rhen why does Apple recommend using WiFi for power saving?
“When you use your device to access data, a Wi‑Fi connection uses less power than a cellular network”
This is why general guidance for years was to use wifi when you are actually using your phone for browsing the internet, taking advantage of wifi's lower power efficiency when in use, but to turn off wifi when your phone is just in your pocket/idle to take advantage of cell network's better idle power efficiency.
However, the above is really only true for urban/suburban areas where you have good signal. If you are in an area with poor signal, your phone will use a lot of battery power via the cell network even when "idle" (because in reality even though your phone is "idle", the cell radio isn't actually idle, it's constantly struggling in the background to maintain the connection through the poor signal).
EDIT: Phones usually only transmit on one channel while receiving anywhere from 1-7 different channels at once, only the recent flagships transmit on 2 or 3 right now.
Nope. And the reason this is obvious is because turning off WiFi via the control center doesn’t actually turn off WiFi so collecting SSIDs wouldn’t be a problem either way.
Testing was conducted in other locations as well. One use-case being discussed doesn't exclude the others.
For example:
> The Metcalf location has flat terrain with thick deciduous trees covering the land.
Also...
> Ignoring all the other social/anticompetitive issues there is with Facebook proposing this, it stinks like a scam to get a tax writeoff or jump onto the same sort of FCC rural internet grant money Starlink is bilking taxpayers out of.
Facebook doesn't build and operate this kind of network. This project (and others such as efforts in middle mile fiber construction and funding cable consortiums) are largely intended to help regional carriers outside of the US past hurdles around capacity and density that limit their growth. Since it's not targeted at the US, the FCC's grants, spectrum allocation, and power limits are not relevant.
Cui bono?
Facebook's learned that just getting people connected to the internet in a content-agnostic way is sufficient for growth. This is why FB funds consortium fiber around and across Africa, funds internet exchanges, and makes free network planning tools available to carriers.
https://www.internetsociety.org/issues/ixps/facebook-ixp-par...
Disclaimer: I'm a Network PE at Facebook, in prod, not in connectivity labs where this project originated, and def not speaking for the company.
Except the comment you're responding to doesn't seem to take issue with the location. It goes on at some length about the problems with LTE Band 41.
How does pointing out that testing occurred in other locations address the problems with Band 41?
Ngara was designed to work in the vacated VHF/UHF TV bands (but will work in other bands). It uses MIMO with a large number (~32) of antennas to do spatial multiplexing rather than FB's "brute force" sectoring.
Sectoring is a disadvantage of FB's method, as the sectoring will limit the multipath and the ability to do spatial multiplexing via MIMO. With sectoring you will only get full capacity if your terminals are evenly distributed in azimuth. With MIMO you can get full capacity as long as the antenna has a big enough aperture to resolve each user, which will work better if you happen to have a small settlement in the cell. MIMO can also trade spatial multiplexing for diversity, which will allow longer range if there are fewer users.
FB could do a lot worse than just buying Ngara.
Totally love it when advertising companies pretend that they're making the world better by trying to be ISPs where people don't have good networks. Google did it too iirc.
-Adam Smith
Similarly, if I am in need of ad subsidized internet then fine but I would not want additional public funding or regulatory capture to assist Facebook.
Because you insist on only eating unleavened breads?
https://vinepair.com/articles/want-to-understand-fermentatio...
Adam Smith died before John Stuart Mill coined the concept, and a full century before electricity was invented.
There are many competitors that use an omnidirectional tower and directional antennas at customer sites.
A recent competitor in this space regularly achieves 6 miles at >100Mbps (~16mbps uplink):
https://www.telecompetitor.com/wisps-get-cbrs-range-as-great...
FB is claiming 6Mbps down (1.2 up) at 12 miles for their approach, which doesn’t seem to rely on fixed location customer antennas.
Both these solutions require that you be in line-of-sight to the tower. You are more likely to be in line-of-sight to 250 meter tower.
So, you're right, not comparable but still.
For example, urban homes and companies may want to chose them for any number of reasons and if they do, their willingness to pay may be higher than for rural folks and definitely higher than rural folks in Africa.
There probably is no market-based way to to do such a thing if there are global bidders for a resource unless there's some kind of non-market intervention such as Starlink setting aside a certain bandwidth per nation, or per economic tranche etc.
Novel solutions to the rural/distance problem are welcome. Even it's just literally 'a higher tower' as long as it works and is sustainable/cheap.
Also if you have to put up a pizza sized box outside your home, your landlord might complain. Even if you are the owner, building codes may prevent you.
BTW any internet provider could, they usually offer a SIP phone anyway. If this could be connected to a femto-cell coveting a household, this could solve the problem of using a phone around the house, in the backyard, etc.
Making it accept a SIM card from an existing provider is another problem.
Telcos would have known this works but haven't done it because of why? Regulations on high towers? They don't want to be stuck managing these unique things? What's the catch.
The solution is probably not technology but some sort of process issue that you need to actually get dirty to find out about and fix. Facebook needs to invest in building towers. Go do it in Africa. If it's profitable they wont lose money and if not they've tried something great.
It is just not profitable. The towers cost money, the equipment inside those towers cost money, the power to towers cost money, if not using radio-links the network to towers cost money, the core network in these rural areas cost money...
And really you can get only so much money out from single tower. Considering how plan prices are fixed for cell services it could be that even over decades of time such installation won't pay itself back.
If the service providers thought they could make money by offering service to area they would be doing it.
https://en.wikipedia.org/wiki/Supercell_(video_game_company)
Trademark filings let you mention that areas of trade and commerce you want the trademark for.
My intuition may be wrong here as I'm not an expert in cell networks, but the tradeoff seems quite analogous to ones faced in distributed computing, storage and other systems. I'm curious to see some more authoritative opinions on this.
Every single one that I heard of petered out or was revealed to be a straight up scam. Like trying to sell wifi to rural homes in the woods.
https://www.makeuseof.com/tag/how-to-make-a-wifi-antenna-out...
Their performance is poor compared with yagi's, dishes, etc.
Plus the name is doubly ironic. To an RF person, a Cantenna is a homemade dummy load which is specifically intended to not radiate.
It's really getting there: ISPs are shifting from a specialized business (they may do TV, web hosting, etc. as well, but it's always related services together) to something that comes bundled with your favorite ad service. They have the money to outcompete any existing ISP they like, so long as they somehow manage to dodge anti-anticompetition laws they can really give the non-ad-supported services a tough time. Ads is were we're headed, it would seem.
Between different companies is a subjective opinion. I'd argue that people who trust FB/Google have already bought into surveillance culture, and so those companies don't have much to lose by adding network traffic to their take.
Reasonable people can agree to disagree about that, but it's just odd to claim that "understand[ing] how networking works" makes for some kind of objective judgement.