Gigabit Cellular Networks Could Happen, With 24GHz Spectrum

An anonymous reader writes A Notice of Inquiry was issued by the Federal Communications Commission (FCC) on Friday that focuses research on higher frequencies for sending gigabit streams of mobile data. The inquiry specifically states that its purpose is to determine "what frequency bands above 24 GHz would be most suitable for mobile services, and to begin developing a record on mobile service rules and a licensing framework for mobile services in those bands". Cellular networks currently use frequencies between 600 MHz to 3 GHz with the most desirable frequencies under 1 GHz being owned by AT&T and Verizon Wireless. The FCC feels, however, that new technology indicates the potential for utilizing higher frequency ranges not necessarily as a replacement but as the implementation necessary to finally usher in 5G wireless technology. The FCC anticipates the advent of 5G commercial offerings within six years.

Comments

Who wants a gigabit cellular network?

[BigButra]

All a gigabit cellular network would do is give you the ability to hit your data limit in less than a minute. I would prefer to take time to savor the precious data I've paid through the nose for and my provider has so thoughtfully allocated to me.

Re:Who wants a gigabit cellular network?

[rudy_wayne]

All a gigabit cellular network would do is give you the ability to hit your data limit in less than a minute.

Exactly. And you'll get the privledge of paying more for the faster speed, too.

Re: Who wants a gigabit cellular network?

[rudy_wayne]

Gotta love unlimited data!

Right.

And after one minute of usage, when you've exceeded your allocation of "unlimited" data, your speed will be throttled. So what's the point.

Re: Who wants a gigabit cellular network?

[AvitarX]

I break 10gb pretty regularly with tmobile .seems pretty unlimited .

Re:Who wants a gigabit cellular network?

[hawguy]

All a gigabit cellular network would do is give you the ability to hit your data limit in less than a minute. I would prefer to take time to savor the precious data I've paid through the nose for and my provider has so thoughtfully allocated to me.

Well. I guess that's one way to take a shit on technology before it even materializes.

And I thought I was a pessimist.

Oh, and by the way, anytime people want to start actually enforcing these things called anti-monopoly laws so you might have a fucking choice in the matter ...

As long as the current duopolies keep feeding legislators with money, there's not going to be any real anti-trust enforcement.

Re:Who wants a gigabit cellular network?

[roccomaglio]

I believe you are missing the point. Verizon and AT&T will not be building out the last mile any more. Supporting the last mile is expensive and they can cover that will cell towers. This will replace the line to your house. This will have implications on Net Neutrality, since in mobile they cap the data and charge companies to not count against the cap.

Re: Who wants a gigabit cellular network?

[SternisheFan]

VirginMobile has gotten quite adept at throttling. For some time after announcing they were going to throttle they wasn't any change. Now, once I hit the 2.5 gb limit, still on 4G, the slowdown kicks right in.

Re:Who wants a gigabit cellular network?

[drinkypoo]

I want a gigabit cellular network so that I can buy a megabit plan. The caps will go up notably if the capacity rises dramatically, and then I can switch to cellular to replace my WISP which sucks nuts, and not erotically

Re: Who wants a gigabit cellular network?

[AvitarX]

Tmobile has stated they will throttle, but only for customers using bittorrent and other P2P.

I will admit I've done that some on my phone, but only over hotel WiFi, I subscript to usenet anyway.

I'm only allowed to tether 5gb on my plan, but that's been enough (this month I'm at 14.5gb total, top users play music 3 gb, podcasts 2.5gb, tethering 2gb).

If I didn't have unlimited, that 14.5 gb would have been far lower, I only use wifi to control my chromecast when my tablet isn't in arm's reach.

Certainly all the podcasts, and most of the music would have been wifi.

It's finally happening

[TubeSteak]

The FCCâ(TM)s notice talks about frequencies as high as 90GHz. Anything over 30GHz is classified as âoemillimeter wave frequencies,â which are blocked by walls. Indoor coverage is going to be tough.

âoe[W]hatever licensing regimes we adopt should take into account the fact that signals from carriersâ(TM) outdoor base stations will rarely be able to penetrate into the interiors of buildings, where around 75 percent of cellular data usage occurs today,â the FCC wrote. âoeReaching such spaces will almost certainly require the deployment of indoor base stations.â

The original concept for the cellular network was a series of big outdoor towers which talked to indoor base stations.
Of course, building owners didn't want the expense of (retro)fitting small indoor cells, which led to a lot more outdoor towers than envisioned.

Re:It's finally happening

[haruchai]

Let's hope pCell is viable - it's supposed to be LTE compatible

http://mobile.slashdot.org/sto...

Re:It's finally happening

[swb]

Some providers used to or maybe still do make them available to people with coverage problems. I looked into them a couple of years ago with the idea that I could pick one up and use it at various client locations where i had good internet access but no cellular coverage. Information was kind of scarce, but supposedly they needed GPS signaling (to control power output/frequency based on real cell towers?) and buy-in from your cell provider to manage it. And it also isn't clear if they do or ever will make LTE versions of them.

I know there are a bunch of ways to get voice service via IP only, I know, but a $200 box that did IP and made cell phone(s) work seemed a simpler solution than buying into a VOIP service I could use on my cell phone and dealing with redirecting or porting my cell number.

What are the RF management issues with small/indoor base stations? Is it a huge problem if they proliferated (like wifi pollution)? Or is there some other network issue with the carriers' ability to accept small-scale backhaul via the public Internet? In some ways it almost seems like carriers would benefit, taking weak(er) signals and their utilization off the big towers and network.

Even better would be the carriers working with handset makers to enable internet-based VoIP so cell phones would work in wifi-only environments to eliminate the cell aspect of it. I'm kind of curious how iPads can now answer calls sent to iPhones.

Water frequency interference

[times05]

When I was in the army my job was Satellite Communications. Long ago I was told that frequencies around 24Ghz are highly susceptible to interference by water such as rain and fog. So those spectra were considered to be too unreliable for communication. I never bothered to to check outside though.

Re:Water frequency interference

[ArtFart]

Not a problem. The cellular companies will lobby the US government to make it stop raining.

Re:Water frequency interference

[schnell]

You're correct. The wavelength of Ka-band frequencies (26-40 GHz) happens to line up nicely with the size of a raindrop in flight. That leads to more atmospheric signal attenuation, but isn't necessarily a deal-breaker; it just means you need a bigger dish to receive it and a more powerful transmitter for the return channel. (The new generation of high-speed satellite Internet services all use Ka band, despite the "rain fade" issues, because the higher frequency enables higher data rates.) In the past, the satellite industry tended to rely on lower frequency bands (such as Ku and C) to save costs on dish/transmitter size because of this concern.

For a cellular service where you're looking laterally at a tower instead of straight up into the sky, the weather issue should be less of a big deal. However, you should note that any frequency that high up will have a very very hard time penetrating indoors through anything thicker than a single-pane window. So expect that this will be used for fixed home Internet applications where a receiver can be permanently mounted outdoors or near a window, rather than traditional cellphone usage that can happen anywhere you go indoors or outdoors.

too much multi pathing at that frequency

[Obscene_CNN]

There will be too much multi pathing at that frequency. At that high of a frequency the signals bounce off objects instead of penetrating through them. This means that you will need clear line of sight to the cell tower for it to work. Leaves , rain, fog, snow etc will block the signal.

Re:too much multi pathing at that frequency

[Buck Feta]

That was true 5 years ago, but MIMO antennas actually benefit from multipath.

Re:too much multi pathing at that frequency

[Obscene_CNN]

The laws of physics are the same as they were 5 years ago. The farther you multipath the more you multipath. The more you multipath the more multipath fading sets in. Each reflection causes a loss in signal strength. Unless they want to set up cell towers every 100 meters its not going to work.

Re:too much multi pathing at that frequency

[__aaltlg1547]

There is no kind of antenna nor any RF signal that is improved by multipath. What MIMO antennas are supposed to do is reduce the detrimental effects of multipath fading.

Re:too much multi pathing at that frequency

[YoopDaDum]

This is made for small cells indeed. Any time you see 5G with gigabit speed, it's only for high density areas covered with small cells. 4G will still be there for larger cells (coverage layer in high density areas, and less dense areas).

Also, there are ways to fight multipath. The primary one used in this scheme is beam-forming with a pretty dense array --- what I've seen on pre-5G tests typically use between 64 to 256 antennas. You then get a very narrow beam, and a primary path that is well above secondary reflections. Of course for this to work the base station must be able to precisely track the device, and that's another rarely mentioned limitation of such high-speed 5G scheme: it's mostly for static / pedestrian usage. You can extend this to vehicular (some demos are using cars) by having some smarts about anticipating movements (constrained to roads, etc.) and a less narrow beam (but then you loose SNR and reduce spectral efficiency). But mostly I would expect such 5G to be for the majority of slow moving devices, with fast moving ones pushed to an overlay of bigger 4G cells (so less HO too). This is consistent with small cells. And besides BF, I guess as 4G the waveform will use OFDM/OFDMA to also help fight multipath.

Last comment: as usual the marketing communication focuses on high bandwidth but the true interest is more capacity. So in real life instead of having a few users at super high throughput such a 5G network will be able to support more users at lower (but still very high) average throughput by multiplexing them.

Re:too much multi pathing at that frequency

[petermgreen]

... or you could rely on that interference at the point of reception to form unique signals for every recevier by synthesizing waveforms from an array of transmitters, dynamically calculated based on the location of each transmitter + receiver + interference pattern. This would effectively give an unlimited number of signals within the same spectrum with no additional bandwidth (constrained only by the number of transmitters).>

MIMO techniques can be useful but they aren't as magic as you seem to think (and a nieve analysis would suggest)

In reality a couple of things limit your performance.

1: the channel estimation is nessacerally imperfect
2: the calculations needed to seperate out the virtual channels also tend to amplify the noise.

This is especially true if the antennas are close together.

This is what Artemis is now testing with their pCell tech, using a data-center of waveform-calculating servers + cheap low-power transmitters about the size and cost of a off-the-shelf wireless router:

Yeah distributed mimo has the potential for significant gains. It also has a significant cost as it needs very high bandwidth fixed line connections from the "waveform calculating servers" to the transcivers.

Be careful not to take marketing material too literally.

Re:Gigabit Cellular has Already Happened

[Xicor]

i think you are off by a factor of 10. i have LTE as well and my max speed is maybe 35mbit

Great...

[RogueWarrior65]

And the signal will be blocked by several pieces of paper.

Re:LOS

[R3d M3rcury]

any foilage[sic] will be a problem.

That's okay. We'll just cut down the trees. They cause pollution, anyway.

the cable-box replay

[pupsocket]

Actually, this is a move by Big Telecom to claim ownership of the next-generation wireless router and fortify its control over television, Internet, and voice transmissions.

Penetration in buildings will be crap

[Hamsterdan]

Seriously? What are they gonna do, put towers on every street corner?

Re:Penetration in buildings will be crap

[K. S. Kyosuke]

Well, one obvious use case is high-bandwidth connection using upper cellular bands when you're outside and using WiFi when you're inside, with low-bandwidth connection using lower cellular bands as a fallback. That may or may not be useful to everyone, but for me, that would be enough.

Re:Penetration in buildings will be crap

[Blaskowicz]

Makes me thinks of femtocells. Farm out coverage to your customers. Also I can see this used in very high density areas : mall, town's main square, stadium, conference center, even ad hoc deployment for events. The effective bandwith for one device may then suck but the shit ton of spectrum may make the connection possible at all.

Range?

[danknight48]

Cellular networks currently use frequencies between 600 MHz to 3 GHz with the most desirable frequencies under 1 GHz

Mostly because the wavelength and potential range at 600-3000MHz(UHF) is greater than those at 24ghz (SHF).

http://patentimages.storage.go...

Longer wavelength, longer range. Rocket science.

Sprint announced a new feature

[gelfling]

"Dial Tone". Sprint announced that in 20-25 years you will be able to move 'data' on the network too. Speeds are estimated to be 100 bits per second.

Re:LOS

[3.5 stripes]

I bet you're somewhere around 15W EIRP though..