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How pCell works and why its a bigger deal than anyone realizes

281 points| followben | 12 years ago |akbars.net | reply

114 comments

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[+] StevePerlman|12 years ago|reply
A couple of clarifications and comments (new whitepaper is coming with a lot more info):

The iPhones (and dongles) we demoed have no software modifications at all, and there is no additional overhead beyond the standard LTE protocol. pCell works with unmodified Android LTE phones, too. (We had wanted to post a lab demo we did of the Galaxy S4 and an Xperia, but we just ran out of time.) Out-of-the-box compatibility is essential for rapid deployment. And, yes, we are meeting many of the core goals of 5G today (e.g. unlimited 4K UltraHD streaming) using Rel. 8 LTE devices in LTE spectrum.

pCell is indeed protocol agnostic, and can concurrently support different protocols in different pCells in the same spectrum. For example, we can support unmodified LTE phones in their own pCells, while concurrently supporting lower cost/lower power devices with far lighter protocols (that are lower latency), since we don't need all of the complexity of LTE. For example, there are no cells, no cell edges (and no need for CoMP), and no cell handoff.

I'm waiting for something to connect the dots and realize this is a vastly more efficient way to use white spaces than anything currently on the table. White spaces will be full overnight with current techniques. With pCell, they will never be full.

More data is coming later. Apologies. We have been utterly overwhelmed in incoming inquiries since launch.

But, I will confirm this: pCell is indeed a much bigger deal than anyone has yet touched on. The "tubes to transistors" analogy is not just marketing speak: Compared to cellular, pCell is far more reliable, enables much smaller and lower power device and can be continually extended in density. Tubes had physical constraints that limited their reliability and scalability. Transistors did not. Cellular (and other interference avoidance protocols like Wi-Fi and cognitive radio) have a physical constraints that limit their reliability and scalability. pCell does not (as far as we know). Cellular has stalled in scalability. There is an entire era of innovation in front of us with pCell. - Steve Perlman

[+] HowardMei|12 years ago|reply
Thanks for the clarifications but it's still hard to get it.

Is pCell an alias of Picocell?

What's the difference between a pCell and a Femtocell with cooperative MIMO and distributed antenna system (DAS)?

"pCell is indeed protocol agnostic" means nothing has been modified in LTE Rx/Tx physical layer or data link layer right? Then does that mean all the inventions are in the antenna system?

Without cellular, how do you handle the dead zone issue, because real time tracking & beaming will be blocked by walls?

[+] aidenn0|12 years ago|reply
From a technical point of view, it would be interesting to know how this performs near an airport. Multiple giant RF-reflective surfaces travelling much faster than 70mph must be very hard to deal with. Perhaps the lower per-transmitter power makes reflections at altitude less of an issue?

I've experimented with similar things in the past, and mainaining coherence for long enough outside the lab is Very Hard, so congrats on doing this.

[+] ksec|12 years ago|reply
Best thing since sliced bread? If Anything this fundamentally solve the Mobile TV problem. or Heck all Internet Connection problem with one go. No more silly ADSL Phone line or Cable Modem which are far worst then today's LTE. It would get rid of Home Router as well, as long as all of our Mobile Devices have LTE. I cant wait to pay for it.

And it seems we move the bottleneck to the cell backbone. Which could get saturated easily.

[+] marshray|12 years ago|reply
Thanks for the info! Seems like a neat system.

Really curious to hear how it's focusing into a 1 cm ball frequencies for which 1/4 wave is significantly larger than that.

[+] tim333|12 years ago|reply
> "no cell handoff" I'm curious how this would work. Presumably in the pCell system the base station focuses the radio signals in something like a beam towards the device but this must have a finite range - I wonder how far - and when you go out of range the system must switch to another base station. Maybe you call this a different name than 'handoff' but presumably the switching base stations thing must happen some how?
[+] hershel|12 years ago|reply
Will this technique work for license free systems like WIFI ?
[+] Alphasite_|12 years ago|reply
I hope you can eventually find a way to work onlive (or its successor) into this (I imagine this is one of your reasons for approaching this problem?).
[+] jtchang|12 years ago|reply
I think the idea of focusing multiple low power radios onto a single point so that they coalesce is simply being rediscovered. While we could do this before the real ingenuity is being able to rapidly update all the parameters when the point you want to focus onto is rapidly changing.

Another scary idea: While we could beam wireless power imagine if this was in any way weaponized. With all these stations beaming power to everyone what would it take for an overwhelming number of them to direct it at a target with the purpose of eradicating it? Certainly not a laser in the traditional sense but surely something just as destructive.

[+] Tloewald|12 years ago|reply
The idea of deliberately burning out devices is interesting, and probably feasible, given a dense enough array of powerful enough transmitters (bear in mind that one of the key benefits of pCell is that it uses far lower-powered transmitters). But it seems to me the inverse square law is going to make it a very inefficient weapon.
[+] musesum|12 years ago|reply
It doesn't have to be high power to be effective. Google search on "russian microwave US embassy" (not Bing search, unfortunately), which yields some interesting background on the Russian's beaming microwaves at the US Embassy. It was within the US legal limit at the time. Health problem ensued. Making an adversary sick without noticing may be more effective for some situations.
[+] ChuckMcM|12 years ago|reply
Nice explanation, does it bother anyone else that you could set up a bunch of antennas such that they could create a lethal 1 cm ball of energy anywhere in the space they can see? Sure they think about powering devices but what about a couple of Watt-Seconds of energy appearing in your frontal lobes? If Perlman can do that its kind of the ultimate 'border' fence is it not?

(I'm tempted to write, "All you would need is an unscrupulous engineer to develop a targeting system ...")

[+] TD-Linux|12 years ago|reply
First of all, your body would likely screw up the interference patterns enough that it wouldn't be a "ball of energy" in the center of the person - it would likely mostly diffusely heat them.

Second, the amount of power to burn a person is many orders of magnitude higher than needed to receive a signal. The transmitters would have to be extraordinarily powerful. I can only see this happening if they plan on making a wireless power transmission service.

Also, a 1cm ball is extremely optimistic, given that LTE frequences have several cm wavelengths. It would also require an enormous number of pCell transmitters to concentrate their transmission into such an area. For communications though, even concentrating into a 20m ball would be a huge improvement over existing technology, so I don't know if there is incentive to place more antennas than required for that.

[+] politician|12 years ago|reply
I just replied to another thread with this exact same thought, then looked down to see yours. And yes, it is scary... If I understand it correctly, the targeting system just consists of normal receivers hacked to offset their targeting feedback by a distance that would park the energy ball inside the victim.

In any of the applications where this is deployed broadly, that is, where we cover our cities in transmitters, then we'll have effectively given over this remote kill capability to anyone who can do trilateration.

[+] yread|12 years ago|reply
You would basically already do that with mobiles. When people use for talking they keep them <1cm from their head. And while 70mph is indeed great speed people sometimes take high speed trains (200mph) or don't turn off their mobile on an airplane (~300mph in vicinity of ground)
[+] tomp|12 years ago|reply
Tin foil hat? (Ok, maybe a Faraday cage hat.)
[+] nathanathan|12 years ago|reply
If this kind of technology were to fall into the wrong hands would we even know? Would it appear as though the victims had a heart attack or stroke?
[+] josephagoss|12 years ago|reply
The first question that comes to mind is this: how can we defend ourselves from being brain burnt?
[+] rayiner|12 years ago|reply
You can already cause injuries with phased array radars, right?
[+] mistercow|12 years ago|reply
What seems to me a more realistic concern is that you could create a beam of energy that would be lethal to an individual device. Brains are typically a lot more durable to EM radiation than electronics.

And more generally, it seems like relying on coordinating devices you don't physically own opens you up to all sorts of new kinds of DoS attack.

[+] mrfusion|12 years ago|reply
Actually if they could make it that small wouldn't it also be useful for surgery? Imagine non invasive surgery.
[+] TheEzEzz|12 years ago|reply
If the latency of pCell is low enough then you could have a thin-client phone tunneling into a cloud OS. Now get rid of most of the CPU/memory hardware complexity on the phone (which should lower power requirements for the phone too). If you can wirelessly send energy then get rid of most of the battery.

Suddenly you've got a very, very thin phone with infinite battery life and computational power only limited by the server you're hooked up to. It's the perfect mobile device. Do the same thing for a laptop and I'm in paradise.

[+] camillomiller|12 years ago|reply
Wow, what a paradise. Total control made simple, that's what I see...
[+] jol|12 years ago|reply
Sorry to rain on your parade, but don't you like idea that computing device is independent from others and does not require network connectivity 100% of time when you want something done?
[+] KaiserPro|12 years ago|reply
And then all you'd need to do is carry a briefcase battery.
[+] Tloewald|12 years ago|reply
Assuming pCell works as advertised it's a huge deal.

It allows you to cover a city in cells for insanely cheaper than current cell technology and provide far, far better reception and bandwidth to far larger numbers of customers AND it works with existing LTE gear while also affording simpler, cheaper, and lighter-weight new gear and reducing power consumption across the board. What's not to like?

I don't think anyone who has heard about pCell thinks it isn't a huge deal, if it works.

One example of a major potential problem: how well does it track erratically moving objects (e.g. most cell phones?), in built-up areas with lots of signal reflection?

[+] nardi|12 years ago|reply
Steve Perlman always comes across as a snake oil salesman, but I didn't think he could do OnLive either, and that technology works fantastically. As a result, I'm pretty excited about pCell, even though it's being preceded by a wave of marketing hype.
[+] chacham15|12 years ago|reply
As many positive things as I have heard about it I have one question: will we ever actually see this as an actual product? I feel like I hear about so many cool things which never come to fruition and I have a nagging feeling that this might be one of them. Why? Because, as I've read, the companies would need data centers to manage all of these connections. What interest do these companies have to risk all of this money (a recurring cost, might I add) when people probably wouldnt spend more for it? I dont profess to know, so can someone who has actual information enlighten me?
[+] XorNot|12 years ago|reply
That isn't why stuff doesn't turn out. It usually has some problem or another which is being assumed will be "solvable" by the time they release.

Never solve it? It's never released.

Alternatively, it does come out, but its gains are just evolutionary improvements not revolutionary.

[+] bprater|12 years ago|reply
"With this technology, it's conceivable that 5G wireless could displace both cable and DSL connections within a few years, as is claimed in the presentation."

A few years?! This statement should give landline data providers, like Cox and Comcast, some serious pause.

[+] tim333|12 years ago|reply
The original Columbia presentation is actually pretty cool ( https://news.ycombinator.com/item?id=7274288 ) I thought I'd mention it as it only got a couple of votes and sarky comments at the time but having just watched it all I think it really look like a major breakthrough, maybe the biggest one of the year and could be giving us 4k video all over the place before long. One of the interesting things is it will work with existing unlicensed spectrum, existing handsets and the backhaul can be done with line of site links on rooftops so it can be rolled out pretty much straight off - well they are talking a year or so.
[+] DonGateley|12 years ago|reply
Once you begin exploring the implications and the possible applications to things other than communications it begins to look like possibly the biggest breakthrough in history.

Only one in energy could surpass it.

[+] mrfusion|12 years ago|reply
I wonder if wireless power like this could be used to provide power for launching spacecraft and this avoiding the tyranny of the rocket equation?
[+] higherpurpose|12 years ago|reply
> Will it work for WiFi as well? It's protocol agnostic, so it could work in unlicensed spectrum as well. The issue is that you don't have complete control over all the other transmitters, so you can't coordinate them.

From the moment I heard of it, the first thing I thought about was: this could make long range Wi-Fi possible (and therefore meshnets and carrier disruption possible).

Seeing this tech being used by wireless carriers would be cool, but I really want to see it (or something like it) being used in new mile long Wi-Fi standards. Now the Wi-Fi Alliance only needs to make one for us.

Long range Wi-Fi could also make communication between self-driving cars much more feasible (got your attention now, Google?) - although that presents a pretty huge security risk, too, but I imagine the industry already wanted them to be connected to the Internet, so it wouldn't be much worse.

[+] redbad|12 years ago|reply

    > Humans use <todo>.
Indeed.
[+] hop|12 years ago|reply
Wireless power transmission will change everything in hardware if someone can pull it off. I'd bet Apple is waiting until they can do low power wirelessly to launch their smart watch.
[+] pazimzadeh|12 years ago|reply
I doubt that Apple is waiting until wireless power to launch the smart watch, but I agree that it will change everything. And it would make sense for Apple to buy pCell. Of course Steve Perlman worked at Apple before.

http://en.wikipedia.org/wiki/Steve_Perlman

[+] atrus|12 years ago|reply
Don't you still have large power losses from the inverse square though?
[+] nardi|12 years ago|reply
Is there any reason this same technology wouldn't work with light? Wouldn't that be a phased light array?
[+] kayoone|12 years ago|reply
With seemingly unlimited mobile bandwidth and speed, the cloud gets a new dimension too. Perlman has already proven that even the most demanding applications, realtime games, work well in a streaming scenario even today. With something like this, i could see my desktop in the cloud being accessible from anywhere through a mobile thin client in my pocket. Hook up multiple monitors/keyboard/mouse to it or just use the device screen itself, with computing power only limited by the cloud provider. Technologies like OnLive or PCoIP show thats its possible even today, all thats missing is the infrastructure to support it and pCell could be the answer to that.
[+] neuromancer2701|12 years ago|reply
While I think charging cell phones and Telsas is a problem, getting cheaper than petrochemical energy is the key. So I have always thought that some sort of space-based energy source was the solution but how do you get it back to earth? 1000's of small solar cell beaming back energy concentrated at one point would be a great solution. How much would this cost would be interesting to find out?
[+] jessaustin|12 years ago|reply
Sort of reminiscent of ESWL, which breaks kidney stones, except in that case they "aim" the sound waves with an elliptical waveguide.