Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
Wireless Networking Network Hardware

Increasing Wireless Network Speed By 1000% By Replacing Packets With Algebra 357

MrSeb writes "A team of researchers from MIT, Caltech, Harvard, and other universities in Europe, have devised a way of boosting the performance of wireless networks by up to 10 times — without increasing transmission power, adding more base stations, or using more wireless spectrum. The researchers' creation, coded TCP, is a novel way of transmitting data so that lost packets don't result in higher latency or re-sent data. With coded TCP, blocks of packets are clumped together and then transformed into algebraic equations (PDF) that describe the packets. If part of the message is lost, the receiver can solve the equation to derive the missing data. The process of solving the equations is simple and linear, meaning it doesn't require much processing on behalf of the router/smartphone/laptop. In testing, the coded TCP resulted in some dramatic improvements. MIT found that campus WiFi (2% packet loss) jumped from 1Mbps to 16Mbps. On a fast-moving train (5% packet loss), the connection speed jumped from 0.5Mbps to 13.5Mbps. Moving forward, coded TCP is expected to have huge repercussions on the performance of LTE and WiFi networks — and the technology has already been commercially licensed to several hardware makers."
This discussion has been archived. No new comments can be posted.

Increasing Wireless Network Speed By 1000% By Replacing Packets With Algebra

Comments Filter:
  • by Anonymous Coward on Tuesday October 23, 2012 @04:14PM (#41744553)

    ...I don't see how it will solve "spectrum crunch" when every nibble of your LTE bandwidth is oversubscribed by 5 to 1. Whether you have 32 users doing 10 Mbps streams, or 320 user doing 1 Mbps streams, it's all accounted for. I'd certainly like to be one of the 10, but 20 Mhz worth of spectrum at 16 symbols/Hertz is not a limitation you can change with fast/excellent forward error correction.

  • by Ignorant Aardvark ( 632408 ) <(cydeweys) (at) (> on Tuesday October 23, 2012 @04:17PM (#41744585) Homepage Journal

    If you've ever used Usenet, and you've used parity files to recover missing segments of data, then you know exactly how this technique works.

    Frankly, I'm surprised it took so long for someone to apply it to lossy network environments. It seems obvious in hindsight.

  • Math! (Score:2, Insightful)

    by Anonymous Coward on Tuesday October 23, 2012 @04:17PM (#41744609)

    To everyone who grew up saying that they never used math after high school, and it didn't have any meaningful use further than simple addition... you can kindly eat your own words now.

    I'll just sit here and watch.

  • by jargonburn ( 1950578 ) on Tuesday October 23, 2012 @04:21PM (#41744653)
    I agree that it's not a magic bullet. The point is, however, that the overall throughput of the network was increased by better usage of the available resources! If the *effective* available bandwidth is increased, then the performance of everyone "nibbling" on that network will *also* presumably increase. Also, think how much more money carriers may be able to squeeze out of users without needing to invest more in infrastructure! [/sarcasm]
  • by Moskit ( 32486 ) on Tuesday October 23, 2012 @04:24PM (#41744697)

    Article is very light in details (except "Libraries of Congress" things), but it looks like those guys implemented a kind of error correction code (ECC) to recover lost data through extra data found in other packets. This has been in use for various types of networks (optical, DSL, GSM) for years.

    Of course it is all down to how good the actual algorithm ("algebra") is in terms of overhead vs extent/capability of error correction vs introduced coding delay. There is always a trade-off, but a particular algorithm can take into account technology specifics (WiFi) and optimize it very well for a given task (whole packet lost, but not so often).

    Journalists like to put BIG BUZZWORDS to well known things.

  • by TheSpoom ( 715771 ) <slashdot.uberm00@net> on Tuesday October 23, 2012 @04:28PM (#41744749) Homepage Journal

    It's an error-correction method that happens to have compression built-in.

    Also, I really wish people would stop shitting on new technologies like they're some sort of oracle. This is awesome. Accept it.

  • by YesIAmAScript ( 886271 ) on Tuesday October 23, 2012 @04:41PM (#41744929)

    It's called forward error correction and it requires sending additional redundant data so you can solve for what is missing. Sending additional redundant data does use more spectrum for the same throughput, because you're sending more data. It may be worth it to avoid retransmissions when data is lost, but it definitely use using additional spectrum.

    This is nothing new, your computer uses FEC on its storage (HDD or SSD) and maybe even on its RAM (if it has ECC RAM).

  • by OrangeTide ( 124937 ) on Tuesday October 23, 2012 @04:45PM (#41744967) Homepage Journal

    Shannon Limit shows that there is only so much information that can fit in a channel.

    Plenty of forward error correction codes exist (algebraic encodings) to enable a channel to approach the shannon limit. Most of you have heard of Reed-Solomon or Hamming Code before.

    NASA has used these since the 1970s to provide a more robust link with the effect of utilizing more bandwidth of that link.

    This is a little fancier than what I mentioned, but conceptually similar I imagine. The advantage of just using some existing forward error correction, perhaps combined with one of the popular compression algorithms, is that techniques that have been in use for the past 4 decades probably can't have enforceable patents placed on it.

  • by Jeng ( 926980 ) on Tuesday October 23, 2012 @04:46PM (#41744989)

    Also, think how much more money carriers may be able to squeeze out of users without needing to invest more in infrastructure!

    This might actually hurt them then because they charge by what was transmitted, not by what was received.

  • by Anonymous Coward on Tuesday October 23, 2012 @05:07PM (#41745267)
    My grandpa used to tell me stories of old men who pulled up into town offering medicinal cures for all sorts of diseases, old age, arthur-itis, bad vision, whatever.

    "Medicine men" would orchestrate a "medicine show" with all sorts of claims and testimonies of the miracles of the precious snake oils he vended. Fistfuls of cash soon filled the air, and his cronies went through them exchanging their hard-earned cash for bottles of God-knows-what. ( Grandpa tells me the most common ingredients were assortments of oily vegetables with a smattering of creosote - same stuff used to preserve telephone poles - thrown in for good measure - and maybe a smattering of moonshine to give it a medicinal smell ).

    These were simple old country folk he sold to - mostly farmers. They knew all about how to run a farm, and respected their doctor - and the charlatans of the medicine show knew full well how to monetize the people's faith in the technical jargon of chemistry.

    A few days after the wagon left town, the people discovered they were no better off, and quite a bit poorer, after the medicine man left.

    Woe to the medicine man if he visited a town a few weeks after another medicine man had pulled his scheme off.

    I think we have seen so much stuff today whose sole purpose is monetizing bullshit, that we are leery of accepting stuff we do not understand. I - for one - would love to understand Rossi's "eCat" cold fusion LENR device, but the shroud of secrecy around it, along with what YouTube video I have seen of it has me believing it is just more snake oil, however much I would love to see something like this actually work..

    As far as packet loss is concerned, if its a problem, put each packet through ECC just as we do on CD's or DVD's - and match the ECC size to the packet size. To me that is obvious - and being I am not advanced in this field - I think I would be reasonable in claiming that is an obvious use of the technology
  • by Bill_the_Engineer ( 772575 ) on Tuesday October 23, 2012 @05:07PM (#41745273)

    Actually they came up with yet another method of Forward Error Correction (FEC). I haven't had time to read the article and look forward to see how they compare to Reed-Solomon or other Reed-Muller codes (Walsh-Hadamard code is used in CDMA).

    This isn't exactly new but I'm glad to see someone take the initiative to apply it to today's WiFi networks. The mentality as of late is that the speed is more than fast enough to deliver the data and the occasional resend. FEC currently used where data rates are quite limited or the latencies are such that retransmissions are prohibitive long.

  • Re:Math! (Score:4, Insightful)

    by Grishnakh ( 216268 ) on Tuesday October 23, 2012 @05:13PM (#41745337)

    Sorry, but those people were right. They don't need anything more than simple addition to work at Starbucks making crappy burnt coffee drinks. The fact that their mobile phones will work better as they send inane messages to each other on Facebook is nice, but it doesn't require them to know any algebra or other higher math; the engineers (in other countries where math is valued) implementing this stuff need to know that math, but the users don't.

  • by Eunuchswear ( 210685 ) on Tuesday October 23, 2012 @05:16PM (#41745363) Journal

    No, they've invented forward error correction.

    How novel.

    "While the exact process is being kept secret (and has already been licensed by “several companies”), "

    Fuck 'em and the horse they rode in to town on.

  • by Gilmoure ( 18428 ) on Tuesday October 23, 2012 @05:23PM (#41745439) Journal

    Think of it as bitmap vs vector graphic.

  • by suutar ( 1860506 ) on Tuesday October 23, 2012 @05:55PM (#41745783)
    It doesn't necessarily need support from the server hosting the content. Any router along the path could take the old-style packets and wrap them in new-style packets. Since the servers are likely to be using wired connections anyway, this technique might not help them a lot anyway; the real win is using this to beef up the connection from the radio tower (be it cell or wifi) to the client (be it cellphone or wireless card), and that's a much smaller set of hardware/firmware to update.
  • by Imagix ( 695350 ) on Tuesday October 23, 2012 @06:46PM (#41746183)
    Car analogy: Somebody ships you a car. It arrives with a bent bumper. Instead of having the source shipping you a new car, you just unbend the bumper.
  • Re:Math! (Score:5, Insightful)

    by CastrTroy ( 595695 ) on Tuesday October 23, 2012 @07:46PM (#41746591) Homepage
    Sadly, most people who are plumbers are probably better qualified then most people who call themselves programmers. I think that all degrees/diplomas should require some kind of apprenticeship/co-operative education/internship program to get you real on the job experience. There's only so much that can be learned in the classroom. Being on the job, doing actual work allows you to learn a lot of stuff that just would not come up in a classroom.

To do two things at once is to do neither. -- Publilius Syrus