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Wi-Fi Gets Multi-Gigabit, Multi-User Boost With Upgrades To 802.11ac (arstechnica.com)
The Wi-Fi Alliance has announced its certification program for IEEE 802.11ac Wave 2, a technology that has been around on the market for more than a year. Wave 2 can deliver up to 6.8Gbps and lets an access point interact with more than one device at a time. Wave 2 features MIMO (or MU-MIMO) which improves the MIMO technology that lets Wi-FI transmit over more than one stream through the air. Wave 2 standard utilizes channels up to 160MHz wide (up from 80MHz channels available with Wave 1). It also creates more spatial streams and uses spectrum more efficiently, the industry group said on Wednesday. Ars Technica adds:On top of MU-MIMO, wider channels, and more streams, the Wi-Fi Alliance says Wave 2 features now being certified bring "support for a greater number of available channels in 5GHz," a change that "makes more efficient use of available spectrum and reduces interference and congestion by minimizing the number of networks operating on overlapping channels." You may have already noticed routers supporting some of these features, since the specification details have been available for a few years. In fact, routers with MU-MIMO started appearing in July 2014, and you can find routers that use 160MHz channels. The certification program takes a while to catch up with real-world implementations, but it ensures compatibility between devices and may spur faster adoption by vendors. End-user devices such as phones, tablets, and laptops must also be updated to take advantage of new features such as MU-MIMO.
And my ISP (AT&T) can only give me 1.5Mbps. I can get more if I pay 3x as much and go with Concast.
Anyway, this would be like hooking up a firehose to my house and using it as my garden hose.
I am now going to spend the rest of the day muttering moo-mimo under my breath....
My eyes reflect the stars and a smile lights up my face.
> "Wave 2 features MIMO (or MU-MIMO)..."
https://www.youtube.com/watch?v=uBrk4v8UrFw
Is there anybody knowledgeable that can explain how a a wi-fi channel with bandwidths in the tens of MHz can deliver 6.8 Gbps? Even with MIMO, I feel like that shouldn't be possible (unless maybe they are talking about the 60 GHz band). Did they change the modulation to some crazy scheme?
Since I am literally 0.5 meters from my HP Procurve managed switch with a nice Cat6 cable, what problems can this solve for me?
Thanks for the reminder that I screwed myself by getting an integrated cable modem/802.11ac router. Meaning the router is controlled by Comcast. Meaning the firmware cannot be upgraded. Ever.
I've abandoned my search for truth; now I'm just looking for some useful delusions.
Is this the kind of thing where most wave 1 devices can be software upgraded to wave 2 devices? Or is it yet another case of tossing out the silicon?
I would guess the glowing vendor support for this on one of TFS links would lead me to believe this will require new hardware.
From an AP support perspective, it really is annoying to have so many active fucking client standards to support. All the gee-whiz latest features are marginal benefits when half the spectrum is used by brain damaged clients vomiting all over the spectrum using old standards.
You mean to tell me that all the Ethernet cable I just finished running through my house is pointless.
Dammit!
Great news! Scientists have found a way make routers modulate information in the x-ray and gamma spectrum. Due to the wavelength this permits incredible transmission speeds in excess of terabits/sec.
Slight downside: You get cancer.
So does this mean it will finally stream video as well as 100mb hard-wired Ethernet?
Strange things are afoot at the Circle-K.
All I really need is 2 megabits a second full-duplex, 60 mile range, with 3 of 4 forward error correction, fail-cleanly, and 80% connection reliability.
So when are we going to get this: https://threatpost.com/ibm-unv...
I mean it's not like I've been waiting or asking for it for years: https://it.slashdot.org/commen...
https://mobile.slashdot.org/co...
Shared key WPA2 means that anyone who knows the shared key can decrypt other people's traffic if they managed to sniff the 4-way handshake messages:
https://mrncciew.com/2014/08/1...
http://www.howtogeek.com/20433...
It's true using WiFi means you still have to trust the entity providing it, but that's the same with a wired network or using an ISP.
To those who say "use VPNs" I'd say:
1) Defense in depth
2) that's a different layer - just because you can workaround a broken layer doesn't mean the broken layer isn't broken. The fact is the layer already has encryption but it has a broken implementation which can be improved.
With more than (two? three?) antennas there are some issues that keep you from synthesizing and extracting as many completely independent channels as there are antennas at the end with the fewer antennas, but it approaches that.
Also: If you've got one central site (like a hotspot or cell tower or coherent array of them) with a lot of antennas and a number of remote devices with only one or a few, you can do things like "steerable null" - computing waveforms that send signals to several remote sites arranged so that each "can't hear" the signals intended for the others. (You make the others maximally quiet, rather than his maximally loud, because the ones intended for others are "noise" and its the ratio of signal to noise that matters.) Your multi-antenna remotes can also get multiple re-uses of the bandwidth and your single-antenna remotes a signle use of the bandwidth - but the cancellation on the multi-antenna remotes isn't quite as good, so it's another case of you can't quite get to data rates equivalent to the ideal of M antennas at the central and a sum of M antennas at the remotes giving you M complete re-uses of the spectrum.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Lost the start of that, trying to recover . Quick summary.
Imagine a flickering-LED optical transmitter on the side of one hill, and (instead of an optic fiber to a receiver) a telescope pointed at it with a photodiode at the corresponding point of the image. The Nyquist limit applies to the amount of data you can send that way (and forward-error-correction coding schemes exist that approach the maximum theoretical bitrate).
Now imagine a billboard on the hill, with an array of flickering-LED optical transmitters, and an array of photodiode receivers at the telescope image plane. The individual signals are flying through the same space and separated by their direction of flight. The Nyquist limit applies to each of these links, but if the optics are good, the aperture large enough, and the air is not dusty, foggy, or the signal so strong it starts ionizing things, the signals don't mix enough to raise each other's noise level. So with N signals you can get up to N times the data rate. (If the separation isn't perfect you get less than Nx because of some of the signals appearing as a noise in the reception of others.)
At any cross-section of the path from the billboard to the telescope, the light is the sum of the light from all of the transmitters. The direction of flight of each individual signal is represented by the way the phase of its contribution changes from point to point across this cross-section. The telescope samples a cross section and the optics "computes" the separation of the beams, bringing each to a focus on a different receiver.
With MIMO the transmitting station does something approximately like synthesizing the signals at several points on such a cross-section and pushing each out through a separate antenna located appropriately. Meanwhile the receiving station does something like sampling several points on the cross-section and computing the separation of the individual flying-slightly-different-directions signals.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way