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802.11ac 'Gigabit Wi-Fi' Starts To Show Potential, Limits
alphadogg writes "Vendor tests and very early 802.11ac customers provide a reality check on 'gigabit Wi-Fi' but also confirm much of its promise. Vendors have been testing their 11ac products for months, yielding data that show how 11ac performs and what variables can affect performance. Some of the tests are under ideal laboratory-style conditions; others involve actual or simulated production networks. Among the results: consistent 400M to 800Mbps throughput for 11ac clients in best-case situations, higher throughput as range increases compared to 11n, more clients serviced by each access point, and a boost in performance for existing 11n clients."
The anonymous coward version of wi-fi.
"Among (sic) the results: consistent 400M (sic) to 800Mbps throughput for 11ac clients in best-case situations"
Best case being: the only device on the network; inside a Faraday cage; on the dark side of the Moon; 3 centimetres away from the antenna.
BTW: Google.... fuck your dictionary. It IS centimetres.
Actually it isn't. By far! 1. On a gigabit wired network you get 1Gbit of transfer speed. There is a very small percentage lost to coding but you get well over 100MB/s (up to about 120MB/s) trough a Gbit connection. If you get slower speeds and don't know why, than start searching for the bottleneck! 2. The 400Mbit to 800MBit in a WLAN is the "wire speed". I've never seen transfer rates that are more than 70% of this. So, I expect to get maybe 56MB/s (which is already quite good) out of "GBit WLAN" while I get 120MB/s out of an Ethernet connection almost all the time. Still impressive how they even reach such speeds! That's engineering at it's best!
Yes. You're absolutely right. Because the only use for a WLAN is using the internet...
2.4GHz is far too crowded. Switch to 5GHz and you should see an improvement, particularly if you're in the same room as the AP.
Hardware manufacturers I'm pointing my my finger at you. The most powerful features of 802.11n are largely unimplemented. Laptop/tablet/phone Support for 3 spatial streams is about as rare and rocking horse shit. Support for even 5 ghz is spotty at best and its hard to find out if whatever piece of hardware you want to consider buying even supports it. Heck even 2 spatial streams at 2 ghz is something your lucky to get unless you spend more than $699 on a laptop. The lowest common denominator for 802.11n and what the "wireless n" wifi support really means for half the devices on the market is a single spatial stream 802.11n at 2 ghz, which is 65 Mbps max. I can buy a mid range smartphone with 4g support and the wifi is still single spatial stream at 2 ghz. Hardware manufacturers have no incentive to put better implementations of 802.11n in their because most customers aren't savvy enough to tell the difference and demand better from device manufacturers. 802.11n is on old specification. There's no excuse why 2 spatial streams can't be the minimum. The silicon to do this is cheap and has been refined for many years.
802.11ac will probably suffer the same fate. The minimum implementation to get the "wireless ac" sticker on the box is going to be what half to three quarters of the devices on the market will support, even 10 years from now.
Fortunately 5GHz penetrates walls very poorly -- I have a 6cm thick concrete interior wall (I'm in Switzerland, after all, they love concrete) that separates too rooms. The 5GHz signal in the room without an AP is so bad that my network card (a PCI-Express card for a desktop with three external antennas) essentially refuses to connect. 2.4GHz works fine. This is in an area with exactly zero 5GHz Wi-Fi users within range, a noise floor of about -95dBm, and no other sources of interference.
Channel bonding on 5GHz makes a lot of sense due to its extremely short range.
Reaching far back to my Cisco knowledge from 2003-ish, that's because 802.11 requires acknowledging every single packet, whereas wired Ethernet allows a larger window, so several packets get sent before an acknowledgement. I don't know if that's still the case (perhaps a modern network engineer will confirm, please), but that could be the reason for seeing just about double the transfer speed through a wire. On wireless, you're using almost twice as many packets to receive the same data.
You do not have a moral or legal right to do absolutely anything you want.
Have they implemented the full 256QAM 5/6 rate yet with full 80+80MHZ bonding yet? (160 MHZ of channel bandwidth) using 8 transmit antennas and 8 receive antennas on both AP and wireless clients?
I expect early APs and early chipsets will not yet fully implement all the advantageous features 802.1AC has to offer
They'll have made compromises to save money.
To get those higher speeds outside the lab, you'll need some wifi spray
> The noise floor across the whole of the RF spectrum is rising by an average of 1db a year.
You are correct, but not for the reasons you discussed. If the millions of Transmitters were clean and well designed, they would not cause RF interference to other users (except where they were sharing common frequencies).
The problem is that much of the electronics junk generate spurious harmonics. Plasma TV's, PC's, BPL, etc. all put out a horrendous range of broadband rubbish.
This is compounded by many manufacturers and importers ignoring the existing EMC standards, as well as the corrupt regulatory bodies (FCC etc) turning a blind eye to the cheap plastic junk being imported.
Just one specific example. Once upon a time, manufactures used linear-mode power supplies with large transformers. In an effort to reduce costs, they have universally changed to using switch-mode supplies. These supplies are certainly cheaper, but they almost always generate much higher levels of radio interference.
There's a trade-off: Being able to buy cheap electronics means that there's a good chance you will be unable to enjoy it due to the resulting interference levels.
Switch to 5GHz and you should see an improvement
Combined with further reduction in range. With an ASUS N56U, in the middle of nowhere with no interference, 2.4GHz becomes unreliable at around 700ft. 5GHz drops out somewhere around 450ft.
That's not the Nagle algorithm. Nagle is about delaying before sending packaets, to prevent lots of small packets instead of one big one.
You're probably being limited by the R/W speed of your hard drive and O/S.
I consistently get 100MB/s over my network between two machines that are capable of reading and writing at least that fast to their storage systems, and this is with cheap Realtek gigabit equipment.