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September 2015
October 2015

2015-09-03 »

Wifi marketing lies reach newer, crazier heights!

http://www.engadget.com/2015/09/02/asus-router-worlds-fastest-wifi/

Interestingly, this one claims 1 Gbps over 2.4 GHz.  How's that possible?  Is it the world's first 8x8 consumer wifi AP?

Nope.  It turns out that while I wasn't looking, 802.11ac seems to have grown two more even-more-unachievable MCS levels: 10 and 11:
https://en.wikipedia.org/wiki/IEEE_802.11ac#Theoretical

At 40 MHz, 4x4, you'd get 4x the 40 MHz value for MCS11 in that channel, so the "marketing rate" would be almost exactly 1000 Mbps.  To deconstruct that a little using my formulas:
- 1000 Mbps advertised
- real clients only get 2x2: 500 Mbps
- real clients only get mcs7 or less: 300 Mbps
- PHY rate to UDP rate: 2/3 -> 200 Mbps
- UDP rate to TCP rate: 90% -> 180 Mbps
- Realistically 2.4 GHz networks can only use 20 MHz channels: 50% -> 90 Mbps.

Thus achieving a world record lie factor of (1000-90)/90 = 1011%.

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