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wast3

Member

Registered: 2012-01-26

Posts: 27

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Can someone explain WIFI to me? (how to get max throughput, that is)

So, I've got a wlan router advertised as "AC750" This means 433Mbit/s on the 5Ghz band + 300Mbit/s on the 2.4Mhz (that only adds to 733, but hey).

Now, I have two laptops: one with a 1x1 ac card driven by iwlwifi+iwlmvm. This one gets its 433Mb on the 5Ghz band as it should. The other has a 3x3 wireless-N card (and three cables), driven by iwlwifi + iwldvm. This one is advertised as "450Mbit capable", which means (I think) that it should be able to combine 300Mbit/s on the 5Ghz band and 150 on the 2.4Ghz band.

However, on the latter laptop I can't get more than 150Mb/s on either band. I remember getting close to 300Mbps with a different N-only router, but I can't be sure.
Can anybody clarify how I am supposed to configure iwlwifi to combine throughput on the 3x3 card? I have the mysterious 11n_disable parameter set to "8" (enable agg TX) but that doesn't seem to have any effect.
iwlwifi also has a parameter called "antenna_coupling", which takes a value in "db". I tried values from 10 to 200 there, but there was no observable effect. Can people explain what "antenna coupling" is?

Overall I am a bit confused about wlan speeds and how to properly configure iwlwifi. If you have a good resource/tutorial/guide please share.

Thank you

Last edited by wast3 (2017-02-09 15:03:10)

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: Can someone explain WIFI to me? (how to get max throughput, that is)

I'm not sure you can actually combine two different bands to get more speed, if anything I'd say that is a marketing trick to get higher numbers to stick on the box.

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R00KIE
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seth

Member

Registered: 2012-09-03

Posts: 51,029

Re: Can someone explain WIFI to me? (how to get max throughput, that is)

Bonding, but you need to have two mac addresses for this.
I don't think you can "simply" use both bands otherwise or at least the access point will have to support that "somehow".

http://www.antenna-theory.com/definitio … upling.php

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mich41

Member

Registered: 2012-06-22

Posts: 796

Re: Can someone explain WIFI to me? (how to get max throughput, that is)

450M is a common rate for single-band triple-antenna 802.11n, no band combining required. In fact, there is no band combining in 802.11 - you need two independent NICs for that and use bonding or bridging. That's how simultaneous dual-band routers work internally. Dual-band NICs can only work on one band at any given time so no such bandwidth aggregation is possible.