802.11n adapter on USB 2: bandwidth throughput concerns

synthead · 2014-02-23 02:11:33

If I attach a 802.11n adapter to a server to use hostapd (to replace a consumer AP unit), would I get bottle-necked by installing it on a USB 2 interface? I know USB 2 is 480 Mb/s while 802.11n is 300 Mb/s at best, but what about overhead data on the USB 2 interface for managing the adapter, etc? Also, would it be beneficial or even possible to install two or more 802.11n interfaces for load-balancing multiple connections, etc?

Rexilion · 2014-02-23 11:26:34

300 MB/s for wireless N is a theoretical maximum. It also requires a client to gobble up the entire bandwidth. Given signal interference and drivers that might not scale probably, you won't have any problems I think. I would be surprised if you did because of the bus bandwidth.

progandy · 2014-02-23 11:31:09

synthead wrote:

I know USB 2 is 480 Mb/s while 802.11n is 300 Mb/s at best, but what about overhead data on the USB 2 interface for managing the adapter, etc?

Even if your wireless network runs at 300 Mb/s, that still leaves 150 Mb/s for usb protocol overhead. That should be enough in all cases.

R00KIE · 2014-02-23 14:28:49

Regarding load balancing, be aware that all devices plugged into the same usb2 root hub will share the maximum available bandwidth, it's easy to forget you don't have an available bandwidth of 480Mb/s x number of devices connected

synthead · 2014-02-24 02:15:55

Right on, I think this idea is pretty solid, then. My wireless router is simply a makeshift AP these days, so I'm looking to get hostapd on my server so I can get rid of it.

I know this is a little OT, but I have picked out a couple USB interfaces in looking at reviews. Anyone have any experience with these? Any other adapters I should consider for the job?
Amped Wireless UA600 High Power Wireless-300N 600mW USB Adapter
ENCORE ENUWI-2XN45 Wireless N300 Adapter with Two 5 dBi antennas, IEEE 802.11b/g/n USB 2.0 Up to 300Mbps

Last edited by synthead (2014-02-24 02:16:38)

Rexilion · 2014-02-24 06:54:57

If I were you I would check what kind of chipset these devices actually carry and inspect the state of the Linux kernel driver.

For the second one I could find documents here. But that did not say much. Google revealed this disturbing post. Someone mentions it here as well. The answer does not confirm nor deny compatibility. I also saw some threads in Spanish.

Well, once you do figure it what driver it is. You should Google for it and see if it's hostapd capabilities are solid.

I would put this specific example on the blacklist if I were you.

Still, it could work though. But you have no reason to assume it would.

Arch Linux

#1 2014-02-23 02:11:33

802.11n adapter on USB 2: bandwidth throughput concerns

#2 2014-02-23 11:26:34

Re: 802.11n adapter on USB 2: bandwidth throughput concerns

#3 2014-02-23 11:31:09

Re: 802.11n adapter on USB 2: bandwidth throughput concerns

#4 2014-02-23 14:28:49

Re: 802.11n adapter on USB 2: bandwidth throughput concerns

#5 2014-02-24 02:15:55

Re: 802.11n adapter on USB 2: bandwidth throughput concerns

#6 2014-02-24 06:54:57

Re: 802.11n adapter on USB 2: bandwidth throughput concerns

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