How do I make OSX connect at 300mbps?

May 9, 2009 12:32 AM

Surely someone on the Internet must know this. How do I get Mac OSX to connect at 300mbps (802.11n wide channel) to my non-Airport Base Station router?

Okay, I have searched far and wide, and have found nothing but "I don't know" and non-answers by people who don't know the answer but like to comment anyway. This must be possible. The WiFi card is an Atheros-based Airport Extreme. Network Utility confirms it can connect at a/b/g/n (I know some Macs need an addon to get 802.11n to work, this is not the case here). I can connect at 300mbps to my router (a Linksys WRT600N running DD-WRT) from other machines running Linux and Windows, and this same laptop can connect at 300mbps when I boot into Windows XP. Therefore, it is obviously not a problem with the router. I have tried connecting at both 2.4GHz and 5GHz (both set to N-only wide channel on the router), and neither works. The only difference is that when connected at 2.4GHz, Network Utility reports 130mpbs, and at 5GHz, it reports 150mbps.

The closest thing I can find to an answer is that if you have an Airport Base Station, you can use the Airport Utility to configure the card (or possibly the base station itself) for wide channel, and that wide channel will only work with 5GHz (which is an artificial limitation). Since I'm using a Linksys router, the Airport Utility is useless and just reports "no Apple wireless devices found". Surely this is possible? Surely Apple doesn't require you to have an Apple wireless router to utilize full 802.11n speeds?

posted by DecemberBoy to computers & internet (8 comments total)

While I risk annoying you with a non-answer, I can at least fill you in on the wideband behaviour on the airport extreme.

It depends upon region; some areas regulate the use of the wide channel in the 2.4ghz and 5ghz band, as one device is effectively taking up twice the bandwidth; in the 2.4Ghz band, two non-overlapping channels takes up 2/3 of the band for one connection - and it is a public band, so you have to take account of your interference with other users, which is why some routers and network cards (the intel 4965 and airport extreme for example) won't use widechannel in the 2.4Ghz band.

Many routers ignore this (such as dd-wrt) and allow you to set widechannel regardless, but the airport doesn't - in the UK for example, you can't have widechannel at all, but if you switch it to Ireland, you can have widechannel in the 5Ghz - note this is setting widechannel on the airport router (as you've done in dd-wrt), it's not affecting the card in the mac itself.
posted by ArkhanJG at 6:25 AM on May 9

I personally have no experience with this router, but I'm pretty good with Google, so I poked around a bit. Here are a few things I found:

This exchange suggests that the 5GHz signal has problems penetrating walls.

This has a specific setting to suggest with your router.

There is some comment here about distance being a factor, as well as possibly the firmware.

There were a lot of other links in my search, and the real answer may be buried in there someplace. However the more I looked, the more I saw people saying that distance is a real factor with speed for the "n" wireless, and that you can't expect the top speeds more than about 10' away from the router.

Again, I don't have any real experience with this setup, so YMMV.
posted by hippybear at 8:28 AM on May 9

and in an interesting cross-reference, this question on the Green seems to suggest that it could be a problem with your Airport card.
posted by hippybear at 8:34 AM on May 9

Surely Apple doesn't require you to have an Apple wireless router to utilize full 802.11n speeds?

What makes you say that? Apple has a long history of crippling interoperability, to sell hardware encourage the use of an all-Apple ecosystem (see also: wireless range extension). They especially do this along the edges of unapproved standards (802.11n is in draft form, it has not yet been standardized).

Since you can connect using Linux on another machine, have you tried using a LiveCD to fire up Linux on your Mac? If you can connect at full-throttle using that, then at least you know the hardware is capable, and that it's the OS, or the firmware blob that it's loading, getting in your way.
posted by toxic at 9:00 AM on May 9

The laptop is capable: this same laptop can connect at 300mbps when I boot into Windows XP

It's probably not going to help much, but have you checked the console to see if it provides any hint at what is going on?
posted by Good Brain at 11:25 AM on May 9

hippybear: I am usually no more than 30 feet from the router and in the same room. I found another post suggesting the WPA Personal/AES thing, and even though it made no sense (security settings should have nothing to do with this), I tried it. Didn't work. Thanks for looking, though.

And yeah, again, it is not the hardware on the client or the router. XP can connect just fine at 300mbps at both 2.4GHz and 5GHz. Other machines can connect to the router at 300mbps. Not only that, but I've observed this problem on other Macs elsewhere: they all connect at 130mbps when other machines connect just fine at 300.

I'm beginning to think that this just isn't possible, which is total bullshit. Wide channel is sort of quasi-against a strict interpretation of the 802.11n standard (some Intel cards refuse to use it), so if it wasn't possible under any circumstances to connect at 300mbps on OSX, I could at least understand that. However, from what I've read, people with Airport routers can connect just fine at 300mbps.

Does anyone know of any software for OSX that allows tweaking "hidden" WiFi settings? Maybe something like that could force wide channel.
posted by DecemberBoy at 12:17 PM on May 9

Oh, and other than not being able to use wide channels, the connection is great. No dropouts and full (such as it is) speed. So it's not that, either. The problem is that there appears to be no way to tell the Airport card to use 40Mhz wide channels except by using Airport Utility to configure an Apple router, which is totally ass-backwards.
posted by DecemberBoy at 12:19 PM on May 9

Just for posterity's sake: This had nothing to do with OSX. It was a problem with DD-WRT. Upon updating to a newer build of DD-WRT, my 5GHz clients automatically connect at 300mbps with no changes to any settings on the client. K-rad!
posted by DecemberBoy at 3:55 AM on June 5