Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

iOS 4.3 breaks Wireless N (802.11n) in 2.4 and 5 GHz bands on iPad, iphone4

It's not just in the 5ghz band as I first thought.

I put 4.3 back on things and did more tests..

4.3 prevents ANY iDevice , including the ATV2 from using 802.11n in any band.

Many ppl don't see this because their routers are in mixed mode. So for 5ghz ppl , the devices drop to 802.11a, and for 2.4ghz ppl, the devices drop to G.

I hate mixed mode on routers because it degrades performance(so I don't use it). So my 5ghz band is N only and my 2.4 is G only. So I noticed this right away. But once I set my 2.4ghz to n only mode , no idevice running 4.3 could connect to any band. nothing would touch it

This also is not a 40mhz vs 20 issue as my 5ghz was forced to 40 and the iPad and ATV used it just fine under 4.2.1, and i tried 20mhz N only on both bansd and still nothing would connect.

I'm a computer engineer and programmer so I troubleshooted every possible cause with this affecting all idevices, and what I see on the forums this is a HUGE screw up in the release of iOS 4.3

I'm just shocked there are NO press releases. 54Mbit is not enough to stream HD movies to an iPad. The iPad does not buffer to storage like the ATV2, it buffers to ram. So on a G/A network, HD video streams to my iPad then stops every 1-2 mins

However, I was able to downgrade everything to 4.2.1 again because apple is still signing it

I started a new thread , this one, with a better title so search engines, etc can find this info easier

Message was edited by: TallBearNC

Dell XPS 720, Windows 7

Posted on Mar 12, 2011 8:33 AM

Reply
60 replies

Mar 12, 2011 2:12 PM in response to TallBearNC

Issue solved. Apparently iOS 4.3 REQUIRES WMM support to be ENABLED or it will refuse connect to a dedicated N router or it will fall back to G on a mixed mode router. I read the final IEEE 802.11n requirements and it hinted WMM is now mandatory.

WHY apple would force this w/o telling ppl is a mystery. But once I enabled it, all my idevices can now do 2.4 and 5gz N again on iOS 4.3

Mar 12, 2011 2:20 PM in response to TallBearNC

My router (D-Link 825) works just fine with my iPads and my MacBook Pro both on the 5 GHz 802.11 band. Of course, if the router is working properly, there is nothing that one device can do to "kick other devices off." It is, after all, the router's job to manage communications between multiple devices.

So don't expect a fix from Apple. if your router doesn't work properly to manage communication between your iPad and other devices, get another router. Even wireless-N routers are pretty cheap these days. Also, many routers can be re-flashed with open source firmware freely available on the web.

I did encounter one odd problem when I first set up my iPad2, in that I was initially getting "unable to connect" alerts from the iPad2 when I tried to join my 5 GHz 802.11n network. I thought that maybe the iPad2 couldn't handle 5 GHz, so I turned on 2.4 GHz on the router and was then able to connect. But then I switched back to 5 GHz only mode, and the iPad2 re-connected just fine.

Mar 13, 2011 1:11 AM in response to TallBearNC

Nice one TallBear - enabling WMM fixes the issue for me too. Why the he'll don't Apple Support know about this and inform us when we call!

This still isn't acceptable as a solution though - what if you want to connect to a public WiFi setup that's N only and they don't have WMM enabled? Say "excuse me, can you change the config on your router please?" Not good Apple - why have you done this?

Message was edited by: Fubar_UK

iOS 4.3 breaks Wireless N (802.11n) in 2.4 and 5 GHz bands on iPad, iphone4

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.