Before people all rush out and buy Apple Routers because they think the WiFi is bad with non Apple kit, please consider what I've been doing.
I have a TP-Link 300M Wireless ADSL router which is a cheap B/G/N router. I've had very expensive routers in the past and they can go wrong just as well as the cheap ones so I've given up spending loads of money on wireless.
Bought my 2013 MBA and it was awful. Wouldn't stay connected to anything. Not my router, not when out and about, nothing. In the end I fixed it by buying an "OpenMedia" WiFi bridge. Not sure if links work or are allowed, but here: http://www.wifibridge.co.uk/
They're only something like £20 from eBay.
To get my issue resolved I attached that to one of my wired devics (Sky+ Box) which allowed me to get that box online wirelessly and free up a cable, but the device is also an extender. Furthermore, the new SSID that get's created when you extend, apart from having to be on the same channel number (13 for me) can have all different settings. So I set it to wireless N only (other was mixed due to game consoles, phones etc.) and WPA-2 AES only (again, previous was mixed). It also happened that my MBA was the only device connecting to this network. I believe I also set my MTU to 1452 which was the value set in my router minus 28.
My MBA then was set to only know about that SSID and those things solved my problem. All for £20. Completely solved. Obviously that doesn't solve anything for when I'm out and about so I was still on the lookout for a more general fix.
I didn't know about the July 18th update until now so I just installed that. I've created a new network location that has all default settings and have just switched back to my original SSID to see how it goes. So far it looks like the connectivity is solved but I will monitor it. I'm also out and about for a week from Thursday so I will know for sure by the time I'm back if it's finally solved.
None of my experiences have anything to do with speeds. I don't have any AC networks, nor am I interested in them (I have gigabit ethernet all over the house if i want speed). I bought my MBA because I wanted a new machine to replace the tablets I've had in the past and it just didn't make any sense to do anything other than wait for the new Haswell model that just so happens to come with AC wireless.
Hope some of that helps someone!
I installed the July 18th updated and, it kinda solved my problem.
My connection is not droping everey 1 minute, as before.
However, I ran the Wireless Monitor (Click on Wifi icon while wolding Option Key) and I can see on the Diagnostics that my connection is still droping every 1-2 minutes.
So, it seems that Apple have found a way to hide this matter from our normal use but, its still there. Very frustating and concerning.
I am still hoping for a definitive solution because here in Brazil its going to be very hard to have it exchanged for a brand new one...
If you sniff the Wireless Diagnostics traffic, it keeps pinging your LAN connection and if it notices 2 ping drops then it detects it as a drop. This does not mean that your WiFi is broken. Just means its a poor connection with some lossy traffic. You ideally would'nt know it unless you ran pings. I think its a good tool to use to improve your network but don't read too much into the drops as it just means a few packets were lost. This could probbaly be happening across all devices on your network and you are just unaware of it. My 2 cents...
Did you ever use your machine on outside public networks or on networks with basic WEP security? If not, I would suggest you test that to make sure your wifi works there too. Please ignore my response if you have done this already.
Your router could possibly have the WPA2 with latest firmware and that could be the reason why you haven't noticed the issue.
I have used it outside on a limited basis and not yet experienced a problem. At home I have not downloaded any new firmware and my router is about 1 1/2 years old but is set on WPA2. Work has recently installed new routers and I do not know what the firmware status is but assume it may be the latest since they were installed about six weeks ago.
Keeping my fingers crossed as I hate to see the issues that have been experienced by so many.
So, what you really recommend is to get on the phone with Apple support and spending time with them?
I recommend returning defective merchandise, increasing the pressure on Apple to fix this.
Apple should have solved this issue by now, or told evebody affected that "Yes, there is a problem, we will fix it!"
Sadly the have not done either.
But I'm glad your setup is working, lets hope it also works outside of your home.
Totally agreed with current point of view.
I returned my defective 2013 AIR 11'', and still use my old 2011 Air 11".
Very sadly to observe how people becomes a slave of the notebook.
User has to operate the machine, but for the time being machine order us to buy brand new routers, call support etc....
MAC, it just works?
I returned a defective mba (13", 4G, 256), and swapped it out for a new one. I downloaded the patch and things seem to be working well! I am running Wireless diagnostics and it has notified me that the signal has failed a couple of times (20, 40 min increments). It has re-connected automatically without me noticing while browsing (I only know it's dropped because of the diagnostics). Is this normal, or should it not disconnect at all? I travel a lot, so I have been testing on all different routers at coffee shops and at my office. I have like 10 days to return, it so I am wondering if a dropped wi-fi signal is normal if it just re-connects automatically?