Apple, kindly fix your Wi-Fi on iOS

Apple, kindly fix your Wi-Fi on iOS

Summary: The latest Wi-Fi routers use 40Mhz channels for best throughput on the 2.4Ghz band. Problem: iOS only supports 20Mhz.

Image: CBS Interactive/ZDNet

For the last couple of weeks, I have been testing the latest 802.11ac Wi-Fi equipment from several networking vendors, including routers and range extenders.

Many of these new routers are expensive, at least by home networking standards, as they retail in the $200 and above range.

However, the performance that can be extracted from them can be significant, especially if you have client devices that can communicate at native speeds, using both 2.4Ghz and 5Ghz networks simultaneously, such as a 802.11ac range extender/bridge device. 

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Although wireless gigabit speeds are possible with these new devices, you also have to take into consideration the speed of your broadband connection, the end-to-end capabilities of the devices on your LAN that are streaming to your clients, and of course, the distance from the Wi-Fi transceiver(s) to the endpoint, as well as any potential wall(s)/obstruction(s) and channel interference. 

Most Wi-Fi devices shipping today support 802.11n or at a bare minimum, 802.11g. 802.11n communicates over the 2.4Ghz and 5Ghz bands, whereas 802.11g, which is an older standard, uses the 2.4Ghz band exclusively.

The wireless performance of your Wi-Fi enabled device (and your router) is also going to depend on how many antennas it has and how many spatial streams it supports (MIMO).

802.11n "draft" devices began shipping in 2007, while second-generation 802.11n Wi-Fi routers have been shipping since 2009. The specification provides for either 20Mhz or 40Mhz channels. The 40Mhz channel width permits data transmission at approximately twice the rate of 20Mhz. 

Most, if not all Wi-Fi routers currently on the market, be it the residential gateway equipment your broadband provider installs on your premises, a 2.4Ghz budget model you pick up at Wal-Mart or the most expensive dual-band 802.11ac for high-definition video streaming and gaming applications that have multiple antennas are configured the same out of the box.

They are all set to "auto" for channel width and "mixed" or "hybrid" on both the 2.4Ghz and 5Ghz bands so that they attempt to negotiate with the client at the fastest data rate possible, and also provide the highest level of backward-compatibility.

Image: CBS Interactive/ZDNet

However, you can further optimize your 802.11n and 802.11ac performance if you set the network mode of 2.4Ghz and 5Ghz bands to "802.11n-only" and 40Mhz channel width rather than "mixed" and "auto", although that will render older 802.11g devices unable to connect, if you still have any of those lying around. I do not, so I set my networks up that way.

All the mobile platforms -- save for one -- will negotiate at the higher data rate on the 2.4Ghz frequency when the router is set to "802.11n-only" and 40Mhz channels. 

Take a wild guess which platform that is. I'll give you a hint, it's not Windows, Windows Phone, any version of Linux embedded into an IoT device or even Android.

In almost every single piece of router equipment I have tested for my own personal use or configured for friends and family, if you set the 2.4Ghz band set to "N-only" and at 40Mhz channel width, your iOS device will simply fail to connect to the wireless network.

I don't care who makes the router in question, whether it is Linksys, Netgear, Asus, D-Link or some other random Chinese or Taiwanese company. It is always the same result.

Apple's iOS, which runs on iPhone, iPad and Apple TV cannot connect reliably to a 2.4Ghz network with a 40Mhz channel, period. Their own documentation says so and it's not recommended for Mac OS X either.

In a large number of cases, I have actually had to force the 2.4Ghz network to 20Mhz channels, rather than use "auto" in order to make wireless networks work with iOS.

That degrades the data rate of any device communicating over that band, be it your nice new laptop you bought with the extended range, fast 802.11ac Wi-Fi built-in or your latest-generation Android or Windows Phone smartphone.

So that $200+ 802.11ac router you just bought? Yeah, not performing optimally now because you own an iPad Air or an iPhone 5s, or the latest-gen Apple TV.

Now, as a small consolation, iOS devices can communicate using both 20Mhz and 40Mhz channels on the 5Ghz band. So just use Apple devices on 5Ghz, right?

Well, no. The reason why dual-bands exist on 802.11n and 802.11ac is because 2.4Ghz and 5Ghz frequencies have different performance characteristics. 

The 2.4Ghz band, while subject to greater interference, has greater range than that of the 5Ghz band, although the bandwidth (data rate) of the 5Ghz band is approximately double that of 2.4Ghz band.

So if your priority is range rather than bandwidth, unless you live in a single bedroom apartment, with few interfering walls, you're kinda screwed if you decide to use the 5Ghz band exclusively with your iOS devices.

There's a workaround, which I ended up resorting to. You could buy a cheap access point for the iOS devices, setting it to 20Mhz on the 2.4Ghz band, with its own unique SSID and isolated to a specific channel number so you can identify it easily, while setting your nice expensive router to 802.11n-only with 40Mhz (and 80Mhz) channels on the respective bands.

Or, maybe Apple could just fix their Wi-Fi implementation.

Does Apple's stone-age Wi-Fi implementation throw you into fits of rage? Talk back and let me know.

Topics: Apple, Broadband, Networking


Jason Perlow, Sr. Technology Editor at ZDNet, is a technologist with over two decades of experience integrating large heterogeneous multi-vendor computing environments in Fortune 500 companies. Jason is currently a Partner Technology Strategist with Microsoft Corp. His expressed views do not necessarily represent those of his employer.

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  • So you get an 802.11ac router ...

    .... and expect 802.11n devices to run outside of normal spec???

    Here is a little basic education about signals: the for an N device to run in the 2.4Ghz band @ 40MHz channel it needs to have at least 82% of the band free for usage. The unlicensed 2.4Ghz band is HEAVILY used by hundreds of devices, meaning that the chances of having enough band free for usage is pretty much zero.

    The problem is not that that iOS doesn't support the option. The problem is that YOUR HOUSE doesn't support the option. Your home has so many devices running in the 2.4GHz band that the spectrum is saturated and the option will not work.

    But don't just trust my word for it. Feel free to Google it.

    It doesn't matter what device you have, if the band spectrum is saturated, there is NOTHING you can do to make it work outside of the 20MHz channel.
    • Jason must be holding his ipad wrong?

      Why does every other device he uses have no issues connecting to his routers at 40 MHz, except apple devices?


      I noticed that there was a disproportionate amount of mac users having issues connecting to high end routers while shopping on Amazon and reading the reviews. Macs had real connection issues with both models I was trying to decide between. Everything else seemed to work fine.
      • I think what the parent is saying is that

        while his other devices are connecting at 40, there is no performance increase because of the saturation issues.
        • You may be right but....

          You may be right but it's the principle of the matter.
          • You are missing the point.

            This was a deliberate decision by Apple to be a "good" citizen by not consuming too much of the frequency range and using 20 Mhz instead of 40Mhz in a high density urban environment. If you want to use 40 then use the 5Ghz band.

            Just because it does exist in the spec, it does not mean that you should necessarily use it if you want to be a considerate neighbour.
          • Frankly it takes choice out of the users hands

            As other have stated, what if you live in an area where wifi congestion is not an issue and you would benefit from the 40mhz range?

            Apple has made the decision to dumb the device down to the lower common denominator. Why?
          • Not about choice, it's about 802.11N draft vs final spec

            See my reply on page 3. This is actually a complicated situation with 802.11 draft vs final spec and while I love to hate Apple, I don't blame Apple in this situation.
          • choice

            I live in an actual house.. my neighbors are 15 meters away on one side and 10 meters away on the other side. I can see other networks on a wireless scan, but the signals are very very weak.. so I run 40 wide channels too.. the one iOS device wouldn't connect, so I sold it and it's now a new nexus 7.
          • The point is....

            This is another example of Apple taking the decision out of our hands... Why can't we decide whether we want to use the feature or not. It should be our choice. We did buy their product at an exorbitant price...
      • Nearest Neighbour 1.5 Km away

        So much for saturation
    • We accept

      Your apology on behalf of Apple. Still does not make sense as to why Apple does not connect to 40 MHz range. I am sure Apple was not thinking to the extent that the Apple apologists believe.
    • Not necessarily

      While my main argument is the same point everyone else is making - the principle of the matter; still, not everyone's house is saturated with 2.4GHz. I'm an IT Director - fully engrossed in the technical world with tons of electronics in my house. Ironically though, except for a few remote controls, I'm not using anything else wireless. I have no cordless phones, all my smart devices are connected via cable and wireless disabled; I do have a 2.4 baby monitor, but it's rarely used anymore, and I have no Bluetooth devices in my home. There may be some RF interference from the microwave used once per week, but I would venture to say there is more than 82% free and I still wouldn't have the option to disable 20MHz.

      Apple products are high-end, flagship devices. I know their primary argument on things is battery life, but they aren't blowing the doors off everyone else in that aspect. Overall, the 20MHz is fast enough in most cases, but still, why the limitation? I guess the profit margin on Apple devices is too low.
    • Connectivity is an issue all around

      For instance my RazrHD on Android 4.12 couldn't see any 5ghz bands. When I put on CM11 4.4, 5ghz worked fine even with the 4.12 radio firmware. Then I put the official 4.4 Moto firmware on and 5ghz disappeared again. After some hunting, it seems only certain channels are visible to the phone on Moto 4.4 (42,44,48 and maybe 52) Changing the router channel fixed 5ghz. Unfortunately Moto v4.4 has another bug. You can't use Bluetooth and 2.5ghz wifi simultaneously. The wifi stack hangs and you don't get internet until you disconnect from BT.
  • still the best quality

    Apple's product quality is still the BEST !!!
    • still the best quality but no longer leading the pack….

      There is now a noticeable gap between Android and iOS and it is not in Apples's favour.

      No I am not Apple bashing as I use their products from the iMac down to the iPhone but iOS in particular is well behind Android in terms of functionality hence I have not upgraded my iOS devices.

      Who would have thought 3 years ago Android would overtake iOS well I certainly wouldn't have. Furthermore iOS8 is bringing little in the way of new to the table.
      • Ditto

        I haven't been upgrading my iOS devices for the same reason. The yearly feature upgrades for the past few years have been minimal, at best. Apple needs to make a big improvement this year or their sales growth is going to disappear.
        • Apple IS making BIG Improvements in iOS 8.0.

          Bill, have you seen the changes coming in iOS8 and Yukon? Prepare to be impressed.

          I use Windows devices all day long and love them, but I also love my iPhone and with the new "Hand-Off" features coming in the next Apple releases, plus the ability to answer calls to my cell right through a MAC, I'm seriously considering a MacBook for Christmas. :)

          As for the article and iOS not using 40... Who cares? I have a Netgear Nighthawk running 2.4ghz and 5G. I connect all my iOS devices to the 5 and it works just fine.
          • MacBook Pro....

            The new MacBook Pros with retina display have dropped in price a little! I own the first MBP with Retina and have have NEVER owned a better laptop (and I have been in IT for the past 20+ years). @JeffLe73, you will LOVE the MBP. ;)
          • big whoop

            Will the iPhone with iOS 8 finally give you audible notifications that you missed a call? Will it reverse the pathetically defective UI changes that render the devices less useful than they were under iOS 6?

            Will Apple pull its head out of its ass and stop making devices needlessly thinner at the expense of battery life?
      • Re. still the best quality but no longer leading the pack...

        You're not Apple bashing - yet you make claims you can't substantiate. Hm.

        Tell us, pre tell, the us about some of those features that are available in Android but not in iPhones? Common, we're listening! Thought not.

        As a matter of fact, other than some minor customization capabilities (which iOS 8 will be addressing), Android is manifestly *inferior* to iOS. Unlike you, I will present a simple example: Apple Maps is available on iOS - but not on Android. Nope - you can't point to Google Maps as a vastly superior Android version - since that's ALSO AVAILABLE ON IOS. Apple's voice assistant is available on iOS - but not on Android. Please don't mention Google Now - since that's available on iOS too. The list goes on and on. There are a bunch of Apple proprietary apps and services that aren't available on Android - but the reverse is almost never true, since Google is quite happy to make its apps and services available on iOS.

        So I ask again: how is Android superior to iOS when most of Android is available as apps on iOS, yet the reverse is not true?