iPhone 5 Probes the Right Way, Too

Quiet when standing still; active when moving.  That is the way that WiFi devices should treat Probe Requests.  Android devices (at least, Android devices that act like yours truly's Samsung Galaxy Tab 2) probe the right way.  After doing a quick test on the iPhone 5, it appears that Apple has their devices probe based on movement as well.

 Apple iOS devices have a terrible reputation in some WiFi circles.  The author has heard complaints about mobility, stickiness, throughput capabilities and just about anything else under the sun.  Heck, just today an article was published decrying the throughput (WHO CARES?) limitations of of the new MacBook Air (not iOS, but still Apple) was viral'd around the web.

To check to see if the iPhone 5 matches the probing behavior of an Andoid device, I associated the iPhone to the office network on channel 36/+1 and started a capture on channel 44/+1.  Then I got up from my chair and started walking around while continuing to use the iPhone.

The results were this:


Notice that the Probe Request frames started coming out immediately when my phone began moving, but then stopped less than one second later.  Most likely what happened was that when I got up from the desk, the iPhone sensed movement and began probing for the next highest 40 MHz channel.  Then the phone probably went from channel to channel as it continued to probe.  All the while the phone continued to stay on channel 36/+1 as much as possible in order to keep communication with the network.

Of course it is hard to draw firm conclusions from a few minutes worth of Wireshark captures, but to these eyes it appears that Apple may be taking steps to get iOS devices in the good graces of WiFi admins and other professionals.  

Comments

  1. NetMinderAugust 26, 2013 at 8:28 PM

    Hey Ben I do think Apple is working hard to be one of the best at Wi-Fi. IOS has support for 802.11k & 802.11r Does Samsung range of mobile device support these standards? Curious?

    ReplyDelete
  2. Ben MillerAugust 30, 2013 at 2:28 PM

    Not sure if Samsung does, but it wouldn't surprise me.

    ReplyDelete

Post a Comment

Popular posts from this blog

Chips, Glorious Wi-Fi 6E Chips!

Qualcomm, owners of the Atheros line of Wi-Fi radios, recently announced the availability of Wi-Fi 6E chips. Game onnnnnnn! 6 GHz Wi-Fi is here. Sort of... Qualcomm is selling Wi-Fi 6E (802.11ax w/ 6 GHz support) chips, but we don't yet know when enterprise-grade APs and mobile devices will begin supporting 6 GHz Wi-Fi. Chip-to-product timelines can vary. Wi-Fi 5 (802.11ac) saw enterprise WLAN vendors sell products only a few months after chip announcements. Wi-Fi 6 (802.11ax) saw the big vendors wait a year or more before introducing new AP models. A ton of concerns factor into a vendor's decision on when to develop, manufacture and market new AP technology. Vendors with small market share may be extra eager. Aerohive tried to boost their enterprise Wi-Fi profile by being a leader in Wi-Fi 6. On the other hand, some vendors' enthusiasm for new Wi-Fi hardware may be dulled by competing organizational initiatives. Aruba/HPE, for example, was veering f
Read more

Five Facts About 6 GHz Wi-Fi

Image
Two pieces of important news hit the wire recently: the 6 GHz band was approved for Wi-Fi, and alcohol sales have skyrocketed .  Combine the two, and what do we get? A five-pack of Coors Light Cold Hard Facts about Wi-Fi in the 6 GHz frequency band. Editor's note: This is a relatively long post, but 6 GHz Wi-Fi is an undoubtably robust topic. If you have questions after reading this blog, comment below or contact Ben via email or Twitter using the information below, and Sniff Wi-Fi will address those answers in a future post. We may be knee-deep in a global pandemic, but that doesn't mean your humble blogger can't brew up a post on the topic of 6 GHz Wi-Fi. Wi-Fi professionals will soon have unlicensed frequency available in the 6 GHz band. Here, then, are five facts to know about Wi-Fi in the soon-to-be-available 6 GHz frequency band. Fact #1: The 6 GHz band adds 1,200 MHz of spectrum for Wi-Fi The Federal Communications Commission (FCC) is the federal
Read more

Go To Sleep, Go To Sleep, Go To Sleep Little iPhone

Image
In some circles, Apple Wi-Fi devices are knows to have problems with lost connections.  iPhones and iPads will unexpectedly miss incoming calls, have delays in receiving push notifications and even be forced to reauthenticate. There is a solution to Apple devices' connection problems, and as with most "device problems", the fix resides on the infrastructure.  The DTIM setting needs to be increased.  ( Apple recommends a setting of 3 or higher .)  Here's why: Some Apple Wi-Fi connection problems stem from Apple iOS devices' use of 802.11 power management.  To understand what Apple devices are doing with power management, one must first understand how 802.11 power management works. Let's start with unicast data.  The 802.11 standard allows devices' Wi-Fi radios to enter the Doze state in order to conserve battery life.  Wi-Fi radios in the Doze state are unable to receive data from the AP, so APs buffer all unicast data that has a destination MAC addr
Read more