Why your event shouldn’t rely on hotel Wi-Fi

I work for a company that does mobile content delivery, typically to field sales teams. We ensure your folks are using content that’s current, pushed to them so they’re not hunting and pecking for it, and that it’s relevant to their role.

Frequently when we have a large company doing a kick-off of our app with their employees, they’ll want to get them all in one place for an initial training session. I’m here to tell you that this isn’t always the best idea because hotel Wi-Fi network are poor if you’re lucky – downright hostile if you’re not.

I have personally witnessed hotels from Hilton, Hyatt, Marriott, and Starwood all exhibiting horrendous Wi-Fi during events, even though they charge a crazy amount of money for event services. Frankly, it just makes your brand look awful when your Wi-Fi is atrocious.

Recently we did a deployment for a customer at a kick-off/training session. While it went better than other customer kick-offs, it still had issues that were squarely laid at the feet of awful hotel Wi-Fi networks.

We’re somewhat at the mercy of the underlying OS, iOS, for network services provided to our app. iOS is generally pretty good about gracefully degrading network service to apps, however there are situations when a combination of packet loss, re-transmission, being in a high-collision domain (such as hotel Wi-Fi), downloading data, and trying to utilize a lot of memory to display files combines into a Perfect Storm™ situation where the app bombs.

I’d like to give a bit of a Wi-Fi explainer as it’s the largest contributor to this problem. The easiest (and most simplified) way to explain how Wi-Fi works is that it’s one giant game of musical chairs, however there’s one chair no matter how many people are playing. A single device (Access Point or client) can only talk at once. Coupled with that, devices do not need to be on the same Wi-Fi network in order to be part of this game of Musical Chairs. They simply need to be on the same or overlapping operating frequencies in order to forcibly take part in this wretched game.

Have a look a “Good Wi-Fi” example:

This is the Wi-Fi situation at my house. I run two 2.4 Ghz SSIDs (Durmstrang for legacy Wi-Fi devices that cannot speak 5Ghz. Beauxbatons is my guest network with a route straight to the internet with no peer discovery. It’s in a separate IP space from everything else.) Over on the 5Ghz side of things, I run 1 SSID, Hogwarts. It’s on the same IP space as Durmstrang. Hogwarts is my production Wi-Fi SSID. Notice in each frequency range, I have 3 “humps” for each. This is because I have 3 Wi-Fi Access Points in my house. Each is set to service a separate frequency within 2.4 and 5Ghz ranges. This way, devices that are on each Access Point only have to play Musical Chairs with the other devices on that single frequency. I’ve also tuned my radios down so that a device isn’t trying to roam to another Access Point that’s further away than a closer Access Point.

Over on the 2.4Ghz range, note that there is a Netgear device and a Compex device. One on channel 11 and one on channel 1, respectively. They’re from my neighbors across the street. I’ve told them many times to tune them down – they doesn’t listen. Though devices are on totally separate networks, air is a collision domain. My devices on Durmstrang/Beauxbatons on channels 1 or 11 must wait their turn for devices that are across the street on the Netgear & Compex networks. Only my 2.4Ghz devices on Durmstrang/Beauxbatons channel 6 (the Access Point in my living room) wouldn’t be part of those games of Musical Chairs.

So, that’s what good Wi-Fi looks like. A client device should see 1 Access Point on each channel within a frequency range at a time, with Access Point radio power turned down so that devices roam properly from one Access Point to the next. Turning down Access Point radio power also prevents my networks from interferring with others beyond the area I wish to cover. I swear if everyone would just turn their radio power down, everyone’s Wi-Fi experience would improve greatly.

Now have a look at this “Bad Wi-Fi” example:

With our “Bad Wi-Fi” example, you can see the 2.4Ghz range is totally saturated. Lots of Access Points. There’s even someone on channel 2 on 2.4Ghz which means that due to the limited frequency spread of 2.4Ghz, he’s interfering with the channel 1 and channel 6 devices making everyone on both those channels wait for him and devices connected to him to get their turns. Jerk. Over on the 5Ghz range, there’s a few standing on top of each other at channel 36 and then a HUGE SWATH of unused frequencies until someone is on 165.

This is exactly what the Wi-Fi situation at the hotel looked like (in this particular case a Hyatt Regency), and unfortunately, it’s completely common. You’ll have crowded 2.4Ghz and completely unmanaged and underutilized 5Ghz. Basically, for training, we had a lot of devices on 2.4Ghz tripping all over themselves waiting for their turn to talk while being forced to listen to every Access Point in their frequency range because the hotel likely thought that “best Wi-Fi” equals “crank up the power.” Right? WRONG. By cranking up the radios to maximum, they’re creating interference and crowded airspace.

Thus, we see a lot of dropped packets, re-transmissions, and a network situation that is difficult to navigate, even for iOS. We’ve seen rollouts on Windows devices and it’s been even worse, believe it or not.

So, the moral of this tale: If customers really want to do a group rollout, beg and plead with them to do it in a Wi-Fi environment that they control. The only well engineered Wi-Fi that I have ever seen in a hotel is one that Apple built themselves specifically for the event they were hosting. (Apple does this as a matter of course because event space Wi-Fi is god awful.)

iOS is typically graceful in poor network conditions, but when an app is trying to really bang on the network stack, it’s downright hostile. Something has to give at that point, unfortunately.

With each iOS release, Apple’s network stack does improve. However what really should happen is that hotels need to get with the program and engineer Wi-Fi networks for when they’re under load. I’m guessing they didn’t plan their channel layout so that clients only saw one Access Point on a given channel at any time. I’m also guessing they never walked their hotel with a spectrum analyzer to see which Access Points should have their radios turned down so they’d prevent interference. These are fairly simple things to do, yet hotels don’t care about it. They’re doing themselves a disservice.

If I find a hotel with decent Wi-Fi under load, I’ll be sure to always recommend them for events if given the opportunity.