An End to ‘Wi-Fi Purgatory’ Is In Sight

on May 16, 2019
Reading Time: 3 minutes

Little has been written or publicly discussed about one of the most vexing consumer frustrations in wireless. I call it ‘Wi-Fi Purgatory’. It’s what happens when your phone hangs on to or attaches to Wi-Fi even when the signal is poor, and doesn’t ‘switch’ over to to a good cellular signal, which results in a very slow or non-existent connection. The phone just stays stuck on Wi-Fi, rendering it useless for data and voice connectivity. Even worse, battery drain accelerates as the phone strives to connect. The only solution seems to be to manually disable the Wi-Fi connection in order to be able to use the cellular network. And of course, this means the user also has to remember to re-enable Wi-Fi the next time they’re in the home or office.

This Wi-Fi Purgatory issue seems to be more prevalent among iPhone owners than Android users. And one of the big culprits is ‘Cable Wi-Fi’ — the millions of Xfinity/Spectrum/Cox hotspots that are not only in the home but spread around all sorts of indoor and outdoor locations. The cable companies have known about this company for years and have done very little about it.

The main cause of the issue is that the current Wi-Fi architecture uses a scheme called ‘listen before talk’, which leads to inefficiencies and latency when moving from access point (AP) to AP, or between LTE and Wi-Fi. The phone sort of ‘half connects’ to the network, resulting in this ‘purgatory’ issue, which to the user looks like hanging on to a bad AP or not properly switching to cellular.

There is potential for this problem to get even worse, with the proliferation of small cells, rollout of 5G in the mmWave bands, and new 802.11ax (Wi-Fi 6) APs that will have even greater range. In theory, it will be even more challenging for a mobile device to distinguish between licensed and unlicensed services as the distinction between Wi-Fi and cellular narrows. After all, mmWave is more like a “super hot-spot” from the outside in, while more sophisticated APs and services such as CBRS have many of the same characteristics, but from the inside out.

Fortunately, there is help on the way. The architecture of Wi-Fi 6, which is scheduled to be rolled out over the next year (see my piece in Fierce Wireless on Wi-Fi evolution), uses the same MAC and physical layer as wireless. There is also a feature called deterministic scheduling, which allows the radio to be used on a particular schedule, rather than a randomized schedule, which is used by previous generations of Wi-Fi. 3GPP-based cellular technologies are also deterministic, which means that Wi-Fi and cellular will be more harmonized. Scheduled, rather randomized access also allows for lower latency and a greater density of devices. This combination of capabilities and improvements should help with the ‘purgatory’ issue.

Industry also needs to play a role here. One way they can do so is to embrace approaches such as Passpoint, which is an industry solution to streamline network access in Wi-Fi hotspots and eliminate the need for users to find and authenticate a network each time they connect. Another key feature of Passpoint is that service providers can set policies that optimize whether users connect to Wi-Fi or LTE/5G. Passpoint has been around since 2012, but it has gained renewed momentum lately, for example being part of AT&T’s recent agreement with Boingo.

Three things need to happen in order for there to be visible progress on this issue. First, we need a critical mass of Wi-Fi 6 infrastructure and CPE to be deployed, which will take a couple of years. Second, more service providers — across the cellular, cable, and Wi-Fi ecosystem — need to adopt industry solutions such as Passpoint and other aspects of Hotspot 2.0. Third, we need both hardware and software upgrades at more venues, such as airports. Cable companies, which operate tens of millions of hotspots between them, need to upgrade their ‘Cable Wi-Fi’ infrastructure, and also, simply, pay some attention to this issue.

There’s also work required in the iOS and Android camps, both natively on devices and in software. I haven’t seen a lot of tuning or adjustments with regard to the order in which SSIDs are prioritized on devices. With all the improvements coming down the pike, the ‘old order’ of how this was done will require a re-look.

We’re at a fork in the road on this Wi-Fi Purgatory issue. With the narrowing of the delta between fixed and wireless networks, and between licensed and unlicensed, complexity will only increase. Which means things could get worse. Fortunately, key vendors and organizations such as the Wi-Fi Alliance have been developing solutions to address the issue. Service providers, device OEMs, and venue owners must also do their part.