Every day, all across the world, people experience the same frustrating glitch with their mobile devices—one that cripples them until they move beyond the range of the offending Wi-Fi hotspot, or they switch off Wi-Fi on their phones.
It’s a problem I call “sticky Wi-Fi”: Our mobile devices are reaching for Wi-Fi hotspots they can “see” but can’t really connect to, while ignoring cell towers all around. The result is that our always-on cloud-connected devices suddenly aren’t. Apps hang, maps blank, downloads stall, calls drop, messages fail, irritation ensues.
It happens when we’re pulling out of our driveway, passing a store we’ve visited before, nearing a home with the same cable provider or even boarding an airplane.
And it’s likely to continue as long as mobile internet providers and handset makers push us to use Wi-Fi to fulfill our ever-increasing need for bandwidth. As much as 80% of existing traffic on mobile devices is already carried over Wi-Fi, according to Michael Calabrese, a wireless expert at the nonpartisan think tank New America.
Even the most basic function of our cellphones—making a call—is being pushed onto Wi-Fi. Both iPhones and Android devices include a setting that enables calls to be routed over Wi-Fi, which is a boon where cell service is limited inside buildings, but a problem when you walk out the door and your phone fails to hand off the call to the cellular network.
Solutions are available, but one reason they’re not more widespread is misaligned incentives: They require tech giants like Apple and Google to invest in new systems—perhaps even redesign how our data moves around the internet—and they’re not necessarily in a position to profit from that.
How we got here
The problem is rooted in the fundamental nature of Wi-Fi and the internet, says Tony Werner, president of technology at
The Wi-Fi standard’s design assumes the device trying to connect to a hotspot is something like a laptop, with a relatively large antenna and enough energy to power it.
With their smaller, relatively low-power antennas, our phones are stuck in a bind: They can “see” the Wi-Fi beacon, but they don’t have the oomph to communicate with it. While your phone may show a bar or two of Wi-Fi connection, “the bearer traffic cannot quite reach it,” says Mr. Werner. The technical name for this phenomenon is “beacon overreach.”
The problem is compounded by networks that are on but not always available: the hotel network that requires a guest login, the airplane network that connects to its service at 10,000 feet. Devices can connect, but there might not be any internet there.
Every time your device jumps from one network to another, there’s a cost in lost time and interrupted service. On the internet, connections between your device and the various servers it talks to at any given time are brittle—the two have a single dedicated channel. If the connection is severed, it can’t just pick up where it left off, but must re-establish the connection once your device is back online. Any switch from a usable network to an unusable one, in other words, is a possible dropped call or stalled download.
Comcast has blanketed the areas it serves with its own customers’ Wi-Fi routers. By default, they’re visible and open—and any other Comcast customers can use them free, if they’re logged in. As I can attest, my phone often locks onto them while I’m driving, leading to occasional interruptions.
The immediate fix
Comcast is trying to solve this problem by lowering the power of its Wi-Fi hotspot beacons, Mr. Werner says, making it so that phones see them only when they can communicate with them. That rollout is still in progress and the company is being cautious so as not to degrade customers’ service.
Various Android phone makers have also tried to solve the sticky Wi-Fi problem at the device level, by offering optional settings that make a phone quicker to switch to a phone’s cellular connection when Wi-Fi appears weak.
Since the introduction of iOS 9 in 2015, Apple has offered Wi-Fi Assist. The feature switches the iOS device to cellular anytime it detects a supposedly poor Wi-Fi connection. It’s on by default but, as nearly any iPhone user can tell you, it doesn’t seem to have solved the problem.
One of the reasons device-level solutions to the sticky Wi-Fi problem don’t seem to work is that devices are satisfied if they find a Wi-Fi router’s beacon signal. They’re not actively checking if the router is able to provide an internet connection, says Fraser Stirling, a senior vice president at Comcast whose team is responsible for Wi-Fi routers. His team’s evaluation of networkwide device performance is one reason the company decided to alter its devices to solve the sticky Wi-Fi problem.
The Wi-Fi Alliance, an industry group that maintains the Wi-Fi standard, created a different solution called Wi-Fi Vantage. In theory, it can do everything from handing off your device from one Wi-Fi network to another to keeping your device on cellular when the Wi-Fi connection isn’t good.
However, the technology requires that device makers and service providers adopt it. It’s entirely optional and not part of any of the current or future Wi-Fi standards, says Kevin Robinson, the Alliance’s vice president of marketing. It’s not clear why Wi-Fi Vantage hasn’t been more widely adopted, other than a collective failure to recognize the problems it could solve.
Since integrated software fixes don’t seem to go far enough, some developers have experimented with a slightly more nuclear option.
A startup called Connectify built a service, Speedify, that tests—sometimes multiple times a second—whether a device’s connection to an existing or just-joined Wi-Fi network actually works. If it doesn’t, the service switches to the cellular connection. The reason Speedify isn’t for everybody is that it requires users to connect through a virtual private network, or VPN. That means traffic going to and from a user device is routed through the company’s servers.
The VPN allows the service to be an intermediary between your device and all the ways it connects to the internet, whether it’s Wi-Fi or cellular, says Connectify Chief Executive Alex Gizis.
But VPNs can have many issues, from speed to security. Naturally, Mr. Gizis says Connectify doesn’t spy on its customers. The biggest issue with the VPN solution is scalability. “I suspect Apple doesn’t want to have hundreds of thousands of servers around the web to do [this],” he adds.
Google also built a VPN system much like this one, and it’s rolling it out to customers of its Google Fi wireless service. Since Google Fi is designed to run on multiple networks that Google has contracted with—not just Wi-Fi but also cellular networks from T-Mobile, Sprint, and U.S. Cellular—it makes sense that the company would want some way to smooth out the handoffs.
Just don’t look to the coming 5G wireless rollout to make the problem go away. Unlike 3G and 4G, which were specific cellular-network upgrades, 5G is a patchwork of improvements to the network infrastructure. In fact, one early piece of the 5G strategy is even more Wi-Fi.
Write to Christopher Mims at email@example.com