“Have you ever had to…”
This phrase sometimes precedes a story about a challenging or difficult experience. For internet users around the world, maybe this rings a bell: Have you ever had to turn off the Wi-Fi on your phone to prevent calls from dropping when leaving home?
It’s likely that many people reading here can relate to this scenario. Why is that?
It’s because mobile devices tend to stick to Wi-Fi (whether at home, in the office or elsewhere) for too long, often switching to cellular when it’s too late. This can lead to dropped voice calls and data connections that stall for 20 seconds or more. This “sticky” behavior has existed ever since mobile devices first integrated Wi-Fi and cellular radios.
The problem stems from a fundamental characteristic of mobile devices, which follow a “Wi-Fi first” approach. However, the problem is exacerbated by the lack of a standardized mechanism to seamlessly transition between Wi-Fi and cellular networks, which leaves users vulnerable to connectivity disruptions.
How Does This Impact the End User?
In today’s digital age, we rely heavily on mobile devices for everything — from video calls and streaming services to online work and social interactions. Yet, many users face a frustrating experience: When moving between cellular and Wi-Fi networks, their devices often struggles to maintain a stable connection, resulting in dropped calls, buffering videos or lost data sessions.
This lack of seamless connectivity not only disrupts user activities but also impacts perceptions of service quality, leading many to disable Wi-Fi altogether or switch to less efficient networks.
How Can We Improve the Experience?
Collaborating with member operators, CableLabs has been working to characterize the poor user experience that this problem creates and to understand how frequently it happens.
Our field testing included evaluating hundreds of video conference calls, testing video calling apps and making voice calls across devices from major manufacturers and operating systems. We assessed the user experience based on audio dropouts, video stutters and freezes, and dropped calls, and compiled the results.
Our members also analyzed hundreds of millions of Wi-Fi signal strength data points during times when phones transitioned from Wi-Fi to cellular networks. We even conducted surveys with actual customers to gather insights into their experience when leaving Wi-Fi coverage.
What Did We Find?
Long story short, the problem is real. It’s disruptive to users and occurs frequently. Our testing highlights the extent of this issue as summarized below.
- Most devices we tested experienced long periods (usually between 19 and 54 seconds) of bad audio, dropped audio and/or frozen video during calls.
- Standard voice-only calls had between 10 and 13 seconds of bad audio during the transition from Wi-Fi to cellular.
- From analysis of operator-provided Received Signal Strength Indicator (RSSI) data, the RSSI is low enough to likely cause issues with Wi-Fi voice calls 60 percent of the time when transitioning from Wi-Fi to cellular. When using other apps problems are likely to occur 40 percent of the time.
- About half of the surveyed users manually switch their mobile device between their home Wi-Fi and cellular at least once per week, with 44 percent of those users experiencing issues during the transition.
The consequence is clear: Without seamless network transitions, user experience suffers, reliability drops and dissatisfaction increases.
While standards development organizations have made some advancements, particularly for Wi-Fi calling, these solutions have not yet fully addressed the latency and disruption challenges during network transitions for other applications.
What’s Next?
This problem is multifaceted, given the diverse set of stakeholders involved — including device vendors, operating system (OS) vendors, chipset vendors, operators and application developers, each using their proprietary algorithms/KPIs to try to solve the sticky Wi-Fi problem. Switching to cellular as soon as Wi-Fi starts to degrade can improve the user experience to a certain extent, but it won’t fully solve the problem.
CableLabs is actively engaging with all the industry stakeholders in an attempt to align on a common, streamlined solution aimed at enhancing the user experience. This will ensure we can address the challenges users face today during network transitions in a consistent manner, regardless of a user’s access network or device.
We are also working with industry vendors and standards organizations (like Wi-Fi Alliance) to test and develop solutions for truly seamless connections that offer reliable and consistent experiences for users. If your company is a mobile device vendor and you would like to engage with CableLabs in this work, contact us to learn how we can collaborate to achieve seamless connectivity.
To read more about this and the CableLabs working group tackling this problem, read our recent blog post, “Unlocking the Power of Seamless Connectivity.”