The Future of Home Wi-Fi

Online media and OTT content are gaining in popularity and, as a result, many service providers are experiencing customer churn. Millions of Americans have already scrapped traditional pay-TV services and the exodus is accelerating in 2018. This year, the number of cord-cutters in the U.S. — consumers who have cancelled traditional pay-TV services and do not re-subscribe — will climb 32.8%, to 33 million adults, according to new estimates from research firm eMarketer.

That said, even as the traditional pay-TV universe shrinks, the number of viewers accessing OTT, Internet-delivered video services keeps growing. About 147.5 million people in the U.S. watch Netflix at least once per month, according to eMarketer’s July 2018 estimates. That’s followed by Amazon Prime Video (88.7 million), Hulu (55 million), HBO Now (17.1 million) and Dish’s Sling TV (6.8 million).

As pay-TV gives way to online subscription services, the need for a fast and reliable broadband Internet connection, supported by excellent Wi-Fi, become vital, as slow Internet with low capacity results in buffering that is unacceptable to subscribers.

According to Broadbandtrends, broadband speeds are also expected to rise dramatically, with 34 percent of subscribers receiving speeds of 100 Mbps or greater by 2022, up from 6 percent in 2016.  

Those faster pipes going to the home mean that consumers also expect their Wi-Fi to deliver similar throughput, all the way to their devices. Service providers will thus have to step up their Wi-Fi offerings accordingly using all the help they can get.

Help coming from Wi-Fi 6

With commercial products supporting Wi-Fi 6 (also known as 802.11ax) starting to enter the market, the new Wi-Fi standard is beginning its lifecycle at just the right time to enable the changing user demands on wireless networks. From the home consumer perspective, Wi-Fi 6 will provide a much-improved experience in dense environments characterized by the simultaneous connection of many devices. With the improved uplink capabilities and increased throughput, there will be much less competition among home users for airtime to send emails, post pictures to social media, and otherwise upload data.

The first improvement of Wi-Fi 6 is to provide additional spectral efficiency, that is using Wi-Fi bandwidth more effectively. This is accomplished with the introduction of ‘Orthogonal Frequency Division Multiple Access (OFDMA)’ a technique developed in the cellular world. OFDMA divides a channel into subcarriers called Resource Units that are dedicated to specific end users at the same time, as shown in the figure below.

This technique will enable multiple users with varying bandwidth needs to be served simultaneously in the home.

The realistic benefits of 802.11ax over 802.11ac

On March 2, 2016, the IEEE released the first draft specification of the 802.11ax WLAN standard, also known as High Efficiency WLAN (HEW) and recently rebranded as Wi-Fi 6 by the Wi-Fi Alliance. Wi-Fi 6 development was launched immediately after the 2013 release of the 802.11ac standard, with the aim to improve upon some of the limitations of 802.11ac for future WLANs. Specifically, Wi-Fi 6 aimed to improve spectrum efficiency and area throughput, as well as to enhance performance in high-density networks.

To achieve the aforementioned goals, Wi-Fi 6 offers several technical advantages over the preceding technologies. In addition to OFDMA, Wi-Fi 6 also operates over both the 2.4 GHz and 5 GHz bands, while 802.11ac only operates on the 5 GHz band. While both standards use quadrature amplitude modulation (QAM), 802.11ac uses 256 QAM, while Wi-Fi 6 uses 1024 QAM, meaning that the radio can achieve higher data rates. However, one caveat is that such modulation rates are impractical in real-world use and only possible when users are sitting next to the access point.

Finally, Wi-Fi 6 employs multi-user multiple-input multiple-output (MU-MIMO) for both uplink and downlink, while 802.11ac uses MU-MIMO for downlink only. Another caveat regarding MU-MIMO is that only few devices/clients support it, as, due to power and size limitations on client devices, adding more spatial streams is in fact impractical.

While MU-MIMO is potentially effective in high-density environments, it does nothing to enhance speed of an individual client device but increases the airtime available to each client.

Altogether, these improvements offer a 37% higher data rate than 802.11ac for a top theoretical speed of around 10 Gbps. As a reminder, data rate is the speed and not actual throughput. Aggregate throughput is usually 30-50% of data rate speed due to medium access methods and overhead.

The Wi-Fi 6 ecosystem

Several hardware providers have already released draft-compliant Wi-Fi 6 products, though these are currently in the draft specification phase. For instance, Quantenna, Qualcomm, and Broadcom have introduced Wi-Fi 6 chipsets. Chipset manufacturers have considerable influence on how new specifications are introduced in the market, as they provide drivers to the AP manufacturers to use the chipset functionality. In essence, every AP manufacturer uses the same “engine” to run its access points.

Changing wireless needs

Wi-Fi 6 is a necessary upgrade to successfully manage the growth of the Internet of Things (IoT), wherein many heretofore unconnected devices are being linked to Wi-Fi and other networks. Many commercial IoT products—such as smart thermostats, smart lighting, smart smoke detectors, and other smart home products—are already available and popular, and all these devices must regularly upload data. Users of these products will find Wi-Fi 6 much more suitable for managing these devices, as their own home networks will become increasingly denser. An additional benefit of Wi-Fi 6 for IoT devices is a feature called Target Wake Time (TWT), a concept originally developed for 802.11ah. TWT provides a way for client devices and wireless APs to coordinate the use of the network and to avoid contention for airtime. This feature ensures that client devices can save power and extend their battery life—which is a critical advantage for IoT devices.

Conclusion

The rise of online content coupled with the proliferation of connected devices in the home represents both an opportunity and a challenge to service providers to deliver on the promised broadband home experience. The need for a solid managed Wi-Fi system is no longer a luxury but a requirement for both service providers and their residential customers. While Wi-Fi 6 promises to ease the pain of competing for airtime, more innovation is needed to optimize resources for multicast and video usage, as we shall see in a future blog.