Adaptability is power: Battery life and Wi-Fi

Posted on July 10, 2015

Battery life is one of the great limiting factors in the evolution of the smartphone, with advances in battery technology lagging behind improvements in other key areas such as screens, processors, and radios.

As these other components improve — and as the apps and operating systems they underpin increase in number, functionality, and activity — the demand for power increases.

So, while the battery life of a trusty Nokia 3310 was expressed in terms of days, most smartphone users now feel gratified if they can get enough hours from a single charge to last them from the time they leave home in the morning to the time they return in the evening. As users we have changed our behavior accordingly; everyone now carries their charger, or a spare battery (for devices that allow it), or a charging pack they can use when they’re not near a power point.

Our arms may feel the strain as much as our battery but adaptability is what sustains life, in smartphones as in nature!

Wi-Fi radios come in for a lot of stick in terms of smartphone battery life — not without good reason. If a Wi-Fi radio is on all day it will act as its nature dictates; constantly seeking opportunities to connect, and sucking up the battery as it does so.

In a recent article heralding the arrival of the Wi-Fi First operator model in the UK with the imminent launch of FreedomPop, the Economist made the following observation in relation to existing Wi-Fi First operations in the US:

“Subscribers need to keep their handsets’ Wi-Fi connections permanently switched on, which is a drain on the devices’ batteries.” This, the author wrote, was one of several drawbacks that could make Wi-Fi First a “tough sell”.

Wi-Fi radio behaviour is of particular importance to any Wi-Fi First operation, but the impact of Wi-Fi on battery life is clear on every smartphone, whatever the network or service to which it’s attached. As a result many users will often manually disable Wi-Fi under certain circumstances in a bid to wring a precious few hours’ more from their device.

The searching nature of the Wi-Fi radio is, in some ways, at odds with the needs of the device user. But disabling Wi-Fi creates a sub-optimal experience. When properly connected over Wi-Fi, smartphones consume less power than they do when accessing data over the cellular network (thanks largely to the user’s proximity to the signal). Moreover, if a user forgets they’ve switched their Wi-Fi off, they may well be sitting at home or in the office consuming mobile data (and more power) when they could be more optimally connected — in terms of cost, performance, and battery life — over their Wi-Fi network.

Sometimes nature needs a little help — and, as always, adaptability is the key. One neat feature of the Devicesape client software is its management of the Wi-Fi Radio. The software keeps the device’s Wi-Fi radio switched off unless it knows there is a good chance of a good quality Wi-Fi connection being made. The software uses a number of circumstantial triggers, some of which are location-based, to wake up the Wi-Fi radio and look for a connection. If it gets one, great; if it doesn’t, the radio is set back into sleep mode. (We won’t, however, override the user’s choice if they manually activate their Wi-Fi radio).

This feature has a dramatic impact on the quality of connectivity end users with Devicescape-enabled smartphones enjoy. And it quite literally puts more power in their hands.