Internet of Things devices likely will be ubiquitous soon—in homes, offices, grocery stores, and hospitals—with many applications designed to improve our quality of life and make the services we use more efficient. But before the devices can be effectively implemented, their short battery life must be addressed.
It’s been estimated by the IEEE 802.11ba standards task group that half of Internet-connected sensors and devices will run on batteries by 2020—which is concerning because replacing batteries is costly. Putting them on sleep mode helps, but that lowers device performance.
That’s why the IEEE Standards Association (IEEE-SA) and the task force are working on a new standard for low-power radio receivers. The IEEE Wake-Up Radio technology could significantly increase battery life, from just a few hours to almost two years, and could allow some devices to remain accessible at all times without draining their battery.
Most smart devices connecting to the IoT rely on three radios: short-range Bluetooth, medium-range wireless local area network (WLAN or Wi-Fi), and longer-range cellular radio. Wi-Fi, which carries the lion’s share of digital data, has a reputation for consuming a lot of battery power.
Various amendments to IEEE 802.11 have called for transmitting data at lower power when appropriate. But such transmissions also lower data rates—which in turn necessitates longer transmissions and requires more power.
One solution for conserving power is to put the Wi-Fi radio in sleep mode. In this power-saving setting, the IEEE Wake-Up Radio wakes up every few milliseconds to see if a signal is trying to get through. The receiver listens for a signal that informs the device that information is being sent its way, and wakes up the Wi-Fi radio so that the data exchange can begin. An always-on 100-milliwatt Wi-Fi radio can drain a 3-volt 130-milliampere-hour battery in about four hours. By adding a second low-power IEEE Wake-Up Radio receiver, the battery life could be stretched to 694 days, according to the IEEE 802.11ba standards task group.
“IEEE Wake-Up Radio is an add-on to existing IEEE 802.11 radios that substantially improves power-saving performance of IEEE 802, removing the need to compromise between power savings and latency,” Senior Member Adrian Stephens, chair of the IEEE 802.11 working group, says in the news release. “This makes the technology suitable for a new class of battery-powered devices that will drive innovation and exciting new applications in the market.”
As engineers continue to streamline signal handling, consumers can look forward to thousand-fold increases in battery life and years of operation on a single charge, according to the report.
IEEE Wake-Up Radio will greatly reduce the need for frequent recharging or replacement of batteries while still maintaining optimal performance.
The report says that IoT devices that run over short-range wireless networks—like those used in transportation and logistics, health monitoring, and smart homes—will benefit the most from the new standard.