Wireless data exchange technologies are the core of wearable functionality. There are various systems in use, differing in their range, data transfer rates and power consumption.
Without the facility to exchange data, wearables could do only a fraction of what they are capable of today: fitness trackers, for example, send pulse rate, speed and distance data to an app on the wearer’s smartphone which works out an appropriate training plan. Smart glasses, on the other hand, show information from the Web about the tourist sight the wearer is currently viewing.
The semiconductor industry offers special chips incorporating the relevant communication modules. A distinction can be made between two basic philosophies when it comes to data transfer: the device communicates with a smartphone or tablet, providing it with indirect access to the Internet; or it has its own Wi-Fi interface to connect directly.
Bluetooth the most successful technology
Many wearables use a smartphone or tablet as their initial direct communication partner. They then use near-field wireless communication technology to exchange data. According to market research organisation IHS Technology, Bluetooth Smart – also known as Bluetooth Low Energy – is the most successful such system because it is compatible with Apple iOS, Google Android, Windows, and the Blackberry operating system. And it consumes very little power: as opposed to a 1 watt reference value for conventional Bluetooth, there are Bluetooth Smart profiles with power consumption of just 0.01 watts. The downside is that its range is only about 10 metres. The Bluetooth Special Interest Group has announced a comprehensive update for 2016, however. New features it is set to deliver include longer range and faster data transfer. Mark Powell, Executive Director at Bluetooth SIG: “Bluetooth has been adopted by countless developers and manufacturers as their connectivity solution of choice for the IoT. The new functionality we will soon be adding will further solidify Bluetooth as the backbone of IoT technology.”
New ultra-energy-saving Wi-Fi technology
When equipped with their own Wi-Fi module, wearables can communicate directly with the Internet without using a smartphone. But Wi-Fi chips currently consume a lot of power, so the wearables fitted with them have to be charged frequently. To address the issue, NASA’s Jet Propulsion Laboratory has been developing a new Wi-Fi technology over the last two years which reflects existing signals instead of generating them internally. This new technology allows wearables such as Google Glass to send data to a computer or smartphone using just one 10,000th of the power needed by other systems. So far, the researchers have been able to transmit at rates up to 330 megabits per second over a distance of 2.5 metres. That is about three times current Wi-Fi data transfer rates, consuming just a thousandth of the power of a conventional Wi-Fi link. “You can send a video in a couple of seconds, but you don’t consume the energy of the wearable device. The transmitter externally is expanding energy – not the watch or other wearable,” Chang said.
(Picture credits: Fotolia: vege)