Striking the right balance for wearables success

Moore’s law has been driving down the price and driving up the performance of semiconductors for more than half a century. Over the last few years though, this exponential improvement trend has driven the technology to a tipping point, at which it has become possible to build complete systems on a chip, often including entire radio systems, sensor interfaces and more, on relatively low cost silicon.

Social trends are making the public much more interested in monitoring their own health, while our increasingly sophisticated leisure pursuits mean we find it attractive to map our runs, count our laps in the swimming pool, track the distance of our treks, and then compare our performance with others.

The third factor has been the rise of the smartphone ecosystem, which has enabled wearable technologies to be controlled from smartphone apps rather than having to include complex and costly physical user interfaces. Smartphones have also taken on the role of personal area network hubs, connecting devices with each other as well as acting as backhaul to cloud-based servers.

Of course, the uptake of wearable technology brings new opportunities and challenges.

For wearable devices, smaller is usually better, and so the pressure to miniaturise is constant. Moore’s law is taking care of this, to some extent, but the increasing sophistication of some wearable technologies demands increasing processing power - which in turn increases energy consumption. Keeping power consumption in check is particularly important in wearable technology, because of the need for long operating lives between battery charges and, in some applications, highly reliable operation even in low battery situations.

Take medical applications. Keeping track of an older person’s vital signs, exercise habits, sleep patterns and so on can provide doctors, carers and family with a shared record of a loved one’s health and wellness in ways that have not previously been possible. In addition the growing use of consumer baby monitoring systems that can monitor an infant’s heart and oxygen rates and trigger alarms if anything seems abnormal.

Wearable technology developers are already having to strike a balance between the cost, capability and consumption of the sensing and processing systems they are developing. They also need to integrate reliable connectivity, to link their wearables to analysis, reporting and back-up services.

In many cases these connections are being brokered through a Bluetooth link to a mobile data connection enabled by a smartphone. Bluetooth Smart 4.0/4.1 technology provides such a link, so that wearables can communicate with consumer devices and other Bluetooth Smart compatible applications.

The introduction of Bluetooth Smart 4.2 is meant to service the need for streamlined functionality and connectivity. Security support is also becoming increasingly important, as health authorities and national regulators demand much stronger protection for what is, in the case of health monitoring wearables and apps, some of the most sensitive data that can exist about a person.

Just to keep wearable designers on their toes, the Bluetooth Special Interest Group has announced Bluetooth 5, a further update to the well-worn standard that should deliver greater range and speed, as well as enabling broadcast messaging. This will be useful for connecting and coordinating small groups of on-body wearables.

More complex wearable devices - think, perhaps, of advanced health monitors to be worn for 24- or 48-hour periods in a hospital or clinic setting – may need more extensive wireless communication capabilities. The latest version of WiFi, the 11ac technology standard, may be applicable to such medical applications that need high throughputs. The 11ac upgrade to the standard brings Ethernet speeds to wireless, enabling high throughput at very low power levels. This feature makes it well suited to the wearable market, since transmissions can happen at high speeds in short bursts, enabling the wearable device to return quickly to a low power sleep mode.

We expect that the market for wearables will be driven over the next few years by devices such as activity trackers, smartwatches and smart clothing in applications ranging from industrial settings and tourism to healthcare. Manufacturers who want to thrive in this evolving market will need to balance their choice of product features and battery life with leading edge processor, sensor and wireless connectivity that is enabling this dynamic new market.