The Limitations of Bluetooth LE with Battery Drain and Accuracy
A recent study by Aislelabs, an analytics and solutions provider, which found that iBeacon (Bluetooth LE) battery drain on the iPhone is worse than on Android (and somewhat inconsistent in that sense), illustrated another limitation with Bluetooth LE technology. While many have been quick to crown Bluetooth LE the champion of indoor location technologies (given Apple’s support with iBeacon), there are limitations.
Although the buzz for Bluetooth LE has been around indoor location, that’s not really what the technology was initially designed for. Its primary use case is around connecting things - think about putting a beacon in your luggage at the airport and receiving a notification when your bag pops into the baggage carousel. Or perhaps its biggest use case to date – connecting smart watches and fitness devices.
These types of short usage cases don’t put the battery drain on devices, which could occur in more active indoor location engagements. AisleLabs test found that the Nexus 5 was more energy efficient using Bluetooth LE than the iPhone 5 in sample situations. Furthermore, other tests have shown that smartphones near Bluetooth LE beacons have been prone to toggle between multiple beacons unless an app is coded to listen for a particular one.
Other iBeacon software glitches can cause it to get overloaded in testing scenarios, resulting in a phone’s location services turning on and off. This could make your smartphone think you are reentering a store and reactivate a welcome message long after you’ve arrived. With little quirks like these still prevalent within indoor location 1.0, there’s a long way to go before iBeacon and Bluetooth LE will be able to handle much more complex functionalities that will accompany indoor location 2.0.
When you approach a Bluetooth LE beacon, the recognizing response usually happens pretty quickly, and you’ll see a message on your phone in seconds. However, iBeacon is also sometimes slow to calculate when you’re moving away from a certain iBeacon area. This means that even when you receive a welcome message instantly upon entering a store, you may pass an entire isle before you get a ping with the right offer for that location. This delay in sensitive response time remains to be fixed if iBeacon and Bluetooth LE is going to fulfill its promise of being real-time, location sensitive within feet of an object.
Overall accuracy is also a limitation of Bluetooth LE when you’re not using with a complementary technology like Visible Light Communication (VLC). Experiments and pilots with Bluetooth LE beacons have found inconsistencies with accuracy and issues with location dropout. In addition to changes in accuracy based on distance. Those same experiments have also found that how a Bluetooth LE beacon is placed (facing certain direction) results in different accuracy levels.
Of course, Bluetooth LE isn’t the only technology in the indoor location market to have limitations. Wi-fi, non-hardware solutions and even VLC have limitations as well. But it’s important to know what they are to pair with complementary technologies for the best user experience in-store.