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Tom Allebrandi

Tom Allebrandi Bio

In Part I and Part II of our story I retold “Goldilocks and the Three Bears” and discussed the reasons why High Speed Bluetooth® technology will be “just right”. Now, we’ll take a look at Bluetooth low energy.

Just as in High Speed Bluetooth, the low energy initiative is driven by applications. The difference however is that the applications will be mostly new applications where Bluetooth technology has not gone before.

Industries such as manufacturing, home and building automation, personal health devices, and others are evolving into a need for low cost, low power wireless solutions. Consider the following:

• On the manufacturing floor there may be a need for a sensor in a place that is hazardous or very inconvenient to reach. In this scenario, the wire leading from the sensor back to a data collection system may make the use of a sensing device impractical.

A wireless sensor would remove that restriction, opening up new opportunities for better control of the manufacturing process.

• Modern office buildings are constantly being reconfigured. Walls and doors get moved around. This becomes an expensive process, not only from moving the physical parts, but from relocating things like light switches and thermostats – resulting in costly rewiring. Being able to move light switches and thermostats without having to move wiring, makes for very convenient and efficient building management.

A wireless light switch or thermostat could simply be placed where it is needed.

• “Smart” shoes that measure the impact of the foot hitting the ground and other abnormalities in walking and running could provide a wealth of information to doctors diagnosing foot, leg, and back pain. Installing sensors in a shoe is not difficult; running the wires from the sensors to a data collection device is another matter.

Once again, a wireless sensor seems to be the solution.

Devices such as those just mentioned have a number of requirements. They need to be reasonably low cost, and generally small and lightweight. The latter requirements impact the battery that powers the device. A lightweight sensor in your shoe should not be powered by a collection of large batteries. The batteries need to be small as well, something on the order of the small (and often slim) batteries used in watches, hearing aids, and other personal devices.

Another requirement for such devices is that the batteries should be expected to last for a reasonably long time. You don’t want to have to change the batteries in your “smart” shoe every day. Or, change the battery in your wireless light switch more than about once a year. Or, change the battery in the hazardous manufacturing location any more often than necessary.

Traditional Bluetooth (aka BR/EDR) does a good job providing power saving capabilities. The design goal, however, is often to make use of the power saving features so that the device containing Bluetooth technology doesn’t need to be recharged as often. For the applications above, needing to recharge the battery is as bad as needing to change it.

So, a new approach to wireless communication that uses as little power as possible is called for. That’s where Bluetooth low energy comes in.

Bluetooth low energy is being designed to address the need for long battery life, while at the same time operating in a manner that is compatible with traditional Bluetooth tecnology. The latter ensures that both BR/EDR and low energy can peacefully coexist, and very importantly, share the same electronics.

Sharing the electronics means that manufacturers building Bluetooth enabled devices will be able to use one radio “chip” for both BR/EDR and low energy, instead of two “chips” – one for each type of operation. This will result in lower manufacturing costs and even greater power savings.

Your “smart” shoe will have a small, low power sensor that uses Bluetooth low energy to communication with a data collection device.

You mobile phone will have a combination Bluetooth BR/EDR/low energy radio “chip” that allows it to communicate with your shoe and act as the data collector. At the same time, that single “chip” will be providing the application services that have made Bluetooth applications popular. Adding High Speed Bluetooth to your mobile phone enhances these capabilities by providing a fast “data pipe” that can be used to quickly move the information collected from your shoe to the diagnostic equipment in your doctor’s office.

 Traditional (BR/EDR) Bluetooth: “Just right”
 High Speed Bluetooth: “Just right”
 Bluetooth low energy: “Just right”

As you can see, our story of “Goldilocks and the three Bluetooths” will clearly have a happy ending for our friend Goldilocks, and for us as well.