The new enhancement to the popular wireless technology allows devices to operate for months or years on batteries as small as a coin or button We all know and use Bluetooth. But the popular technology has evolved a lot and the latest enhancement is Bluetooth Low Energy that runs, as the name suggests, on ultra low power.Previous evolution of Bluetooth was mostly targeted towards adding more features and enhancing data rates. But this enhancement actually decreases the power consumption and allows devices to operate for months or years on batteries as small as a coin or button.
Speaking at a webinar, Naresh Gupta, vice president,Nucleus Software Exports and author of Inside Bluetooth Low Energy,explains how this new Bluetooth differs from other communication technologies and why it has the potential to change the wireless industry.
Bluetooth v/s Near Field Communication
One side are Global Positioning Systems and satellite communications
that work across thousands of kilometres and on the other side are
ultra wide bands that provide data rates of gigabytes per second. Then
there is Near Field Communication (NFC) that provides very low data
rates and works on very low distances (nearly 1 cm). Bluetooth Low
Energy sits somewhere in-between. It provides bigger distances
compared to NFC so the range could be 30 metres to 100 metres even
as it provides low data rates. So typically, the data rates of Bluetooth
Low Energy are lesser. They are in the range of a few kilobytes per
second though theoretically, this technology can go up to maximum of
305 kilobytes per second.
Bluetooth Low Energy terminologies
Dual mode and single mode: Single mode devices are ultra low power
energy devices such as watches, key or health equipments. These
devices are sensors that collect information and send that information
to another device.
For example, the second device could be a mobile phone. The phone classic Bluetooth devices. So, classic Bluetooth devices could be
keyboards, mouse, printers and headsets that people have already been
using. So without disturbing the practicality of existing devices, dual
mode devices are able to talk to the new low energy devices.
Bluetooth SMART and Bluetooth SMART READY:
A Bluetooth Smart
device gathers information and sends it to Bluetooth Smart Ready
device. This device may either process the information (for example a
mobile phone may display the heart rate on the screen itself) or relay
the information for further processing (the heart rate may be sent to a
doctor who may be in the remote part of world processing that
information over the internet). So this whole ecosystem is allowing very
small devices to gather information and then transmit it into any part of
the world.
Key features
Ultra low power:
A device like a heart rate sensor will be mostly off. It
gets switched on only when it has to send a reading and at that time it
will do a very fast data transfer and then disconnect, which means that
will again go into a low-power mode or off mode. What this technology does is it uses very small packets so that the radio consumes low
power. The technology does it in a secure manner which means that the
connection between two Bluetooth devices is encrypted. There are
features that provide an encryption as a link and then this technology
builds on the existing ecosystem.
Applications
Bluetooth Low Energy finds a lot of application in the healthcare
industry. This can be a glucose meter, weighing machines,
thermometers and blood pressure sensor. It has application in sports
and fitness equipment. This could be shoes that track your movement --
how many miles you have jogged. It could be a satellite belt or exercise
equipment or a security application.
For example, you could use your mobile phones to locate your lost
keys. If you press a button on a mobile phone, key will start beeping.
How Bluetooth Low Energy works
Bluetooth architecture:
The lowest layers for the protocol stack run on
a Bluetooth chip which is also called controller. The remaining layers
may run on an application processor. For example, the mobile phone
application processor may run on remaining layers of the stack. In that
case, the application messenger is also referred to as a host. And the
interface between the host and the controller is called the host
controller interface. For example the application processor with the
mobile phone may be connected to the Bluetooth tip on a USB
interface.
So these three things -- the upper layer, the host controller interface
and the controller lower layers -- form what is called the Bluetooth protocol stack. Besides stacks, the specification also designs the concept of profiles. Profiles are used case scenarios of protocol stack.
For example: Each layer of the protocol stack will define what are the features it provides and the profiles will define how these features are to be used to define a real work scenario. For example if the mobile phone has to connect to a headset, then the profiles will define what are the ingredients or layers that will be needed to make that correction to the headset.
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