Bluetooth Low Energy (BLE)

Bluetooth low energy or Bluetooth LE, is known as Bluetooth Smart. BLE is a new version of Bluetooth Wireless technology, specially designed to reduce power consumption as compared to classic Bluetooth. It works for years on a single coin cell battery. Its small size makes it very portable. In addition, it is maintenance free and compatible with any form of BLE devices such as   smartphones, laptops, sports & fitness devices, Google wearable devices, etc. The Bluetooth smart beacon is a Bluetooth low energy device that is taking the market by storm.

What is BLE technology?

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The technology is perfect for devices which run on a tiny battery for years. The advantage of Bluetooth Smart is its unique ability to work with the applications on your smartphone or tablet.   The technology makes it easier for developers to create solutions that will work with the billions of Bluetooth-enabled products already in the market today.

The technology has gained an early foothold in several industries such as automotive, PC peripherals, and consumer electronics. With the advancement of Bluetooth Smart, many fitness and sports companies have started to integrate the new technology because of its low power consumption and ability to connect to smartphone apps. It is the perfect fit for a wide range of devices, from heart-rate monitors to exercise cycling counters. Now Bluetooth Smart technology is powering many verticals from wireless medical instruments and home automation to retail and wearables. The only disadvantage is that Bluetooth Smart is not backward-compatible with classic Bluetooth. The Bluetooth 4.0 specification requires devices to implement Low Energy beacons/systems.

BLE supported smartphones:

  • Phones with Android version 4.3 and Bluetooth 4.0
  • IOS 5 and later.
  • Windows phone 8.1.
  • BlackBerry 10.

Advantages of BLE:

  • Power independent.
  • Low power requirements. Can operate for years on coin-cell batteries.
  • Small in size to fit anywhere and available at a lower cost.
  • Compatible with mobile phones, laptops, tablets computers and fitness devices.

Applications of BLE:

  • Health Care:
    1. Temperature measurement.
    2. Blood glucose monitors.
    3. Blood pressure measurement.
  • Fitness and Sports:
    1. Heart rate measure.
    2. Exercise monitoring with measuring counts and speed.
    3. Location tracking sensors and Navigation.
  • Proximity sensing:
    1. Misplaced devices or BLE attached objects can be found.
    2. Detects range between two BLE devices.

Features of BLE:

  • Data transfer speed upto 1 mbps
  • Range 100 m (>330 ft.)
  • Client – server model
  • Short commands based communication
  • Secure uses UUIDs to identify devices

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BLE is not the  future. It  is already out there on the field, battling the current technology warfare.

 Exploring BLE Architecture

Now that we are aware about BLE basics, let’s take a deeper look at its technical insights and architecture. Let’s begin with understanding the BLE paradigm in detail. The BLE paradigm operates in a pair, where every device performs a role. This role could be as a Central, Peripheral, Receiver or Broadcaster.
The first pair in the BLE paradigm would be Central-Peripheral. The central device scans for the peripherals (devices) and advertisements where peripheral produces advertisements. The primary objective of the  Central-Peripheral pair is to establish a connection. The central device establishes a connection to the peripheral device and requests for  more data. Basically, the pair works on a request and response model.

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Another pair, the Broadcaster-Receiver, is the best one. In this pair, we need not establish a connection. The Broadcaster device simply broadcasts data packets continuously without knowing who is consuming it. The Receiver receives data packets transmitted from the broadcaster device.
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This pair is based on the ‘No connection, no requests, No response’ model. Simply transmit data packets in the air and compatible devices will consume it and use for its purpose.

Now we are well aware of roles of BLE devices and can easily differentiate them according to  the various categories. Before we move further and transmit or receive data we must know the data structure inside the device.

Every peripheral device has a profile specification for exposing data. The Generic Attribute Profile (GATT) specification determines how these small data will be sent and received over BLE networks. These small data packets are known as an Attribute.
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GATT is nothing but a collection of services, where services include different Characteristics (functions) for a device. Every characteristic is explained by a Descriptor. Each function of a service can have multiple descriptors. These descriptors contain metadata about the type of  value or any other configuration information. For example, in a heartbeat proximity sensor, the Descriptor can tell  the unit of distance; i.e. weather it is a feet or meters.

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