Introduction to Bluetooth® Low Energy

This page provides a brief introduction to the Bluetooth® Low Energy (BLE) Specification.

What is Bluetooth® ?

Bluetooth is a set of specifications for common short-range wireless applications, covering

  • Radios
  • Protocols
  • Profiles

The Bluetooth® Core Specification is maintained by the Bluetooth® Special Interest Group (SIG).

Features of the "classic" Bluetooth radio:

  • 2.4 GHz ISM band, 1 Mbps, GFSK, 4PSK or 8PSK
  • 1 MHz channel spacing, with frequency hopping
  • Adaptive frequency hopping, for co-existence with Wi-Fi®
  • Up to 100 mW, more than 100 m range is possible

Bluetooth® Low Energy (BLE)

An extension to the Bluetooth 4.x Core Specification, targeted to supporting Internet-of-Things (IoT) applications:

Basic Tenets

Operation using button-cell batteries

  • Low peak current
  • Low energy (Power*Time)
    • Small Packet Size
    • Minimize Duty Cycle & Latency

Asymmetry

  • The device with the lower energy source is given less to do

IoT Ready

  • Client/Server data model
    • Things have data
    • Web services want this data

Bluetooth® 4.2: Key Improvements for BLE

Faster Data Synchronization/Firmware Updates

  • In 4.2, there is up to 2.5x higher throughput with a huge packet data capacity increase - nearly 10x more than earlier versions of BLE
ble42-key-improvements.png

Highly Secure

  • Features FIPS-compliant encryption
  • LE Security Mode 1, Level 3 & 4
    • Meets the requirements of the Payment Card Industry (PCI) for Pin Transaction Security (PTS) Point of Interaction (POI) financial transactions, where BT 4.2 must be used and the device must support Security Mode 1, Level 3 or 4.

Designed for Exposing State

What kinds of data transfer are most suited to BLE?

  • Small, discrete data transfers
  • State information, triggered by local events
  • Not streaming
discrete-data-types.png

Protocol Stack

The following diagram depicts the architecture (major layers) of the BLE protocol stack. Please select the links below to jump to the specific sections (follow the menu on the left-hand-side for further navigation):

ble-protocol-stack.png

  Return to Top

© 2019 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.