Bluetooth Low Energy (BLE) or Bluetooth Smart is the low energy version of Bluetooth and integrated into the Bluetooth standard v4.0. The presentation briefs about the BLE and its architecture. Presented at Robert Bosch Centre for Cyber Physical Systems at Indian Institute of Science, Bengaluru

1. Robert Bosch Centre for Cyber-Physical Systems
Bluetooth Low Energy:
An insight
Saptadeep Pal
Amrit Anand

2. Overview

Universal short-range wireless Capability

2.4 GHz ISM Band

Available globally for unlicensed users

Achievable data-rate of 0.2 Mbit/s

Used mainly for low-powered devices and IoT to collect sensor data

Low power requirements, operating for "months or years" on a button
cell

Small size and low cost

Compatibility with a large installed base of mobile phones, tablets
and computers

3. Bluetooth Vs Bluetooth Low Energy
Technical Specification
Classic Bluetooth technology
Bluetooth low energy technology
Distance/Range
Over the air data rate
100 m (330 ft)
1–3 Mbit/s
50 m (160 ft)
1 Mbit/s
Application throughput
0.7–2.1 Mbit/s
0.27 Mbit/s
Active slaves
7
Not defined; implementation dependent
Security
56/128-bit and application layer user defined
128-bit AES with Counter Mode CBC-MAC and
application layer user defined
Robustness
Adaptive fast frequency hopping, FEC,
fast ACK
Adaptive frequency hopping, Lazy
Acknowledgement, 24-bit CRC, 32-bit
Message Integrity Check
Latency (from a non-connected state)
Typically 100 ms
6 ms
Total time to send data (det.battery life)
100 ms
3 ms[citation needed], <3 ms[25]
Voice capable
Network topology
Yes
Scatternet
No
Star-bus
Power consumption
1 as the reference
0.01 to 0.5 (depending on use case)
Peak current consumption
<30 mA
<15 mA
Service discovery
Profile concept
Yes
Yes
Yes
Yes
Primary use cases
Mobile phones, gaming, headsets, stereo
audio streaming, automotive, PCs, security,
proximity, healthcare, sports & fitness, etc.
Mobile phones, gaming, PCs, watches, sports
and fitness, healthcare, security & proximity,
automotive, home electronics, automation,
Industrial, etc.

4. History of BLE

Bluetooth LE was originally introduced under the name Wibree by Nokia in
2006

It was merged into the main Bluetooth standard in 2010, when the Bluetooth
Core Specification Version 4.0 was adopted

In 2011, the Bluetooth Special Interest Group announced the Bluetooth
SMART logo scheme, intended to clarify compatibility between LE devices

Bluetooth Smart Ready indicates a dual-mode device, typically a laptop or
smartphone, whose hardware is compatible with both Classic and LE
Bluetooth peripherals

Bluetooth Smart indicates an LE-only device, typically a battery-operated
sensor, which requires either a SMART Ready or another SMART device in order
to function

iPhone 4S was the first ever commercial device to include BLE

5. Modulation Technique: Adaptive Frequency Hopping Spread Spectrum

Resists Interference and multi-path effects

Provides a form of multiple access among co-located devices in different
piconets

Total Bandwidth of 80 MHz is divided into 40 channels of 2 MHz each

FH occurs by jumping from one frequency to other using a pseudo-random
sequence

Hopping sequence shared across entire piconet

6. Architecture

7. Link Layer

8. Link Layer Packet format
 Preamble used in the receiver to perform frequency synchronization, symbol
timing estimation and automatic gain control
 Access address used to ensure that there is minimum interference in between
BLE devices which uses the same physical channel
 When a packet is transmitted in advertising physical channel, the PDU shall
be advertising channel PDU and when the packet is sent in data physical
channel, the PDU shall be data channel PDU.
 At the end of every link layer packet, there is a 24-bit Cyclic Redundancy
Check

9. Open areas of Research

Automotive Technology

Consumer Wellness

Smart Energy

Home Automation

Security & Proximity

Sports and Fitness
There is an INNNOVATION World Cup every year conducted by Bluetooth SIG

10. THANK YOU