Introduction to Bluetooth

1. Introduction to
Bluetooth
Yong Heui Cho @ Mokwon University
Most of slides are referred to and all credits should go to:
[1] Victer Paul, Bluetooth, slideshare, 2011.
[2] Erin Yueh, Android Bluetooth Introduction, slideshare, 2009.

2. 2
Smart Device Structure
8. Introduction to IoT
9. Smart Device RF & Antennas
10. Introduction to RTOS
11. Introduction to Bluetooth

3. 3
Why Bluetooth?
• Aims at so-called ad hoc piconets which
are local area networks with a very
limited coverage and without the need
for an infrastructure.
• Designed to be used to connect both
mobile devices and peripherals that
currently require a wire
□ Courtesy to Victer Paul, Bluetooth, slideshare.

4. 4
Spec. (I)
• “USB without wires”
• Short range wireless radio technology
– Operation range of 10 meters
– RF is centered at 2.45 GHz. (RF Channels:
2420+k MHz, k = 0~78)
– Frequency hopping is used to combat
interference in wireless environment.
– TDD for full duplex communications
□ Courtesy to Victer Paul, Bluetooth, slideshare.

5. 5
Spec. (II)
• Power levels
– Sleeping power - 30 uA
– Transmission power - 800 uA
– Standby mode - 300 uA
• Price is less.
• Operates on circuit and packet switching
modes
• Provides both asynchronous and
synchronous data services.
□ Courtesy to Victer Paul, Bluetooth, slideshare.

6. 6
Spec. (III)
• Compared to wired and wireless LAN(10
Mbps), Bluetooth is slower.
• Bluetooth can
– Recognize Bluetooth device in radio range.
– Permit easy connection of devices.
– Be aware of device types.
– Support service discovery.
□ Courtesy to Victer Paul, Bluetooth, slideshare.

7. 7
Possible Devices
• Bluetooth will soon be enabled in
everything from:
– Smartphones
– Headsets
– Computers
– Cameras
– Smart devices
– Cars
– etc.
□ Courtesy to Victer Paul, Bluetooth, slideshare.

8. 8
Radio Coverage
• Class 3 radios – have a range of up to 1
meter or 3 feet
• Class 2 radios – most commonly found
in mobile devices – have a range of 10
meters or 30 feet
• Class 1 radios – used primarily in
industrial use cases – have a range of 100
meters or 300 feet
□ Courtesy to Victer Paul, Bluetooth, slideshare.

9. 9
Overview
• Capacity
– 1 Mbps per channel
– Theoretical capacity of 79 Mbps cannot be
reached due to non-orthogonal hopping
sequences
• Link types
– Synchronous connection-oriented link (SCO)
– Asynchronous connectionless link (ACL)
• Topology and medium access control
– Master-slave architecture
□ Courtesy to Victer Paul, Bluetooth, slideshare.

10. 10
Link Types
• SCO (Synchronous Connection-Oriented)
– The SCO link is point-to-point between master and
slave. The master maintains the link by using
reserved timeslots at regular intervals. Packet
retransmissions are not allowed.
• ACL (Asynchronous Connection-Less)
– ACL provides packet-switched connections
between the master and all active slaves. Packet
retransmissions are usually applied to assure data
integrity.
□ Courtesy to Victer Paul, Bluetooth, slideshare.

11. 11
Power States
□ Courtesy to Victer Paul, Bluetooth, slideshare.
low power mode

12. 12
Power Management
• Stand-by (SB) or idle
– Devices not connected in a piconet
– Extremely low duty cycle (less than one percent): scan for 10 ms
every 1.28-3.84 seconds
• Park (P)
– Devices are part of a piconet, but not active, low power mode
– Assigned an 8-bit parked member address (PMA) and loses active
member address (AMA).
• Hold (H)
– Similar to parked mode, but devices keep AMA address
– Resume sending at once after transition out of HOLD state
• Sniff (Sn)
– Used only by slave devices for power conservation
– Device is active, but listens to channel at a reduced rate. Not on
every slot
□ Courtesy to Victer Paul, Bluetooth, slideshare.

13. 13
Piconet
□ Courtesy to Victer Paul, Bluetooth, slideshare.

14. 14
Scatternet
□ Courtesy to Victer Paul, Bluetooth, slideshare.

15. 15
Protocol Stack
□ Courtesy to Victer Paul, Bluetooth, slideshare.
• OBEX: Object Exchange
• RFCOMM: RF Communication
• SDP: Service Discovery Protocol
• TCS: Telephony Control Protocol
• WAP: Wireless Application Protocol

16. 16
Android Bluetooth
□ Courtesy to Erin Yueh, Android Bluetooth Introduction, slideshare.

17. 17
Bluetooth Architecture
□ Courtesy to Erin Yueh, Android Bluetooth Introduction, slideshare.