3 Engineering IoT Networks
115
Table 3.1 Transmission power and range as a function of the Bluetooth class
Max permitted power
Typical range
Class
(mW)
(dBm)
(m)
1
100
20
100
1.5 (BT 5 Vol 6 Part A Sect 3)
10
10
20
2
2.5
4
10
3
1
0
1
4
0.5
−3
0.5
Network Layer functionality is not addressed in Bluetooth since topology is kept
mainly point-to-point. One exception is given by Mesh Profile in Bluetooth 4.0
which calls low-level services to move data over point-to-point links as in a
mesh. Regardless of version, Bluetooth classifies transmitters as a function of
emitted power. Transmission power affects range and energy consumption that
determines battery lifetime or enables energy-harvesting operations. Table 3.1
reports transmission power and range as a function of the Bluetooth class.
3.3.3.1 Bluetooth Versions
All versions of the Bluetooth standard support downward compatibility. Therefore
the latest standard covers all older versions. The main milestones in Bluetooth
development are:
• Bluetooth 1.x. This set is also denoted as Bluetooth Basic Rate (BR). It contains
the first versions of the standard supported by IEEE 802.15.1 working group.
Physical bitrate was up to 721 kb/s. Its target was the basic replacement of cables
and audio transmissions.
• Bluetooth 2.x. Physical bitrate was increased to 3 Mb/s, thanks to Enhanced Data
Rate (EDR) technique. Security was enforced.
• Bluetooth 3.0. Alternative MAC/PHY was introduced to use 802.11 as a highspeed transport network. Unicast Connectionless Data mode was introduced.
Power control was improved.
• Bluetooth 4.0. It introduces the so-called Bluetooth Low Energy or Bluetooth LE
or simply BLE. The features introduced in the previous versions of the standards
are still maintained and referred to by using the single-word term “Bluetooth” or
“Classic Bluetooth” or “Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR).”
Table 3.2 reports a comparison between Classic Bluetooth and Bluetooth Low
Energy. Compared to Classic Bluetooth, Bluetooth Low Energy is intended to
provide considerably reduced power consumption and cost while maintaining a
similar communication range. Maximum physical bitrate is 1 Mb/s. New profiles
and protocols have been introduced to support IoT applications such as beacon
advertising. Mesh topology was introduced.
115
Table 3.1 Transmission power and range as a function of the Bluetooth class
Max permitted power
Typical range
Class
(mW)
(dBm)
(m)
1
100
20
100
1.5 (BT 5 Vol 6 Part A Sect 3)
10
10
20
2
2.5
4
10
3
1
0
1
4
0.5
−3
0.5
Network Layer functionality is not addressed in Bluetooth since topology is kept
mainly point-to-point. One exception is given by Mesh Profile in Bluetooth 4.0
which calls low-level services to move data over point-to-point links as in a
mesh. Regardless of version, Bluetooth classifies transmitters as a function of
emitted power. Transmission power affects range and energy consumption that
determines battery lifetime or enables energy-harvesting operations. Table 3.1
reports transmission power and range as a function of the Bluetooth class.
3.3.3.1 Bluetooth Versions
All versions of the Bluetooth standard support downward compatibility. Therefore
the latest standard covers all older versions. The main milestones in Bluetooth
development are:
• Bluetooth 1.x. This set is also denoted as Bluetooth Basic Rate (BR). It contains
the first versions of the standard supported by IEEE 802.15.1 working group.
Physical bitrate was up to 721 kb/s. Its target was the basic replacement of cables
and audio transmissions.
• Bluetooth 2.x. Physical bitrate was increased to 3 Mb/s, thanks to Enhanced Data
Rate (EDR) technique. Security was enforced.
• Bluetooth 3.0. Alternative MAC/PHY was introduced to use 802.11 as a highspeed transport network. Unicast Connectionless Data mode was introduced.
Power control was improved.
• Bluetooth 4.0. It introduces the so-called Bluetooth Low Energy or Bluetooth LE
or simply BLE. The features introduced in the previous versions of the standards
are still maintained and referred to by using the single-word term “Bluetooth” or
“Classic Bluetooth” or “Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR).”
Table 3.2 reports a comparison between Classic Bluetooth and Bluetooth Low
Energy. Compared to Classic Bluetooth, Bluetooth Low Energy is intended to
provide considerably reduced power consumption and cost while maintaining a
similar communication range. Maximum physical bitrate is 1 Mb/s. New profiles
and protocols have been introduced to support IoT applications such as beacon
advertising. Mesh topology was introduced.