3 Engineering IoT Networks
143
Fig. 3.25 NB-IoT modes of
operation [71]: (a)
Standalone, (b) In Band,
(c) Guard Band
GSM Band(s)
200 kHz
a
LTE Band(s)
200 kHz
b
LTE Band(s)
200 kHz
c
battery life. At Layer 1, the maximum transport block size (TBS) for the downlink is
680 bits, while uplink is 1000 bits. At Layer 2, the maximum payload size is 1,600
bytes. NB-IoT operates in half-duplex frequency-division duplexing mode with a
maximum uplink data rate of 60 kb/s and downlink of 30 kb/s.
3.3.17.5 LTE Cat M1
LTE category M1 (LTE Cat M1 or simply LTE-M) is 4G profile specifically
designed for IoT and M2M communications. It features a transmit power of
20 dBm and provides an average upload bitrate between 375 kb/s and 1 Mb/s. Main
advantages of this technology are: extended battery lifecycle, excellent in-building
range, and support of voice functionality through Voice over LTE (VoLTE).
LTE-M supports two duplex modes:
• Full-duplex: data can be downloaded and uploaded simultaneously at a rate of
1 Mb/s;
• Half-duplex: data can travel only in one direction at a time at a rate of 375 kb/s.
The advantage of the second mode is that it requires less power, which makes it
suitable for scenarios where there is no need to both send and receive at the same
time.
It is worth noting that both NB-IoT and LTE-M were designed to support a large
number of sensors for environmental monitoring or fleet tracking. LTE-M requires
an LTE infrastructure, while NB-IoT can be hosted in GSM infrastructure. With low
data rate applications, NB-IoT consumes less energy than LTE-M but at the cost of
a lower bitrate.
143
Fig. 3.25 NB-IoT modes of
operation [71]: (a)
Standalone, (b) In Band,
(c) Guard Band
GSM Band(s)
200 kHz
a
LTE Band(s)
200 kHz
b
LTE Band(s)
200 kHz
c
battery life. At Layer 1, the maximum transport block size (TBS) for the downlink is
680 bits, while uplink is 1000 bits. At Layer 2, the maximum payload size is 1,600
bytes. NB-IoT operates in half-duplex frequency-division duplexing mode with a
maximum uplink data rate of 60 kb/s and downlink of 30 kb/s.
3.3.17.5 LTE Cat M1
LTE category M1 (LTE Cat M1 or simply LTE-M) is 4G profile specifically
designed for IoT and M2M communications. It features a transmit power of
20 dBm and provides an average upload bitrate between 375 kb/s and 1 Mb/s. Main
advantages of this technology are: extended battery lifecycle, excellent in-building
range, and support of voice functionality through Voice over LTE (VoLTE).
LTE-M supports two duplex modes:
• Full-duplex: data can be downloaded and uploaded simultaneously at a rate of
1 Mb/s;
• Half-duplex: data can travel only in one direction at a time at a rate of 375 kb/s.
The advantage of the second mode is that it requires less power, which makes it
suitable for scenarios where there is no need to both send and receive at the same
time.
It is worth noting that both NB-IoT and LTE-M were designed to support a large
number of sensors for environmental monitoring or fleet tracking. LTE-M requires
an LTE infrastructure, while NB-IoT can be hosted in GSM infrastructure. With low
data rate applications, NB-IoT consumes less energy than LTE-M but at the cost of
a lower bitrate.