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E. Fraccaroli and D. Quaglia
The first 4G networks were introduced in 2008. The first-release Long Term
Evolution (LTE) standard was commercially deployed in Oslo, Norway, and
Stockholm, Sweden, in 2009 and has since been deployed throughout most parts
of the world. It has, however, been debated whether first-release versions should be
considered 4G LTE, as discussed in the technical understanding section below.
As opposed to earlier generations, a 4G system does not support traditional
circuit-switched telephony service, but all-Internet Protocol (IP)-based communication such as IP telephony. As seen below, the spread-spectrum radio technology
used in 3G systems is abandoned in all 4G candidate systems and replaced
by OFDMA multi-carrier transmission and other frequency-domain equalization
(FDE) schemes, making it possible to transfer very high bit rates despite extensive
multi-path radio propagation (echoes). Smart antenna arrays further improve the
peak bit rate for Multiple-Input Multiple-Output (MIMO) communications.
3.3.17.4 NB-IoT
Narrowband IoT (NB-IoT) is a low-power wide area network radio technology
standard developed by 3GPP to enable a wide range of cellular devices and services [70]. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro),
in June 2016. Other 3GPP IoT technologies include eMTC (enhanced MachineType Communication) and EC-GSM-IoT [37].
NB-IoT focuses specifically on indoor coverage, low cost, long battery life,
and high connection density. NB-IoT uses a subset of the LTE standard but limits
the bandwidth to a single narrow-band of 200 kHz. It uses orthogonal frequencydivision multiple access (OFDMA) modulation for downlink communication and a
couple of options for uplink communication (for more information on the uplink
options, refer to the 3GPP specification TR 36.802.). OFDMA is a modulation
scheme in which individual users are assigned subsets of subcarrier frequencies.
This enables multiple users to transmit low-speed data simultaneously.
As depicted in Fig. 3.25, NB-IoT can operate in three different modes:
• Standalone: A GSM carrier is used as an NB-IoT carrier, enabling reuse of
900 MHz or 1800 MHz.
• In-band: Part of an LTE carrier frequency band is allocated for use as an NBIoT frequency. The service provider typically makes this allocation, and IoT
devices are configured accordingly. You should be aware that if these devices
must be deployed across different countries or regions using a different service
provider, problems may occur unless there is some coordination between the
service providers, and the NB-IoT frequency band allocations are the same.
• Guard Band: An NB-IoT carrier is between the LTE or WCDMA bands. This
requires coexistence between LTE and NB-IoT bands.
The link budget of NB-IoT is 164 dB. The GPRS link budget is 144 dB, used
by many machine-to-machine services. The additional 20 dB link budget should
guarantee better signal penetration in buildings and basements while improving
E. Fraccaroli and D. Quaglia
The first 4G networks were introduced in 2008. The first-release Long Term
Evolution (LTE) standard was commercially deployed in Oslo, Norway, and
Stockholm, Sweden, in 2009 and has since been deployed throughout most parts
of the world. It has, however, been debated whether first-release versions should be
considered 4G LTE, as discussed in the technical understanding section below.
As opposed to earlier generations, a 4G system does not support traditional
circuit-switched telephony service, but all-Internet Protocol (IP)-based communication such as IP telephony. As seen below, the spread-spectrum radio technology
used in 3G systems is abandoned in all 4G candidate systems and replaced
by OFDMA multi-carrier transmission and other frequency-domain equalization
(FDE) schemes, making it possible to transfer very high bit rates despite extensive
multi-path radio propagation (echoes). Smart antenna arrays further improve the
peak bit rate for Multiple-Input Multiple-Output (MIMO) communications.
3.3.17.4 NB-IoT
Narrowband IoT (NB-IoT) is a low-power wide area network radio technology
standard developed by 3GPP to enable a wide range of cellular devices and services [70]. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro),
in June 2016. Other 3GPP IoT technologies include eMTC (enhanced MachineType Communication) and EC-GSM-IoT [37].
NB-IoT focuses specifically on indoor coverage, low cost, long battery life,
and high connection density. NB-IoT uses a subset of the LTE standard but limits
the bandwidth to a single narrow-band of 200 kHz. It uses orthogonal frequencydivision multiple access (OFDMA) modulation for downlink communication and a
couple of options for uplink communication (for more information on the uplink
options, refer to the 3GPP specification TR 36.802.). OFDMA is a modulation
scheme in which individual users are assigned subsets of subcarrier frequencies.
This enables multiple users to transmit low-speed data simultaneously.
As depicted in Fig. 3.25, NB-IoT can operate in three different modes:
• Standalone: A GSM carrier is used as an NB-IoT carrier, enabling reuse of
900 MHz or 1800 MHz.
• In-band: Part of an LTE carrier frequency band is allocated for use as an NBIoT frequency. The service provider typically makes this allocation, and IoT
devices are configured accordingly. You should be aware that if these devices
must be deployed across different countries or regions using a different service
provider, problems may occur unless there is some coordination between the
service providers, and the NB-IoT frequency band allocations are the same.
• Guard Band: An NB-IoT carrier is between the LTE or WCDMA bands. This
requires coexistence between LTE and NB-IoT bands.
The link budget of NB-IoT is 164 dB. The GPRS link budget is 144 dB, used
by many machine-to-machine services. The additional 20 dB link budget should
guarantee better signal penetration in buildings and basements while improving