Cellular Technologies

Cellular technologies refer to wireless communications that cover a significantly larger geographical area than short-range wireless. Information is distributed to and from a cell tower, correspondent to each cell.

2.6.2.1 Extended Coverage-GSM-IoT (EC-GSM-IoT)

Extended Coverage-GSM-loT is 3GPP standard-based LPWAN technology. EC-GSM-loT is based on enhanced GPRS (eGPRS), designed to support long-range, low-power, and high-capacity communication. EC-GSM-loT is backward compatible with existing GSM technologies. Hence, it can be added to the existing cellular network as a software upgrade, reducing the cost of infrastructure and deployment.

EC-GSM-loT extends the coverage of GPRS by 20dB. To support various application requirements, EC-GSM-loT provides two modulation options, Gaussian Minimum Shift Keying (GMSK) and 8-ary Phase Shift Keying (8PSK). Using these two modulations, it achieves peak data rate of 10 kbps and 240 kbps, respectively. Additionally, EC-GSM-loT improves battery lifetime by using extended Discontinued Reception (eDRX) technique, which allows the device to choose the number of inactivity periods depending on the application requirements. EC-GSM-loT can support up to 50k devices using a single BS.

Hence, EC-GSM-loT can provide coverage for M2M devices in locations with challenging radio coverage conditions.

2.6.2.2 Narrow-Band IoT (NB-IoT)

NB-IoT (Narrowband IoT) is a 3rd Generation Partnership Project (3GPP) LPWAN technology. It is a 3GPP Release 13 feature that reuses various principles and building blocks of the LTE physical layer and higher protocol layers. NB-IoT is offering flexibility of deployment by allowing the use of a small portion of the available spectrum. It supports up to 50k devices per cell and requires minimum 180 kHz of bandwidth to establish communication. It can be deployed as a standalone carrier with available spectrum exceeding 180 kHz, in-band within an LTE physical resource block, or in the guard-band inside an LTE carrier. NB-IoT uses resource mapping to preserve the orthogonality of LTE signals by avoiding mapping signals to resources currently used by LTE signals.

2.6.2.3 LTE-Machine Type Communication (LTE-MTC) and Enhanced Machine Type Communication (eMTC)

LTE for Machine Type Communication (LTE-MTC), similarly to NB-IoT, is a 3GPP low-power wide area network, used for various cellular devices and services, particularly for IoT or M2M applications. LTE-MTC optimizes the production of next-generation IoT devices with low costs, longer battery life, and better coverage. This is achieved by supporting data rates of up to 10 Mbps for LTE-MTC devices, which will further decrease the production cost, ensuring however that LTE will effectively compete against long-range wireless technologies [19].

eMTC is a modified version of the LTE-MTC standard, supporting a bandwidth of 1.08 MHz within an existing LTE deployment, and 1.4 MHz in standalone deployment. The key difference between LTE-MTC EMTC is that the latter supports data rates of up to 1 Mbps, since it is limited to a 1.08 MHz channel width [20].

The summary of LPWAN technologies can be seen in Table 2.1.

Long Range Wireless Technologies

Long-Range Wireless Communications enables information distribution through larger geographical areas, which can reach a few kilometers in size.

LoRa (LoRa PHY and LoRaWAN)

LoRa stands for Long Range and it is a digital wireless data communication technology which uses license-free sub-gigahertz radio frequency bands like 169 MHz, 433 MHz, 868 MHz (Europe), and 915 MHz (North America). LoRa enables very-long- range transmissions (above 10 km in rural areas) with low battery.

LoRaWAN defines the communication protocol and system architecture for the network, while the LoRa physical layer enables the long-range communication link. LoRaWAN is also responsible for managing the communication frequencies, data rate, and power for all devices. LoRa and LoRaWAN permit inexpensive, long- range connectivity for the IoT devices in rural, remote, and offshore industries. Typical uses of LoRa products can be found in the following industries: mining.

TABLE 2.1

Accelerometer Sensors Suitability for Different Applications (Adapted from [64])

Application

Piezoelectric

Capacitive MEMS

Piezoresistive

Static Acceleration (gravity)

X

X

G- Force (aircraft)

X

X

Seismic (earthquake)

X

Low Frequency Vibrationlhuman motion)

X

X

X

General Vibration (electric motor)

X

X

High Frequency Vibration (gear noise analysis)

X

General Shock (general testing)

X

X

X

High Impact Shock (drop testing)

X

X

Extreme Shock (vehicle crash testing)

X

X

natural resource management, renewable energy, transcontinental logistics, and supply chain management. Fleet Space Technologies [21] uses LoRaWAN to provide massive connectivity to IoT sensors and devices in rural, remote, and offshore areas.

 
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