Iot sdk thesis

2.1
 
Low-power Wide-area Networks 
Often, IoT nodes have to be deployed at a location where their batteries cannot be 
recharged 
or replaced very easily. So, while considering the applications having similar requirements, the 
emphasis must be given to the optimum utilization of the available source of power. In most 
applications these devices are only required to use the communication facilities only 
intermittently, to send tiny amount of data over long distances.
The need for wireless telecommunication scheme to address the market with these 
requirements gave rise to the LPWAN technologies [13]. The technologies under 
LPWAN umbrella differ in range, frequency, licensing, speed, power consumption, cost, 

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security, industry support etc. The main technologies under LPWAN are Sigfox, LoRaWAN, 
NB-IoT, Weightless P, Symphony Link, LTE – M etc. These technologies have been compared 
in Table 2.1.1 
Table 2.1.1 Comparison of LPWAN Technologies
 
[14]
 
NB-IoT among others uses significantly low device power for all the wireless 
communication activities. The hardware design is much simpler than the modems for the rest 
of the technologies. Apart from that, The SARA development board by SODAQ – one of the 
boards evaluated for possible LWM2M porting – has an on-board NB-IoT modem.
Hence within the scope of this thesis, NB-IoT has been studied out of other LPWAN 
technologies appearing in Table 2.1.1. NB-IoT has been discussed in section 2.2. 
2.2
 
Narrow-Band IoT (NB-IoT)
NB-IoT came as a response from 3rd Generation Partnership Project (3GPP) to the 
growing market for IoT and LPWAN [15]. 
2.2.1
 
Overview 
LPWAN technologies have been there for more than 10 years. There are some 
shortcomings in existing technologies such as poor reliability and security, high cost of 
maintenance, high cost of operation, complex deployment and absence of standardization [16].
NB-IoT is designed to operate on already-existing Long-term Evolution (LTE) functionalities. 

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Hence, it is possible to make use of existing LTE infrastructure (hardware and spectrum) to 
implement NB-IoT.
An LPWAN technology should be increasingly deployable: indoor or outdoor. Current 
GSM technologies that were developed with human users in mind do not provide enough 
coverage for M2M scenario. NB-IoT overcomes this shortcoming and provides around 20 
decibel more signal strength in comparison with GSM.
Most applications addressed by LPWAN should be deployable for long term when it 
comes to their battery life. Requirement for frequent recharging increases the maintenance cost. 
Also, the number of active devices in an application could be several thousands. It is not feasible 
to replace the power sources again and again. Since NB-IoT enables sporadic data transmission 
at of small size, the node can go in sleep mode whenever it can, thus enabling long battery life 
of up to 10 years.
NB-IoT supports cheap basic chipset with inexpensive communication module to 
make it an affordable option. With the predicted growth in IoT devices and the long range 
requirement, NB-IoT cells should also be able to support massive interconnection of devices 
within the cell [16]. 
NB-IoT enables low-cost power-constrained devices to communicate over long range 
(up to up-to 100 km in rural settings), long battery life and massive capacity and scalability 
(>52000 devices per channel per scale). NB-IoT also allows better penetration in case the node 
is located indoors. NB-IoT however, has been allowed relaxed latency of 10 seconds for 
exception reports. Hence, the primary advantages NB-IoT has over other LPWAN radio 
technologies are [17]: 
•
Wide area ubiquitous coverage 
(20 dB improvement over 
GPRS) 
•
Faster upgrades over network 
•
Long battery life for devices 
due to low power consumption 
(Supports LTE PSM, LTE 
eDRX modes of power saving) 
•
LTE backward compatibility 
•
Low cost of hardware 
•
High reliability 
•
Carrier-class security 
•
Massive capacity