Iot sdk thesis

Figure 3.4.1 Reading from SODAQ SARA using Leshan LWM2M server 
Now the ‘write’ operation has been shown in following figures. The value in ‘Lifetime’ 
resource is changed to 600. Note that only the resources with ‘write’ access can be written. 
Others can only be observed or read. A window to write the new resource value pops-up on 
hitting the ‘Write’ button for ‘Lifetime’ resource. Observe this in Figure 3.4.2. 

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Figure 3.4.2 Updating the value of ‘Lifetime’ resource 
Hitting ‘Update’ leads you back to the previous dashboard and now the updated value 
can be observed next to ‘Lifetime’ resource.
Figure 3.4.3 Updated value of ‘Lifetime’ resource 
Also, be reminded that this device management has been performed over encrypted 
messages sent over NB-IoT network. Performing the device management with Leshan hosted 
on private Linux server can allow it to be seen that, the device management data packets are 
categorized as ‘Application Data’ by DTLS. 
Figure 3.4.4 LWM2M Device Management: DTLS Observation 
The number of packets sent and received by the client over NB-IoT can be observed on 
DEBUG terminal of the PlatformIO, as shown in Figure 3.4.5 

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Figure 3.4.5 Traffic observed over NB-IoT during device management activities 
In this way, it has the end-to-end testing objective of the thesis has been successfully 
attained. 

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4
 
Conclusion 
The thesis spans over wide range of technologies in the context of device management 
in Internet of Things ecosystem. This thesis not only touched several otherwise eclectic 
domains, but also required to study, investigate, compare and implement some of the core 
technologies of those domains. There can be several conclusions drawn from the thesis, that 
have been inferred from my experience during the study and implementation these 
technologies. 
NB-IoT is emerging as a strong candidate from the LPWAN bracket to address the 
power and bandwidth-constrained use-cases, along with offering scope for massive scalability, 
indoor penetration for nodes requiring infrequent access to the transmission channel to 
exchange tiny amount of data. The hardware manufacturers are now emerging with on-board 
NB-IoT modem and API support, which can open doors for ultra-low power application 
development on the hardware with small form factor. 
The advent of applications prioritizing low latency (and ultra-low latency in 5G context) 
have increasingly demanded a secure packet exchange over UDP. DTLS, since it is based on 
tried and tested TLS, can meet this requirement for such applications. The open source library 
Eclipse tinydtls, comes with a strong encryption engine and several encryption suites, which 
can be integrated to the C/C++ based IoT applications, but with a several intense modifications. 
The concept of device management is very useful in managing the client-server type 
IoT ecosystems comprising massive number of independently functioning nodes. LWM2M as 
a particular device management standard offers flexibility at each layer of the protocol stack 
making a huge number of usecases possible, based on circumstances and the availability of 
technology. Open source projects from Eclipse enable modification of their LWM2M 
implementations (e.g., Wakaama) to reconcile with the available hardware and software 
resources. Hence, the IoT developers should keep provision for LWM2M integration for a 
secure and robust application management. 
By porting Wakaama LWM2M implementation on Arduino-like SODAQ SARA, it has 
been shown that a device no-longer needs to have Linux library support to be securely managed 
by a LWM2M server. Also, the newly ported Wakaama provides enough abstraction from low-
level details. So, it can be used to convert a device into a LWM2M client to be managed securely 
by DTLS over NB-IoT. This opens a door for seamlessly developing secure, scalable 
applications requiring placement of nodes in remote locations with low power and bandwidth 
availability. 

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