Part A
1. Describe IoT and Digitization.
Internet of Things (IoT)
IoT focuses on connecting physical objects and machines to a computer network, such as
the Internet, enabling seamless communication between them. It is widely recognized in
the industry and plays a crucial role in enabling smart applications. For example, in a
shopping mall, Wi-Fi tracking uses connected devices to analyze customer movement,
helping businesses optimize store layouts and advertising placements. IoT also plays a key
role in home automation, where devices like sensors, cameras, and alarms are integrated to
create a connected experience.
Digitization
Digitization involves converting information into digital form and integrating connected
devices with data to generate business insights. Various industries have undergone
digitization, such as photography, which shifted from film-based cameras to digital ones
embedded in mobile phones. Similarly, video rental stores have been replaced by digital
streaming services, transforming how people access movies. The transportation industry
has also been digitized through services like Uber and Lyft, which use mobile apps to
connect riders with drivers, disrupting traditional taxi businesses. Companies and
governments see digitization as a key differentiator, with IoT serving as a major driving
force behind this technological shift.
2. Describe the functions of various layers of simplified IoT architecture model.
“Things” layer: At this layer, the physical devices need to fit the constraints of
the environment in which they are deployed while still being able to provide the
information needed.
Communications network layer: When smart objects are not self-contained, they
need to communicate with an external system. In many cases, this communication
uses a wirelesstechnology. This layer has four sub layers:
1. Access network sub layer: The last mile of the IoT network is the access
network. This is typically made up of wireless technologies such as 802.11ah,
802.15.4g. The sensors connected to the access network may also be wired.
2. Gateways and backhaul network sub layer: A common communication
system organizes multiple smart objects in a given area around a common
gateway. The gatewaycommunicates directly with the smart objects. The role
of the gateway is to forward the collected information through a longer-range
medium (called the backhaul) to a headend central station where the
information is processed. This information exchange is a Layer7 (application)
function, which is the reason this object is called a gateway. On IP networks,
this gateway also forwards packets from one IP network to another, and it
therefore acts as a router.
3. Network transport sublayer: For communication to be successful, network
and transport layer protocols such as IP and UDP must be implemented to
support the variety of devices to connect and media to use.
4. IoT network management sublayer: Additional protocols must be in place
to allow the headend applications to exchange data with the sensors.
Examples include CoAP andMQTT.
Application and analytics layer: At the upper layer, an application needs to
process thecollected data, not only to control the smart objects when necessary,
but to make intelligent decision based on the information collected and, in turn,
instruct the “things” or other systems to adapt to the analyzed conditions and
change their behaviors or parameters.
3. Illustrate how sensors and actuators interact with the physical world.
Sensors are designed to sense and measure practically any measurable variable in the
physical world. They convert their measurements (typically analog) into electric signals
or digital representations that can be consumed by an intelligent agent (a device or a
human). Actuators, on the others hand, receive some type of control signal (commonly an
electric signal or digital command) that triggers a physical effect, usually some type of
motion, force, and so on.
4. Describe SANET.
A sensor/actuator network (SANET), as the name suggests, is a network of sensors that
sense and measure their environment and/or actuators that act on their environment. The
sensors and/or actuators in a SANET are capable of communicating and cooperating in a
productive manner. Effective and well-coordinated communication and cooperation is a
prominent challenge, primarily because the sensors and actuators in SANETs are diverse,
heterogeneous, and resource-constrained. SANETs offer highly coordinated sensing and
actuation capabilities. Smart homes are a type of SANET that display this coordination
between distributed sensors and actuators.
5. Explain the parameters need to be considered while choosing between IP
adaptation/adoption for last mile communication.
Parameters that are need to be considered while choosing between IP adaptation/adoption
for last mile communication are:
 Bidirectional versus unidirectional data flow
Some last-mile technologies optimize for unidirectional communication, even
though bidirectional communication is generally expected. Certain IoT devices, as
classified in RFC 7228, only need to send small amounts of data occasionally, such
as fire alarms, electrical switches, and utility meters using LPWA technologies.
While skipping a full IP stack may be efficient, it limits the ability to update
firmware or add new features, posing challenges for security and functionality
improvements.
 Overhead for last-mile communications paths
IP adoption introduces a layered architecture with varying per-packet overhead,
with IPv4 having a minimum 20-byte header and IPv6 having 40 bytes. When
transmitting small, infrequent data—especially in LPWA technologies—the header
overhead can exceed the actual device data, making efficiency a concern. This
necessitates evaluating whether IP adoption is essential and, if so, optimizing both
data and control plane traffic for low-bandwidth, last-mile links.
 Data flow model
A key advantage of the IP adoption model is its end-to-end communication
capability, allowing any node to exchange data within a network, though security
and privacy may impose restrictions. In many IoT solutions, data flow is limited to
one or two applications, making the adaptation model feasible since traffic
translation occurs only between the device and a few servers. Depending on
network topology and data flow requirements, both IP adaptation and adoption
models can be useful for last-mile connectivity.
 Network diversity
A major drawback of the adaptation model is its reliance on specific PHY and MAC
layers, such as ZigBee devices being limited to ZigBee network islands or G3-PLC
nodes operating only within their networks. This requires careful planning to
determine which applications should run on the gateway connecting these islands
to the wider network. In contrast, the adoption model does not face these
constraints, making integration and coexistence of new technologies less of a
concern.
6. Differentiate between CoAP and MQTT.
Factor
Main transport protocol
Typical messaging
Effectiveness in LLNs
CoAP
UDP
Request/response
Excellent
Security
Communication model
DTLS
One-to-one
Strengths
Lightweight and Fast
Weakness
Not as reliable as MQTT
MQTT
TCP
Publish/subscribe
Low/fair (Implementations
pairing UDP with MQTT are
better for LLNs.)
SSL/TLS
many-to-many
Provide robust
communications.
Higher overhead for
constrained devices and
networks
7. Discuss structured data and unstructured data.
Structured data means that the data follows a model or schema that defines how the data is
represented or organized, meaning it fits well with a traditional relational database
management system (RDBMS). A spreadsheet contains structured data which are in a
simple tabular form where data occupies a specific cell and can be explicitly defined and
referenced.
Structured data can be found in most computing systems and includes everything from
banking transaction and invoices to computer log files and router configurations. IoT
sensor data often uses structured values, such as temperature, pressure, humidity, and so
on, which are all sent in a known format. Structured data is easily formatted, stored,
queried, and processed; for these reasons, it has been the core type of data used for making
business decisions.
Because of the highly organizational format of structured data, a wide array of data
analytics tools is readily available for processing this type of data. From custom scripts to
commercial software like Microsoft Excel and Tableau, most people are familiar and
comfortable with working with structured data.
Unstructured data lacks a logical schema for understanding and decoding the data through
traditional programming means. Examples of this data type include text, speech, images,
and video. As a general rule, any data that does not fit neatly into a predefined
data model is classified as unstructured data.
8. Differentiate between supervised learning and unsupervised learning.
9. List and explain Raspberry Pi interfaces for data transfer.
Raspberry Pi interfaces for data transfer are:
 Serial
 SPI
 I2C
Serial
The serial interface on Raspberry pi has receive(Rx) and transmit(Tx) pins for
communication with serial peripherals.
SPI
Serial Peripheral Interface(SPI) is a synchronous serial data protocol used for
communicating with one or more peripheral devices using a master slave architecture. SPI
requires 4 wires:
1) MOSI (Master Out Slave In)-Master line for sending data to the peripherals.
2) MISO (Master In Slave Out)-Slave line for sending data to the master.
3) SCK-clock generated by master to synchronise data transmission.
4) CE0: To enable or disable slave device 0
CE1: To enable or disable slave device1
I2C
The I2C interface pins on Raspberry Pi allow you to connect hardware modules. I2C
interface allows synchronous data transfer with just two pins -SDA (data line) and SCL
(clock line).
10. Write a python program for controlling an LED with switch.
from time import sleep
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
#switch pin
GPIO.setup(25, GPIO.IN)
#LED pin
GPIO.setup(18, GPIO.OUT)
state =false
def toggleLED(pin):
state = not state
GPIO.output(pin,state)
While True:
try:
if (GPIO.input(25) == True):
toggleLED(pin)
sleep(.01)
except KeyboardInterupt
exit( )