This document discusses experiments conducted using the Contiki operating system and RPL routing protocol in wireless sensor networks. It describes setting up networks with different numbers of relay and client nodes. Experiments were run with sensor nodes sending data at various frequencies to measure network performance over time periods ranging from a day to multiple days. Results on packet loss are presented. Further work is proposed to conduct more extensive RPL testing under additional configurations and add sensor nodes to track object movement.

1. Contiki Project about RPL
Protocol in WSN
Soultana Ellinidou
UnderGraduate Student at University of Western Macedonia , Kozani
Department of Engineering Informatics & Telecommunications

2. Introduction: Contiki platform
 Οpen source operating system for the Internet of
Things.
 Focus on low-power wireless Internet of Things
devices.
 Provides powerful low-power Internet
communication.
 Supports fully standard IPv6 and IPv4, along with the
recent low-power wireless standards: 6lowpan, RPL,
CoAP.
 Cooja simulator Contiki networks can be emulated
before burned into hardware.
 Easy and fast development: Contiki applications are
written in standard C.

3. Introduction: RPL Protocol
 IPv6 routing protocol for Low power and Lossy
Networks
 M2H &H2H
 Forms a tree like topology
 Supports both upward and downward routing
 RPL is responsible for getting routing info and
forwarding packets
 Needs to be optimized to gain performance and
utilize constrained resources
DODAG

4. Introduction: How RPL Protocol works
 RPL uses 3 control messages:
DODAG Information Object (DIO)
DODAG Information Solicitation (DIS)
DODAG Advertisement Object (DAO)
The path selection is provided by Objective Functions
based on routing metric and constraints:
OF0 (hop count)
ETX (Expected Transmission Count)

5. Client-Relay Code
Sets up UDP
connection
Check if the
mote is client or
relay
If it is client,
sends packet to
UDP server
periodically.
If it is relay, wait
to receive packet
from the client
and then to

6. Server Code
Initializes RPL
DAG
Sets up UDP
connection
Waits for packets
from client,
receives and print
them

7. Cooja Simulator

8. Cooja Simulator: Mote Output

9. Network
Devices that we use in our network:
Zolertia motes
CO2 sensor K30
Raspberry Pi 2 (Gateway)
Cases:
1 server, 1 relay, 1 client
1 server, 4 relays, 1 client
1 server, 7 relays, 1 client
1 server, 5 relays, 2 clients

10. 1st Experiment (B6 Building)
Batteries power
supply

11. 2nd Experiment (B6 Building)
Nodes Neighbors
S #61 R #62
R #62 R#64, R#65, R#68
R #64 R#62, R#65, R#68
R #65 R#64, R#62, R#68
R #68 R#64, R#65, R#62
C #63 R #68
Batteries power
supply

12. 3rd Experiment (B6 Building)
Nodes Neighbors
S #61 R #66, R#64
R #66 R#64, R#69, R#64,R#65,
R#67, R#68
R #62 R#66, R#69, R#64,R#65,
R#67, R#68
R #69 R#64, R#66, R#64,R#65,
R#67, R#68
R #64 R#64, R#69, R#66,R#65,
R#67, R#68
R #65 R#64, R#69, R#64,R#66,
R#67, R#68
R #67 R#64, R#69, R#64,R#65,
R#66, R7#68
R #68 R#64, R#69, R#64,R#65,
R#67, R#66
C #63 R#66, R#68
Batteries power
supply

13. 3rd Experiment (B6 Building)

14. 4th Experiment (B6 Building)
Batteries power
supply

15. 4th Experiment

16. 5th Experiment
CTTC Building:
Ground floor: 5 relies,
1 client, 1 Co2 sensor,
1 raspberry pi
1st floor: 2 relies, 1
server , 1 raspberry pi
Plug power supply

17. 5th Experiment (B4 Building)
Client is sending a packet every 10 seconds
Running time: During the
day

18. 6th Experiment (B4 Building)
Client is sending a packet every 20 seconds
Running time: During the
day

19. 7th Experiment (B4 Building)
Client is sending a packet every 60 seconds
Running time: From
6pm until10am

20. 8th Experiment (B4 Building)
Client is sending a packet every 120 seconds
Running time: 2days

21. Network Metrics
Histograms of simulation, that was running during the
morning
Frequency: 10sec Frequency: 20sec

22. Network Metrics
Histograms of simulation, that was running during days
Frequency: 60sec Frequency: 120sec

23. Network Metrics
Results about Packet loss of different frequencies

24. Future Work
Complete the RPL tests in your network for more
settings(frequencies, time, number of motes).
Add a sensor to track the movement in the stairs.
Make a script to restart the client and server motes in the same
time.
Communication between different network layer protocols.

25. Thank you for your attention.