1. A Study of Data Dissemination on Vehicular Ad Hoc Networks using IEEE802.11p Communication System
Final Report
Passakon Prathombutr, Ph.D
NECTEC
Kultida Rojviboonchai, Ph.D.
Kulit Na Nakorn, Ph.D.
Kiattikun Kawila
ISEL, Department of Computer Engineering, Chulalongkorn University

2. System Architecture Device Installation Environment Detail
Study Results
Example Cases
Unexpected Issues

3. Application : displays information to passenger
System Architecture
Application : displays information to passenger
Wi-Fi Hotspot : connects IEEE802.11p to Wi-Fi standards
IEEE802.11p : bus-to-bus and bus-to-bus stop comm.
GPS, Traffic Status, …
Intelligent Bus Stop
IEEE802.11p
Communication
Device
Wifi Hotspot
Bus
Passenger

4. System Architecture IEEE802.11P Communication Device (Bus/Bus Stop)
Smartphone
(Passenger)
Application
Application
Reliable Broadcast Prot.
(API)
Reliable Broadcast Prot.
(API)
App
Wi-Fi
Wi-Fi
802.11P
Wi-Fi
802.11P

5. System Architecture Access Point Raspberry Pi + Sensors
Ethernet Switch
DENSO WSU-5001T
Voltage Step Down Circuit

6. Device Installation : Buses
IEEE802.11p
Antenna
GPS
Antenna
IEEE802.11P
Device

7. Device Installation : Pictures
Buses

8. Device Installation : Base Station
IEEE802.11p
Antenna
GPS
Antenna 1
IEEE802.11P
Device
Battery
Position of base stations
on the covered walkway
Position of base stations
on the map

9. Device Installation : Pictures
Base Station
Device
Box
Battery
Box

10. Environment Detail System Architecture Device Installation
Study Results
Example Cases
Unexpected Issues

11. 1 2 4 Environment Detail : Bus Routes and Base Stations Buses
Line 1 : 6 Buses 2
Line 2 : 5 Buses 4
Line 4 : 4 Buses
Base Stations
2 Base Stations

12. Broadcasting Protocol: DECA
DECA performs periodic beaconing to gather local density information of 1-hop neighbors.
A node selects a neighbor with highest density.
Selected node is responsible for rebroadcasting the message immediately.

13. Environment Detail : Message Configuration
Sending Interval
Every 1 Minute
Message Lifetime
30 Minutes
Message Size
512 bytes
Message Header
Source IP
(4 bytes)
Msg ID
(4 bytes)
GPS
(16 bytes)
Timestamp
(8 bytes)
Payload
(512 bytes)

14. Study Results System Architecture Device Installation
Environment Detail
Study Results
Example Cases
Unexpected Issues

15. Study Results: Online Activity Ratio
Tue 3 Nov 2015
Install devices
Mon 9 Nov 2015
Install more devices
Online Activity Ratio
Tue 10 Nov 2015
Add fuse

16. Study Results: Online Activity Ratio
Wed 11 Nov 2015
Unplug devices to check power problem
Thu 13 Nov 2015
Install more devices without being connected to power
Online Activity Ratio
Fri 19 Nov 2015
Fix AC power problem:
Add Diode

17. Study Results: Online Activity Ratio
Fri 20 Nov 2015
Sat 21 Nov 2015
Online Activity Ratio
Mon 23 Nov 2015
Fix file format issue:
Change format from FAT32 to EXT4

18. Study Results: Online Activity Ratio
Tuesday 24 November 2015
Online Activity Ratio

19. Study Results: Packet Delivery Ratio
*Packet Delivery Ratio = Packet Sent / Packet Received
Packet Delivery Ratio
Date

20. Study Results: Packet Delivery Ratio
Mon 23 Nov 2015
07:05 – 07:35 AM
Packet Delivery Ratio
Tue24 Nov 2015
06:55 – 07:25 AM
Shuttle Bus ID

21. Study Results: Transmission Delay
Transmission Delay (Sec)
Number of hops (Number of Rebroadcast events)

22. Example Cases System Architecture Device Installation
Environment Detail
Study Results
Example Cases
Unexpected Issues

23. Sample Log of Bus 85

24. Example Cases: Log Field Extraction
Send Data
Timestamp
Flag
Latitude
Longitude
Source IP
Seq #
Selected IP
7:05:18 AM
SendData
735
Receive Data
Timestamp
Flag
Latitude
Longitude
Source IP
Seq #
7:05:18 AM
RecvData
735
Rebroadcast Data
Timestamp
Flag
Latitude
Longitude
Source IP
Seq #
Selected IP
7:05:19 AM
RebcData
735
*Selected IP = Node/Bus that is responsible for rebroadcasting the message immediately.
*Seq = Sequence Number to track the same packet/message

25. Example Cases: Broadcasting Data
At 07:05 AM
7:05:18 AM SendData
7:05:18 AM RecvData
7:05:18 AM RecvData
7:05:19 AM RebcData
7:05:19 AM RecvData
7:05:19 AM RecvData

26. Example Cases: Broadcasting Data
At 07:10 AM
7:10:13 AM RebcData
7:10:14 AM RecvData
7:10:14 AM RebcData
7:10:44 AM RebcData
7:10:44 AM RecvData
7:10:44 AM RebcData
7:10:45 AM RecvData

27. Example Cases: Broadcasting Data
At 07:30 AM – 07:35 AM
7:30:03 AM RebcData
7:30:04 AM RecvData
7:30:27 AM RebcData
7:30:29 AM RecvData
7:35:01 AM RebcData
7:35:01 AM RecvData
7:35:01 AM RecvData
7:35:02 AM RebcData
......

28. Unexpected Issues System Architecture Device Installation
Environment Detail
Study Results
Example Cases
Unexpected Issues

29. Unexpected Issues
New electrical system of CU shuttle bus
AC leaking in main power line damages the voltage step down circuit.
Heavy rain causes water leaking and double-side tape degeneration

30. Unexpected Issues
File format issue and read only problem
FAT32 EXT4
DENSO WSU-5001-T
Red light notification – not boot

31. Project Presentation at NBTC

32. Pictures

33. Summary
Data can be delivered up to 83.93%.
Results were gathered from 10 buses and 1 RSU.
Maximum number of online buses was 9 buses.

34. Future Work Problem: Solution:
There are 5 WSUs that do not work properly.
Solution:
Recover 5 WSUs using the DENSO firmware
Deploy 4 WSUs on 4 buses
Deploy 1 WSUs as 1 RSU
Performance Measurement & Evaluation

35. Our Team
NECTEC
Passakon Prathombutr, Ph.D
Information System Engineering Lab (ISEL), Department of Computer Engineering, Chulalongkorn University
Kultida Rojviboonchai, Ph.D.
Kulit Na Nakorn, Ph.D.
Kiattikun Kawila
Tanapoom Danmanee
Nattakan Pramuanyat
Pakawat Chumcharoen
Tanapat Ruengsatra
Adsadawut Chanakitkarnchok