Our research interests include

      Wired/Wireless Networking Protocols

      Mobile Ad Hoc Networks (MANET)

      Vehicular Ad Hoc Networks (VANET)

      Software Defined Networks (SDN) & Future Internet

      Computer Architecture & System Design

      Software Engineering for Embedded Systems


A little bit more on our recent researches …

Vehicular Networks

Nowadays, the IEEE 802.11p standard is considered as a part of a future transportation system, which increases communication ability between vehicles. The vehicular networks can support applications of Intelligent Transportation System (ITS) such as driver assistant, safety transport applications, streaming or entertainment applications. This research focuses on following topics.

-Data Dissemination Protocol

Data dissemination in vehicular ad-hoc networks is challenging due to unique characteristics of a vehicular environment including intermittent connectivity and various vehicular scenarios. In order to handle these issues, we focus on designing a reliable broadcasting protocol that does not require any geographical knowledge to provide an efficient forwarder selection while minimize a number of retransmissions. A beacon mechanism and waiting timeout calculation are also improved in this work.

- Query Protocol For Data Access

Most of systems that rely on location divide a map into many small regions. Each region is identified by region ID. Recognizing region ID for querying data from the specific location affects to memory size directly. In order to address the mentioned problem, our work applies a Bloom filter technique that is a probabilistic data structure to keep these region IDs into fixed size data structure.

- IEEE802.11p Communication on Public Transport

IEEE 802.11p is an approved amendment to the IEEE 802.11 standard and adds enhancements to 802.11 required in the VANET in 2010. Since then, the 802.11p has been pushed forward to be a new standard for vehicular networks. We deploy our proposed reliable broadcasting protocol on the 802.11p devices and evaluate its performance on shuttle buses in Chulalongkorn University areas as a public transport environment.



Localization System

Localization is a process to determine the current location of the mobile phone. Now, there are many mobile applications providing location information to users. These applications are called as “location-service application”.  Location-service application has many advantages, for example, tracking people, online map and navigation, searching for victims in an emergency situation and location-based advertising. This research focuses on following topics.

- Floor Localization

Although the GPS sensor smartphone can provide the current location precisely over outdoor scenario, it cannot localize over indoor scenario because the obstacles of the building block the signal sent from GPS satellites. Many indoor localization systems have been proposed to address the problem. However, they are developed for single floor scenario only, the localization result misses the dimension of altitude. Therefore, our research focuses on system design to detect the current floor of the smartphone using Wi-Fi signal fingerprints and sensors in the smartphone. Our approach does not need building survey and back-end server.

- Boat Arrival Time Prediction

Transportation is a part of our daily life because we travel everyday. The boat is one of popular public transportation in Bangkok, Thailand. However, the boat does not have any tracking device to tell the location and arrival time of the boat. Our proposed system utilizes smartphones of passengers to collect location of the boat as a crowdsourcing technique. The system uses Wi-Fi access points to locate the boat and uses sensors in the smartphones to define users’ activities. Therefore, the system does not require the GPS sensor on smartphones that drains the battery.


Disaster Recovery System

Communication is important for disaster situation because it allows victims to request for help. However, infrastructures are usually destroyed in a disaster area. Thus, the traditional communication system depending on the infrastructures cannot operate during disaster. To recover the communication in the disaster area, we construct ad-hoc networks or mesh networks using credit card-size single-board computers in the disaster area. We focus on architecture designing and security issues of networks. This work also considers an efficient communication solution to extend the battery life of devices.

List of Publications