I have earned my master’s degree in June 2008, honored by National Taiwan University. Ultimately, I hope to do network research in academia and apply the results to industrial technologies. To this end, the rigorous training and independent research ability is exactly the reason why I apply for your prestigious Ph.D. program.
I am always curious about everything.As a student graduating with honor, taking courses simply cannot satisfy my curiosity. Thus, during my undergrad years, I seized every opportunity to explore further knowledge. In 2003, I got my first project founded byNational Science Council[1] namely Development ofWireless Campus Information Services, where I learned practical system and network administrative experiences; In my senior year, I also joined a research lab led by Prof. Jean-Lien C. Wu and investigated into the relation between the burst error in wireless communication and the performance of TCP protocols, which also received the research grant from the National Science Council. However, being familiar with the current network services, it is intuitive for me to ask: ARE THOSE SERVICES GOOD ENOUGH?
This question led me to the realm of research. In my senior year, I joined a project led by Prof. Ai-Chun Pang. Starting with IEEE 802.16j (WiMax + Relaying), the goal of the project is to develop an efficient mechanism to guarantee the network QoSs for different types of traffics. To solve this problem, a joint routing and link scheduling algorithm was first designed for best-effort services. Through the theoretical analysis and simulation, we showed the throughput of the proposed algorithm is within a factor of 3 of the optimal value in worst case, while the problem is well-known NP-hard even only considering the link scheduling. Through the simulation, our joint routing and link scheduling algorithm does have a chance to outperform others in both worst-case and average-case! The result of this exciting work has been accepted with minor revision by IEEE Transactions on Wireless Communications.With it, we are able to efficiently support the best-effort traffics. However, this work could not deal with real-time services due to lack of considerations of packet delay.
As compared to the best effort traffic, the real-time service flows are delay-sensitive data stream. To tackle with that, we therefore provide efficient mechanisms (including admission control, routing and interference-aware link scheduling) to provide soft QoS and hard QoS guarantee, respectively. For soft QoS applications, we proposed a mechanism to achieve the bandwidth and delay requirement of the applications such that the global resource efficiency is maximized. Our routing and scheduling mechanism are innovative while remaining simple. It allows multi-path routing to balance link traffics and thus a higher degree of spatial reuse can be achieved. It further improved the resource efficiency and the system throughput. I presented the result of this work in IEEE Wireless Communications & Networking Conference (WCNC’07), and the audiences are attracted by its promising preliminary result. We also proposed the mechanism to provide hard QoS guarantee. It is very difficult to explicitly guarantee the bandwidth and delay requirement of each service flow since each flow could pass through multiple relay stations in IEEE 802.16j-based Wireless relay networks, and our work presents the first attempt. We show the problem is NP-hard, and no “theoretically” small approximation factor exists for any polynomial time algorithm. Therefore, we present a polynomial time algorithm to provide hard QoS guarantee with a “practically” small approximation factor. The results aresubmitted to IEEE Conference on Computer Communications (INFOCOM’09).
With five-year practical experiences in the field of computer networking, I have prepared myself to become a highly competitive Ph.D. student. As a researcher, I always keep a curious mind and polish my skills by participating in research projects. Now, with the urge to know more about this world, I am applying for Fulbright PH.D.Program and seeking for the opportunity to explore further in my research field!
[1]National Science Council in Taiwan is equal to National Science Foundation in United States.