The years I spent on my PhD study in NTU have without doubt been the most rewarding part of my life. Campus life, research challenges, working with professors and colleagues have equipped me with necessary skills to thrive. I am eternally grateful to the people who shared these memories with me and to those who made it possible. My deepest gratitude goes to my supervisor, Prof. Tan Hee Beng Kuan. Tan has provided me with invaluable guidance, continuous support and encouragement. He has spent much effort on finding different research topics and approaches to make progresses and achievements for my project. His insistence on excellence has influenced my way of life and made me a fine researcher, writer, and critical thinker. I also thank Prof. Lionel C. Briand from SnT Centre, University of Luxembourg, for his insightful suggestions and advices. He has shared with me his unique problem solving skills. My special thanks go to my fellow research students, Ding Sun, Bindu, and Kaiping, who have shared with me some of their research works and with whom I have exchanged ideas. I would also like to thank my colleagues in InfoComm Research Lab for many fruitful discussions about the research issues and for sharing ideas about the project and contributing suggestions. I am also grateful to the Master students from Communication Software and Networks course who have worked with me in developing prototype tools and carrying out experiments. Last but not least, I wish to thank my parents and Thinzar, my lovely wife, to whom I am eternally indebted. I am grateful for all their love, care, encouragement, and support throughout this journey. I would not have come this far without them.