Aphirak Jansang received his D.Eng. degree in Computer Engineering from Department of Computer Engineering, Faculty of Engineering, Kasetsart University, Bangkok, THAILAND, since February 2012. He also received Bachelor’s and Master’s degree of Computer Engineering from Kasetsart University. His dissertation under supervision of Assoc. Prof. Anan Phonphoem, is focusing on the enhancement of the IEEE 802.11e HCCA mechanism to handle the transmission of Variable Bit Rate (VBR) traffic. His interested topics are Wireless LANs, Quality of Service (QoS) and Embeded Linux Implementation.