ECE Special Seminar: Heesu Im (Seoul National University) – “TCP in Wireless Networks: Issues and Approaches”
Speaker : Heesu Im
TCP (Transmission Control Protocol), one of the most essential protocol for the Internet, has carried the most of the Internet traffic since its birth. With the deployment of various types of wireless networks and proliferation of smart devices, a rapid increase in mobile data traffic volume has been observed and TCP has still carried the majority of mobile traffic, thus leading to huge attention again on TCP performance in wireless networks. Recently, bufferbloat has drawn much attention in the network community for its negative impact on TCP delay performance and user QoE. In this talk, we tackle two different problems that aim to improve TCP performance under bufferbloat.
Firstly, we dealt with the downstream bufferbloat problem in wireless access networks such as LTE and Wi-Fi. We clarify the downstream bufferbloat problem in resource competitive environments such as Wi-Fi, and design a receiver-side countermeasure for easy deployment that does not require any modification at the sender or intermediate routers. Exploiting TCP and AQM dynamics, our scheme competes for shared resource in a fair manner with conventional TCP flow control methods and prevents bufferbloat. We implement our scheme in commercial smart devices and verify its performance through real experiments in LTE and Wi-Fi networks. Secondly, we consider the upstream bufferbloat problem in LTE networks. We clarify that the upstream bufferbloat problem can significantly degrade multitasking users’ QoE in LTE networks and design a packet scheduler that aims to separate delay-sensitive packets from non delay-sensitive packets without computational overhead. We implement the proposed packet scheduler in commercial smart devices and evaluate the performance of our proposed scheme through real experiments in LTE networks.
– 서울대학교 전기공학부 학사 (2008)
– 서울대학교 전기컴퓨터공학부 석사 (2010)
– 서울대학교 전기컴퓨터공학부 박사 (2015)
– 관심분야: TCP/MPTCP 성능 최적화, 네트워크 프로토콜 설계, P2P 네트워크