Performance measurement over Mobile WiMAX/IEEE 802.16e network

WiBro (Wireless Broadband) is a Korean version of Mobile WiMAX/IEEE 802.16e system, which is designed for mobile broadband wireless access. Being a subset of IEEE 802.16e, WiBro employs orthogonal frequency division multiple access (OFDMA) and time division duplexing (TDD) schemes operating at 2.3 GHz bands. In mid 2006, the world first commercial Mobile WiMAX service, based on WiBro specification, started in Seoul, Korea. In this paper, we analyze the performance of commercial WiBro networks through traffic measurements. Many experiments are conducted in the various environments. We analyze the link capacity when the user datagram protocol (UDP) packets from multiple users fully utilize wireless links. We also analyze goodput performance with transmission control protocol (TCP) as well as round trip time performance. The measured performances are compared with those of HSDPA (High-Speed Downlink Packet Access) which is a competing system of Mobile WiMAX. We found that the RTTs of WiBro and HSDPA are very large compared with conventional data networks, e.g., Ethernet or Wireless LANs. Furthermore, it is shown that the user-perceived performance is limited by such long round trip times when TCP is utilized. It motivates us to improve round trip time performance of WiBro system. Finally, we analyze the VoIP performance and the performance when the user moves around the whole city.