Comparison of Web traffic performance in W-CDMA mobile satellite systems

We analyze and compare the performance of Web traffic in two 3G W-CDMA mobile satellite systems, namely GEO and MEO systems assuming random frame error rate (FER). The effect of using two different data rates (i.e. 64 kbps and 144 kbps), two TCP initial window (2*512 and 4*512 bytes) and segment sizes (512 and 1460 bytes) on Web page download time are examined for the two systems. Simulation results presented here show that for 144 kbps data rate the Web traffic requires a FER≤5*10^-3 to avoid any significant increase in Web page download time. The results strongly suggest the use of a data rate ≥144 kbps in order to avoid unacceptable increase in Web page download time in the two mobile satellite systems. The results also show that the MEO system (15000-km altitude) provides only slight reduction in Web page download time in comparison to that in the GEO system. Hence, this slight improvement in Web page download time alone might not merit the selection of MEO over GEO satellites taking into consideration the complexity and the risk associated with the AEO system. Similarly, using larger TCP segment size such as 1460 bytes provides a small but significant reduction in Web page downloads time in comparison to that of 512 bytes.