Influence of the Cellular Environment Scenario on TCP Performance in UMTS Radio Systems

In the paper, the authors aim to quantitatively and qualitatively assess the impact of the cellular environment on TCP performance. The analysis is carried out through a test bed platform working in real time. Its core is represented by the GALATEA emulator, which allows the users to include all the characteristics of a real UMTS system. Four cellular environments, derived from the MORANS database developed within the COST 273 action, and two alternative RLC configurations are considered in the paper. The corresponding results, achieved through specific GALATEA settings, highlight the complex cross-layer interactions between the cellular environment and both the TCP and the UMTS-RLC protocols. Although the study confirms the effectiveness of the RLC ARQ mechanism in reducing the channel impairments impact on the upper layers, it also shows that the cellular environment still has a significant influence in determining TCP traffic performance.