On the UMTS RLC parameters setting and their impact on higher layers performance

In this work the performance of the radio link control (RLC) level of the Universal Mobile Telecommunications System (UMTS) is investigated. The role of a correct setting of link layer parameters is evaluated by considering both forward and backward channel metrics. End-to-end performance is obtained considering the TCP flow. The main findings of our investigation are that: i) a correct setting of RLC parameters is pivotal to avoid deadlock events, that would lead to a dramatic performance degradation; ii) schemes using receiver-driven retransmission requests give the best performance; iii) the EPC mechanism gives very good performance in terms of delay, throughput and energy; iv) anomalous behaviors, leading to delay jitter performance degradation, are observed for some receiver-driven schemes. Again, EPC is able to overcome these problems.