Comparison of different active queue management mechanisms for 3G radio network controllers

In WCDMA networks, radio network controller (RNC) is a potential bottleneck for TCP connections - due to difference in available bandwidth between the core network (CN) and the radio access network (RAN). This may result in packet data convergence protocol (PDCP) buffer overflows or excessive delays at the RNC, as PDCP buffers are flow-specific. In order to avoid PDCP buffer overflows, different active queue management (AQM) methods may be applied at the RNC. This paper is a comparison of four AQM schemes: three well-known ones and one new-TTLRED