3GPP Radio Resource Control in Practice

3GPP-standardized networks have been evolving at a very fast pace over the last decade. Cell capacities increased more than an order of magnitude, latencies have become considerably smaller, and worldwide deployment has changed the way people access services. In this evolution, efficient mechanisms for radio resource control have played a key role. In this article we review the RRC state transition model and follow its development from its early stage at the outset of UTRAN deployments to state-of-the art HSPA-enhanced networks. This article also overviews previous work on empirical measurements from 3G networks that study the "theory and practice" of RRC state transitions. Finally, we present our 3G Transition Triggering Tool and use it to empirically study network configuration parameters that prompt RRC transitions. Our results come to the aid of fully understanding the behavior of RRC state transitions and lead us from "theory" to "practice" on RRC mechanisms.