File:Lte-ue-rrc-states.png

The changes of UE RRC state model for LTE module in relation to the GSoC 2013 project.The first figure is the state model before the project begins, while the second figure is the state model after the "standard" cut point.One of the reviews received by the project is to expand the states related to cell selection. The expansion aims to distinguish the status of each System Information message (i.e. MIB, SIB1, and SIB2) and the network attachment method used (i.e. manual or automatic). This expansion may provide better debugging capability compared to the previous state machine. The expanded state model is depicted in the third figure.The last figure is another expansion proposed for the later part of the state model. The expansion is the objective of the development of realistic handover, which is one of the future deliverables of the project. It includes Random Access failure, handover failure, RRC Connection Re-establishment (RRD CONN RE-EST in the figure) and Radio Link Failure (RLF).