 RRC connection request message (layer 3 message) is delivered to lower layers within the UE and it initiates the random access procedure to establish synchronization between the UE and the eNodeB as shown in Figure 12.9. The RRC connection setup supervision timer, T300, is started in the UE layer 3 when it delivers the RRC connection request message to lower layers (T300 is stopped if RRC connection setup message is received). After successful random access setup (i.e. the UE receives the random access response), the RRC connection request message is sent to the eNodeB. The eNodeB responds with RRC connection setup message and RRC connection is successfully setup when eNodeB receives the RRC connection setup complete message from the UE. During the RRC connection setup signalling, the power control and link adaptation have very limited knowledge of the UE radio conditions. means that the transmission power levels and coding rates need to be set by fixed parameter values given by the network (explained in following sections) combined with retry algorithms which can dynamically modify those given parameter values. Poor success rate to receive any of the RRC connection establishment procedure messages leads to extra call setup delays and interference increase due to the retransmissions. The addi- tional retransmissions increase physical random access channel PRACH, physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH) and physical downlink shared channel (PDSCH) loads and therefore also the interference level increases for each of those channels. The increased interference means reduced uplink and downlink efficiency, LTE Key Performance Indicator Optimization MSG1 - RACH: RA Preamble - PDCCH/DCI1C/RA-RNTI; PDSCH/DL-SCH/CCCH/SRB0 MSG3 - PUSCH/UL-SCH/CCCH/SRB0: RRC Connection Request MSG4 - PDCCH/DCI1A/T - C - RNTI; PDSCH/DL- SCH/CCCH/SRB0: Contention Resolution + RRC Connection Setup PUCCH: Scheduling Request PDCCH/DCI0/C-RNTI MSG5 - PUSCH/UL-SCH/DCCH/SRB1: RRC Connection Setup Complete 