e selected RA-RNTI in order to receive message 2. The message 2 PDCCH and PDSCH transmission parameters for handover procedure are defined in the same way as for the RRC Connection Setup procedure. Message 2 defines the PUSCH resource allocation for the initial transmission of message 3. The resource allocation for message 3 retransmissions (in case of contention-free random access procedure) is done following adaptive HARQ retransmissions and the allocation informed to the UE by PDCCH DCIO. Message 3 resource allocation should be large enough for RRC Connection LTE Small Cell Optimization Reconfiguration Complete message and long buffer status report (BSR) and power head room report (PHR). The number of PRBs and the MCS for handover procedure (for message 3 transmission) should therefore be optimized in a similar way as for RRC Connection Setup procedure (minimizing the transmission power needed to send the whole message 3 in single PUSCH transmission). It should be noted that in case the resource allocation is too small message 3 is segmented causing additional delay in handover procedure completion. When message 3 resource allocation is optimized in a similar manner as for RRC Connection Setup procedure, the handover procedure failure rate in poor coverage conditions in terms of failed message 3 receptions by the eNodeB can be reduced significantly (up to 20% in one exam- ple cluster). In case of challenging radio conditions the handover procedure failure can also be caused by the source cell problems, that is, the UE might not hear the RRC Connection Reconfiguration message. In case the MRO algorithms (too early or too late handovers) cannot improve this problem then the source cell link adaptation in terms of sending the RRC Connec- tion Reconfiguration message (PDCCH and PDSCH) to the UE needs to be made more robust. 12.5.2 UE-Triggered RRC Connection Re-establishments UEs monitor the radio link performance and in case of problems RRC connection re- establishment can be triggered unless the problem can be r