Many use cases are meant to be supported by the fifth generation (5G) wireless technology. The one which is occupying the research area for its challenging requirements is the Ultra Reliable Low Latency Communications (URLLC). Hybrid Automatic Repeat reQuest (HARQ) protocol is used to ensure reliability but it induces delay. Furthermore, the transmission in the Radio Access Network (RAN) should be taken into account in the delay budget. In this paper, we jointly analyze the reliability and the delay with two RAN architectures : the legacy one where only one radio unit receives the packet from a terminal and a Centralized-RAN (C-RAN) architecture where several radio units can decode a packet. We propose to combine these approaches in a flexible architecture. The observed enhancement is a division by 850 of the packet erasure rate compared to the legacy architecture with a latency of 3 milliseconds.