In fifth generation (5G) wireless technology, the centralization of some base station functions will be possible using the new radio access network (RAN) architecture: centralized-RAN (C-RAN). The most challenging type of service to be served by 5G is ultra reliable low latency communication (URLLC), which requires high reliability and low latency simultaneously. In this paper, we compare three RAN architectures. The first has all the processing close to the user and involves single reception. The second and the third architectures, have some centralized BS functions, allowing multiple-cell coordination and thus multiple reception points. We study the impact of architecture and macro-diversity both on the reliability of uplink (UL) packet transmission and on latency.