This paper presents a novel SDN-based 5G network architecture, conceived to support next generation delay critical services. Following a 4G systems delay analysis, new design principles towards a “zero latency” network are discussed. Based on these guidelines, and under the assumption of a broad adoption of emerging SDN and NFV technologies, a novel “plastic” architecture for 5G systems is devised. Together with the architecture, new procedures for device attachment, connectivity and mobility management are presented. Latency improvements from the proposed architecture have been estimated up to 75% compared to 3GPP Release 12 compliant 4G systems.