Industrial sixth generation (6G) wireless subnetworks are expected to support very short control communication cycles for multiple sensors. The achievement of demanding communication requirements in terms of latency and reliability might be challenged by signal fading and the presence of obstructors. In this paper, we propose a novel communication protocol for industrial subnetworks that leverages secondary access points (APs) acting as relays for improving the successful execution of short cycle times in a subnetwork, while reducing the overall emitted power. Our solution relies on a classification procedure for identifying the nodes to be served in relay mode, and an algorithm for minimizing the transmit power while coping with the timing constraints. Simulations results show the capability of the proposed approach of reducing the emitted power of up to 7.5 dB, while guaranteeing error probability and rate of resource overflow below 10 −6 .Index Terms-In-X subnetworks, cooperative communication, decode and forward.• We introduce a novel transmission protocol where sensors are scheduled into single-hop and two-hop transmission modes -with corresponding serving secondary AP-based on their channel state information (CSI), while coping with the tight timing constraint. • We address the critical issue of minimizing the total transmit power while ensuring that the stringent cycle