Distributed and networked gas sensing is increasingly important for industrial, safety and environmental monitoring applications. Optical nondispersive infrared (NDIR) gas sensors offer the highest sensitivity, stability and specificity in the market, but for most applications, the existing sensors are too bulky and expensive. To enable the broad utilization of high-performance gas sensor networks, there is a critical need for small, low-power and networked gas sensor systems. In ULISSES, we will develop an integrated multi- channel optical gas sensor system-on-a-chip (SoC) and demonstrate its capability to detect three gases simultaneously. Furthermore, we will develop the networking technology required to bring these SoCs onto the Internet of Things (IoT). We will implement a new edge-computed self-calibration algorithm that leverages node-to-node communications to eliminate the main cost driver of low-cost gas sensor fabrication and maintenance (the calibration). Finally, ULISSES will deliver the wafer-scale mass production methods necessary to enable production volumes of millions of sensors per year, and thus provide an order of magnitude reduction of sensor module cost. By leveraging recent breakthroughs of the ULISSES partners on waveguide integrated 2D materials-based photodetectors, 1D nanowire mid-IR emitters, and mid-IR waveguide-based gas sensing using MEMS-tunable filters, we target a three-order-of-magnitude reduction in sensor power consumption, thus permitting maintenance-free battery powered operation for the first time. Between the participants, we cover the full range of competences required for the task. The market for low cost IoT gas sensors is in its infancy, but at a 7.3% compound annual growth rate (CAGR) it is lucrative enough for players with older less specific gas sensor technologies to fight for gaining a first mover advantage. Thus, the window of opportunity for a new disruptive entry into this market is rapidly closing.