Coatings of large-area optics with demanding thin-film systems such as dichroic mirrors or beam splitters are asked for by the astronomy sector and large laser facilities. To address these requests, the Laser Zentrum Hannover e. V. (LZH) is developing a novel ion beam sputtering (IBS) process in the project “IBS 2000” that can coat optics with a diameter of up to 2 meters. Key criteria for the coatings are low optical losses, stability against laser radiation, and precise spectral properties. Therefore, the ion beam sputtering process is chosen since this technology delivers coatings of the highest optical quality as well as high mechanical and environmental stability. To realize IBS concepts for coating of large optics, both the material source and the vacuum chamber would need to be enlarged. Due to the growing substrate sizes, an enlargement of the vacuum chamber is inevitable, but for the sputtering unit, more innovative approaches can be considered. The concept chosen applies a mobile sputter assembly comprising of the ion source and the target. In combination with a rotating substrate, a homogeneous deposition can be achieved over the entire substrate. This contribution presents the current project status with the realized mechanical concept and simulation of the deposition and process conditions. Simulations regarding the homogeneity, as well as the layer deposition parameters, are made with a virtual coater concept. Firstly, the material distribution is calculated for a static sputter material carrier. This calculation then provides the material distribution in the substrate plane, and the calculated sputter distribution is combined with the movement of the sputter unit carrier and the substrate rotation. This provides a first indication of the 2D distribution over the full substrate scale and allows precise optimization of the final coating homogeneity.