In the JET tokamak, it was demonstrated that injecting gas in the Outer Mid-Plane (OMP) can result in a peripheral plasma density increase, which improves the Lower Hybrid (LH) wave coupling. Gas puffing proved to be useful in JET particularly in cases with a relatively large distance of about 10cm between the LH grill mouth and the plasma. It was shown by EDGE2D modelling that the increase in the Scrape-off-Layer (SOL) density and the consequent LH wave coupling improvement can be explained by ionisation of the SOL neutral due to heating by the LH wave. In contrast to the computational grid for configurations considered in that have a SOL width of about 10cm at the OMP, ITER relevant magnetic configurations, with the 2nd.