TileCal Trigger Tower studies considering additional segmentation on the ATLAS upgrade for the high luminosity LHC

The ATLAS Tile hadronic calorimeter (TileCal) provides highly-segmented energy measurements of incoming particles. The information from TileCal's last segmentation layer can assist in muon tagging and it is being considered for a future upgrade of the level-one trigger to reject triggers due to radiation background effects. In addition, studies with better TileCal trigger tower energy precisions for the level-one trigger system are performed in order to check their impact at the ATLAS upgrade phase I and II scenarios, where higher luminosity and pile-up are expected. The motivation is to improve the ATLAS level-one trigger system, to be able to keep an acceptable trigger rate, while keeping the current $\pt$ thresholds for single and isolated objetcs. Here, it's summarized these studies which are currently still on-going.