@conference {, title = {Indoor Positioning in Large Environments: Ultrasonic and UWB Technologies}, booktitle = {International Conference on Indoor Positioning and Indoor Navigation }, year = {2019}, month = {10/2019}, pages = {1-8}, publisher = {IPIN}, organization = {IPIN}, address = {Pisa, Italia}, isbn = {978-1-7281-1788-1}, author = {Gualda, D and A. Hernandez and J. M. Villadangos and Ure{\~n}a, J. and Jimenez, A. and F. Seco} }