ICC Workshops Varela, M, Zwickl, P, Reichl, P, Xie, M & Schulzrinne, H 2015, From Service Level Agreements (SLA) to Experience Level Agreements (ELA) : The challenges of selling QoE to the user . in Communication Workshop (ICCW), 2015 IEEE International Conference on . IEEE Institute of Electrical and Electronic Engineers, pp. 1741-1746, IEEE International Conference on Communication Workshop, ICCW 2015, London, United Kingdom, 8/06/15 . https://doi.org/10.1109/ICCW.2015.7247432