 technologies appeared with the 3G (third-generation) mobile networks in the late 2000s, and they continue with 4G (fourth-generation) and 5G (fifth-generation) mobile networks in the second and third decades of the twenty-first century. The widespread mobile technologies which belong to the mobile broadband world include UMTS/HSPA (universal mobile telecommunication system/high speed packet access) as part of the 3G standards umbrella, Mobile WiMAX (3G and 4G umbrella), and LTE/LTE-Advanced (LTE stands for long-term evolution) as the most successful 4G technologies. One may note that WiFi is not presented under a separate bullet here, due to the fact that WiFi is more a local wireless extension of fixed or mobile broadband access networks. According to the ITU [2], by early 2016 total international Internet bandwidth had reached 185,000 Gbit/s, a significant increase from the globally available bandwidth of about 30,000 Gbit/s in 2008. However, there is no equal connectivity of all regions on the global scale. For example, Africa has the lowest international connectivity of all regions, while there is twice as much bandwidth per inhabitant available in Asia and the Pacific, eight times as much in the Americas, and more than 20 times as much in Europe [3]. Also, one may note that always-on access, mobile broadband penetration, as well as the massive adoption of broadband-enabled devices have irreversibly changed the consumers of telecommunication/ICT services, including their social and economic 1 Introduction behaviors as well as QoS expectations, which are constantly increasing over time for certain services (e.g. video). The more diverse telecommunications/ICT world requires more effort in maintain- ing the QoS, including provision, measurements, and enforcement. QoS and quality of experience (QoE) are becoming more and more complex because the quality can be impacted by many different factors coming from the telecommunication networks as well as along the value chain, which includes the end-user's device, the