  Over the last few years, the evolution of network and user handsets'
technologies, have challenged the telecom industry and the Internet ecosystem.
Especially, the unprecedented progress of multimedia streaming services like
YouTube, Vimeo and DailyMotion resulted in an impressive demand growth and a
significant need of Quality of Service (QoS) (e.g., high data rate, low
latency/jitter, etc.). Mainly, numerous difficulties are to be considered while
delivering a specific service, such as a strict QoS, human-centric features,
massive number of devices, heterogeneous devices and networks, and
uncontrollable environments. Thenceforth, the concept of Quality of Experience
(QoE) is gaining visibility, and tremendous research efforts have been spent on
improving and/or delivering reliable and addedvalue services, at a high user
experience. In this paper, we present the importance of QoE in wireless and
mobile networks (4G, 5G, and beyond), by providing standard definitions and the
most important measurement methods developed. Moreover, we exhibit notable
enhancements and controlling approaches proposed by researchers to meet the
user expectation in terms of service experience.
