ironment. TV over IP with QoS guarantees end-to-end is called IPTV. 6.2 QoS-enabled Video and IPTV Services End user Network provider Service provider Content provider Movies Sports Figure 6.3 IPTV domains. However, one should note that due to much higher demand for bandwidth of TV com- pared with voice services, the transition of analogue to digital TV happened later than the transition from analogue to digital telephony (analogue to digital TV transition was completed globally by the middle of the 2010s, while the transition for voice from ana- logue to digital telecommunication networks was completed by the end of the twentieth century). TV refers to a real-time service where the same content (e.g. live content) is broadcast to all recipients tuned to watch a given TV channel (on a given frequency, either via terrestrial broadcast or cable broadcast of the channels). In the case of IP delivery of TV content, the TV is not more the broadcast, because Internet network do not use broadcast for delivery of user contents, but its delivery is based on unicast (point to point) and multicast (point to multipoint) transport. Considering IPTV definition, the ITU-T defines IPTV as multimedia services such as TV, video, audio, pictures/graphics, and data, delivered over IP-based networks that are designed to support the necessary level of QoS and QoE [6], interactivity, reliabil- ity, and security. So, a TV stream provided over the public Internet network cannot be considered as IPTV (according to the given definition) because the public Internet net- work does not provide QoS guarantees to individual streams of data due to the network neutrality principle. For the provision of IPTV services four IPTV domains can be differentiated: (i) content provider; (ii) service provider; (iii) network provider; and (iv) end-user (Figure 6.3). However, one provider entity can manage more than one IPTV domain. That is the typical case when telecom operators provide IPTV service. In fact, with IPTV the telecom operators (first fixed one