user data traffic; and GTP (GTP for charging data). GTP-C and GTP-U are used in all 3GPP mobile systems with IP connectivity. With that approach 3GPP has full control over the stan- dards used for delivery of QoS in its mobile systems, although all such mobile systems are all-IP starting from 4G and onward. How is QoS bound with the user connection? Well, in 2.5G and 3G mobile networks from 3GPP that is accomplished by PDP (packet data protocol), which contains session information when mobile user has an active IP connection. Each PDP context includes 5 QoS for Mobile Ultra-Broadband the subscriber's IMSI (international mobile subscriber identity), which is stored in the SIM (subscriber identity module) card and given an IP address (by using the DHCP) which may be IPv4 or IPv6, as well as a logical connection with a QoS profile (which includes a set of QoS attributes) through the UMTS mobile network. QoS in 4G Ultra-Broadband: LTE-Advanced-Pro In 4G mobile networks from 3GPP, the QoS approach has similarities to the QoS approach in 3G networks, being directly related to bearers. The number of bearers in the LTE/LTE-Advanced mobile networks (Figure 5.7) is similar to that in UMTS. The bearer over the mobile network (between user equipment and P-GW) is called the EPS bearer. The EPS itself has two main parts: E-UTRAN and EPC. Each mobile terminal connected to the EPS-based mobile network has at least one established bearer for IP connectivity (the default bearer). Additional bearers can be set up for the same terminal. Different flows with similar QoS requirements can be mapped on the same bearer, with the same QoS treatment (e.g. different flows over the public Internet accessed through the mobile network). The EPS bearer consists of the following three main bearers: radio bearer, which covers the LTE/LTE-Advanced radio interface; S1 bearer for the S1 interface, which is between eNodeB and S-GW; S5/S8 bearer on the S5/S8 interface, between S-GW and P-GW. The two main gateways in the EPC for the user data traffic, 