 example, the RAN in 3G mobile net- works, standardized by 3GPP (3G Partnership Project), is called UTRAN (Universal Mobile Telecommunication Systems Terrestrial Radio Access Network), while the RAN in 4G mobile networks from 3GPP is based on LTE (long-term evolution) technology and is called E-UTRAN (Evolved Universal Mobile Telecommunication Systems Terrestrial Radio Access Network), as an evolution of its predecessor. 2.2 Fundamental Internet Network Architectures Region 1 Region 2 Country B Country K Region 3 Country A Provider 1 Provider 2 Region N Provider M Basic network model Regional Regional network A network B Access Transit Access network A network network B Figure 2.4 Basic network model for QoS analysis. However, from the QoS point of view, end-to-end IP networks can be divided into three main groups (Figure 2.4): Access networks. They include all types of fixed and mobile access networks, either LAN or MAN, through which the end-hosts (either users with devices or various "things") are attached. Regional networks. They connect different access networks which are under admin- istrative control of a single network provider such as a telecom operator, and provide their connection to the Internet and to a set of common functionalities (e.g. control functions, management functions). They consist of core networks (where the main gateways are located) and transport networks (which are used for interconnection of different nodes in the core and in the access parts). Transit networks. These types of networks are used for interconnection of different regional networks on a national or regional basis. 2 Internet QoS 2.2.4 Autonomous Systems on the Internet The Internet as a global network is built on the principle of a network of many networks that are interconnected through routers. Certainly, there must be routers between dif- ferent IP networks. However, several smaller or larger networks can be administered by a company, such as an Internet service provider. In this case we actually have inde- pendently o