ance with 802.11 standard. The eNB entity is the anchor point for channel aggregation. MPTCP (Multi-Path Transmission Control Protocol) aggregation has the advantage of transmitting data using multiple paths without causing changes in existing infrastructures (4G mobile network, Wi-Fi network). The aggregation is performed by an MPTCP server. xxxvi Wi-Fi Integration to the 4G Mobile Network LTE Aggregation LAA Aggregation 1,8 GHz 1,8 GHz 2,6 GHz 5 GHz LWA Aggregation MPTCP Aggregation 1,8 GHz 1,8 GHz Wi-Fi Wi-Fi 5 GHz 5 GHz Access MPTCP Access Point Server Point Figure I.8. Wi-Fi and LTE access aggregation Architecture Based on Wi-Fi Access 1.1. Functional architecture EPS (Evolved Packet System) is the name of the 4G mobile network. It consists of an evolved packet core (EPC) and an evolved universal terrestrial radio access network (E-UTRAN). The E-UTRAN network presents the LTE (Long-Term Evolution) radio interface to the mobile. Wi-Fi (Wireless Fidelity) interface is subsequently integrated into the EPS network and is a component of a set of technologies grouped under the term Non-3GPP Access. Its introduction has an impact on the core network (EPC) architecture, which has several variants depending on the following characteristics: - Wi-Fi access is trusted or untrusted by the operator; - mobility is managed by the network or the mobile. 1.1.1. Architecture based on the S2a interface The functional architecture based on the S2a interface corresponds to trusted Wi-Fi access and network-based mobility (Figure 1.1). Wi-Fi Integration to the 4G Mobile Network, First Edition. André Perez. C ISTE Ltd 2018. Published by ISTE Ltd and John Wiley & Sons, Inc. Wi-Fi Integration to the 4G Mobile Network Server Trusted Wi-Fi Access Figure 1.1. Functional architecture based on the S2a interface The mobile stream travels through the Wi-Fi radio interface and the S2a tunnel to access the packet data network (PDN). The PGW (PDN Gateway) entity is an IP (Internet Protocol) router that acts as a gateway for the mobile stream. 