Implementation of the 3GPP LTE-WLAN Inter-working Protocols in ns-3

LTE/Wi-Fi Link Aggregation (LWA) and LTE WLAN Radio Level Integration with IPSec Tunnel (LWIP) are two approaches put forward by the 3rd Generation Partnership Project (3GPP) to enable flexible, general, and scalable LTE-WLAN interworking in the context of 5G. These techniques enable operator-controlled access of licensed and unlicensed spectrum and allow transparent access of operator's evolved core. This article describes the design details of LWA and LWIP protocols and presents the first ns-3 LWA and LWIP implementations in ns-3. In particular, this work focuses on the adaptation and concurrent usage of different ns-3 modules and protocols of different technologies to enable the support of these inter-working schemes.