Software Defined Radio (SDR) enables the execution of many hardware-based operations through software. With an open-source LTE software and an SDR, we are able to run a LTE base station on a PC or a portable and low-cost device. At the same time, simple devices such as Raspberry Pi can be turned into WiFi APs. In this work, we will work on the developed LTE/WiFi integration solution using OpenAirInterface software that implements the LTE eNB and the core network.

Nowadays, mobile IP data traffic is increasing exponentially and predictions tells that it will triplicate its actual value in 2020. A solution to this dare is LTE/WLAN Aggregation technique where cellular networks such as LTE and WLAN networks such as WiFi are combined to improve its performance. In this thesis, a prototype, based on very tight coupling between LTE and WiFi, is evaluated for their performance. There will be three policies assessed: No Offload policy, when data traffic is sent over LTE link; Full Offload, when data packets is sent over WiFi link and control packets through LTE link; and LWA with different techniques to split traffic through both links: Time division, Par/Impar, Low ICMP RTT and Port division. In very tight coupling, eNB manages offloading and aggregation techniques, and does not require the core network in any case. PDCP layer, as common layer between both technologies, switches the traffic depending on the policy. Moreover, prioritizing reliability in front of throughput, an analysis of TCP flow control and default TCP congestion control method employed by Linux, namely CUBIC, theoretically and showing their functioning through physical experiments was performed.