LTE-WiFi Link Aggregation at Femtocell Base Station

In this paper, we propose the architecture and an algorithm of LTE-WiFi Link Aggregation (LA) provided by an LTE femtocell base station. The link aggregation simultaneously uses both an LTE link and a WiFi link in order to improve the throughput of an IP traffic flow. Our proposed LA architecture is transparent to any application and supports multiple PDN (Packet Data Network) connections for a mobile operator's Evolved Packet Core (EPC) and Local IP Access (LIPA) in a home network. For the above purposes, any application transmits/receives IP packets to/from an LA control module in a terminal via two virtual network layer device TUNs, for EPC and LIPA. Our proposed LA algorithm distributes a TCP traffic flow to LTE and WiFi links based on the Modulation and Coding Scheme (MCS) and Physical Resource Block (PRB) usage of the LTE link. We have shown in an experimental evaluation that the TCP traffic flows to PC and Android terminals make use of the available bandwidth of LTE and WiFi links by using our proposed algorithm.