Proportional Traffic Splitting for Efficient LTE-WLAN Aggregation in Multi-RAT Heterogeneous Networks

Traffic splitting across different radio access technologies in Multi-RAT heterogeneous networks plays a crucial feature in the recently introduced 3GPP-Release-13 cellular standard for LTE-WLAN aggregation (LWA). In this paper, an efficient dynamic traffic splitting technique for LWA network architecture is proposed. The key direction of this technique is to provide proportional load balancing while enabling packet scheduling at the packet data convergence protocol (PDCP) layer based on the estimation of sojourn time delay on both of LTE and Wi-Fi radio links. Therefore, a closed form for the traffic splitting ratio is derived such that proportional load balancing across the two radio access networks (LTE and Wi-Fi) is achieved. Then, the packet streams are proportionally scheduled on both radio links in such a way that the reordering delay is compensated by considering the packet delivery time discrepancy on both links and hence avoiding throughput degradation. Simulation results prove that the proposed mechanism can significantly improves the average system throughput especially at high density of users.