In the case of WLAN, the IEEE 802.11 has two primary mechanisms for QoS, namely, Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA is a form of differentiated QoS. Traffic can be classified into four access categories (AC): AC_VI (for video), AC_VO (for voice), AC_BE (for best effort), and AC_BK (for background). The WLAN AP announces the EDCA parameter set (in beacon frames) consisting of several AC specific parameters (TXOPlimit, AISFN, CWmin, and CWmax). Each station (STA) is expected to access the channel based on these parameters and the AC to which the traffic belongs. In contrast, HCCA is a form of integrated QoS that relies on AP scheduling, and utilizes the notion of traffic stream (TS) and traffic specification (TSPEC) element. Since HCCA is not used widely, this disclosure focuses on EDCA.

LTE-WLAN Aggregation (LWA) is a tight integration at radio level, which allows for real-time channel and load-aware radio resource management across LTE and WLAN to provide significant capacity and QoS improvements. When enabling LWA, S1-U is terminated at eNB whereby all IP packets are routed to eNB and perform PDCP layer operations (i.e., ROHC, ciphering) as an LTE PDU. Afterwards, eNB 103 can schedule whether LWA-LTE link 110 or LWA-Wi-Fi link 120 the LTE PDU shall go. LWA borrows the concept of existing dual connectivity (DuCo) to let WLAN network being transport to the core network (CN) for reducing CN load and support “Packet level” offload.