Background/Objectives: Next generation heterogeneous network will comprise multi access systems with multiple service support. Call management scheme is necessary to provide low call dropping probability for high priority services. Call management scheme for mixed cells (i.e., a 4G cell with embedded WLANs) increase cellular system capacity and reduce dropping probability of cellular-to-WLAN vertical handoff calls. Methods: We propose an efficient call management scheme which considers all possible vertical handoff scenarios and provides the maximum usage of WLAN. A blocked request in WLAN is taken back by the overlaying cellular system, if channels are available. Several existing models do not reflect the effect of configuration of neighbor cells which is important for cell planning for a cellular operator. Findings: Call management scheme is executed by diverting every request of WLAN that was blocked, to cellular system. Improvements/ Applications: The proposed call management scheme shows that new call and handoff call dropping probability is decreased when compare with Complementary-WLAN scheme (C-WLAN) and also increases in system throughput.