The Heterogeneous networks are expected to become a main focus in the development toward the Next Generation (NG) wireless network. The convergences of heterogeneous wireless access technologies characterize the NG or Fourth Generation (4G) wireless networks. The NG wireless networks are envisioned to provide high bandwidth to mobile users via bandwidth Aggregation over heterogeneous wireless architectures. Thus, the integration of the existing medium access schemes, e.g., CSMA, TDMA and CDMA, dictates an adaptive and seamless medium access control (MAC) layer that can achieve high Network utilization and meet diverse Quality of Service (QoS) requirements. In this paper, we proposed an Effective Medium Access Control Layer (EMAC) to improve the performance of a network terminal. In this work, a Virtual Pentagon concept is introduced as a unified metric to model heterogeneous access schemes and capture their behavior. Based on the Virtual Pentagon concept, EMAC provides architecture-independent decision and QoS based scheduling algorithms for efficient multi network access. EMAC performs seamless medium access to multiple networks without requiring any additional modifications in the existing network structures. It is shown via extensive simulations that EMAC provides adaptivity to the heterogeneities in NG wireless networks and achieves high performance. © EuroJournals Publishing, Inc. 2012. © 2014 Elsevier B.V., All rights reserved.