The main challenge in the development of future wireless communication systems is to provide users with a wide range of services across different radio access technologies through a single mobile terminal, while maintaining the quality of service requirements. Thus, the need for seamless interworking between heterogeneous wireless communication systems consisting of multiple radio access technologies and overlapping networks emerges. In this article, we address the main issues that arise while implementing the interworking mechanisms between different radio access networks. An interworking mechanism based on IEEE 802.21 framework is proposed and described in detail. We combine concepts of autonomic networking in the design of the framework in order to use intelligence to provide flexibility, accessibility and transparency to the mobile users.