An enabler of interoperability in heterogeneous wireless networks

In the context of the rapid development of mobile terminals which are utilizing multiple wireless technologies, the QoS demands while roaming from one type of wireless network to another have increased, leading the way towards redesigning the TCP/IP stack, introducing therefore, the concept of vertical handover. The support came in the form of a module that will sustain interoperability between heterogeneous networks. This paper describes the need of an independent interoperability module and the role it plays in the context of a multi-layered stack. The design respects the guidelines of the IEEE 802.21 standard, enabling communication between multiple medium access control technologies and the network layer that suffered a series of enhancements in order to process the information provided by a 2.5 layer entity.