A Proactive horizontal handover algorithm for WiFi-WiMax interoperable networks

Abstract

Two important high bandwidth wireless certifications in our days are Worldwide Interoperability for Microwave Access (WiMax) and Wireless Fidelity (WiFi). They can interoperate to form a geographical wider network in wchich Mobile Client (MC) can move. We suppose a combination of two WiFi Access Points (AP) and a WiMax Base Station (BS) that interoperate putting a WiMax Wireless Network Interface Card (WNIC) in the WiFi AP. The BS can request real time video or Video on Demand (VoD) from a server allocated in the fixed network (to which the BS is connected). In order to model the movement of the MC, we build a diagram state to represent the areas in which MC can be and from what area to which one the MC passes. Classifying the areas in connected and disconnected ones we can discover the different actions that are achieved by different entities of a simple protocol that are allocated in the BS and the AP. These entities are in charge to control the buffers to efficiently support disconnections due to handover and out of coverage situations (disconnected states). Up to our knowledge, no other authors have studied this complex problem.