Master Thesis - 2009

With advances in communication technologies, network services provided via the In- ternet have been widely diversi?ed, and people can use these services not only via wired networks but also via wireless networks. There are several wireless systems in practical use such as Cellular, WiMAX and WiFi. Although these wireless network systems have developed independently, they should be integrated for seamless access from users.

On the other hand, spreading multimedia communications causes the spectrum short- age. Though, each system uses an individual spectrum prescribed by law to avoid radio interference, and some spectrum may not be used on a certain time and space in each system. To overcome this problem, dynamic spectrum access technology receives much attention.

In this thesis, I propose a dynamic spectrum assignment method in which a WiFi sys- tem temporarily uses a spectrum band of the WiMAX system to reduce call blocking probability of multimedia communication services. The proposed method assigns addi- tional spectrum from WiMAX to WiFi access point based on call blocking probability prediction.