Master Thesis - 2010

With advances in wireless communication technologies, people can use multimedia services not only via wired networks but also via wireless networks such as Cellular, WiMAX, and WiFi. Although these wireless systems have developed independently, they should be integrated for seamless access from users.

On the other hand, spreading multimedia communications causes the spectrum shortage. Though each system uses an individual spectrum prescribed by law to avoid radio interference, 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.

We proposed the spectrum sharing method based on genetic algorithm in which a WiFi system temporarily uses a spectrum band of WiMAX system in WiFi/WiMAX integrated network. However, this method does not take the fairness into account.

In this paper, we enhance the spectrum sharing method to improve fairness in addition to providing higher throughput. Finally, we confirm the effectiveness of the proposed method by simulation experiments.