الفهرس 
chapter 1Only 14 pages are availabe for public view
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Abstract
According to the recent research studies, the data encryption weakness and the unencrypted management messages are found to be major limitations of mobile WIMAX. These limitations stand against WIMAX from becoming a key technology for high-speed multimedia service delivery. Advanced encryption standard (AES) is a traditional cipher that has several advantages in data encryption in IEEE 802.16e.
However, it is not suitable for the multimedia applications and the management messages. In this thesis three algorithms based on chaotic maps are proposed to encrypt multimedia files. Moreover, other traditional algorithms such as blowfish and IDEA are used to encrypt the management messages. A comparison has been conducted for these encryption algorithms for different data types in terms of encryption time and throughput. The performance of these encryption algorithms is examined when the encrypted data are transmitted through the IEEE 802.16e physical and MAC layers.
The proposed algorithms are examined using anti statistical and differential attacks. In addition, physical layer is developed by employing turbo encoder instead of convolutional encoder to enhance the performance of physical layer and security sublayer.