WiMAX (Worldwide Interoperability for Microwave Access) provides wide transmission range and broadband network services. However, in IEEE 802.16 standard, there is no specific definition for SS (Subscriber Station) to select an optimal route in a mesh-based WiMAX network. In this thesis, we propose an Optimal Route Selection Scheme (ORSS) for SS to select a route to its BS (Base Station). ORSS basically considers three influential factors, the bandwidth SS to be assigned, the number of interference nodes around SS, and the hop counts to BS. We also investigate QoS (Quality of Service) issue in a mesh-based WiMAX network; an SS transferring the rtPS traffic type will share bandwidth with the neighboring SS of the same level that transmit the same traffic type. To ensure the selected route that can meet the bandwidth requirements of rtPS and the delay constraints, we estimate the average transmission delay from SS to BS. For the purpose of evaluation, we establish a mathematical model to analyze the proposed ORSS and discuss the impact of varying network parameters on the successful rate of route selection. Through the Matlab simulation, we validate our mathematical model. The simulation results demonstrate that our ORSS, in comparison to a previous work, is more effective in ensuring the delay constraints when selecting a route to transfer rtPS traffic.

The IEEE 802.16 (WiMAX) is the promising technique to overcome some disadvantages on the Security concern of the widespread IEEE 802.11 standard. For providing high speed wide area broadband wireless access, WiMAX is an emerging wireless technology for creating multi-hop Mesh network. Based on the wired backbone wireless Mesh networks serve to get over present dependencies of wireless system. Wireless operates on Physical later and MAC layer in the air interface to provide fixed and Mobile Broadband Wireless Access (BWA) in broad range of frequencies. Due to the lack of Physical infrastructure of wireless networks are inherently less secure. In order to protect data exchange between the MAC layer and PHY layer WiMAX specifies a security sub-layer at the bottom of the MAC layer. The security sub-layer provides privacy with SS and BS from service hijacking. For providing authentication, data traffic privacy services and key management a PKM protocol defined by the WiMAX MAC as a sub-layer where the PKM protocol is the main protocol work in the security sub-layer. WiMAX is only a “Paper based” newly established technology based on Wi-Fi system then it is tough to find out its security holes in all the way. Keeping all the fact in mind the objectives of the thesis are to analyze the WiMAX security architecture security keys (AK, KEK and HMAC) are used for authorization, authentication and key management and TEK is for secure data transmission, possible security vulnerabilities, threats and risks are classified according to different layer with 802.16 std Mesh network. In addition, vulnerabilities comparison between IEEE 802.11 and 802.16 std has been pointed out in details, as well as security improvements and possible solutions has been proposed to protect WiMAX attacks.