The primary motivation for this research is to focus on issues of WiMAX security problems and analyzes of vulnerabilities on IEEE 802.16, which is a new and promised topic in telecommunication and wireless networks. Mobile WiMAX system based on the IEEE 802.16e-2005 amendment has more improved security features than previous IEEE 802.16d-based WiMAX network system. WiMAX authentication is achieved by using public key interchange protocol privacy key management and it is supported by RSA cryptography exchange and RSA based authentication applies X.509 certificate together with RSA encryption. In this tutorial we identify potential security requirements for future WiMAX environment and propose promising security technologies to address these requirements through the integration of specific security algorithms into WiMAX environment to enhance security. We expect this call for interest to motivate planning for evolution of 802.16e against security challenges.

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Researchers have focused on security aspects of different Mobile Ad Hoc Network (MANET) protocols to prevent Physical Layer attacks through different complex mechanisms. DoS attacks are one of the most harmful attacks against functionality and stability of network systems. MANETs are more vulnerable to Physical Layer attacks due to limited resources that force them to be greedy in resource utilization. Physical layer attacks aims to paralyze the member of the network (a node or service provider) or the entire network, by flooding excessive volume of traffic to consume the key resources of the member of the network or the entire network. In this research, OPNET simulation package is used to simulate different DoS attack scenarios for popular MANET protocol, Dynamic Source Routing (DSR) protocol. The results and performance comparisons of MANET protocol is illustrated through performance metrics.

This research presents design and implementation of the ultra-fast parallel lithium charging architecture with an embedded algorithm using an active PWM charge pump supported by a hybrid control mechanism consisting of Temperature, humidity and current sensors. The new architecture guaranties the ultra-fast parallel charging cycles of lithium cells without lifespan reduction due to possible overheat side effects in mission critical applications.

Semantic Web technology is based on the OpenWorld Assumption (OWA) where absence of entities being searched does not entail negative response rather simply treated as facts "not available at the moment." On the one hand that indicates anticipation of future enhancements of the fact store while in other cases it is not preferred in situations where an authoritative answer is needed. Closed World Assumption (CWA) on the other hand returns definitive yes/no answers even in situations where future enhancements are inevitable. We wish to distinguish among the situations where one or the other assumption would be advantageous to use. Such distinction could cater for faster services discovery and more wholesome services orchestration. We apply this approach to discovering semantic Web services being offered by autonomous semantic robots out in the field and for building the unified worldview common to all. Consequently, the OWA-based paradigm alone is not suitable for most robotics platforms where cardinality and negation is not sound as well as in CWA. Therefore, we argue and display that a strategy to draw and utilize benefits of both world assumptions is beneficial.