This paper presents an advanced wireless communications system using an enhanced version of Orthogonal Frequency Division Multiplexing (OFDM)/Adaptive OFDM OFDMA) called Dynamic Adaptive OFDM (DAOFDM). The main focus of this work is the creation of a receiver-centric improved OFDM wireless transmission system that has a reduced Bit Error Rate (BER) and increased channel capacity usage interference-prone wireless bands. This scheme dynamically adapts to the time-varying communications channel and avoids carrier frequencies experiencing interference levels in excess of a specific power-spectral density threshold level without incurring extra transmission overheads.
It outlines the key research challenges to be addressed in order to achieve real-time coordination. Therefore, to undertake safety-critical missions, the applications will have to coordinate the behavior of their components in real-time, while overcoming the limitations of (ad hoc) wireless communication. Safety-critical mobile applications running on resource-constrained embedded systems will play an increasingly important role in domains such as automotive systems, space, robotics and avionics.
The assumption of the availability of port information at design time of service compositions in Service-Oriented Architectures (SOAs) is not valid for an increasing number of hosts on the Internet that do not have a public, static IP address. This paper presents a workflow engine that supports runtime look-up of service endpoints based on a P2P middleware. Using a service identifier based on a DHT identifier, Service Proxy objects that encapsulate port information are downloaded over the structured P2P network from the host where the service is deployed.
A number of different security models have recently been proposed, which aim to ease the administration of access control. Various security models have been proposed in recent years for different purposes. This research paper, propose a new access control paradigm, which is already well established in virus and SPAM protection as partial delegation of administration to external expertise centers. Well-known vulnerabilities can be filtered out and known sources of attacks can be automatically blocked. They describe how partial outsourcing can be achieved in a secure way. A framework, which enables this process, has already been developed.
Ad hoc wireless networks comprise sets of mobile nodes connected by wireless links that form arbitrary wireless network topologies without the use of any centralized access point or infrastructure. Ad hoc wireless networks are inherently self-creating, self-organizing and self-administering. This paper presents the analysis of the impact of mobile ad hoc wireless networks on achieving real-time guarantees. It introduce the ongoing work on the use of a proactive routing and resource reservation protocol using mobility awareness and prediction to reduce the unpredictability of a dynamic mobile ad hoc wireless network.