A Survey on Simulation Tools and Testbeds for Cognitive Radio Networks Study

Efficient utility of radio spectrum has been a hot topic as the wireless communication spectrum is a precious resource. The past decade has witnessed intensive research in spectrum sharing techniques. Most of the techniques are based on cognitive radio networks (CRNs) because cognitive capabilities are essential for optimizing spectrum efficiency and guaranteeing safe coexistence in the presence of the spectrum uncertainty. However, due to the high complexity of the problem, most research has been limited to theoretical analysis. It is non-trivial to build a simulator that is capable of carrying out a comprehensive experimental study. In this paper, a survey is conducted to provide a big picture of the available simulators in CRNs research. By illustrating their major functionalities, the insight enables researchers to select tools that match their needs. In addition, with a better understanding of the advantages and constraints, this survey aims at providing a guideline for simulator designers who have been trying to meet the requirements from the CRN research community

Authenticated Reliable and Semi-reliable Communication in Wireless Sensor Networks

Secure communication in wireless ad hoc sensor networks is a major research concern in the networking community. Especially the few available resources in terms of processing power and available memory are challenging factors. Additionally, a typical characteristic of wireless ad hoc sensor networks is the error-proneness and, therefore, the unreliability of communication paths. In this paper we describe a new approach and an according protocol for usage in ad hoc networks that provides reliable as well as semi-reliable communication services in combination with security services. Thus, the proposed methodology allows to ensure data integrity and message authentication. The main aspects during the development were the limitations of typical sensor nodes used in ad hoc networks in terms of available storage, processing power, and energy. Our solution provides the capability of acknowledging correct receptions as well as the check of data integrity and message authentication in a single step. Therefore, a low overhead solution applicable to wireless sensor networks was created providing all the mentioned communication goals