Piotr Gajewski

This paper presents properties of a mobile ad hoc network (MANET) with dynamic spectrum management (DSM) and is devoted to the concept and implementation of the new traffic engine that is used in a High-Fidelity simulator of MANET with cognitive nodes for special applications. The communication traffic generated by each node is defined according to its role in the hierarchical structure of the operational scenario, determining its priorities, permission to use particular real time and non-real time services. The service usage is a source based model, defined in the user’s profile containing its statistical properties, describing periodicity, duration and randomness of traffic generation. The overall traffic generated by the node is a combination of traffics related to specific services. Their statistical parameters are based on real exercises results. The model was defined in the Matlab environment and next verified using the MAENA simulator for complex, operational scenarios. The achieved results show that use of both central and distributed DSM provides a better performance of the MANET network with complex traffic.

The problem of waveform construction for mobile ad hoc networks with cognitive radio (MANET-CR) is discussed. This is the main limitation to widely use this very attractive technique, which does not need the deployment of expensive communication infrastructure. Two main questions correspond to MANET-CR effectiveness: spectrum sensing and spectrum sharing. The paper presents the structure of CR nodes that enables Opportunistic Spectrum Sharing. Procedures for advanced Dynamic Spectrum Management together with the concept of policy-based radio and a sensing method are presented. In the proposed system, the basic policy is to avoid interference generated by other users or jammers. The experiments were performed in a real environment, using the elaborated testbed. The results show that the use of sensing and cognitive management mechanisms enable more efficient use of the spectrum while maintaining reasonable overhead values related to the management procedures.

The paper describes the MANET Cognitive Radio test bed. The proposed architecture consists of a number of CR nodes connected to the RF Switch Matrix, and enables simulation, scenario definition and management. Proposed procedures for Opportunistic Spectrum Access in MANET CR are described as well and chosen results of simulations obtained during laboratory tests are presented. The performance of these solution makes them fit for use in special and military applications.

The paper presents a method of monitoring the basic parameters of cognitive mobile ad hoc network (MANET) with opportunistic access to the spectrum. The collected parameters are based on metrics from different communications layers, combined into single utility function, being a global indicator of the network health. The proposed method was tested and validated using a real time cognitive radio network demonstrator. Results for example test scenario are also presented.

The Dynamic Spectrum Management is a key to increase the spectrum efficiency usage in rapidly growing demand for spectrum in military operations. In the paper, the main results of national project concerning DSM proposals for Polish Armed Forces are presented. Two concepts have been proposed and demonstrated. Coordinated DSA uses the frequency broker for centralized management of spectrum resources available for operation time, and decentralized one uses OSA solutions for spectrum sharing. In both demonstrators, the radio nodes are equipped with some cognitive functions, but the main effort was concerned to present DSM possibilities to use on the tactical and battlefield MANETs. The experiments show significant increase of spectrum efficiency and jamming resistance for both DSM solutions. CDSA concept is ready to introduce in military networks based on legacy radios, assuming that they have an ability to implement OTAR procedures. To introduce in practice the OSA concept some research and legislative activities are needed, both in national and international perspectives. It concerns policies definitions, descriptions language agreement, new security procedures elaboration and agreement, etc.

The rapid development of systems which use wireless technologies causes the escalation of the spectrum shortage problem. That is why the concept of coordinated dynamic spectrum management has appeared. It improves efficiency of the spectrum use and makes radio communication systems more resistant to interferences. The main element of the proposed solution is a frequency broker which provides frequency assignment plans for radio networks. Direct communication between the frequency broker and radio networks enables fast change of radio data. This paper presents an anti-interference method based on dynamic spectrum management, which is an implementation and extension of IST- 104/RTG-050 research task group “Cognitive Radio in NATO II” recommendations. The solution presented by the authors was tested in emulated and real environment. The designed algorithm of frequency assignment can effectively prevent interferences (including jamming) thanks to the implementation of monitoring mechanisms capable of obtaining information about the current state of radio channels from radio networks. Directions for further development of frequency planning algorithm based on belief distorted Nash equilibria for deterministic or stochastic beliefs were proposed. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Efficient Dynamic Spectrum Management balances the energy consumption problem, eliminates conflicts between the nodes, reduces the channel interference, divides the traffics over different channels and time slots. In this paper, we propose a new channel management algorithm for Cognitive Radio Sensor Networks, which heightens the energy efficiency using hidden Markov model (HMM). The proposed algorithm adaptively selects its operation mode among channel sensing, channel switching, and data transmission/reception, according to the channel-sensing outcome. The results obtained using HMM as a spectrum occupancy predictor are very promising and they show that HMM offer a new paradigm for predicting channel behavior in Cognitive Radio.