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Environment protection and climate changes are depending on the efficiency of the energy usage, electricity networks structure and consumer behavior. This paper is presenting the universal communication model of provider-consumer ICT ecosystem as a driver for energy efficiency. The system is analyzed with game theoretic approach and considers electricity market behavior of multiple players on both provider and consumer side, including the elements of variable price of production of electricity, renewable sources and bidirectional fluctuation of electricity in distributed networks. The main idea consists of the transfer of benefits of usage of the ICT energy efficiency system into investments for green energy and smart grid solution, which consequently will reduce carbon emission.

The next generation of mobile systems, the 5G, requires significant advances in system architecture design and development, as a result of the tremendous increase of mobile traffic, the omnipresence of mobile services and the ever-increasing number of connected devices. Several technologies, such as cloud computing, softwareization and virtualization have been identified to pave the road towards the efficient rollout and deployment of 5G. In order to address the strict service requirements, in terms of latency, reliability and throughput, they will have to be deployed at the radio access network edges. This paper discusses the importance and necessity for resource scaling in the mobile edge computing (MEC), as a promising technology approach for 5G. It also elaborates on the potential virtualization technologies, hypervisor-based and container-based, and the underlying resource scaling approaches for different relevant scenarios. The evaluation is performed on a laboratory demo platform capable of virtualizing several types of radio access systems, such as GSM, LTE, etc. The results clearly show that container-based virtualization provides the most efficient and robust resource scaling that does not significantly affect the communication performance of the mobile users.

eHealth technology can bring a variety of benefits to patients, caregivers, and health institutions, by facilitating improved healthcare services through the utilization of Information and Communication Technologies (ICTs). The forthcoming generation of healthcare services will require advances in computing and Wireless Sensor Networks (WSNs) in order to leverage truly intelligent and adaptive features for smarter eHealth services. This paper proposes a multi-sensory cloud based system capable of monitoring and tracking the patient's behavior with respect to his vital signs. The paper also showcases the proposed system on a real testbed, performing real-time vital signs data acquisition, processing, and monitoring.

The significant penetration of the WiFi technology in the last decade and the lack of solutions for coordinated and efficient interference management between WiFi networks in unlicensed bands often lead to poor spectrum utilization and network performances. The synergy between Radio Environmental Maps (REMs) and Radio Resource Management (RRM) can offer a viable solution for so called Smart-WiFi that significantly improves the ISM spectrum utilization and the overall WiFi performances. REMs enable efficient usage of environmental data sets, such as WiFi device locations, estimated pathloss models, real-time interference levels, statistical channels occupancies etc. for an intelligent RRM in WiFi related scenarios. This paper proposes a novel RRM approach for WiFi coordination and optimization that exploits the available REM information. The paper also showcases the proposed approach on a real prototype, performing real-time REM data acquisition/ processing and enhanced WiFi coordination and optimization.

The unlicensed bands recently became overcrowded due to the WiFi networks, as the main populates of these bands. This is owed to the significant growth of WiFi users in the last decade, as well as the absence of solutions for coordinated and efficient interference management between WiFi devices. The synergy between Radio Environmental Maps (REMs) and Radio Resource Management (RRM) for Smart-WiFi, can be a viable solution to improve the spectrum utilization in the unlicensed bands and hence, WiFi performances. Environment data such as empirical propagation models, transmitters' locations, up-to-date interference levels, statistical channels occupancies, can serve as input to an enhanced RRM for these scenarios. The proposed demonstration aims to showcase the benefits of using REM information in the WiFi optimization. The demonstration utilizes a REM-facilitated Smart-WiFi prototype, performing real-time REM data acquisition, processing and inference as input to an enhanced WiFi optimization.

Due to the fundamental tradeoffs, achieving spectrum efficiency and energy efficiency are two contending design challenges for the future wireless networks. However, applying radio-frequency (RF) energy harvesting (EH) in a cognitive radio system could potentially circumvent this tradeoff, resulting in a secondary system with limitless power supply and meaningful achievable information rates. This paper proposes an online solution for the optimal time allocation (time sharing) between the EH phase and the information transmission (IT) phase in an underlay cognitive radio system, which harvests the RF energy originating from the primary system. The proposed online solution maximizes the average achievable rate of the cognitive radio system, subject to the $\varepsilon$-percentile protection criteria for the primary system. The optimal time sharing achieves significant gains compared to equal time allocation between the EH and IT phases., Proceedings of the 2015 IEEE International Conference on Communications (IEEE ICC 2015), 8-12 June 2015, London, UK

Recent advances in cognitive radio have identified the small-cells among the most promising future wireless networking scenarios. Utilizing radio context information, smallcells should perform the most optimal radio resource management (RRM) to maximize performances and minimize inter-cell interference. Radio Environmental Maps (REM) data: empirical propagation models, active transmitters’ locations, upto-date interference levels, statistical channels occupancies, are especially beneficial in these scenarios. The proposed demonstration aims to showcase the benefits of using REM information in the small-cell optimization. The demonstration utilizes a modular/flexible REM prototype, performing a realtime REM data acquisition, processing and inference as input to an enhanced small-cell optimization.

The beamforming has been extensively studied as possible enabler of the underlay spectrum sharing and recently has been tightly related to the concept of cognitive small cells. This work proposes a more generic underlay sharing system model, which takes into consideration the interference caused to the secondary system and develops a combined (transmit and receive) beamforming design that is applicable in both uplink and downlink use cases. The paper presents a successive transmit/receive beamforming optimization algorithm, which substantially decreases the computational complexity of the combined beamforming design. The performance analysis results show that the proposed combined beamforming achieves satisfying performances (i.e. mitigating the interference from the primary to the secondary system, satisfying the interference constraints to the primary system etc.). The results show that the proposed successive optimization algorithm decreases the complexity of the combined beamforming without degrading the underlying system performances, which makes it applicable for scenarios such as HetNets and cognitive small cells, which require agile and real-time operation.

The prospect of increasing wireless capacity via secondary access to spatio-temporally underutilized chunks of spectrum, so-called whitespaces, has been proposed as a central aspect of emerging radio systems in response to the imminent spectrum scarcity problem. In this demonstration we present a novel software tool that helps researchers, industry, and regulators in assessing the feasibility and value of secondary spectrum access beyond simple whitespace availability calculation. Whereas existing software applications merely provide visualization of estimated secondary spectrum over a geographic area, our tool uniquely enables a holistic evaluation of the realistic potential of whitespace technologies, by modelling the performance of entire secondary systems in the envisioned eco-system of dynamic spectrum access policy and technology. Our tool provides a unified and flexible software framework and assessment methodology to conduct such studies, and is composed of an extensive primary spectrum usage database, a graphical interface for user interaction, and an interface to an extensible MATLAB backend for numerical calculations. We showcase the deployment scenarios of cellular and Wi-Fi-like secondary networks in TVWS (TV whitespaces). We also compare the impact of employing FCC-type of regulatory rules (with a fixed power/no-talk distance configuration) against European WG-SE43 regulatory proposals (with probabilistic access and power control). The case studies we will demonstrate are based on real network configuration data of European and US TV networks.

In this demonstration paper we describe a prototype of an LTE system deployment that opportunistically exploits the spectral white spaces in the upper UHF TV bands, intelligently guided in its spectum access by a radio environment map (REM). The architecture is modular in the sense that interfaces are generic and minimal. In the proposed demo we will illustrate how information of primary transmitters and other secondary transmitters as well as estimates of the radio field strength over frequency, time and space can be made available and exploited by a secondary TDD-LTE base station to make judicious decisions on its spectral occupation.

Spectrum modeling represents an important tool, of the cognitive radio concept. Number of works have focused on developing accurate methods for modeling the spectrum usage in order to provide reliable and efficient assessment of the possible spectrum availabilities. This paper proposes a novel method for modeling of spectrum usage based on classification of measured quantities into multiple levels. The distribution of the measured quantities of each level is fitted using a known mathematical model. The proposed method utilizes practical measurements in different frequency bands focusing on both uplink and downlink channels. The validation results show that the proposed model performs more accurate fitting compared to the existing single-level models for each of the inspected frequency bands.

Detection of potential transmitters' location is one of the vital aspects for efficient practical deployment of secondary spectrum access solutions. It requires accurate and up-to-date radio environmental estimation. Spatial interpolation techniques can allow partial or complete insight into the radio field, the interference and the possible geo-locations of various field transmitters depending on the number of radio measurements performed in sparse locations. This paper presents an effective solution based on spatially interpolated Received Signal Strength (RSS) values for location estimation of radio transmitters, which operates on Radio Interference Field (RIF) maps obtained by interpolating measurement data from N sparsely distributed sensors. In contrast to the known range based localization methods the developed technique also achieves higher computational efficiency. The performance analysis shows that the proposed method is suitable for both outdoor and indoor environments and is capable of reliable detection of multiple sources even for low number of sensors.

In this demonstration proposal we describe a prototype of a radio environment map (REM) for storing and reasoning about spectrum data obtained from heterogeneous sources. The architecture of the REM prototype is both modular and extendible, and can be used with very diverse spectrum sensors, ranging from high-fidelity spectrum analyzers to dedicated low-cost embedded solutions. In the proposed demonstration we will illustrate how information such as transmitter locations and estimates of spectrum occupancy over space and time can be inferred and made available through the REM, based on information obtained from a network of different spectrum sensors deployed specifically for the demonstration.

The different wireless and wired communication technologies are converging towards a heterogeneous communication network, requiring comprehensive resource management. This paper summarizes the development of a reconfigurable mobile multi-interface terminal, enabled with efficient heterogeneous resource management architecture, called RIWCoS. The created terminal prototype is able to perform seamless vertical handovers among three different networks: Ethernet, WLAN and UMTS. RIWCoS platform utilizes IEEE 802.21 defined entities in combination with Network Driver Interface Specification (NDIS) application programming interface (API). The functional testing is performed through specially developed graphical user interface (GUI). The paper presents an insight of the terminal architecture and the measured results regarding the throughput and average inter-packet delay. The results can also be observed on a specially designed GUI.

The concept of wireless heterogeneous networks is based on the coexistence and interoperability of different types of radio access technologies in a unified wireless heterogeneous platform. A key process in the wireless heterogeneous networks is the initiation and execution of vertical handovers. Variety of mechanisms are proposed in the literature that are tailored to optimize the choice of radio access network in the process of vertical handover initialization. This paper proposes a novel mechanism for radio access technology (RAT) selection, the Hopfield neural network Rat selection Mechanism (HRM), that utilizes the Hopfield neural networks as a powerful decision making tool. The main advantage of the proposed mechanism lays in its ability of Artificial Intelligence (AI) reasoning and the use of multi-parameter decision by exploiting the options of IEEE 802.21 protocol. This approach allows improvements in terms of service retainability, decreased packet loss, jitter, etc. The performance of the novel mechanism is compared with two other types of RAT selection mechanisms (RSS based, and Multi-criteria policy based mechanism) throughout extensive simulations. The results clearly show the benefits of the proposed new mechanism and its justified usage in wireless heterogeneous systems.

Convergence of different wireless access networks and development towards 4G yields a necessity for more efficient resource management procedures in the integrated heterogeneous platform. The notion of resource is fundamentally different in heterogeneous environments (compared to homogeneous ones) as it is spanned across several different wireless solutions. This paper summarizes the development process of a novel architecture for resource management in heterogeneous wireless networks named RIWCoS. The architectural focal point is on the emerging IEEE 802.21 standard because of its ability to enable seamless and transparent vertical handovers. The paper shows simulation results of the IEEE 802.21 benefits and reports on a novel simulation analysis (using newly introduced metrics) of the RIWCoS architecture showing that it outperforms traditional serving policies of users in heterogeneous wireless environments. Moreover, the paper elaborates on a distinguished RIWCoS feature (the SAES algorithm) that enables efficient handling of emergency situations making the RIWCoS architecture suitable for military communications.

This paper presents a prototyping and optimization approach for reconfigurable mobile multi-interface terminal. The mechanism that controls the operation of the available miniport drivers on the mobile device utilizes IEEE 802.21-defined entities in combination with Network Driver Interface Specification (NDIS) application programming interface (API). The created terminal prototype is able to perform seamless vertical handovers among three different networks: Ethernet, WLAN and UMTS. The testing of the developed prototype with different traffic generators resulted in optimization of its transmission parameters. Furthermore, the paper proposes an optimization of the handover procedure from a local to global wireless network by implementing intelligent prediction of imminent handovers. The results show that this optimization reduces the handover latency and the average inter-packet delay.

The rapid growth of diverse wireless communication networks, each with its own unique characteristics, led to proliferation of the wireless heterogeneous network concept. The integration of various networks is not trivial, especially if one targets high performances. Modeling and simulation — based analysis provides sufficient means for performance evaluation, even in the abstract phases of the network development. This paper provides a unique combination of protocol development and network simulation method by merging the Specification and Description Language (SDL) developer and QualNet simulator. Moreover, the paper gives a detailed insight of the modeling process of novel resource management architecture (RIWCoS), along with valuable SDL codes and sequences.

A wireless heterogeneous network consists of various wireless networks such as Worldwide Interoperability for Microwave Access (WiMAX), Wireless Fidelity (WiFi), cellular networks etc. Vertical handover (VHO) is a procedure that enables continuous seamless communication in these heterogeneous systems. This paper considers the speed as an aspect of motion as input parameters for the handover decision. Two novel methods for speed estimation are proposed: Velocity Aware Handover Approach (VAHA) is the more simple approach and it uses the FSPL equation for estimation of the speed, and Angle of Arrival VAHA (AoA_VAHA) that is more complex and it uses the Angle of Arrival as additional information for the handover decision. The paper analyzes the performance of both methods and compares them to a RAT selection mechanism based on radio quality (RQ) in terms of user's perception quality (jitter), energy efficiency, and signal overhead in the network. Both proposed approaches are analyzed on a hybrid WiMAX — WiFi simulation platform. The results show that AoA_VAHA outperforms the RQ mechanism and the VAHA. The advantage of VAHA is in its simplicity and energy efficiency.

RAT selection mechanisms focus on situations in heterogeneous networking environments where a certain access network (or a portion of it) fails and a number of users should be assigned to other active access networks. This paper proposes a novel RAT selection mechanism specifically tailored for emergency situations. The proposed mechanism, named Sorting Applications in Emergency Situations (SAES), aims to boost the performance of RAT selection and outperform existing RAT selection schemes under emergency scenarios. The paper conducts an analytical performance comparison between SAES and a common RAT selection mechanism in terms of load balancing and blocking probability. The results show that SAES improves upon the performance characteristics and may be used for providing increased network performance in future wireless networks.

WiMAX and WiFi are considered as complementary technologies for serving broadband users in the last mile, despite their differences in technical terms, regulatory constraints and business models. Therefore the scenario of using WiMAX network as a backup in case of WiFi networks failure is a realistic one. This paper provides an example for evaluating the effects of such scenario by considering two main aspects: user-perceived quality of service and service provider revenue. Both aspects are analyzed using a combination of analytical approach, proposed pricing approach per application and simulations for a sample scenario, providing methodology for further development of backup approaches for coexisting wireless networks.