Paper accepted for publication!


Let me share with you some good news!!! We were just informed that our paper entitled “A Quantitative Look at Directional Terahertz Communication Systems for 6G: Fact Check” was accepted for publication in IEEE Vehicular Technology Magazine (Impact factor: 10.384). I would like to thank my co-authors ‪Josep Miquel Jornet‬ and Angeliki Alexiou for their great collaboration. The abstract of the paper is:Abstract: Sustaining a flexible and ubiquitously available high-data-rate network, capable of supporting a massive number of end-users, demands the exploitation of higher frequency bands, such as the terahertz (THz) band (0.1-10~THz). However, the utilization of THz wireless systems comes with a number of challenges, many of them associated with the very high propagation losses of THz signals, which require the utilization of high-gain directional antennas with strict beam alignment requirements, as well as the low signal penetration of (sub) millimetric waves, which leads to intermittent blockage and shadow areas. In this paper, a quantitative discussion of these phenomena and their implications in both backhaul and fronthaul applications of the THz spectrum is provided. Starting from state-of-the-art demonstrated THz technology parameters, the directivity requirements, the impact of beam misalignment, and the opportunities for multi-hop relaying in two different application scenarios are described. For the same conditions, the impact of blockage is quantified, and the benefits of reconfigurable intelligent surfaces are studied. Finally, the implications of blockage on the physical layer security of THz systems are presented.

Paper accepted for publication


Let me share with you some great news! Our paper entitled “An Experimentally Validated Fading Model for THz Wireless Systems” has been accepted for publication in Scientific Reports. It is worth noting that Scientific Reports belongs to the journals of Nature family.

Abstract: As the wireless world moves towards the sixth generation (6G) era, the demand for supporting bandwidth-hungry applications in ultra-dense deployments becomes more and more imperative. Driven by this requirement, both the research and development communities have turned their attention to the terahertz (THz) band, where more than 20 GHz of contiguous bandwidth can be exploited. As a result, novel wireless systems and network architectures have been reported promising excellence in terms of reliability, massive connectivity, and data rates. To assess their feasibility and efficiency, it is necessary to develop stochastic channel models that account for the small-scale fading. However, to the best of our knowledge, only initial steps have been so far performed. Motivated by this, this contribution is devoted to take a new look to fading in THz wireless systems, based on three sets of experimental measurements. In more detail, measurements, which have been conducted in a shopping mall, an airport check-in area, and an entrance hall of a university towards different time periods, are used to accurately model the fading distribution. Interestingly, our analysis shows that conventional distributions, such as Rayleigh, Rice, and Nakagami-m, lack fitting accuracy, whereas, the more general, yet tractable, α-µ distribution has an almost-excellent fit. In order to quantify their fitting efficiency, we used two well-defined and widely accepted tests, namely the Kolmogorov-Smirnov and the Kullback-Leibler tests. By accurately modeling the THz wireless channel, this work creates the fundamental tools for developing the theoretical and optimization frameworks for such systems and networks.

Best Oral Presentation Award


In this contribution, we presented a dynamic dual-hop relaying network topologies that enable access to end-users through intermediate individual and/or commercial, static as well as moving, infrastructure. Although, the idea of using relays in order to extend the cell coverage and/or improve the link performance has already been presented in long-term evolution (LTE) as well as LTE-advanced, for each service provider, it was required to use only its own equipment in order to guarantee high-levels of security and privacy. However, the ownership limitation may increase the network deployment cost and also create coverage holes. On the other hand, blockchain technology has been recognized as a key pillar of the higher (network, transfer, and application) layers of sixth-generation (6G) networks, since it can boost the network-to-application layer security and privacy capabilities. Motivated by this, we took a step back and examined whether blockchain can also be applied in lower layers, such as MAC. The result of this study is a new architecture that we named dual-hop blockchain radio access network (DH-BRAN). DH-BRAN enables individual and commercial intermediate nodes to become wireless access providers independently of their ownership. As a result, it creates a new ecosystem for the next-generation networks.

Great news!!! Yesterday, we received the Best Oral Presentation Award in the International Conference on Modern Circuits and Systems Technologies (MOCAST) for our contribution entitled “Dual-hop Blockchain Radio Access Networks for Advanced Coverage Expansion.”

In addition to the award and the contribution itself, another important point that needs to be highlighted is that the first author of this work is an undergraduate student of our department (Electrical & Computer Engineering of the University of Western Macedonia).

Last but not least, I would like to thank all the co-authors (Theofilos Sachinithis and Panagiotis Sarigiannidis) for their effort, as well as the conference organizers.



Great news!!! We have just been informed that our paper entitled “On the impact of beam misalignment in reconfigurable intelligent surface assisted THz systems” has been accepted for presentation in IEEE 22nd International Workshop on Signal Processing Advances in Wireless Communications (SPAWC). The main message of this paper is that beam misalignment can have a detrimental effect of the performance of RIS-empowered THz wireless systesm.