Angelos Michalas

University of Western Macedonia | UOWM · Department of Electrical and Computer Engineering

The Internet of Things (IoT) is what we have as a great breakthrough in the 5G network. Although the 5G network can support several Internet of Everything (IoE) services, 6G is the network to fully support that. This paper is a survey research presenting the 5G and IoT technology and the challenges coming, with the 6G network being the new alternat...

Internet of Things (IoT) is what we have as a great breakthrough in 5G network. Although 5G network can support several Internet of Everything (IoE) services, 6G is the network to fully support that. This paper is a survey research presenting the 5G and IoT technology and the challenges coming, with the 6G network being the new alternative network...

Virtual reality (VR) is one of the applications with the most strict requirements in the performance of next generation networks, since it requires both high throughput, low delay, and packet loss. As the performance of networks, and the level of congestion varies over time, a need for adaptation in the stream’s data rate, in order to maintain reas...

In this paper, we investigate the physical layer security capabilities of reconfigurable intelligent surface (RIS) empowered wireless systems. In more detail, we consider a general system model, in which the links between the transmitter (TX) and the RIS as well as the links between the RIS and the legitimate receiver are modeled as mixture Gamma (...

Until recently, researchers used machine learning methods to compensate for hardware imperfections at the symbol level, indicating that optimum radio-frequency transceiver performance is possible. Nevertheless, such approaches neglect the error correcting codes used in wireless networks, which inspires machine learning (ML)-approaches that learn an...

Until recently, researchers used machine learning methods to compensate for hardware imperfections at the symbol level, indicating that optimum radio-frequency transceiver per- formance is possible. Nevertheless, such approaches neglect the error correcting codes used in wireless networks, which inspires machine learning (ML)-approaches that learn...

This paper introduces a novel semi-grant-free non-orthogonal multiple access protocol that ensures reliable massive connectivity of both scheduled and random access devices of diverse data rate (DR) requirements while tripling the network’s capacity. In more detail, the protocol classifies the devices into two categories, namely primary and seconda...

Despite the numerous pompous statements regarding 5G, it is indisputable that 5G creates a radical shift in telecommunications. The main reason is that 5G is an enabler of numerous applications we have long envisioned and either simulated or implemented in test environments, partially or on a smaller scale. 5G will soon unlock the potential of smar...

Next generation mobile networks are expected to integrate multiple drones organized in Flying Ad Hoc Networks (FANETs) to support demanding and diverse services. The highly mobile drones should always be connected to the network in order to satisfy the strict requirements of upcoming applications. As the number of drones increases, they burden the...

Fifth-Generation (5G) vehicular networks support novel services with increased Quality of Service (QoS) requirements. Vehicular users need to be continuously connected to networks that fulfil the constraints of their services. Thus, the implementation of optimal Handover (HO) mechanisms for 5G vehicular architectures is deemed necessary. This work...

This paper presents a novel unmanned aerial vehicle (UAV)-aided mobile edge computing (MEC) architecture for vehicular networks. It is considered that the vehicles should complete latency-critical computation-intensive tasks either locally with on-board computation units or by offloading part of their tasks to road side units (RSUs) with collocated...

The scenario of an uplink two-user non-orthogonal multiple access (NOMA) communication system is analytically studied when it operates in the short packet transmission regime. The considered users support mobility and each is equipped with a single antenna, while they directly communicate with a multi-antenna base station. Power-domain NOMA is adop...

The scenario of an uplink two-user non-orthogonal multiple access (NOMA) communication system is analytically studied when it operates in the short packet transmission regime. The considered users support mobility and each is equipped with a single antenna, while they directly communicate with a multi-antenna base station. Power-domain NOMA is adop...

Citation: Skondras, E.; Michailidis E.T.; Michalas, A.; Vergados, D.J.; Miridakis, N.I.; Vergados, D.D. A Network Slicing Framework for UAV-Aided Vehicular Networks. Drones 2021, 5, 70. https://doi.

Fifth generation (5G) vehicular networks support various services with strict Quality of Service (QoS) constraints. Network access technologies such as the LTE Vehicle to Everything (LTE-V2X) and the IEEE 802.11ac/ax provide network access to users, while Software Defined Networking (SDN) provides centralized control of the heterogeneous network en...

Mobile edge computing (MEC) represents an enabling technology for prospective Internet of Vehicles (IoV) networks. However, the complex vehicular propagation environment may hinder computation offloading. To this end, this paper proposes a novel computation offloading framework for IoV and presents an unmanned aerial vehicle (UAV)-aided network arc...

Fifth generation Vehicular Cloud Computing (5G-VCC) systems support various services with strict Quality of Service (QoS) constraints. Network access technologies such as Long-Term Evolution Advanced Pro with Full Dimensional Multiple-Input Multiple-Output (LTE-A Pro FD-MIMO) and LTE Vehicle to Everything (LTE-V2X) undertake the service of an incre...

This paper presents a novel unmanned aerial vehicle (UAV) aided mobile edge computing (MEC) architecture for vehicular networks. It is considered that the vehicles should complete latency critical computation intensive tasks either locally with on-board computation units or by offloading part of their tasks to road side units (RSUs) with collocated...

The IETF 6TiSCH working group fosters the adaptation of IPv6-based protocols into Internet of Things by introducing the 6TiSCH Operation Sublayer (6top). The 6TiSCH architecture integrates the high reliability and low-energy consumption of IEEE 802.15.4e Time Slotted Channel Hopping (TSCH) with IPv6. IEEE 802.15.4e TSCH defines only the communicati...

Virtual tours using drones enhance the experience the users perceive from a place with cultural interest. Drones equipped with 360o cameras perform real-time video streaming of the cultural sites. The user preferences about each monument type should be considered in order to decide the appropriate flying route for the drone. This article describes...

The IETF 6TiSCH working group fosters the adaptation of IPv6-based protocols into Internet of Things by introducing the 6TiSCH Operation Sublayer (6top). The 6TiSCH architecture integrates the high reliability and low-energy consumption of IEEE 802.15.4e Time Slotted Channel Hopping (TSCH) with IPv6. IEEE 802.15.4e TSCH defines only the communicati...

Flying Ad-hoc Networks (FANETs) use 5G network access technologies to fulfill the requirements of their services. In this environment, Drone to Infrastructure (D2I) communication is supported, while each drone could use both Disaster Management (DM) and non-Disaster Management (nDM) services. Efficient network selection algorithms are required to s...

Fifth generation (5G) Vehicular Cloud Computing (VCC) systems use heterogeneous network access technologies to fulfill the requirements of modern services. Multiple services with different Quality of Service (QoS) constraints could be available in each vehicle, while at the same time, user requirements and provider policies must be addressed. There...

Virtual tours using drones enhance the experience the users perceive from a place with cultural interest. Drones equipped with 360o cameras perform real-time video streaming of the cultural sites. The user preferences about each monument type should be considered in order the appropriate flying route for the drone to be selected. This paper describ...

Video streaming currently accounts for the majority of Internet traffic. One factor that enables video streaming is HTTP Adaptive Streaming (HAS), that allows the users to stream video using a bit rate that closely matches the available bandwidth from the server to the client. MPEG Dynamic Adaptive Streaming over HTTP (DASH) is a widely used standa...

The performance of all-optical dual-hop relayed free-space optical communication systems is analytically studied and evaluated. We consider the case when the total received signal undergoes turbulence-induced channel fading, modeled by the versatile mixture-Gamma distribution. Also, the misalignment-induced fading due to the presence of pointing er...

Fifth generation (5G) vehicular systems support multiple services with strict Quality of Service (QoS) constraints. To fulfill the increased communication needs, 5G Vehicular Cloud Computing (5G-VCC) architectures with dense deployments of the access network infrastructures have been proposed. In such systems, the network resources manipulation is...

The performance of all-optical dual-hop relayed free-space optical communication systems is analytically studied and evaluated. We consider the case when the total received signal undergoes turbulence-induced channel fading, modeled by the versatile mixture-Gamma distribution. Also, the misalignment-induced fading due to the presence of pointing er...

Fifth Generation Vehicular Cloud Computing (5GVCC) systems use heterogeneous network access technologies to fulfill the requirements of modern vehicular services. Efficient network selection algorithms are required to satisfy the constraints of Driver Assistance (DA) services, Passengers Entertainment and Information (PEnI) services and Medical (ME...

Virtual tourism is a novel trend that enhances the experience the users perceive from touristic places, such as archaeological sites. Drones are equipped with 360o video cameras and used for video capturing of the heritage sites. The video material is streamed to the users in real time, enriched with additional 3D, Augmented Reality (AR) or Mixed R...

Fifth Generation Vehicular Cloud Computing (5G-VCC) systems use heterogeneous network access technologies in order to fulfill the requirements of modern services, including medical services with strict constraints. Therefore, the need for efficient Vertical Handover (VHO) management schemes must be addressed. In this paper, a VHO management scheme...

A new detection scheme for multiuser multiple-input multiple-output (MIMO) systems is analytically presented. In particular, the transmitting users are being categorized in two distinct priority service groups, while they communicate directly with a multi-antenna receiver. The linear zero-forcing scheme is applied in two consecutive detection stage...

The recently created IETF 6TiSCH working group combines the high reliability and low-energy consumption of IEEE 802.15.4e Time Slotted Channel Hopping with IPv6 for industrial Internet of Things. We propose a distributed link scheduling algorithm, called Local Voting, for 6TiSCH networks that adapts the schedule to the network conditions. The algor...

Following the Always Best Connection (ABC) principle of the 4th generation wireless networks users of mobile services would be provided with connectivity to the best access technology all the time. In such a context, mobile devices are equipped with multiple radio interfaces allowing connectivity to the most suitable network environment based on us...

Single Carrier Frequency Division Multiple Access (SCFDMA) is currently adopted by 3GPP in the LTE cellular systems for the uplink due to its high data rate and low peak-to-average power-ratio (PAPR). In this work, the PAPR for IFDMA (Interleaved Frequency Division Multiple Access), LFDMA (Localized Frequency Division Multiple Access), and DFDMA (D...

The 3GPP Long Term Evolution Advanced (LTE-A) standard specifies a set of pioneer features such as relay nodes and carrier aggregation. At the same time, the Software Defined Networks (SDN) have become an emerging technology which provides centralized control and programmability to modern networks. In the current communication environment, cloud co...

In this work we consider the numerical integration of Maxwell equations with symplectic integrators with special properties.

Cloud Computing constitutes an emerging computing paradigm consisting of elements of grid computing, utility computing and software-defined networks. The aggregation of these technologies offers a new environment for the deployment of services. Cloud computing environment provides capabilities which are unique covering the existing and future needs...

A spectrum sharing system with primary and secondary nodes, each equipped with an arbitrary number of antennas, is investigated. Particularly, the outage performance of an underlay cognitive system is analytically studied, in the case when the end-to-end ( ) communication is established via an intermediate relay node. To better enhance the communic...

The 3GPP Long Term Evolution Advanced (LTE-A) standard specifies a set of pioneer features such as relay nodes and carrier aggregation. At the same time, the Software Defined Networks (SDN) have become an emerging technology which provides centralized control and programmability to modern networks. In the current communication environment, cloud co...

The evolution of broadband connection technologies, along with the explosive growth of mobile handheld devices, has made video content one of the major Internet traffic types. HTTP adaptive streaming (HAS) is one factor assisting the growing popularity of Internet video. One of its standards, the MPEG dynamic adaptive streaming over HTTP (DASH), al...

The performance of a distributed multiple input-multiple output (MIMO) system with m single-antenna transmitters and a receiver with n ≥ m antennas is analytically investigated. Particularly, the transmitters simultaneously send their information streams to the receiver, operating under the spatial multiplexing regime. To this end, the receiver uti...

Distributed systems built in open competitive and highly dynamic pervasive environments are composed of autonomous entities that act and interact in an intelligent and flexible manner so as to achieve their own goals and aims. System entities may be classified into two main categories that are, in principle, in conflict. These are the service resou...

The performance of an underlay cognitive (secondary) dual-hop relaying system with multiple antennas and hardware impairments at each transceiver is investigated. In particular, the outage probability of the end-to-end (e2e) communication is derived in closed-form, when either transmit antenna selection with maximum ratio combining (TAS/MRC), or TA...

The wide spread of real-time services in wireless networks demands scheduling mechanisms supporting strict Quality of Service (QoS) requirements. Nevertheless, the specifications of the LTE standard for mobile connectivity defined by the 3rd Generation Partnership Project (3GPP) does not impose any specific scheduler for the proper allocation of re...

The MPEG-Dynamic Adaptation Streaming over HTTP (MPEG-DASH) tries to improve the quality perceived by the user by allowing the user's centric access to different resolutions of the video content via the Hypertext Transfer Protocol (HTTP). However, although it eliminates data packet loss, depending on the rate adaptation strategy adopted by the user...

A QoS aware scheduler, the FLS-Advanced (FLSA), a modified version of FLS, for the LTE downlink transmission is proposed. The main idea is to prioritize the real-time type traffic against the other types. FLSA has been built on three distinct levels which cooperate each other to allocate the network resources to users.

Next generation wireless networks consist of many heterogeneous access technologies that should support various service types with different quality of service (QoS) constraints, as well as user, requirements and provider policies. Therefore, the need for network selection mechanisms that consider multiple factors must be addressed. In this paper,...

In modern wireless networking technologies, the need to support the nodes mobility is growing rapidly. This need is even greater in vehicular environments, in which the nodes are characterized by high mobility. In this paper, we study the basic protocols for mobility support in vehicular environments, such as Fast Handovers for Proxy Mobile IPv6 (P...

Although MPEG-Dynamic Adaptation Streaming over HTTP (MPEG-DASH) eliminates data packet loss, based on the rate adaptation strategy adopted by the user and the network conditions, still playback interruptions may not be avoided. In this paper an algorithm for rate adaption in MPEG-DASH is proposed that employs fuzzy logic to estimate the resolution...

Following the Always Best Connection (ABC) principle of the 4th generation wireless networks users of mobile services would be provided with connectivity to the best access technology all the time. In such a context mobile devices are equipped with multiple radio interfaces allowing connectivity to the most suitable network environment based on use...

Multimedia information has been increased in the recent years while new content delivery services enhanced with personalization functionalities are provided to users. Several standards are proposed for the representation and retrieval of multimedia content. This paper makes an overview of the available standards and technologies. Furthermore a prot...

The Long-Term Evolution (LTE) standard is a promising solution to mobile connectivity. It provides high data rates at a relatively low cost. At the same time, video traffic has so far outpaced other traffic types in growth, making it the dominant traffic type in current wireless networks. In this paper we study the concept of Quality of Experience...

The LTE standard is a promising solution to wireless connectivity. It promises high data rates at a low cost. At the same time, video traffic has so far outpaced other traffic types in growth, making it now the dominant traffic type in wireless networks. In this paper we study the concept of Quality of Experience for video traffic in LTE systems, S...

One of the most valuable design issues of the Worldwide Interoperability for Microwave Access (WiMAX) standard is its flexibility. It allows multiple downlink-to-uplink duration definitions concerning the width of the corresponding sub-frames, thus, the telecommunication companies and businesses are able to define the downlink-to-uplink width from...

The aim of this paper is, in accordance with efficient web search service operation objectives, to propose enhancements to the sophistication of the functionality that can be offered by search engine services. A metasearch third-party result ranking mechanism is proposed, which is capable of adapting over the continuous changes that occur on the we...

This paper presents a semantic model which delivers personalized audio information. The personalization process is automated and decentralized. The metadata which support personalization are separated in two categories: the metadata describing user preferences stored at each user and the resource adaptation metadata stored at the server. The multim...