Digital Communications and Networks

3rd Course of Study (Start: Academic Year 2020-21)

1st Semester

ΨΣ-ΨΕΔ-302 Wireless Access Technologies [M] G. Efthymoglou, A. Alexiou


This course aims to analyze the fundamental techniques and advance infrastructure technologies for the Future Internet. The first part of the course addresses physical layer aspects: modulation, coding, multiplexing and diversity techniques. The second part of the course addresses multiple access schemes, resources and interference management techniques. In the third part, architectural aspects are studied, placing the emphasis on the cellular, local area network and proximal communications (i.e. wireless sensor networks, machine to machine and device to device communications) infrastructures paradigms. In the last part, architectural challenges and bottlenecks in the design of Future Internet Infrastructures are discussed, namely backhaul and latency limitations, centralization requirements, virtualization and heterogeneity.

Course Contents

  • Introduction on Future Internet Infrastructures: Basic principles and technologies, trends and challenges and Key Performance Indicators
  • Baseband transmission and physical layer techniques: modulation, coding, multiplexing, diversity, Multiple Input Multiple Output (MIMO)
  • Spread Spectrum techniques: Direct Sequence Spread Spectrum, interference, multipath channels and RAKE receivers, Code Division Multiple Access (CDMA)
  • Orthogonal Frequency Division Multiplexing: orthogonal subcarriers, cyclic prefix for multipath channels, peak-to-average power ratio, frequency and timing offset
  • Multiple access schemes: Time/Frequency/ Code/Space/.. Division Multiple Access, scheduling, contention based random access
  • Cooperation and coordination techniques : interference management, ‘cell-edge’ improvements, Coordinated Multipoint Transmission/Reception, Distributed Input Distributed Output (DIDO)
  • The cellular architecture paradigm: GSM, UMTS, LTE, LTE-Advanced, 5G
  • The local broadband access architecture paradigm: IEEE 802.11b/g/n/ac/ax
  • The Internet of Things architecture paradigm: machine-to-machine communications over cellular
  • Future Internet Infrastructures implementation challenges and bottlenecks
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ΨΣ-ΨΕΔ-303 Wireless Network Design [M] A. Kanatas, A. Rouskas


The objective of the course is the presentation of modern wireless communication networks architecture, technologies and techniques. The area of wireless communications and networks is one of the most dynamic areas in the ICT field. The course covers the wireless channel characteristics, multi-antenna techniques, radio resource planning and management, packet scheduling, mobility management, and novel design techniques of wireless networks. At the end of the course, the students will be able to analyze and evaluate main principles and planning design options for wireless communication networks.

Course Contents

  • Categories of wireless communications networks. Coverage, services and performance requirements of wireless networks. Network examples. Duplexing techniques, multiple access techniques and random access. Fundamentals of cellular network design.
  • Analytic and empirical propagation channel models for outdoor and indoor environments. Shadowing and lognormal distribution. Calculation of coverage range and percentage.
  • Propagation environment, mechanisms and propagation phenomena. Fading, types of fading. Delay dispersion and frequency selectivity. Frequency dispersion and time selectivity. Direction dispersion and space selectivity.
  • From SISO to MIMO. Multi-antenna techniques and gains for beyond 3G systems (applications in LTE and LTE-A networks).
  • Case study: design of a of a cellular mobile communications system step-by-step (initial planning based on traffic requirements, area, equipment costs, frequency bands, etc.)
  • Wireless resource management, handoff management, communication management, mobility management in mobile communication networks. Examples and exercises.
  • Packet scheduling principles. Wireless packet scheduling algorithms. Scheduling algorithms in 3G and 4G.
  • Mobility management protocols in wireless packet networks. IP mobility management. Examples and mobility management architectures in 3G and 4G.
  • TCP protocol principles and problems in wireless networks. TCP protocol adaptation techniques for wireless links. Multipath TCP.
  • Cloud computing and software defined networking in next generation wireless networks. Architectures and design options for Cloud Radio Access Network (CloudRAN), Network Function Virtualization (NFV), wireless SDN and Mobile Edge Computing (MEC) in 5G. Laboratory example of SDN network management in wireless networks.
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ΨΣ-ΨΕΔ-203 Application Development for Mobile Devices [M] A. Meliones


The objective of this course is to familiarize students with the main principles and concepts of mobile applications programming. The focus is on the Android development framework which is used in the great majority of modern smartphone and tablet devices, featuring powerful processing, a touch screen, and a variety of sensors including a GPS unit. Furthermore, the course addresses network programming techniques for the implementation of network applications with the use of Java. The goal of this lab/course is to demystify the Android development framework towards developing modern applications for mobile devices. Working with Android applications, students will gain experience with a modern technology in the fast moving market segment of computationally powerful Internet-enabled smartphones and similar devices.

Course Contents

  • Lecture 1: Overview of device and operating system architecture for modern smartphones. Introduction to the Android development platform.
  • Lecture 2: Introduction to the Android development framework and tools for mobile application development. Android application model and basic application elements. Android SDK overview. Getting familiar with the Android emulator. Android programming synopsis. Application development using the Android SDK and the Eclipse framework.
  • Lecture 3: Creating User Interfaces: Using XML-based layouts (comparison with java powered layouts), basic widgets (labels, check boxes, buttons, input boxes, etc), containers (widget collections), input method framework, drop-down menus, fonts, etc. Layout methods. Handling multiple screen sizes and resolutions.
  • Lecture 4: Android application components and component interaction: Android Activities and Android Intents.
  • Lecture 5: Using data and databases in Android.
  • Lecture 6: Creating map-based activities. The Google Maps Application Programming Interface (API) and the MapView class.
  • Lecture 7: Location Based Services.
  • Lecture 8: Cases studies – Lab development: Development of Android Applications.
  • Lecture 9: Cases studies – Lab development: Development of Android Applications.
  • Lecture 10: Cases studies – Lab development: Development of Android Applications.
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ΨΣ-ΨΕΔ-322 Network Design and Management [M] K. Tsagkaris

  • Course Code ΨΣ-ΨΕΔ-322 Type of Course Mandatory [M]
  • Semester 1st Semester FacultyK. Tsagkaris
  • ECTS Credits 7,5


The course “Network Design and Management” aims at teaching the contemporary methodologies and technologies in the areas of design and management of computer networks. In this context, network design problems are presented and properly formulated, whereas algorithms for their solution are presented, developed and validated using commercial software packages. Furthermore, the fundaments of computer network management, with respect to architectural, functional, information and communication models, are presented, thoroughly discussed and validated. Last but not least, recent advancements and future trends in networks and their management are presented and analyzed. The course is comprised of both theoretical lectures and specialised laboratory and programming exercises and platform demonstrations.

Course Contents

  • Introduction: Course/lectures overview. Overview of computer networks, Wireless/Fixed access. Core networks. High level presentation of design, management and optimization problems.
  • Advanced network design problems: Advanced design problems in fixed/wireless access networks and core networks. Topology and Resource assignment problems (Routing & Wavelength, Virtual Machines Placement, Spectrum/Power Assignment, Traffic Engineering, Mobile Offloading) in optical networks, 4G/5G Small Cell/HetNets, Radio-over-Fiber Networks and Data Centers. Mathematical modeling (Energy Efficiency, Cost Reduction).
  • Methods and algorithms for solving computer network design problems: local search, greedy, (meta-)heuristics, simulated annealing, genetic algorithms, taboo search, neural networks, bio-inspired and learning techniques. Application to and solution of the above design problems. Programming exercises.
  • Introduction to network management: Configuration, Fault, Accounting, Performance and Security management functions – (CFAPS). Management layers, (element, network, service, business), manager(s), agents, network management architectures and standards. The internet management model, Simple Network Management Protocol (SNMP) protocol, Management Information Base (MIB), Structure of Management Information (SMI)/Abstract Syntax Notation.1 (ASN.1) languages. The Netconf protocol, YANG information model.
  • MIB design, processing and development: Reading and processing of MIB contents. Introduction to well established MIBs (MIB-II, RFC 1213). Focus on system, interfaces, IP and TCP groups. Monitoring and configuration of MIB parameters based on SNMP. Configuration, performance and fault management functions. Application of theory in lab network infrastructure (servers, host PCs, switches etc.) using open source tools, lab exercises and analysis of results.
  • Design and development of network management applications: Development of management applications particularly for performance and fault management. Usage of scripts, high level programming languages and open source tools and libraries. Programming and lab exercises, derivation and analysis of results.
  • Network monitoring techniques and tools: Packet inspection, Protocol analysis. Traffic monitoring and analysis. Active/Passive monitoring. Network monitoring tools (ping, Traceroute, TCPdump, MRTG, IPFIX/NetFlow, HP Openview, SNMPc, MRTG/PRTG, Nagios, OpenNMS). Event and alarm generation. Event/alarm correlation (Aggregation, Filtering, Masking, Root cause analysis, Τεχνικές Case-, Model-, Rule- Based Reasoning).
  • Autonomic Network Management: Mechanisms self-management (self-configuration, self-optimization, self-healing), cognitive management, application of machine learning in network management. Policy-based management. Network governance. The case of 3GPP LTE Self-Organizing Networks (SΟΝ).
  • Management of SDN networks: Introduction to Software Defined Networks (SDN). The OpenFlow protocol. Virtual Switches and SDN controllers. Network virtualization and SDN Applications. Network Function Virtualization.
  • Management /Programming of SDN: Installation and configuration of SDNs using source tools (Openflow vSwitches, mininet, JAVA/Python based controllers). Lab exercises on networking management/programming and development of networks functions/applications.
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2nd Semester

ΨΣ-ΨΕΔ-309 Broadband Communications [M] A. Alexiou


The objective of this course is to study broadband network architectures, focusing on the most recent developments in the evolution of communication and computer networks to the next generation and key enabling technologies. The first part of the course addresses the requirements, technology enablers and limitations in the design of broadband networks and the implementation of broadband applications and services. Wireline and optical broadband networks are analyzed in the second part of the course, with emphasis placed on transmission and baseband processing, multiple access and network architecture issues. In the third part, recent technological advances in the area of broadband wireless access are studied, including next generation WiFi and 5G communications. Finally, the most critical technology trends and system concept principles targeting ubiquitous broadband access in future networks are discussed, namely, Densification, Extreme Resource Sharing and Cloudification.

Course Contents

  • Broadband access requirements, technological advances and applications
  • Fundamental broadband transmission principles: capacity, spectral efficiency, connectivity, reliability, quality of experience
  • Efficient spectrum utilization techniques for broadband access: modulation, coding, multiplexing, spatial/MIMO processing, spread spectrum, cooperative techniques, coordination and interference management
  • Digital Subscriber Line: baseband processing, physical layer procedures architecture, advanced features for ADSL2, VDSL, multiuser DSL
  • Next generation Ethernet: baseband processing, physical layer and MAC protocols. xGigabit Ethernet architectures, crosstalk, Ethernet in the first mile
  • Optical fibre and optical transmission: transmission, attenuation, optical signal amplification, Wavelength Division Multiplexing
  • Optical networks design and architecture: optical network components, Optical Transport Network Hierarchy, WDM optical networks design
  • Broadband Wireless Local Access and the next generation WiFi: OFDM technologies, multiuser MIMO, random and scheduled access
  • Ubiquitous broadband access in Future Networks with 4G and 5G Communications: cooperation, coordination, massive MIMO, millimeter wave, user-centric, cell-less architectures
  • Recent technological advances in Broadband communications: Ultra Dense Networks, Universal Resources Management and Cloudification
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ΨΣ-ΨΕΔ-301 Wireless and Satellite Communications [M] A. Kanatas , D. Vougioukas


The objective of the course is a comprehensive presentation of the analysis and design techniques of wireless and satellite communication links. The course includes two sections. In the first section we attempt a review of fundamental concepts of antenna technology and electromagnetic propagation. An analytic description of propagation aspects in current wireless communication systems is given for the mostly used frequency bands. Propagation mechanisms and prediction models are provided for successful design of fixed wireless access systems. We analyze international standards and recommendations (ITU-R) for the efficient design of wireless links providing the critical metrics and quality parameters. The section closes with the analysis of antenna arrays, the methods used for array signal processing and typical applications of optimum beam formers. The second section deals with the review of Satellite communications networks technology providing the current state of structural blocks of these networks, discussing the multiple access techniques and network topologies used. Typical examples are given for VSAT networks and the design of satellite links.

Course Contents

  • Electromagnetic waves and wave polarization. Antennas as radiators and several antenna types. Antenna parameters, radiation patterns, directive gain, power gain, effective aperture, effective length.
  • Electromagnetic wave propagation mechanisms: Reflection and refraction, propagation in the troposphere.
  • Electromagnetic wave propagation mechanisms: Scattering, diffraction, propagation models. Quality parameters for effective link design.
  • Analysis of antenna arrays. Types, topologies, geometry of arrays. Fundamental parameters for antenna array system representation. Narrowband assumption. Basic structures for beamforming.
  • Array signal processing. Uniform linear arrays. Visible region, antenna array weighting-feeding. Radiation patterns parameters and beamsteering.
  • Statistical antenna array signal processing. Narrowband processing, conventional beam former, null steering beam former. Wiener filters and digital beamforming techniques for optimum beam formers.
  • The development of satellite communication networks. Review of services. Geometrical parameters and orbits (GEO, LEO, MEO, HEO). Satellite transponders and basic structures. Antennas on board the satellite.
  • Noise in satellite communications (antennas and receivers). Receiver architectures. Non-linearities in satellite high power amplifiers. Quality parameters and performance evaluation criteria for clear sky and under rain conditions.
  • Transmission techniques and satellite link design. Design examples for fixed as well as mobile communication systems.
  • Multiple access techniques for satellite communication networks (TDMA, FDMA, CDMA). VSAT Networks, topologies and architectures.
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ΨΣ-ΨΕΔ-310 Development of Software Defined Radio Systems [M] Κ. Maliatsos

  • Course Code ΨΣ-ΨΕΔ-310 Type of Course Mandatory [M]
  • Semester 2nd Semester FacultyΚ. Maliatsos
  • ECTS Credits 7,5


The objective of this course is to introduce the students to the practical design, analysis and performance evaluation of wireless communication systems, using the software defined radio (SDR) technology. During the course, the students will have the opportunity to experiment with signals that are used in today’s wireless communication systems, such as LTE and Wi-Fi, by designing the corresponding transmitter and receiver digital processing chains. The signal generation and analysis blocks will be designed using software, whereas the transmission/reception will be realized using SDR hardware (digitizer boards) and general purpose computing platforms (linux-based desktop hosts).

The course consists of three parts. During the first part the students are familiarized with the SDR concept, the use of SDR hardware (Ettus USRP boards) and software management tools, as well as develop a baseline SISO-OFDM (Single-antenna Orthogonal Frequency Division Multiplexing) transceiver. In the second part, the students develop more complex blocks, extending the baseline transceiver in order to support MIMO (multi-antenna) techniques. In the third and final part the students are experimenting with existing open source wireless communication system implementations (e.g. OpenAirInterface), creating and testing an experimental private 4G network.

Course Contents

  • Part 1:
    • Introduction to Software Defined Radio (SDR),
      • SDR Architectures (Ideal, Practical etc.,) SDR systems, SDR transceiver components.
      • Introduction to the SDR hardware and management software used in the course
      • SDR technology applications: Cognitive Radios and Dynamic Spectrum Sharing.
    • Signals / Spectrum Analysis and Detection
      • Generation of basic signals (sine, square pulse) and implementation of basic signal processing procedures (filtering with sampling rate conversion
      • Basic principles of detection and estimation theory, statistical signal characterization, maximum likelihood detector/Bayesian, etc.
      • Energy detector, matched filter, filter-bank detector
    • Implementation of a baseline QPSK transceiver using Software
      • Familiarization with software code tools (MATLAB or C++).
      • Development of OFDM modulator and demodulator
      • Pilot and preamble insertion – Synchronization
      • Frequency offset estimation
      • Channel estimation and equalization
      • Over-the-air experimentation using SDR hardware – Performance Evaluation.
  • Part 2:
    • Baseline transceiver extension and experimentation with MIMO techniques
      • Implementation of MIMO in SDR hardware.
    • Receiver Diversity Techniques
      • Development of selection diversity
      • Development of Maximum Ratio Combining (MRC).
    • Transmitter Diversity Techniques
      • Space Time Block Coding using the Alamouti method.
  • Part 3:
    • Development of a 4G experimental network using existing open source software code (e.g. OpenAirInterface)
    • Familiarization with 4G systems. Experimentation with practical resources allocation methods.
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ΨΣ-ΨΕΔ-311 Future Internet and Cloud Computing [M] D. Kyriazis , E. Haleplidis


The course aims at presenting and analyzing design and implementation aspects in Future Internet. To this effect, the first part of the course provides an overview of the today’s Internet, as well as of the problems-challenges of the latter. It then presents and analyzes the most recent technologies and architectures focusing on the emerging new network architecture, 5G. In this context, a set of topics will be covered addressing Virtualized Network Functions (VNFs), profiles compilation and analysis, management and orchestration of VNFs, while emerging standards (such as ETSI MANO) will also be analysed.

The second part of the course focuses on the infrastructures per se, that comprise variant entities (Things) and computing Clouds. The course offers the theoretical fundaments of these infrastructures, whereas it aims at the familiarization of the students with both the functional and programming technologies and the application execution in these environments through lab exercises and the use of specific tools (e.g. OpenStack, Google AppEngine). Techniques and methodologies in all infrastructure layers are thoroughly examined and analyzed, in particular focusing on modern cloud architectures (computing clouds, storage clouds, event-driven etc), their structural components (resource types service classes, service level and event level agreements, synthesis and multilayer service orchestration), as well as on networking technologies.

Course Contents

  • Overview & Challenges of today’s Internet: Overview of Internet architecture and applications. Web (data, interconnections, access, communication types and services, standards, identification). Overview of application layer protocols, architectures, processes, HTTP, SMTP, File transfer, DNS service, P2P systems, content delivery. Overview of transport layer protocols and algorithms. Overview of network layer protocols and algorithms. Challenges and trends (performance, scalability, security) – Towards Future Internet.
  • 5G Networks – Introduction: Virtualization / Software Defined Networking, Virtual Switches and SDN controllers, The OpenFlow protocol, Network virtualization, SDN Applications, Network abstractions / languages. Network Function Virtualization (NFV).
  • 5G Δίκτυα – Management of Virtualized Network Functions: Description, storage and retrieval of virtualized network functions (VNFs), Compilation and update of VNFs profiles, Composition of VNFs for the development of network services (chains), Monitoring and corrective actions for the provision of quality of service guarantees in virtualized infrastructures.
  • 5G Δίκτυα – Orchestration of Virtualized Network Functions: Mapping of virtualized network functions to network resources, Orchestration of virtualized functions, Adaptive actions during runtime, The ETSI MANO standard.
  • 5G Research & Experimentation: Platforms and infrastructures for research and experimentation in 5G networks. Introduction and Hands-on experience: management, description, composition and orchestration of VNFs.
  • Future Internet Infrastructures: Computation clouds and Internet of Things. Challenges, aims, application domains. Architectural approaches for computational clouds. SPI Model: Software-Platform-Infrastructure, functionality, attributes, interfaces and interconnection of layers. Cloud deployment models: private, public, hybrid, federated, community.
  • Cloud Computing Technologies: Application and infrastructure monitoring (Nagios, Ganglia). Workflow management: Requirements and description languages (XPDL, WS-BPEL, QoWL). Virtualization: Deployment and provisioning of virtual resources, Virtualization types (native, hardware, OS-level, application), Hypervisors (KVM, Xen). Virtual network resources, Network virtualization L2 (VLAN stacking, OTV, OpenVZ, vNetwork, SUNCrossbow), Network virtualization L3.
  • Internet of Things: Objects description, things ontologies (OWL, SUMO, SensorML). Technologies and networking protocols (Zigbee, KNX, Z-wave, MQTT). Object management (centralized, distributed, cognitive). Applications, future challenges.
  • Storage and Data Management Technologies: Scalability approaches, elasticity, data coherence, namespace management. Computational storage model. Access and management of stored objects based on content. Laboratory exercise using Apache Hadoop.
  • Deployment of Computational Clouds and Cloud Applications Development: Laboratory exercises using OpenStack and Google App Engine.
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3rd Semester

ΨΣ-ΨΕΔ-333 MSc Dissertation [M] Member of faculty

  • Course Code ΨΣ-ΨΕΔ-333 Type of Course Mandatory [M]
  • Semester 3rd Semester FacultyMember of faculty
  • ECTS Credits 30

The master thesis project is carried out under the supervision of one of the faculty members and involves – at a first stage – the identification of the research topic/ technological problem to be addressed and the research of literature for existing state-of-the-art. The output of the project, namely the description of the research area, the problem formulation, the solution definition and implementation and the illustration of results and final conclusions and recommendations, is presented in the master thesis.

The master thesis project aims to

  • Extend the student’s academic skills, introduce them to a certain research area and potentially motivate them to continue their research work beyond the completion of their Master’s Degree. This may be achieved not only by exploiting particular skills and knowledge acquired from taught courses but also by enhancing their ability to tackle a novel research area and/or problem.
  • Expand the student’s professional skills by developing/improving their ability to research, manage/organise information, think creatively, pursue innovation and report adequately the findings of their research.
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