Performance Evaluation of an Adaptive Self-Organizing Frequency Reuse Approach for OFDMA Downlink

Orthogonal frequency division multiple access (OFDMA) is extensively utilized for the downlink of cellular systems such as long term evolution (LTE) and LTE Advanced (LTE-A). In OFDMA cellular networks, orthogonal resource blocks (RBs) can be used within each cell. However, the available resources are rare and so those resources have ...

Uplink Pilot Allocation for Multi-Cell Massive MIMO Systems

Pilot contamination due to the pilot reuse in adjacent cells is a very serious problem in massive multi-input multiple-output (MIMO) system. Therefore, the pilot allocation is significant for improving the performance of the system. In this paper, we formulate the pilot allocation optimization problem for maximizing uplink sum rate of ...

Transparent Tx and Rx waveform processing for 5G new radio mobile communications

Several different waveform processing techniques have been studied and proposed for the 5G new radio (NR) physical layer, to support new mixed numerology and asynchronous services. The evaluation and comparison of these different techniques is commonly based on matched waveform processing in the transmitter and receiver units. In this article, ...

Investigating the polarization of an omni-directional patch antenna

The ever-present need for higher data rates in telecom networks has a profound effect on what is required from the ideal antenna. In Ultra Dense Networks (UDN), for example, the challenge is to find an omnidirectional, yet orthogonally polarized, antenna of reasonable size. For this purpose, a new antenna type, ...

Wavelength-stable burst-mode laser for next-generation PONs

We developed a novel wavelength-stable burst-mode (BM) laser based on a multi-electrode distributed-feedback (DFB) laser. Our main use-case for the multi-electrode laser (MEL) is a time- and wavelength-division multiplexed passive optical network (TWDM-PON) (NG-PON2), but the wavelength-stable BM laser might also enable future coherent TDM-PON systems and high-rate PON systems ...

Mining competition in a multi-cryptocurrency ecosystem at the network edge: A congestion game approach

Copyright is held by author/owner(s). We model the competition over several blockchains characterizing multiple cryptocurrencies as a non-cooperative game. Then, we specialize our results to two instances of the general game, showing properties of the Nash equilibrium. In particular, leveraging results about congestion games, we establish the existence of pure ...

Communication Aspects of a Modified Cooperative Adaptive Cruise Control Algorithm

This paper investigates the ability of modified Cooperative Adaptive Cruise Control to support high-density car platooning. We first use a simplistic communication model to study the impact of actuation lag, message periodicity, and communication delay on the minimum feasible inter-car spacing. We then use a detailed IEEE 802.11p simulation model ...

Security Witnesses for Compiler Transformations

Compiler optimizations can be correct and yet be insecure. Program changes made during optimization may weaken security guarantees -- for instance, by introducing new ways to leak secret data. This work presents a methodology for ensuring that security properties are preserved during compilation. Properties are expressed as automata operating over ...

Scaling of random walk betweenness in networks

We study the betweenness centrality (BC) of vertices of a graph using random walk paths. Random walk BC (RWBC) provides an alternative measure to the shortest path centrality of each vertex in a graph as it aggregates contributions from possibly all vertex-pairs in the graph and not just from those ...

Precoding and Detection for Broadband Single Carrier Terahertz Massive MIMO Systems Using LSQR Algorithm

The terahertz (THz) communication utilizes the frequency spectrum above 300 GHz and is widely considered as a promising solution to the future high-speed shortrange wireless communication beyond millimeter wave (mmWave) communication. While providing tens of gigahertz bandwidth, it is subjected to high propagation path loss, intersymbol and inter-user interferences. The ...

The paradigm-shift of social spambots: Evidence, theories, and tools for the arms race

  • Cresci S.
  • Petrocchi M.
  • Pietro R.
  • Spognardi A.
  • Tesconi M.

© 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Recent studies in social media spam and automation provide anecdotal argumentation of the rise of a new generation of spambots, so-called social spambots. Here, for the first time, we extensively study this novel ...

Simultaneous Sensor Placement and Scheduling for Fusion-Based Detection in RF-Powered Sensor Networks

When deploying RF-powered sensor networks for mission-critical applications such as security surveillance, it is often required to maximize or guarantee the quality of surveillance. Both placing and scheduling the charging/work modes of sensors are of key importance in order to ensure a satisfying quality of surveillance continuously. Traditionally, sensor placement ...

Accurate Quality of Transmission estimation with machine learning

In optical transport networks the Quality of Transmission (QoT) is estimated before provisioning new connections or upgrading existing ones. Traditionally, a physical layer model (PLM) is used for QoT estimation coupled with high margins. Margins are used to account for the uncertainty in the evolving physical layer conditions and ensure ...

Optimization model for Cross-Domain Network Slices in 5G Networks

Network Slicing (NS) is a key enabler of the upcoming 5G system and beyond, leveraging on both Network Function Virtualization (NFV) and Software Defined Networking (SDN), NS will enable a flexible deployment of Network Functions (NFs) belonging to multiple Service Function Chains (SFC) over various administrative and technological domains. Our ...

Analytical Modeling and Experimental Validation of NB-IoT Device Energy Consumption

The recent standardization of 3GPP Narrowband IoT (NB-IoT) paves the way to support Low-Power Wide-Area (LPWA) use cases in cellular networks. NB-IoT design goals are extended coverage, low power and low cost devices, and massive connections. As a new radio access technology, it is necessary to analyze the possibilities NB-IoT ...

Context-Awareness Enhances 5G Multi-Access Edge Computing Reliability

The fifth generation (5G) mobile telecommunication network is expected to support Multi- Access Edge Computing (MEC), which intends to distribute computation tasks and services from the central cloud to the edge clouds. Towards ultra-responsive, ultra-reliable and ultra-low-latency MEC services, the current mobile network security architecture should enable a more decentralized ...

Survey on UAV Cellular Communications: Practical Aspects, Standardization Advancements, Regulation, and Security Challenges

The rapid growth of consumer Unmanned Aerial Vehicles (UAVs) is creating promising new business opportunities for cellular operators. On the one hand, UAVs can be connected to cellular networks as new types of user equipment, therefore generating significant revenues for the operators that guarantee their stringent service requirements. On the ...

400 Gbps Dual-Polarization Non-linear Frequency-Division Multiplexed Transmission with b-Modulation

We demonstrate in simulation a 400 Gbps polarisation-multiplexed 1050x32-QAM NFDM transmission using b-modulation on the continuous nonlinear spectrum. A significant improvement in Q-factor over $q_c$-modulation is observed.

Beam Management in 5G NR using Geolocation Side Information

A machine learning solution leveraging geolocation side information is proposed for enhancing beam management in 5G NR millimeter wave (mmWave) wireless systems. An important building block of our solution are the support vector machines (SVMs), which are used to model the mapping between the user equipments' (UEs) geolocations and their ...

Pre-Matched Eigenmode Antenna With Polarization and Pattern Diversity

In this paper we propose an antenna design procedure based on the eigenmode decomposition technique which avoids the use of the external matching networks that are typically required at the input ports of the mode decomposition network (MDN). We illustrate the technique by examining the properties of a circularly symmetrical ...