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Asynchronous Background Processing for Accelerated Simulation of Wireless Communication on Multi-Core Systems

September, 2022

Most popular discrete event simulation software packages run single-threaded. Thus, they achieve only limited performance improvements from more modern multi-core CPUs. At the same time, existing approaches for parallel simulation of networks do not perform well on wireless systems or require complex paradigm shifts in simulation models. In this paper, we propose Asynchronous Background Processing (ABP) to accelerate the simulation of wireless communication on multi-core systems. By moving expensive computation from the main thread into asynchronous tasks computed by background threads, it accelerates the progression of events and thus reduces response time. Tasks are started as early as possible to exploit the time the main thread spends processing other events, ideally providing results before they are needed in the simulation.
  • Dominik S. Buse, Georg Echterling and Falko Dressler, "Asynchronous Background Processing for Accelerated Simulation of Wireless Communication on Multi-Core Systems," Elsevier Computer Communications, Special Issue on ACM MSWiM 2021, vol. 193, pp. 396–409, September 2022. [DOI, BibTeX, PDF and Details...]

Adaptive Blind MPSK Constellation Recovery and Equalization for Cognitive Radio Applications

August, 2022

This work proposes a novel single-step blind adaptive filter solution, inspired by an adaptive interference canceler, for joint equalization and constellation symbol recovery from received phase shift keying (PSK) waveforms. Furthermore, we propose new coefficients update mechanisms based on the constant amplitude of PSK signals. The proposed solution exhibits reduced computational complexity compared to the state of the art and a reduced time of convergence. Additionally, the proposed scheme does not require a training sequence to operate properly. The obtained results clearly show that the proposed scheme significantly improves accuracy regarding phase symbol estimation and ISI reduction.
  • ‪Liset Martínez Marrero, Jorge Torres Gómez, Falko Dressler and Maria Julia Fernández-Getino García, "Adaptive Blind MPSK Constellation Recovery and Equalization for Cognitive Radio Applications," IEEE Transactions on Vehicular Technology (TVT), July 2022. (online first) [DOI, BibTeX, PDF and Details...]

Siting and Sizing Charging Infrastructure for Electric Vehicles with Coordinated Recharging

July, 2022

We analyze daily schedules of drivers to find suitable locations for slow and fast charging stations. In simulation, we test how many charge points to assign to each charging station. Vehicles can be charged with either en-route or destination charging using a realistic model for charging and energy consumption for five electric vehicle models of different car segments. To reduce waiting times at charging stations, we use a centralized charging station database (CSDB), that coordinates charging between vehicles. We found that a combination of a few centralized fast charging stations and many distributed slow charging stations is the best option to improve the average extra time spent with charging for all vehicle types.

Wi-Fi Meets ML: A Survey on Improving IEEE 802.11 Performance with Machine Learning

June, 2022

The Wi-Fi community is currently deploying Wi-Fi 6 and developing Wi-Fi 7, which will bring higher data rates, better multi-user and multi-AP support, and, most importantly, improved configuration flexibility. These technical innovations, including the plethora of configuration parameters, are making next-generation WLANs exceedingly complex as the dependencies between parameters and their joint optimization usually have a non-linear impact on network performance. While classical optimization approaches fail in such conditions, machine learning (ML) is able to handle complexity. Much research has been published on using ML to improve Wi-Fi performance and solutions are slowly being adopted in existing deployments. In this survey, we investigate proposed solutions and highlight open challenges in the field of ML for Wi-Fi.

V-Edge: Virtual Edge Computing as an Enabler for Novel Microservices and Cooperative Computing

May, 2022

As we move from 5G to 6G, edge computing is one of the concepts that needs revisiting. In this position paper, we discuss a way forward, namely the virtual edge computing (V-Edge) concept. V-Edge helps bridging the gap between cloud, edge, and fog by virtualizing all available resources including the end users' devices and making these resources widely available. Thus, V-Edge acts as an enabler for novel microservices as well as cooperative computing solutions in next-generation networks. We introduce the general V-Edge architecture and we characterize some of the key research challenges to overcome in order to enable wide-spread and intelligent edge services.
  • Falko Dressler, Carla Fabiana Chiasserini, Frank H. P. Fitzek, Holger Karl, Renato Lo Cigno, Antonio Capone, Claudio Ettore Casetti, Francesco Malandrino, Vincenzo Mancuso, Florian Klingler and Gianluca A. Rizzo, "V-Edge: Virtual Edge Computing as an Enabler for Novel Microservices and Cooperative Computing," IEEE Network, vol. 36 (3), pp. 24–31, May 2022. [DOI, BibTeX, PDF and Details...]

Hybrid-Fidelity: Utilizing IEEE 802.11 MIMO forPractical Aggregation of LiFi and WiFi

March, 2022

This paper introduces Hy-Fi, a system that aggregates light fidelity (LiFi) and radio frequency (RF)-based communication on the 802.11 (WiFi) physical layer by utilizing the MIMO capabilities in IEEE 802.11-compliant commodity WiFi chips. Hy-Fi is based on two key ideas. First, we use inexpensive commodity hardware to facilitate direct transmission of WiFi waveforms over the optical wireless channel, as this is proposed in the IEEE P802.11bb task group. Second, we use the MIMO signal processing from WiFi to aggregate LiFi and radio signals directly at the physical layer.

Multi-Technology Cooperative Driving: An Analysis Based on PLEXE

February, 2022

This work tackles the fallback and recovery mechanisms that the longitudinal controlling system of a platoon of vehicles can implement as a distributed system with multiple communication interfaces. We present a protocol and procedure to correctly compute the safe transition between different controlling algorithms, down to autonomous (or manual) driving when no communication is possible. To empower the study, we also develop a new version of PLEXE, which is an integral part of this contribution as the only Open Source, free simulation tool that enables the study of such systems with a modular approach, and that we deem offers the community the possibility of boosting research in this field.

Reducing Waiting Times at Charging Stations with Adaptive Electric Vehicle Route Planning

January, 2022

Electric vehicles are becoming more popular all over the world. With increasing battery capacities and a growing fast-charging infrastructure, they are becoming suitable for long-distance travel. However, queues at charging stations could lead to long waiting times, making efficient route planning even more important. We propose a central charging station database (CSDB) that helps estimating waiting times at charging stations ahead of time. This enables our adaptive charging and routing strategy to reduce these waiting times.

Dwell Time Estimation at Intersections for Improved Vehicular Micro Cloud Operations

December, 2021

The idea of vehicular micro clouds is to turn cars into (virtual) edge computing infrastructure. One of the challenging questions in this domain is to maintain data within and among such micro clouds. In this paper, we focus on this task and present a novel solution for such data exchange between vehicular micro clouds. For efficient operation, the dwell times of cars in such a micro cloud need to be known or accurately predicted. In an extensive study based on trace data, we investigate the distribution of dwell times of cars at intersections.

Vehicular Visible Light Communications: A Survey

November, 2021

In this survey article, we study the state of the art of Vehicular Visible Light Communication (V-VLC) and identify open issues and challenges. We study the V-VLC communication system as a whole and also dig into the characteristics of the VLC channel. For the beginner in the field, this review acts as a guide to the most relevant literature to quickly catch up with current trends and achievements. For the expert, we identify open research questions and also introduce the V-VLC research community as a whole.

LSTM-characterized Deep Reinforcement Learning for Continuous Flight Control and Resource Allocation in UAV-assisted Sensor Network

October, 2021

This paper proposes a new deep reinforcement learning based flight resource allocation framework (DeFRA) to minimize the overall data packet loss in a continuous action space. DeFRA is based on Deep Determin- istic Policy Gradient (DDPG), optimally controls instantaneous headings and speeds of the UAV, and selects the ground device for data collection. Furthermore, a state characterization layer, leveraging long short-term memory (LSTM), is developed to predict network dynamics, resulting from time-varying airborne channels and energy arrivals at the ground devices.
  • Kai Li, Wei Ni and Falko Dressler, "LSTM-characterized Deep Reinforcement Learning for Continuous Flight Control and Resource Allocation in UAV-assisted Sensor Network," IEEE Internet of Things Journal, August 2021. (online first) [DOI, BibTeX, Details...]

Duality between Coronavirus Transmission and Air-based Macroscopic Molecular Communication

September, 2021

This paper exploits the duality between aviral infection process and macroscopic air-based molecularcommunication. Airborne aerosol and droplet transmission through human respiratory processes is modeled as an instance of a multiuser molecular communication scenario employing respiratory-event-driven molecular variable-concentration shift keying. Modeling is aided by experiments that are motivated by a macroscopic air-based molecular communication testbed. In artificially induced coughs, a saturated aqueous solution containing a fluorescent dye mixed with saliva is released by an adult test person. We confirmed the experimental data by simulation.
  • Max Schurwanz, Peter Adam Hoeher, Sunasheer Bhattacharjee, Martin Damrath, Lukas Stratmann and Falko Dressler, "Duality between Coronavirus Transmission and Air-based Macroscopic Molecular Communication," IEEE Transactions on Molecular, Biological and Multi-Scale Communications (T-MBMC), Infectious Diseases Special Issue, vol. 7 (3), pp. 200–208, September 2021. [DOI, BibTeX, PDF and Details...]

Towards an IEEE 802.11 Compliant System for Outdoor Vehicular Visible Light Communications

August, 2021

This paper introduces a complete IEEE 802.11 compliant V-VLC system. The system relies on USRP software defined radios programmed using the GNURadio framework, a typical car headlight plus a custom driver electronics for the high-power car LEDs (sender), and a photodiode (receiver). Our system also supports OFDM with a variety of Modulation and Coding Schemes (MCS) up to 64-QAM and is fully compliant with IEEE 802.11. We, for the first time, experimentally explore the communication performance in outdoor scenarios, even in broad daylight, and show that rather simple optical modifications help to reduce the ambient noise to enable long distance visible light communication.

Low-Power Downlink for the Internet of Things using IEEE 802.11-compliant Wake-Up Receivers

July, 2021

We go beyond classic wake-up system concepts and show how wake-up receivers can be used for an efficient and multi-purpose low power downlink (LPD) communication channel. We demonstrate how to (a) extend the wake-up signal to support low-power flexible and extensible unicast, multicast, and broadcast downlink communication and (b) utilize the WuRx-based LPD to also improve the energy efficiency of uplink data transfer.
  • Johannes Blobel, Vu H. Tran, Archan Misra and Falko Dressler, "Low-Power Downlink for the Internet of Things using IEEE 802.11-compliant Wake-Up Receivers," Proceedings of 40th IEEE International Conference on Computer Communications (INFOCOM 2021), Virtual Conference, May 2021. [DOI, BibTeX, PDF and Details...]

Hy-Fi: Aggregation of LiFi and WiFi using MIMO in IEEE 802.11

June, 2021

We present Hy-Fi, a system which combines light fidelity (LiFi) and radio based on the WiFi physical layer waveform by using the MIMO features available in IEEE 802.11-compliant commodity chip sets. Hy-Fi is based on two key ideas. First, we use inexpensive COTS hardware to facilitate direct transmission of WiFi waveforms over the optical wireless channel, as this is proposed in the IEEE P802.11bb task group. Second, we use the MIMO signal processing to aggregate LiFi and radio signals at the physical layer.

Age of Information in Molecular Communication Channels

May, 2021

This paper introduces the age of information (AoI) concept in molecular communication channels. We derive a theoretical equation to compute the average peak AoI. This allows analyzing the trade-off between an increased rate of transmission (thereby a reduced latency) and the produced inter-symbol interference (ISI) (thereby an increased error rate).

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