News and Announcements

Vehicular Visible Light Communications: A Survey

November 15, 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 31, 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, PDF and Details...]

Duality between Coronavirus Transmission and Air-based Macroscopic Molecular Communication

September 20, 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 13, 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 30, 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 10, 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.
  • Anatolij Zubow, Piotr Gawłowicz, Kai Lennert Bober, Volker Jungnickel, Kai Habel and Falko Dressler, "Hy-Fi: Aggregation of LiFi and WiFi using MIMO in IEEE 802.11," Proceedings of 22nd IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM 2021), Virtual Conference, June 2021, pp. 100–108. [DOI, BibTeX, PDF and Details...]

Age of Information in Molecular Communication Channels

May 21, 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).