[SEMINAR] February 2, 2021 – Vyacheslav Loginov – The coexistence of Wi-Fi and cellular networks in unlicensed bands

We invite you to the next talk of Moscow Telecommunication Seminar which will be held at 6.30 PM, on Tuesday, February 2, 2021, in Zoom. The seminar is dedicated to the coexistence of Wi-Fi and cellular networks in unlicensed bands.

Title: Collision Resolution Method for LTE-LAA/NR-U Base Stations Coexisting with Wi-Fi Networks in an Unlicensed Frequency Band

Abstract: In order to increase the throughput of cellular networks, a number of technologies (e.g., LTE-LAA, NR-U) have been developed. These technologies allow cellular base stations to transmit data in unlicensed bands in the 5 GHz frequency range. Since these bands are already used by Wi-Fi networks, LTE-LAA/NR-U networks use channel access method for unlicensed bands that has much in common with the Wi-Fi one.
In particular, similar to Wi-Fi devices, the LTE-LAA/NR-U base station performs a backoff procedure before each transmission attempt. However, since transmissions on all channels must be synchronized, the cellular base station can start a data transmission only at the slot boundaries in the licensed channel. The LTE-LAA/NR-U specifications do not describe the behavior of the base station in the interval between the end of the backoff procedure and the next slot boundary in the licensed channel. In most papers, it is proposed to transmit a reservation signal which does not containing data during this interval to forbid other devices to occupy the channel. Although this approach has a positive effect on the throughput of cellular networks, it can lead to a significant reduction of the throughput of Wi-Fi networks operating on the same channel. As an alternative, in the seminar we will consider a collision resolution method, using which cellular base station may suspend the transmission of the reservation signal several times to listen to the channel and detect a collision, and abort the transmission if the collision is detected. For both approaches, during the seminar, we will describe mathematical models that allow estimating the throughput of LTE-LAA/NR-U and Wi-Fi networks when they coexist in an unlicensed channel and compare their efficiency.

Bio: Vyacheslav Loginov is a Senior Researcher at the Wireless Networks Lab and Network Protocols Research Lab, Institute for Information Transmission Problems of the Russian Academy of Sciences and Telecommunication Systems Lab of NRU HSE. He received his B.Sc., M.Sc., and Ph.D. degrees from Moscow Institute of Physics and Technology, Moscow, Russia, in 2014, 2016, and 2020, respectively. He has authored more than a dozen articles published in international peer-reviewed journals and conference proceedings. His research focuses on coexistence issues of WLANs and cellular networks in the unlicensed spectrum, development, and performance analysis of wireless network protocols.

To join the Seminar, follow the instructions at http://wireless.iitp.ru/seminar/.