DISCRETE AND CONTINUOUS MODELS AND APPLIED COMPUTATIONAL SCIENCE

The blockage of the propagation path is one of the major challenges preventing the deployment of fifth-generation New Radio systems in the millimeter-wave band. To address this issue, the Integrated Access and Backhaul technology has been proposed as a cost-effective solution for increasing the density of access networks. These systems are designed with the goal of avoiding blockages, leaving the question of providing quality-ofservice guarantees aside. However, the use of multi-hop transmission negatively impacts the end-to-end packet latency. In this work, motivated by the need for latency reduction, we design a new link activation policy for self-backhauled Integrated Access and Backhaul systems operating in half-duplex mode. The proposed approach utilizes dynamic queue prioritization based on the number of packets that can be transmitted within a single time slot, enabling more efficient use of resources. Our numerical results show that the proposed priority-based algorithm performs better than existing link scheduling methods for typical system parameter values.

As the standardization of 5G New Radio (NR) systems operating in micro- and millimeter-wave frequency bands is over, scientific and industrial communities have begun to address the question of what 6G communications systems might or should be. While technological specifics are still in their early development phase, there is a common agreement that these systems will utilize the lower part of the terahertz band, namely, 100–300 GHz. This band poses a number of specific challenges for system designers, including the effects related to channel characteristics and the conceptually new requirements for electronics. This paper aims to report the current state-of-the-art channel characterization and communications system design. With respect to the former, we consider dynamic human body blockages and micromobility impairments. For the latter, we mainly concentrate on the physical layer devices for direct conversion schemes and the design of the so-called reconfigurable intelligent surfaces that will potentially serve as a cost-efficient blockage mitigation technique.