Petar Popovski is a Professor of Wireless Communications with Aalborg University. He received his Dipl. Ing and Magister Ing. degrees in communication engineering from the University of Sts. Cyril and Methodius in Skopje and the Ph.D. degree from Aalborg University in 2005. He is a Fellow of IEEE, a holder of a Consolidator Grant from the European Research Council (ERC), recipient of the Danish Elite Researcher Award, and a member of the Danish Academy for technical sciences (ATV). He is currently an Area Editor of the IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, General Chair for IEEE SmartGridComm 2018 and General Chair for IEEE Communication Theory Workshop 2019. He was featured in the list of Highly Cited Researchers 2018, compiled by Web of Science. His research interests are in the area of communication theory, with focus on wireless communication and networks.
Tutorial: Wireless Access in Ultra-Reliable Low-Latency Communication (URLLC)
Abstract: During the past three decades, wireless connectivity has become a commodity, assumed to be practically always present and visible only when absent. This has naturally increased the confidence in wireless-enabled applications and services, leading to the idea of using wireless at a large scale to support mission-critical communication links. This trend has been termed ultra-reliable communication (URC), where the level of connectivity guarantees, e.g. > 99.999 % of the time, matches the cable-based communication systems.
Ultra-reliability has inevitably become a part of the emerging 5G wireless systems. Indeed, 5G aims to cover three generic connectivity types: enhanced Mobile Broadband (eMBB), massive Machine-Type Communication (mMTC) and Ultra-Reliable Low-Latency Communication (URLLC). As it can be seen from the name, ultra-reliability is entangled with the requirement for low latency in the context of 5G systems. This makes URLLC very challenging.
This tutorial will provide a broad perspective on the fundamental tradeoffs in URLLC as well as the principles used in building access protocols. The objective is to provide the students with a framework that can be used to analyze and design ultra-reliable wireless systems. The tutorial will start from an overview of the URLLC use cases that create the context for developing wireless access protocols, as well as the requirements associated with them. This will be followed by discussion on communication-theoretic principles of URLLC, providing a perspective on the relationship between latency, packet size, bandwidth, and finite-blocklength treatment. It will also elaborate on the challenges that occur due to the fact that URLLC is often associated with short data payloads, which exacerbates the impact of the control information. An important problem in URLLC is the design of the access networking, where the tutorial will clarify the main tradeoffs in grand-based and grant-free access. Two specific enabling technologies for URLC will be elaborated upon: massive MIMO and multi-connectivity (interface diversity). Finally, the tutorial will touch upon an important question, largely ignored in the URLLC literature so far: what are the statistical requirements to measure and verify ultra-reliability.
Keynote: Communication-Theoretic Modeling of Wireless Network Slicing in 5G
Abstract: The grand objective of 5G wireless technology is to support three generic services with vastly heterogeneous requirements: enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Service heterogeneity can be accommodated by network slicing, through which each service is allocated resources to provide performance guarantees and isolation from the other services. Slicing of the Radio Access Network (RAN) is typically done by means of orthogonal resource allocation among the services. This work studies the potential advantages of allowing for non-orthogonal sharing of RAN resources in uplink communications from a set of eMBB, mMTC and URLLC devices to a common base station. The approach is referred to as Heterogeneous Non-Orthogonal Multiple Access (H-NOMA), in contrast to the conventional NOMA techniques that involve users with homogeneous requirements and hence can be investigated through a standard multiple access channel. The study devises a communication-theoretic model that accounts for the heterogeneous requirements and characteristics of the three services. The concept of reliability diversity is introduced as a design principle that leverages the different reliability requirements across the services in order to ensure performance guarantees with non-orthogonal RAN slicing. This study reveals that H-NOMA can lead, in some regimes, to significant gains in terms of performance trade-offs among the three generic services as compared to orthogonal slicing.