IEEE International Symposium on Personal, Indoor and Mobile Radio Communications
13–16 September 2021 // Virtual Conference // By 6G Flagship

Integrated Access and Backhaul for 5G and Beyond


Dr. Mohamed-Slim Alouini,
King Abdullah University of Science and Technology, Saudi-Arabia

Mohamed-Slim Alouini was born in Tunis, Tunisia. He received the Ph.D. degree in Electrical Engineering from the Califonia Institute of Technology (Caltech) in 1998. He served as a faculty member at the University of Minnesota then in the Texas A&M University at Qatar before joining in 2009 the King Abdullah University of Science and Technology (KAUST) where he is now a Distinguished Professor of Electrical and Computer Engineering. He is a Fellow of the IEEE as well as of the OSA and he is currently particularly interested in addressing the uneven global distribution, access to, and use of information and communication technologies in far-flung, low-density populations, low-income, and/or hard-to-reach areas.

Dr. Behrooz Makki,
Ericsson AB, Sweden

Behrooz Makki [Senior Member, IEEE] received his PhD degree in Communication Engineering from Chalmers University of Technology, Gothenburg, Sweden. In 2013-2017, he was a Postdoc researcher at Chalmers University. Currently, he works as Senior Researcher in Ericsson Research, Gothenburg, Sweden.

Behrooz is the recipient of the VR Research Link grant, Sweden, 2014, the Ericsson’s Research grant, Sweden, 2013, 2014 and 2015, the ICT SEED grant, Sweden, 2017, as well as the Wallenbergs research grant, Sweden, 2018. Also, Behrooz is the recipient of the IEEE best reviewer award, IEEE Transactions on Wireless Communications, 2018. In 2020, Behrooz was selected as the outstanding nominee in the IEEE ComSoc Young Professional award, the industry branch. Currently, he works as an Editor in IEEE Wireless Communications Letters, IEEE Communications Letters, the journal of Communications and Information Networks, as well as the Associate Editor in Frontiers in Communications and Networks. He was a member of European Commission projects “mm-Wave based Mobile Radio Access Network for 5G Integrated Communications” and “ARTIST4G” as well as various national and international research collaborations.

His current research interests include integrated access and backhaul, Green communications, millimeter wave communications, and backhauling. He has co-authored 64 journal papers, 46 conference papers and 60 patent applications.

Dr. Erik Dahlman,
Ericsson AB, Sweden

Erik Dahlman received his PhD in Telecommunication from the Royal Institute of Technology in Stockholm Sweden and is currently Senior Expert in Radio Access Technologies within Ericsson Research. He has been deeply involved in the development of all 3GPP wireless access technologies, from the early 3G technologies (WCDMA/HSPA), via 4G LTE, and most recently the 5G NR technology. He current work is primarily focusing on the evolution of 5G as well as technologies applicable to future beyond 5G wireless access.

Erik Dahlman is the co-author of the books 3G Evolution – HSPA and LTE for Mobile Broadband, 4G – LTE and LTE-Advanced for mobile broadband, 4G – LTE-Advanced Pro and The Road to 5G and, most recently, 5G NR – The Next Generation Wireless Access Technology.

In 2009, Erik Dahlman received the Major Technical Award, an award handed out by the Swedish Government, for his contributions to the technical and commercial success of the 3G HSPA radio-access technology. In 2010, he was part of the Ericsson team receiving the LTE Award for “Best Contribution to LTE Standards”, handed out at the LTE World Summit. In 2014 he was nominated for the European Inventor Award, the most prestigious inventor award in Europe, for contributions to the development of 4G LTE.

Dr. Filip Barać,
Ericsson AB, Sweden

Filip Barać was born in Belgrade, Serbia, where he obtained a Dipl. -Ing. Degree in Telecommunications from the University of Belgrade, in 2009. He then earned an MSc degree in Communication Engineering from the Chalmers University of Technology in Gothenburg, Sweden, in 2011, and a PhD degree in Industrial Wireless Communication from Mid Sweden University in Sundsvall, Sweden in 2016.

Since 2016, Filip has been with Ericsson AB in Stockholm, Sweden, where he works as a 3GPP RAN3 delegate and researcher, responsible for the following topics on behalf of Ericsson in 3GPP RAN3: Integrated Access and Backhaul, Quality of Experience, Resource Coordination, Interference Management and User Plane.


To cope with the exponential growth of demand on wireless communications, 5G and beyond will densify the network with many base stations (BSs) of different types. The BSs, however, need to be connected to the operators’ core network via a transport network. On a global scale, fiber and wireless microwave technology are dominating media for backhauling. Fiber offers reliable connection with demonstrated Tbps data rates. However, fiber deployment may take long installation time, requires noteworthy initial investment, and may even be not allowed in, e.g., metropolitan areas. Wireless backhaul, on the other hand, comes with significantly lower cost and time-to-market as well as higher flexibility.

Traditionally, wireless backhaul hasbeen mainly based on proprietary technology operating in millimeter wave (mmw) spectrum and constrained to line-of-sight (LoS) propagation conditions. However, with 5G NR, cellular technology is extending into mmw spectrum; the spectrum historically used for backhauling. Also, with small-cells deployed on street level, the backhaul links need to operate also under NLoS (N:non) conditions. These, along with reducing the time-to-market/operation cost, are the main motivations for the integrated access and backhaul (IAB) concept. The aim of IAB is to provide flexible wireless backhaul using 3GPP NR technology, providing not only backhaul but also the existing cellular services in the same node.

The objective of the tutorial is to bring new insights to the analysis, design and standardization of IAB networks. Such networks guarantee the communication requirements in future smart cities and solve the ubiquitous connectivity problems in many challenging network environments, e.g., coverage/capacity enhancements in rural areas. The tutorial will 1) go through the recently finished Release 16 and ongoing Release 17 IAB work-items of 3GPP, as the world’s biggest 5G research program, 2) present proof-of-concept results for the usefulness of IAB, and 3) provide a vision for IAB-related research towards 6G.

Structure and content

  • Part 1. Integrated Access and Backhaul: An Enabler for Network Densification in 5G and Beyond (30 min)
    • Motivation of dense small-cell networks in 5G and beyond.
    • An overview of different backhaul technologies.
    • The introduction of IAB;a candidate backhauling technology in 5G.
    • Proof-of-concept simulations for IAB.
  • Part 2. IAB Standardization in 3GPP (90 min)
    • IAB in 3GPP Release 16
      1. IAB Architecture
      2. IAB node integration procedure
      3. Backhaul Adaptation Protocol and packet routingover the backhaul
      4. Spectrum for IAB
      5. The IAB radio link
      6. Timing alignment
    • IAB Enhancements in 3GPP Release 17
      1. Topology adaptation and topology redundancy for load balancing and robustness
      2. SimultaneousTx/Tx, Tx/Rx, Rx/Rx, Rx/Txoperation
      3. End-to-end performance, fairness, and spectral efficiency
      4. Congestion mitigation
  • Part3. IAB in the beyond 5G era; Open research problems (60 min)
    • Mobile IAB-Meshed IAB-IAB using network coding
    • Caching-based IAB
    • IAB using a combination of parallel technologies
    • Unmanned aerial vehicle(UAV)-assisted IAB Networks
    • IAB performance optimization using machine learning
    • Intelligent reflective surface (IRS)-assisted IAB