It's been a while since I last wrote about IAB on this blog here. At that time 3GPP Release-16 was being discussed. Since then things have moved on. While Release-16 is being prepared for final release soon, Release-17 study and work items have just been agreed upon.
IAB is included as part of Rel-16 but there isn't a comprehensive document or presentation easily available to details all that it will contain. Similarly the enhancements for Release-17 are available only superficially. Qualcomm is well known for making some really excellent presentations available on 5G. One of their presentations from January (here) has some details on IAB (pg. 32 - 35). There was also an excellent presentation by Navid Abedini, Qualcomm from IEEE Sarnoff Symposium, 2019 which is embedded at the end.
In a 3GPP RAN#84 discussion document RP-191181, Samsung has provided a comprehensive summary of what is being done as part of Rel-16 and what did not make in that:
- Rel-16 IAB aims at basic operations
- Architecture and protocol design
- IAB integration procedure
- Routing, BAP and BH configuration
- CP and UP data transmission via IAB
- Topology support:
- Spanning Tree (ST) and Directed acyclic graph (DAG)
- Intra-Donor adaptation is prioritized
- The following cannot be supported in Rel-16
- Mobile IAB
- Topology support: Mesh
- Some functionalities in Rel-16 may not be completed due to time constrains e.g.
- Topology adaptation between IAB donors
- Mechanisms for efficient control signaling transmission
- IAB Rel-16 provide basic support for multi-hop and multi-path relaying.
- The solution supports
- QoS prioritization of traffic on the backhaul link
- Flexible resource usage between access and backhaul
- Topology adaptivity in case link failure
- In Rel-17 it would be possible to further evolve the IAB solution targeting increased efficiency and support for new use cases
Meanwhile in the recently concluded RAN#86, AT&T provided a good detailed summary on what enhancements are required for IAB as part of Rel-17 in RP-192709
- Duplexing enhancements
- Multiplexing beyond TDM (FDM/SDM/multi-panel Tx/Rx) including multi-parent scenarios, case 6/7 timing alignment, power control/CLI optimizations
- Topology enhancements
- Mobile IAB: CP/UP split + Group mobility
- Inter-CU topology adaptation
- Mesh-connectivity between IAB nodes for local control/user plane routing
- User plane enhancements
- Multi-hop scheduling enhancement – exchange of benefit metric between IAB nodes to enable radio-aware multi-hop scheduling to improve throughput performance
- Network Coding
- Study benefits compared to duplication over redundant backhaul routes
We will have to wait and see what makes it into the enhancements and what don't. Meanwhile here is a video from Navid Abedini, Qualcomm from IEEE Sarnoff Symposium, 2019
Related Posts:
- Connectivity Technology Blog: Integrated Access and Backhauling (IAB) - Today and Tomorrow
- 5G Evolution with Matthew Baker, Nokia
- Summary of #CWTEC 2019 Conference: 5G, Satellites & Magic MIMO
- 5G and Fixed-Mobile Convergence (FMC)
- R&S Webinar on LTE-A Pro and evolution to 5G
- Introduction to NR-Light a.k.a. NR-Lite
- An Introduction to Non-Terrestrial Networks (NTN)
