Integrated Access and Backhaul (IAB) is a successor to LTE Relay and is part of release 16 within technical specification TS 38.401.

KEY SPECIFICATIONS

3GPP NR Release R 16
Duplexing TDD
Frequency Bands mmWave [FR2]
Bandwidth 200 MHz
SCS 120 KHz
Modulation Scheme Up to 64-QAM for UL/DL
Throughput (DL) 1.4 Gbps
Throughput (UL) 500 Mbps
Sub Layers MAC, RRC, NAS, BAP, PDCP-C, RLC
Single Relay Mode Yes, Supported
Multi HOP Relay Mode Yes, in roadmap
10 GbE Interface Supported with IAB-DU (<GHz BTS)
UICC Terminal Interface Yes, Supported
OAM Support Yes

What is IAB – MT ?

Integrated Access Backhaul allows for single or multi-hop backhauling using the same frequencies employed for user equipment (UE) access or a distinct, dedicated, frequency. IAB leverages the spectral efficiencies of new radio and the increased capacity afforded by the higher bands available in 5G to deliver an alternative to optical cell site backhaul. This alleviates one of the primary issues surrounding the deployment of 5G that can be employed as a short-term alternative to fiber or as a permanent option for more isolated antennas or those without right of way access. Any future migration is aided by IAB’s adoption of the Internet Protocol (IP) over a new Backhaul Adaption Protocol (BAP) layer defined within 3GPP TS 38.340.