Integrated Access and Backhaul for 5G mmWaves.

One of the core technologies integrated into 5G is the ability to use mmWaves. these waves are at 26GHz and 4GHz. Due to the physics of electromagnetic waves, whilst these waves have a very large capacity they have short transmission distance. So if these are deployed in a High Street or a shopping mall, there would be a number cells provided to allow the customers access to the network. Each of these small cells needs a backhaul route to the core network. The traditional way to do this in network that run with more usual frequencies (up to 3.8GHz) each cell would be connected by a dedicated fibre cable back to the gateway to the core network.

One problem with mmWaves is that they do not cover large areas and therefore each cell, of which there will be many, needs a way back to the core gateway. To reduce the number of cables going back to the core gateway, the 5G network itself can be used as the backhaul. This is the Integrated Access and Backhaul technology.

In LTE (and earlier) networks, and indeed in 5G networks using lower than mmWave frequencies the use of the mobile network for backhaul was potentially possible but not used as the frequency resource was scarce and needed for access. But in mmWave environments there is much more capacity and backhaul is a possibility. Whilst not used for all mmWave backhaul, it can be used as a mix of technologies to provide a more cost effective solution