What is Fronthaul, Midhaul and Backhaul in 5G?

What is Fronthaul, Midhaul and Backhaul in 5G?

  • My friend: Hi Ibrahim, I have a question for you.

    • Me: Please, go ahead.
  • My friend: What is meant by Fronthaul, Midhaul and Backhaul in 5G?

    • Me: These are the links that are connecting the RU (Radio Unit), DU (Distributed Unit), CU (Centralized Unit) and the core network together. So, Fronthaul refers to the link between the RU and DU, while Midhaul refers to the link between the DU and CU, and lastly the Backhaul is representing the link between the CU and the core network. Please check the below graph.
  • My friend: So, all of it are open interfaces and standardized by 3GPP, right?

    • Me: Not all of it. The Midhaul or the F1 interface is standardized by 3GPP and it is a new interface that exists in 5G due to the RAN split technique which allows the BBU (Baseband Unit) to be divided into two parts which are DU and CU that can deployed in different locations. Also, the Backhaul refers to the NG interface which is also standardized by the 3GPP. However, the Fronthaul was implemented by large equipment vendors in a proprietary fashion which limits the operators to a single-vendor approach as you can’t connect RU and DU from different vendors. But if you are going to implement 5G using Open RAN, then O-RAN Alliance was responsible for standardizing Fronthaul using option 7-2x and also the Small Cell Forum using split option 6 for small cells.
  • My friend: Thank you very much. You made it very clear.

    • Me: You are most welcome.

Link for the LinkedIn Post: Ibrahim Sayed, PMP on LinkedIn: #5g #5gnr #5gtechnology | 16 comments

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