My friend: Hi Ibrahim, I need you support.
- Me: You’re welcome, please tell me.
My friend: My manager asked me to prepare a design for one operator to implement 5G using Open RAN, but I don’t know from where I can start, could you please help me here?
- Me: Sure. You need first to discuss with this operator about the 5G use cases they need to implement in their network like eMBB, URLLC, mMTC, etc. And, whether all these 5G services need to be implemented at all sites or some use cases will be particular at some specific sites due to market needs for example. Then based on the requirements for each 5G use case, you should start designing the 5G network.
My friend: But how can I do that?
- Me: Let’s have an example. So, assuming URLLC use case is requested in some specific sites, so that means you need to determine what is the latency required at these sites as per the operator requirements and then in your design, you can place the DU and CU-UP at the Edge data center to provide the target latency and if more lower latency is required, you can even go for DU+CU-UP+UPF in the Edge data center or even at the enterprise premises itself which will provide the lowest possible latency. While, for eMBB use case, you can just place the DU at the nearest data center from the cell sites and keep the CU and the UPF centralized at the regional data center. Please check the below figure.
My friend: So, what is the next step?
- Me: As you determined the locations of DUs, CUs and UPFs, then you can start the dimensioning as you need to decide how many Cells will be connected to one DU and how many DUs will be connected to one CU and the capacity needed between them. So, for example, if 12 Cells can be connected to one DU located at the Edge data center, so you need to design the fronthaul capacity to accommodate the 5G throughput expected from these sites as per the customer strategy. Then if 20 DUs, will be connected to one CU, you need to design the Midhaul capacity needed as well, and the same process will be done from CU towards the UPF at the backhaul. Take care that the no. of Cells supported by one DU and the no. of DUs supported by one CU will depend on the RAN vendor that will be used in this network.
My friend: Thank you so much. You made it very clear.
- Me: You are most welcome.