My friend: Hi Ibrahim, I have a question for you.
- Me: Please, go ahead.
My friend: I was wondering how DSS is implemented in Open RAN?
- Me: DSS (Dynamic Spectrum Sharing) is one of the most important 5G features to achieve quick deployment for 5G networks using the same 4G spectrum, antenna, and RF units. So, it was very important to include it in the O-RAN use cases to make sure DSS can be realized in open RAN smoothly as an application inside the RIC framework. Thus, vRAN implementation will benefit a lot from this approach specially when both the CU and DU of 4G and 5G are from different vendors and as you know virtualization is a very important aspect in open RAN, please check the below figure.
My friend: But how Open RAN architecture can help in DSS implementation?
- Me: If DSS is used, either in 5G NSA or SA, that means coordination should be done between the 4G scheduler and the 5G scheduler using resource management and interference mitigation functions in the RIC between both schedulers. So, we can have some rApps and xApps used for DSS inside the non-RT RIC and the near-RT RIC respectively. Each app is responsible for executing some functions.
My friend: So, what are the functions of these Apps inside the RIC?
- Me: Inside the non-RT RIC, the DSS rApps are responsible for providing long-term scheduling policy to the 4G and 5G schedulers considering the 4G/5G traffic load, business factors, etc. and make sure that these DSS policies are translated into specific RAT policies that can be delivered to the DSS xApps inside the near-RT RIC. Then the DSS xApps execute resource sharing models and algorithms, translating RAT specific policy to configuration, control, and data subscription over E2 interface towards the CU and DU inside the RAN. Then, the RAN will execute the resource sharing enforcement rules and policies, collect and report RAN statistics and performance over E2 and O1 interfaces to the near-RT RIC and the SMO respectively.
My friend: Thank you so much. You made it very clear.
- Me: You are most welcome.
Linkedin: Ibrahim Sayed, PMP on LinkedIn: #5g #5gnr #openran #oran | 17 comments