radisys.com 18
Radisys Series — Who Disaggregated My RAN?
eBook
The O-RAN Alliance has specified two new layers for the mobile network architecture with its RAN Intelligent
Controller (RIC):
• Near Real-time RAN Intelligent Controller
• Non Real-time RAN Intelligent Controller
The Near Real-time RIC
If we look at the latency numbers in the figure above, the Near Real-time RIC acts within 10 to 1000 milliseconds
to make decisions based on metrics from RAN nodes. These decisions are driven by sophisticated algorithms built
in to the "xApps." But, why is there the need for these algorithms or XApps?
An average user of a mobile network expects quality of service and constant connectivity – even when moving
through zones with limited coverage. As the device begins to lose signal strength from one base station, the
connection is handed off to another base station to allow the user to enjoy seamless connectivity, even while
traveling at high speeds in a car. However, on 4G networks, this isn't the experience that users always get. For 5G
networks we are trying to achieve that seamless connectivity experience by making the RAN smarter, not only in
the connection management, but also in the quality of service, the data rates, and priority of service. There can be
Figure 1: O-RAN RIC: Intelligence and Control in Action