NWDAF is about analytics not Monitoring.
5G is taking the Telco to the cloud however the Telcos are still not completely ready for the change. At least not all of them. Consider the case of NWDAF (NetWork Data Analytics Function). It is probably the most misunderstood function in the set of 5G functions.
I have been conversing with a series of customers and colleagues on this network function and can tell you with authority that not everyone has the same idea when we say network analytics. I can divide them in following general categories.
NWDAF is for monitoring.
NWDAF is the intelligent node.
NWDAF is just acquisition node.
Let evaluate them one by one.
NWDAF is for monitoring
This thought is mostly propelled by the wishes of the operations team which is already using a lot of tools for monitoring the existing 3G/4G networks. The wish here is that NWDAF would do the same things the monitoring tools do today. The use cases are limited for sure, like revenue assurance with CDR's based on signaling monitoring, or signaling fraud detection.
NWDAF provides more than just monitoring. Release 16 of 3GPP now has defined over 23 different use cases that can be enabled by NWDAF. The keyword being enabled.
NWDAF is the intelligent node
The NWDAF is for sure the intelligent node as long as it get all the information to be intelligent. It follows the same principle as the brain, garbage in can lead to garbage out so the key here is the type of data that gets into the NWDAF. The use cases defined by 3GPP are therefore focusing lot on defining the right inputs for the intelligence that is sought from the NWDAF.
For example to enable the enabling intelligent routing based on the UE congestion predictions the NWDAF needs to get the almost real time information from the AMF, PCF and UPF to be able to analyze how these data correlate across the network and then create a user profile to match the predictions for the user. This all needs to be done near real time to be able to help AMF not get overloaded while PCF apply right policy to make sure the user also gets the right QoS.
NWDAF is just acquisition node
This is probably the most recent development as the discussions have matured where the vendors and operators have started to realize that the node that is supposed to provide predictive analytics for the complete network would need a lot of resources and to provide so many resource just on the NF may not be the right approach or possibility.
To counter this the idea being floated is an analytics platform across the network which takes input not only from the control plane, but also from data plane and data management plane. A sort of catch all for all data and then correlate all this information to provide even more rich predictions that can solve business problems and let the operators realize the benefits of 5G networks. All the use cases for this king of architecture are not completely defined. In fact there are already competing architectures available to study and implement.
While operators may be divided in their understanding of the NWDAF and its implementation options in the networks for 5G, the analytics would play a big role in success or failure of 5G network operators. The ones who can leverage the analytics to their advantage in the networks would come out as winners.