In reply to David H Deans.

Thank you for your comment David and for highlighting another very important consideration in the overall costs faced by service providers. That is probably a topic all in itself for a paper etc.

Briefly though:
There are two main aspects: virtualization software licensing and network function software licensing.
The former already has cause some concern because it becomes a significant cost burden with scale.

I think the licensing of software elements will shake out over time as producers and consumers of them converge on their true value.

In some use cases but not all, the virtualization software (hypervisor) will get eliminated because operators will need to use bare metal for performance and predictability reasons.

Open source has a cost for the operators too - someone has to integrate it and maintain it and likely continue to develop it to suit the operators evolving needs.

Once this all matures though, the net economic benefit just due to increased flexibility, potential for higher resource utilization, and potential for power savings should be very positive.

The message for operators is to closely look at the whole economics including projecting large scale and over the technology and service expected lifetime.