1.5 How many sites (edges) are required for Federated Validation?

Federated Validation system is supposed to run on multiple sites, to collect the validation results from all places and then generate the final summarized report. 

However, Taiwan AI Labs Federated Validation system could also run on a single site. What's more, the FV Aggregator could also be running on the same edge machine, which makes it easier for special condition.