“…In SON, unsupervised learning is applied in several domains, ranging from configuration of operational parameters [83], [84], caching [82], [85], [86], resource optimization [56], [87], [88], HO management [89], [90], mobility [91], load balancing [92], fault detection [93]- [102], cell outage management [49], [103]- [106], to sleeping cell management [50], [107].…”