Toward Digital Twin-as-a-Service (DTaaS) Platforms: A Survey on Architecture, Design Requirements, and Performance Metrics. - Kübra Duran; Lal Verda Çakir; Yagmur Yigit; Khayal Huseynov; Sushmitha Ram Kusu; Mehmet Ali Ertürk; Berk Canberk (IEEE Commun. Surv. Tutorials, 2026)