You need a GSM Core Network[1]. For more details, you can take a look at HLR and AuC components which are responsible for authentication.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Network_switching_subsystem#Authentication_center_.28AuC.29" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Network_switching_subsystem#Au...</a>