This process might not even be essential. A protection researcher, Roger Piqueras Jover, discovered that 4G / LTE authentication occurs after a cell phone has now exposed its IMSI range to an IMSI catcher. The GSM specification needs the handset to authenticate for the network, but isn't going to require https://www.shoghicom.com/all-products/integrated-imsi-catcher--mobile-locator-system