Unique data in gsm network?

Question

mobile connection

There are rumors that even if you change imei, for example, set it to zero and change the SIM card, then some more data unique to the phone is still transmitted over the network. Rumor has it that this is the serial number of the gsm module. It's true? who understands the protocol of gsm networks?

Answer 1

Briefly: no, it is not transmitted. The reason is either pointless or redundant. The unique s / n of the module is just the mentioned IMEI.
Caveat: there are fields in which ( theoretically ) a single module module can transmit information that is not specified in the standard. But they simply will not be accepted, and if they are - as raw-hex will be written to the BS log, they will not go beyond the log - BSC will not process them.
You can read more: GSM02.07 , and if someone spreads a rumor that everything is different in 3G / LTE, then here and here . And in general, there is a collection of ETSI standards - choose a technology and read.

Answer 2

As for the telephone set itself, only its IMEI/IMEISV is transmitted over the network, and nothing else!