How to determine the phone numbers connected to a specific base station?

Question

mobile connection

The question consists of two questions, so to speak.
Is it possible to create a portable base station with a range of at least 100 meters? It is also necessary that any mobile phone, any operator that falls within the radius of action, tries to connect to it.
The second question: is it possible to determine the phone number of the device that connected to the base station?
Suppose the task is as follows: to determine the mobile numbers of all people in the same room.

Answer 1

Buy a femtocell not tied to an operator from a huawei, for example.

Answer 2

openbts.org
phone number is not mentioned in communication with BS

Answer 3

1. Maybe. Both the creation and the purchase of a finished one. The budget depends not so much on the radius (although on it), but on performance. Google the words OpenBTS and Osmocom, for example. The issue of legality is left to the discretion of the questioner and the prosecutor's office.
2. You can't. AT knows nothing about some kind of MSISDN number and that it even has it. Only the operator knows about MSISDN. The AT itself knows about the IMEI, the SIM card knows the IMSI assigned to it. You can ask the operator which IMSI number is assigned. You can buy an SS7 channel and organize an automatic way to match IMSI=MSISDN