Patent ID: 9628994
Date: 2017-04-18
CPC Classifications: H04W

Claim:
1. A method to detect a fake base station in a 3G cellular network, the 3G cellular network primarily providing 3G coverage and also providing 2G coverage when the 3G coverage is unavailable, the method comprising the steps of: maintaining a database comprising data collected in real-time from the 3G cellular network, said database storing a 3G subscribers list and a 2G cells white list; maintaining for a cell c: (a) a first counter L of 2G calls made by 3G users in the 3G subscribers list in cell c over a pre-determined period of time, and (b) a second counter Lt of all 2G calls made over the pre-determined period of time to include multiple calls made by the same user, and comparing a function of L and Lt against a pre-determined threshold and determining when cell c is a 2G cell and placing cell c into the 2G cells white list, wherein 3G and 2G call volumes in the cell is used to determine when the cell is a 2G cell providing the 2G coverage or a 3G cell providing the 3G coverage, with determined 2G cells being placed in the 2G cells white list; detecting a 3G subscriber in the 3G subscribers list in the database that is forced to make a 2G call in a 2G cell that is not in the 2G cells white list in the database; and outputting a warning identifying the 3G subscriber as a victim of man-in-the-middle attack.