Ankur Bhattacharjee

US Patent:

20210067972, Mar 4, 2021

Filed:

Jan 8, 2020

Appl. No.:

16/737230

Inventors:

- San Diego CA, US
Subrato Kumar De - San Diego CA, US
Ankur Bhattacharjee - San Diego CA, US
Krishna Ram Budhathoki - San Diego CA, US
Mattias Kaulard Huber - Solana Beach CA, US
Brandon Luu - San Diego CA, US
Sai Eshwar Prasad Muppalla - San Diego CA, US

International Classification:

H04W 12/12
H04W 4/90
H04W 4/06
H04W 12/06
H04W 4/12

Abstract:

Methods for detecting and responding to unauthorized alert messages. In an example embodiment, a wireless device may detect a first system information block (SIB1) broadcast from a base station that includes an alert message flag that indicates that an emergency alert message is scheduled for broadcast in another system information block (e.g., in one of SIBs 10-14, etc.). The wireless device may detect an unauthorized alert based on inconsistent inputs from various base stations, and the server may detect fake or unauthorized base stations or detect unauthorized alerts based on inconsistent inputs from various UEs about same Cell ID, or same PLMN and geolocation, etc.

US Patent:

20200178065, Jun 4, 2020

Filed:

Aug 21, 2019

Appl. No.:

16/546582

Inventors:

- San Diego CA, US
Subrato Kumar De - San Diego CA, US
Ankur Bhattacharjee - San Diego CA, US

International Classification:

H04W 8/26
H04W 68/00
H04W 76/28
H04W 24/08
H04W 76/27
H04W 76/11

Abstract:

Methods for countering a shared paging channel hijack attack. In an example embodiment, a wireless device may monitor the shared paging channel during a paging occasion in a DRX cycle to detect a first IMSI-based paging message in the paging occasion, and continue monitoring for IMSI-based paging in subsequent radio subframes in the paging frame and radio subframes in subsequent radio frames within the DRX cycle to determine whether there are indications of a paging channel hijack attack. In an example embodiment, this monitoring may be to determine whether one or more subframes that are not the paging occasion receive IMSI-based paging messages, in response to which a threat probability may be increased. The wireless device may perform an operation (e.g., an actuation operation such as disabling monitoring of, and preventing connection attempts to, the base station, etc.) to protect against a shared paging channel hijack attack.