False base station detection based on time of arrival or timing advance
A base station determines a window of time for arrival of uplink signals, wherein the window of time includes a start based on a first expected time of arrival for a first uplink signal from a first UE and an end based on a second expected time of arrival for a second uplink signal from a second UE. The base station detection detects a false base station, such as a L1 man-in-the-middle false base station, based on an uplink signal being received outside of the determined window of time for the arrival of uplink signals.
1. A method of wireless communication at a base station, comprising:
determining a timing advance based on a cell radius of the base station;
determining a timing advance threshold associated with detection of a false base station (FBS) by a user equipment (UE), the timing advance threshold being longer than the timing advance based on the cell radius of the base station; and
transmitting the timing advance threshold to the UE for the detection of the FBS by the UE.
2. The method of claim 1 , wherein the base station determines the timing advance based on the cell radius and a time for the base station to switch from an uplink slot to a downlink slot in a time division duplex (TDD) system.
3. The method of claim 1 , wherein the base station transmits the timing advance threshold in system information.
4. The method of claim 1 , wherein the base station transmits the timing advance threshold in UE specific signaling.
5. The method of claim 1 , wherein the base station determines the timing advance threshold based on the cell radius for the base station.
6. An apparatus for wireless communication at a base station, comprising:
a memory; and
at least one processor coupled to the memory and configured to:
determine a timing advance based on a cell radius of the base station;
determine a timing advance threshold associated with detection of a false base station (FBS) by a user equipment (UE), the timing advance threshold being longer than the timing advance based on the cell radius of the base station;
and transmit the timing advance threshold to the UE for the detection of the FBS by the UE.
7. The apparatus of claim 6 , wherein the at least one processor is configured to determine the timing advance based on the cell radius and a time for the base station to switch from an uplink slot to a downlink slot in a time division duplex (TDD) system.
8. The apparatus of claim 6 , wherein the at least one processor is configured to transmit the timing advance threshold in system information.
9. The apparatus of claim 6 , wherein the at least one processor is configured to transmit the timing advance threshold in UE specific signaling.
10. The apparatus of claim 6 , wherein the apparatus determines the timing advance threshold based on the cell radius for the apparatus.
11. The apparatus of claim 6 , wherein the apparatus determines the timing advance threshold based on a time difference between uplink and downlink slot boundaries.
12. The apparatus of claim 6 , wherein the apparatus determines the timing advance threshold based on a prior uplink signal.
13. The apparatus of claim 6 , wherein the at least one processor is configured to receive a FBS detection report from UE.
14. The apparatus of claim 13 , wherein the at least one processor is configured to perform a mitigation operation in response to receiving the FBS detection report.
15. The apparatus of claim 14 , wherein the mitigation operation comprises handing over the UE to a different cell or updating one or more communication parameters for cell selection or cell reselection to de-prioritize a cell corresponding to the FBS.