Wireless channel power profile false base station detection
In a wireless access network, a false base station (FBS) may imitate a legitimate base station by repeating the transmissions of the legitimate base station at a higher power level such that one or more user equipment (UEs) synchronize with the FBS instead of the legitimate base station. The present disclosure provides a UE that detects an FBS. The UE may estimate a time of arrival of different multipath components of a downlink signal corresponding to a physical cell identity. The UE may determine an existence of FBS based on a difference between the times of arrival of two of the different multipath components exceeding a threshold amount of time. The UE may perform a mitigation operation in response to determining the existence of the FBS.
1. 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 threshold amount of time that signifies a maximum allowable difference between arrival of different multipath components of a downlink signal from the base station; and
transmit the threshold amount of time to a user equipment (UE) for detection of a false base station (FBS) by the UE.
2. The apparatus of claim 1 , wherein a source of the downlink signal is indicated by a physical cell identity (PCI) associated with the downlink signal.
3. The apparatus of claim 1 , wherein the downlink signal is a synchronization signal block (SSB).
4. The apparatus of claim 1 , wherein the downlink signal is a channel state information reference signal (CSI-RS).
5. The apparatus of claim 1 , wherein the at least one processor is configured to:
receive a report that the UE has detected the FBS based on a difference between two of the different multipath components exceeding the threshold amount of time; and
perform a mitigation operation in response to the report.
6. The apparatus of claim 5 , wherein to perform the mitigation operation, the at least one processor is configured to update one or more communication parameters of the UE to access a communication network using a different cell, frequency, band, or system.
7. The apparatus of claim 5 , wherein to perform the mitigation operation, the at least one processor is configured to update one or more communication parameters of another device connected to the base station to access a communication network using a different cell, frequency, band, or system.
8. The apparatus of claim 1 , wherein to transmit the threshold amount of time, the at least one processor is configured to transmit the threshold amount of time within system information.
9. The apparatus of claim 1 , wherein to transmit the threshold amount of time, the at least one processor is configured to transmit the threshold amount of time in UE specific signaling.
10. The apparatus of claim 1 , wherein to determine the threshold amount of time, the at least one processor is configured to compute the threshold amount of time based on a maximum expected delay spread in a wireless channel.
11. The apparatus of claim 1 , further comprising at least one transceiver coupled the at least one processor.
12. A method of wireless communication at a base station, comprising:
determining a threshold amount of time that signifies a maximum allowable difference between arrival of different multipath components of a downlink signal from the base station; and
transmitting the threshold amount of time to a user equipment (UE) for detection of a false base station (FBS) by the UE.
13. The method of claim 12 , wherein a source of the downlink signal is indicated by a physical cell identity (PCI) associated with the downlink signal.
14. The method of claim 12 , wherein the downlink signal is a synchronization signal block (SSB).
15. The method of claim 12 , wherein the downlink signal is a channel state information reference signal (CSI-RS).
16. The method of claim 12 , further comprising:
receiving a report that the UE has detected the FBS based on a difference between two of the different multipath components exceeding the threshold amount of time; and
performing a mitigation operation in response to the report.
17. The method of claim 16 , wherein performing the mitigation operation comprises updating one or more communication parameters of the UE to access a communication network using a different cell, frequency, band, or system.
18. The method of claim 12 , wherein transmitting the threshold amount of time comprises transmitting the threshold amount of time within system information.
19. The method of claim 12 , wherein transmitting the threshold amount of time comprises transmitting the threshold amount of time in UE specific signaling.
20. The method of claim 12 , wherein determining the threshold amount of time comprises computing the threshold amount of time based on a maximum expected delay spread in a wireless channel.