Patent ID: 9747736
Date: 2017-08-29
CPC Classifications: B60R,G07C

Claim:
1. A control system, comprising: a UHF (ultra-high frequency) transmitter arranged for transmitting to a paired electronic key a UHF wakeup signal having a frequency in a UHF frequency range; a receiver for receiving an acknowledgement reply transmitted from the paired electronic key in response to the UHF wakeup signal; and an LF (low frequency) transmitter that is arranged to transmit a plurality of LF wakeup signals comprising adjacent LF wakeup signals to the paired electronic key, wherein the UHF transmitter transmits one or more UHF wakeup signals in between the transmission of each adjacent LF wakeup signal of the plurality of LF wakeup signals, wherein the plurality of LF wakeup signals is transmitted in response to a determination that a measured amount of UHF noise exceeds a threshold.