ARFCH

Hi, I am using Nokia 3310 to look at GSM traffic. The system information messages are displayed in wireshark. Is it possible to get the ARFCN of the becaon channel of the cell to which the phone has locked from the System Information messages( SI ) ? I am getting confused because of the following screen shots which I have attached. Screen shot 1 says that the SI 4 message is in ARFCN 108. Screen shot 2 says that the SI 4 message is in ARFCN 57. So now which is the real ARFCN of the beacon channel in my cell ? Regards, RM