The GSM Alarm System main panel includes ports on the BUS panel on the back which allow you to connect a more powerful antenna to the panel. This will often increase the effectiveness of the system in picking up signal from nearby cellular towers.
Ports 15 and 14 (ANT and G_ANT) are for an antenna and a ground cable, respectively. We recommend using a length of copper wire approximately 6 inches or more to increase your panel's reception.
Below, for your reference, is a picture of the BUS bar on the back of the main panel.