With concern about crime, vandalism, and terrorism continuing to increase, the need for security increases, and the place most businesses and residences start is with installing a perimeter security system such as fence with a gate. When a gate is installed, a wireless intercom becomes an essential part of the system so visitors can still get in.
A wireless intercom at the gate will need to be water resistant, but it should also be vandal resistant as well. It will be exposed to the elements and to people who may want to damage it. Therefore the chosen intercom must be very durable.
If wires cannot be installed in the ground, then a wireless intercom is needed. The range these devices can transmit varies widely, but you can get intercoms that transmit as much as a mile or more.
The other factor is the appearance of the intercom. In some installations a wireless intercom with an industrial appearance is OK. In others, you may need one that is a little less unobtrusive like the one pictured here.
Whichever type of wireless intercom you choose, make sure you get one that can remotely activate the gate if you need that feature.