A cell phone network intercom is an outdoor intercom that
communicates wirelessly over the cell phone network with any landline or mobile
phone anywhere in the world. They are also sometimes called GSM intercoms since
the technology is based on the Global System for Mobile Communications standard.
This standard is currently used worldwide, however, in the United States, only
AT&T and T-Mobile and a few other service providers use GSM. Sprint and Verizon
use CDMA (Code Division Multiple Access) technology so they are not compatible.
A cell phone intercom has a module in it that is
essentially the hardware of a handheld cell phone that has been redesigned for
the needs of a callbox intercom. The main difference is that the hardware is
mounted inside a weather and vandal resistant stainless steel box and the
speaker and microphone of the hardware are attached to the box. A Subscriber
Identity Module (SIM) card is in inserted into the cell module and it identifies
the subscriber to the network for billing and calling purposes.
A cell phone intercom has several benefits over traditional
wireless intercoms. For one, there are no range issues like a traditional
wireless intercom. As long as there is cell phone service at the location where
you want to put the intercom, it can essentially communicate around the world!
The way it works is that when a visitor comes to the
intercom and presses its button, the intercom starts dialing the first number
programmed into it. If no one answers on that number, then it moves to the next.
Three phone numbers can be programmed into the unit so someone should always be
able to be reached.
When the property owner on the telephone end answers, a
normal telephone conversation can take place. If property owner presses the star
key on their phone’s keypad, the gate will open if an automatic gate
opener is installed.
Another nice feature is the ability for visitors to use
their telephones as a remote control gate opener. If the visitor's phone number is
programmed into the intercom, the gate opener automatically activates when the
they call the intercom. Since the intercom doesn’t actually answer the call,
no minutes are used on the intercom’s cell phone plan.
The property owner can also send text messages from a cell
phone to the control the gate. Sending a code plus a password latches the gate
open until another code and password combination is sent. This works well for
letting in landscaping people or if a party is in progress. There is also a code
that can be sent that temporarily opens the gate. As long as a sensor switch is
installed, the status of the gate can be checked to see if it is is opened or closed
just by sending another code.
Instead of text messages, there is a software app available
in the Android store that automatically sends the various text messages to the
intercom. An app for the iPhone will soon follow. The app has the following
- Hold open gates feature (app send a pre-configured text message to
latch open gates)
- Check reception button.
- Check gates open or closed button
- Check stored numbers button.
This cell phone network intercom is available on