First Facts: What is a GSM Intercom?

13 March 2025Appears in First Facts
First Facts: What is a GSM Intercom?
A GSM intercom is a wireless access control system that uses mobile networks to allow remote entry management. In this blog, we explore the pros and cons of GSM intercoms, from their flexibility and easy installation to potential signal limitations. Plus, we answer the most common questions to help you choose the right intercom for your needs. Whether you're considering a GSM intercom for your home or business, this guide will help you make the right choice!

At a Glance 

What is GSM?

Global System for Mobile communication. A wireless mobile communication system, giving a connection to mobile devices - Worldwide

How does it work?

The intercom runs off its own sim card. When someone presses its call button on the device, it sends an outgoing call to whichever phone number it has been assigned to call first. This can be a landline or a mobile number.

What does this mean?

Freedom - you can answer a call from the intercom from anywhere in the world on your mobile phone. Never miss a delivery again!

It sounds complicated!

It really isn’t - All the major branded GSM intercoms have their own user-friendly app to operate and update settings on the intercoms. If you get stuck - give First Fence a call on 01283 512111.

Our Top Tips:

Always check the mobile network strength in the area - if the signal on a specific network is poor, avoid it, as it will mean loss of connection during calls

Stick to the main branded sim cards, such as Vodafone, O2 and EE. 

Get a monthly contract SIM with unlimited data and calls.

Pros and Cons of GSM 

Pros of GSM Intercoms 
  1. Answer the call from anywhere in the world.
  2. Quicker and easier to install as it isn’t hard wired back to the property.
  3. User-friendly apps for answering calls and using other settings.
  4. Diverted calls - most devices will dial 3 or 4 numbers in sequence until one is answered.
  5. Video GSMs allow you to see who is at the entrance before granting access.
Cons of GSM Intercoms
  1. Initial expense - more expensive to purchase than a hard wired intercom.
  2. Signal - if the signal for the sim card drops, the calls wont come through.
  3. Ongoing costs - need to remember to top up if PAYG or have a monthly contract going out - the more the intercom is used, the more it may cost.
  4. Video quality isn’t as good as if you had CCTV there.

Any other functions with a GSM?

Can a GSM intercom do anything more than call me when the outdoor station is pressed?

Dial To Open Set up regular visitors or employees with dial-to-open, so their call automatically opens the gate.

 Logged Events Using the smartphone app, you can track events showing when the gate was opened and how. 

Keypads & Proximity Readers Most GSMs offer a keypad for coded access, and some include proximity readers for fob entry. 

Timed Access Using the app, most intercoms enable you to set timers - meaning the gate can only be opened during certain times - Enhancing security.

How Can First Fence Help?

List of brands available from us:

  • Videx
  • Commtel Ltd
  • Comelit
  • AES- Advanced Electronic solutions 

Commonly Asked Questions...

How much will it cost per month?

This depends how often the intercom is used at the entrance. We recommend getting a monthly contract sim card with unlimited data and calls.

Which sim card provider is best to go with?

Whichever has the best and most consistent signal strength at the install location. We recommend sticking to the major brands Vodafone, O2 and EE.

Do I go with audio or video?

Personal preference - if you want to see who is at the entrance rather than just speak to them then go with video. If not, then audio only is a cheaper option.

What if I run out of credit - PAYG sim cards only

Calls can’t be made if the sim card hasn’t got credit, we recommend setting up an automatic top up - you can monitor the spend over a time period to know what you are spending on average.

Do I need a keypad on the intercom?

The keypad provides added access options, allowing staff or visitors to enter with a code for quick entry.

How long will my intercom last?

Your standard warranty is 1 year, but we have had systems in and fitted for a lot longer than that. Regular firmware updates help with keeping the intercoms up to date too.

Products Available at First Fence 

At First Fence, we offer a top selection of intercom systems for secure and convenient access control. Whether for residential, commercial, or gated properties, our GSM and proximity-based intercoms provide advanced security and remote accessibility.

Our Comelit GSM intercoms, including the GSM4-K, GSM3-K, GSM2-K, and GSM1-K models, offer wireless, mobile-controlled access with high-quality audio and a sleek design. Similarly, Telguard intercoms, like the ML Trio+ and ML Duo+, provide durable, easy-to-install solutions for driveways and secure barriers.

Videx GSM intercoms, such as the GSM4K series, feature 4G connectivity and remote access control, while the AES OPYN-4G GSM video intercom adds real-time visitor verification for extra security.

For hands-free entry, our VIDEX PBX-1E fobs and Mini-SA2 readers provide reliable proximity-based access.

Explore our full range today for the best in modern security solutions!

Need help finding the right Intercom for you? Call us on 01283 512111. 

Download our pdf version of First Facts: What is a GSM Intercom?

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