While most mobile plans offer unlimited calls and SMS, there are few that do not impose a data envelope. Large internet consumers will therefore have an interest in keeping an eye on their data consumption even if it means blocking 4G access to certain mobile apps..
Limited unlimited plan
You should be wary of unlimited plans which often only have unlimited names. Indeed, it is important to remember that most mobile operators offer plans with data limitations. It is the famous Fair-Use . This envelope varies from a hundred MB to several GB depending on the plan chosen.
Once this limit is exceeded, your operator can either reduce the speed of your 3G connection, cut it until the end of the month or you charge each additional megabyte. Needless to say, the latter option is by far the most painful for your wallet..
It is for this reason that your data consumption should be monitored with the greatest vigilance . Android smartphones integrate by default different tools to monitor and measure live mobile data traffic: Set a mobile data limit
We often forget it but data does not only concern web browsing but also and above all mobile applications. Some tend to be very greedy in data, this is particularly the case with Facebook.
Block data consumption of applications
Obviously nothing prevents you from deactivating your 3G / 4G connection when you are not using your smartphone. It's simple, effective but very restrictive. This method will prevent you for example from being notified of the arrival of a new email or a new post on Facebook..
If you want to take full advantage of your Android smartphone while reducing your data consumption, you should consider blocking internet access to non-essential applications. Why authorize a flashlight to use your 4G plan?
- Open your phone settings
- In the network section, click on Data consumption
- At the bottom of the window, you will see the list of applications consuming the most mobile data.
- Select the one for which you want to block internet access
- Click the Limit Background Data option
Unfortunately this solution suffers from some limitations. To effectively prevent an application from accessing the internet, it is preferable to opt for a firewall.
NetGuard, firewall for Android mobile
The NetGuard application has various tools to block incoming and outgoing traffic on a mobile phone. You can thus authorize or not the internet access to the applications installed on your device. 
The firewall also makes it possible to prevent malicious apps from connecting to the network and thus to recover your personal information. Note that NetGuard does not need root access to operate.
- Open the Play Store and type in the search field NetGuard no root firewall
- Download and install the app
- Then launch NetGuard
- Press the green switch to the right of the shield icon
A warning message will appear on your mobile screen explaining that NetGuard uses a local VPN system to filter internet traffic . If you accept these terms of use click the OK button. Note that no data passing from your mobile will be sent to a remote VPN.
- Then select from the list of apps for which you want to block incoming and outgoing connections
- Click on the 3G / 4G icon to prevent access to your mobile plan
- Click the Wi-Fi icon to deny access to your wireless connections
- Once the filtering is effective, the pictogram will turn orange
- Then tap on the app name to view additional settings
From this window, you can, for example, authorize an application to connect to the internet only when you are using your phone (screen lit). 
You will also find in the list an option to prevent applications from using the internet abroad (roaming).
No doubt that thanks to this application, you will be able to drastically reduce your data consumption.
