Even if your data plan is unlimited, you should keep watch on the usage of your mobile data. To ensure how much data you are using for your monthly plan, go to Data Usage in Settings. Here you can see which data apps are using.

Here you can set the date range of your data usage and set the limit of data. In addition to this, you can set the data for automatic disable when the data limit is crossed.

• Turn on the Set mobile data limit to set the data limit.
• Then drag the orange color line and set the data limit.
• You will be alerted when you reach this data limit.