# Create the simulations


`+ ADD Simulation`

Use the following procedure to define the simulations to run.

1. Navigate to the Simulations page.

2. Choose Add Simulation

3. On the Create Simulation page, take the following actions:


a. In the Simulation name field, enter a name.

b. In the Select a device type drop-down menu, select the device type you want to simulate. To select more than one device type, choose Add type.

c. In the Number of devices drop-down menu, select the number of devices you want to simulate.

d. In the Data transmission interval field, enter the interval time that the devices will send data.

:::info
**Note**
Data transmission interval is a key cost driver of AWS IoT Core messaging expense.
:::

e. In the Data transmission duration field, enter the length of time that the simulation will run.


4. Choose Save.