Yes, it is.
In addition to the basic authentication to the Splash Portal, the platform also supports the IEEE 802.1X authentication.
When a Venue is properly configured for this, an end-user with a IEEE 802.1X client is able to access the service without needing to connect to the Splash Portal and perform the authentication.
In order to support IEEE 802.1X protocol, the Venue must be configured in a proper way. In particular, the field Type must be set with one of the following values:
You can find how to set this by reading the following articles dealing with the creation or the management of a Venue: