When using the Plusdial mobile ticketing system, the end-user purchases a ticket by sending a text message to the service number. A reply SMS acts as the ticket, containing information and instructions for the customer about the ticket and some encoded information for checking the validity of the ticket.
The passenger presents the ticket on the display of the mobile phone to the driver/ticket inspector, who can then check the validity of the ticket by reading the human readable security control code in the ticket.
To automatically validate the SMS ticket in a bus or tram, the passenger puts the phone, displaying the ticket, on the reader. Audio and LED indicators tell the passenger and the driver whether the ticket is valid or not. Information about the validity (time, zone, ticket type etc) is encoded in the ticket and it is impossible to create a new or successfully manipulate the existing encoded ticket.
Different functionalities for safety against fraud, e.g. copied tickets, are provided depending on the ticket type and the level of the data communication infrastructure in the transportation system.