Micro Aggregation Engine (MAGGIE)

The MAGGIE prototype was developed as a showcase for the New York public transport agency, demonstrating how RFID-based credit card payments could be used to purchase subway tickets.

The Micro AGGregatIon Engine prototype demonstrates the concept of aggregating small transaction amounts into larger values before settling them against a traditional payment backend such as a credit card or bank account. This kind of system is useful in markets with very low transaction amounts, where immediate settlement fees would exceed the actual transaction value.

The first screen shows the start page. From here the user can enter the shopping area, and the consumer or merchant self-administration.

Start Page

One of the shops in the shopping area is a prototype showing how New York’s public transport system (MTA – Metropolitan Transportation Authority) could let passengers buy subway tickets using the new RFID credit cards. The user swipes an RFID credit card over the card reader; the card is charged with the ticket price and the user is granted access to the station. This can be demonstrated by dragging one of the credit cards over the picture. The green display between the credit cards and the turnstile image shows the transaction result.

New York MTA Shop

In the ringtone shop, the user can purchase ringtones for their mobile phone.

Ringtone Shop

After selecting a ringtone, the user must provide their payment details. In this case, a credit card is the only accepted payment method.

Customer Payment Data

In this prototype, no SMS with the ringtone is sent. Instead, the user receives a download link.

Ringtone Download

On the following screen, the consumer enters their authentication data to view their transaction history.

Consumer Self Administration - Authentication

In the transaction view, the consumer can review their personal transactions. The screenshot below shows transactions that were aggregated up to 7 USD and then settled, meaning the credit card had already been charged at that point. The last transaction is still in the “aggregated” state and will be settled later.

Consumer Self Administration - Transaction View

A similar view is available for merchants which shows the transactions of all consumers.

Merchant Self Administration - Transaction View

A merchant can individually define when settlements should take place by setting up aggregation rules. These rules specify an amount threshold at which settlement is triggered. In this case, the threshold is set to 7 USD, meaning that as soon as aggregated amounts reach 7 USD, a settlement is initiated.

Aggregation Rules

The subway ticket showcase uses AJAX (Asynchronous JavaScript and XML) to send payment requests to the server and receive responses without a full page round-trip. The user interface is built on JSF.