ns, contactless payments at retail www.TechnicalPDF.com outlets, and instead of cash at subways and toll roads. These mobile payment options include the following: Payments for mass transit Users can pass their smartphone near a reader to pay for subway, bus, and train transportation instead of using tokens or purchasing monthly passes. Apps on mobile phones can take advantage of a short-range wireless technology called Near Field Communications (NFC) to interact with the reader. The user simply needs to pass her phone within 1.56 inches (4 cm) of the payment reader. Check deposits Smartphone apps use the device's camera to take a picture of the check and then transmit the image to the user's bank for deposit. Money transfers directly to a mobile phone in a developing country When a relative or friend sends money to a person in a developing country via Western Union, the electronic cash is sent directly to the receiver's handset. MoreMagic, a Massachusetts software developer, created this application. Online payments People surfing the Internet on their smartphone can make online purchases through PayPal rather than having to type in their credit card number along with their name, postal address, and e-mail address. All of these transactions require some type of software platform that sits between credit card processing companies or banks and the mobile network. The platform must have integrated security protocols and the ability to communicate with the financial institutions that process payments. They also need to communicate with servers at merchants' sites and devices that act as "readers" of the mobile device making the transaction. Each mobile handset and reader requires chips with NFC capability or special software. The cost of these readers is often a stumbling block for retailers because they need to place one at every cash register. Alternatively, readers can be embedded in portable devices that sales associates use to process credit card sales. Another challenge for retailers is that there is no agreed