Check this out: CGAP M-banking Technologies Matrix (pdf)

The explosive growth of mobile phones offers an opportunity to profitably bank large numbers of the unbanked. Fifty-nine percent of the more than 2 billion mobile users live in developing countries and many of them are among the unbanked: one-third of South Africans and Botswanans without bank accounts do have mobile phones or access to one. Conducting transactions with a mobile phone can be up to six times cheaper than processing the same transaction via teller window. Though cheaper, mobile phones alone are not sufficient - a cash handling network needs to be in place for accepting withdrawals and deposits.

Banks or mobile network operators may exploit these opportunities. In the Philippines, Globe Telecommunications has signed up 1.5 million people for G-Cash, which enables customers to store value, pay bills, send money and purchase goods in stores through an electronic wallet. Globe’s competitor, SMART has 3 million subscribers to its mobile banking services, which are offered in partnership with a bank (Banco de Oro). Globe itself has recently forged a relationship with 31 rural banks to allow bank clients to use G-Cash to make deposits, repay microloans, receive remittances and make payments, all remotely.

A number of challenges remain. Some early pioneers experience low transaction volumes. Most offer a transaction account and payments capability, but little else. Often, there are limited service points where poor people can deposit and withdraw cash. Finally, it is unclear whether early pioneers have reached break even yet, and what would enable them to make a profit.

Research Questions:

• What steps are necessary to generate intensive customer adoption?
• How to reach a wide range of customer segments, including urban and rural, young and old, the formally employed versus self-employed and farmers?
• How to offer a range of financial services? How will the service be priced, and will it be affordable to low-income customers?
• How will low-income customers who live in a primarily cash economy be able to easily deposit and withdraw cash?
• How to ensure interoperability with a range of phone types, including more affordable handset models preferred by lower-income customers?
• How to ensure security for both institutions (authentication, transaction accuracy, non-repudiation, information privacy) and consumers (data privacy, receipts, dispute resolution, liability for fraudulent transactions)?