
28
■
Handbook on Mobile and Ubiquitous Computing: Status and Perspective
Cardholder
Merchant
Initiate_request
Initiate_response
Purchase_request
Purchase_response
Acquire
Payment
gateway
Issuer
The internet
Authorization_
response
Authorization_
request
Settlement
Financial networks
Figure 2.2 Processing flows for purchase request and authorization in SET.
■ Clearing and settlement: Settlement can take place in real time during the purchase or in a
postpaid mode. Real-time settlement can be conducted via a prepaid account if the TTP is
a Telco or directly through a bank account if the TTP is a bank. In postpaid mode, the PSP
sends the billing information to the TTP. ...