| 摘要 |
A front end processor (FEP) performs in-line call processing and provides enhanced paystation services on ordinary paystation lines. The FEP is part of an overall system composed of paystations (10) comprising smart telephones, an FEP (or multiple FEPs) (12), a central office (CO) (14), and a maintenance/management system (16). The FEP can interface a number of different types of paystations, including coin, coinless, collect call only, cash card, and debit card. Depending on the particular application, the FEP may screen and restrict calls, offer enhanced services, or perform call rating functions in cash/debit card systems. The FEP (12) communicates with smart telephones by employing a data over voice (DOV) technique. The FEP communicates with the central office by either an analog or digital technique. Digital line interface modules (20, 22, 24) in the FEP supply two-wire lines that carry full duplex voice and data as well as power to charge a battery and operate circuits within the paystation telephones. |
