Embedded modems are hardware devices that enable appliances to communicate to distant hosts through the internet.
How do embedded modems work?
Embedded modems contain a Data Access Arrangement (DAA), data pump and modem code. The data pump employs modem code to translate data to a standard protocol (internet or fax) at a specific bit rate. This means that devices connected to the embedded modem have email capability, offer standard web-page hosting and can download files.
Handheld computers and appliances become more useful when they can link to remote hosts. Set top boxes for interactive satellite and cable television rely on embedded modems to communicate shopping orders, billing information, pay-per-view and interactive programming.
Unlike wired modems which are in their own enclosure, most embedded modems are typically surface mounted directly onto the surface of printed circuit boards.
Types of embedded modems
Embedded modems can be distinguished from one another by their architecture (where the processing takes place). They fall into two main categories: Controller based (processing takes place in the modem) and controllerless (the generation of commands and data compression are performed by the PC).