Bluetooth Profiles : DUN and FAX Profiles

Dial-Up Networking (DUN) Profile

Dial-Up Networking Profile defines how a Bluetooth device can use a modem that is physically attached to another Bluetooth device to access a public network. In typical application, a computer (desktop PC or laptop) connects to the Internet through a cellular network (such as GPRS, EDGE, 3G, EV-DO, HSDPA) or fixed telephone network (PSTN/ISDN) using a mobile phone as modem or dial-up (voiceband) modem. The computer functions as a data terminal, while the mobile phone or the dial-up modem functions as a gateway device. To enable this service, you must have an Internet subscription for using mobile Internet or dial-up Internet access. 

Figure: Dial-Up Networking Profile
A notebook connects to the Internet using a mobile phone as modem.
The notebook links with the mobile phone using Bluetooth.

In other scenario, using DUN you can connect your handheld device (e.g. PDA) to the Internet using your computer internal modem. Your PDA and computer must have an internal or external Bluetooth adapter.

Fax Profile

Fax profile is comparable to DUN profile. It allows a device to send a fax using another Bluetooth device as a gateway device. In typical application, a computer uses a mobile phone or dial-up modem as a fax modem that connects it to mobile (cellular) network or fixed telephone network (PSTN/ISDN). You must subscribe to a fax sending and receiving service from your mobile operator to start using this service.

Figure: Fax Profile
A notebook sends fax using a mobile phone as fax modem.
A typical fax machine on the other end connects to a fixed telephone network (PSTN).

Software like WinFax can help you send/receive fax from your computer. You can also use built-in fax application in Windows. Most PDAs and smart phones also have the capability to send and receive fax. All you need to do is pick the right fax modem for your device and have a fax service subscription.

DUN and FAX profiles are very useful for mobile workers because both profiles provide connectivity solution while the workers are on the move and have no access to fixed telephone network. These profiles are also valuable if using mobile network is cheaper than using fixed telephone network.

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