Bluetooth Applications
October 22, 2008
Most network protocols just provide channels between communicating entities and let applications designers figure out what they want to use them for. For example, 802.11 do not specify whether users should use their notebook computers for reading e-mail, surfing the Web or something else. In contrast, the Bluetooth V1.1 specifications names 13 specific applications to be supported and provides different protocol stacks for each one. Unfortunately, this approach leads to a very large amount of complexity, which we will omit here. The 13 applications, which are called profiles, are listed in following. By looking at them briefly now, we may some more clearly what the Bluetooth SIG is trying to accomplish.
| Name | Description |
| Generic Access | Procedures for link management |
| Service Discovery | Protocol for discovering offered services |
| Serial Port | Replacement for a serial port cable |
| Generic Object Exchange | Defines client-server relationship for object movement |
| LAN Access | Protocol between a mobile computer and a fixed LAN |
| Dial-up Networking | Allows a mobile fax machine to talk to a mobile phone |
| Cordless Telephony | Connects a handset and its local base station |
| Intercom | Digital walkie-talkie |
| Headset | Allows hands-free voice communication |
| Object Push | Provides a way to exchange simple objects |
| File Transfer | Provides a more general file transfer facility |
| Synchronization | Permits a PDA to synchronize with another computer |
The generic access profile is not really an application, but rather the basis upon which the real applications are built. Its main job is to provide a way to establish and maintain secure links (channels) between the master and the slaves. Also relatively generic is the service discovery profile, which is used by devices to discover what services other devices have to offer. All Bluetooth devices are expected to implement these two profiles. The remaining ones are optional.
The serial port profile is a transport protocol that most of the remaining profiles use. It emulates a serial line and is especially useful for legacy applications that expect a serial line.
The generic object exchange profile defines a client-server relationship for moving data around. Clients initiate operations, but a slave can be either a client or a server. Like the serial port profile, it is building block for other profiles.
The next group of three profiles is for networking. The LAN access profile allows a Bluetooth device to connect to a fixed network. This profile is a direct competitor to 802.11. The dial-up networking profile was the original motivation for the whole project. It allows a notebook computer to connect to a mobile phone containing a built-in modem without wires. The fax profile is similar to dial-up networking, except that it allows wireless fax machines to send and receive faxes using mobile phones without a wire between the two.
Posted in Computer Hardware, Networking, Technology
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