From GSM to LTE: An Introduction to Mobile Networks and Mobile Broadband

7.6 Bluetooth Profiles

As shown at the beginning of this chapter, Bluetooth can be used for a great variety of applications. Most applications have a server and a client side. A client usually establishes the Bluetooth connection to the master and requests the transfer of some kind of data. Thus, the master and the client sides of a Bluetooth service are different. For example, for the transfer of a calendar entry from one device to another the client side establishes a connection to the server. The client then transfers the calendar entry as the sending component. The server, on the other hand, receives the calendar entry as the receiving component. To ensure that the client can communicate with servers implemented by different manufacturers, the standard defines a number of Bluetooth profiles. For each application (dial-up services, calendar entry transmission, serial interface, etc.), an individual Bluetooth profile has been defined, which describes how the server side and the client side communicate with each other. If both sides support the same profile, interoperability is ensured.

It is noteworthy that the client/server principle of the Bluetooth profile should not be confused with the master/slave concept of the lower Bluetooth protocol layers. The master/slave concept is used to control the piconet, that is, who is allowed to send and at which time, while the client/server principle describes a service and the user of a service. Whether the Bluetooth device, which is used ...