Page 502 - From GMS to LTE

488 From GSM to LTE-Advanced Pro and 5G

Application profiles

File transfer Object push Synchronization

Application profiles
use OBES commands
like PUT, GET, SETPATH…
OBEX OBEX is dened by the
Generic Object Exchange
Profile (GOEP)
Figure 7.21 The FTP, object push and synchronization profiles are based on GOEP.

way as the FTP, as it also uses general OBEX commands like PUT and GET. The object
push profile, however, does not support directory operations or the deletion of files.
This simplification accelerates the process for single objects, as only a few decisions
have to be made by the user before the object is transmitted.
Many devices allow an incoming object push transfer without prior authentication
and ciphering. The object is then stored in a buffer and only inserted into the calendar
or address book or copied to the file system once the user has authorized the transfer.
For the transmission of calendar and address book entries, the Bluetooth standard
requires the use of vCalendar and the vCard format, which are standardized in [9–13].
This is a precondition to exchange address book and calendar entries between any pro-
gram and any end‐user device. For other objects such as pictures, the file name exten-
sion (e.g. .gif, .jpg, etc.) can be used by the receiver to make a decision on how to treat
the received object.
Even though the profile is called ‘object push’, it also defines an optional business card
pull functionality which can be used to send a predefined business card to a remote
device upon its request. The business card exchange feature extends the functionality to
automatically send the business card stored in the retrieving device during a request for
a business card to the remote device.
The third profile based on GOEP is the synchronization profile [14]. Like the file
transfer profile described before, it is not used much in practice anymore but shall be
described for completeness. The synchronization profile allows automated synchroni-
zation of objects like calendar entries, address book entries, notes, and so on. Again,
general OBEX commands like GET and PUT are used. While the object push profile
can only transfer a single address‐book entry to a remote device, the synchronization
profile describes how to synchronize all records of a database. During the first synchro-
nization attempt, all entries of the database on both devices are exchanged with each
other. During all subsequent synchronizations, only objects that have changed since the
last synchronization session are updated on both sides. This is achieved by recording
every change of an object in a journal. To allow the exchange of database records of
products of different vendors, the synchronization profiles also use the standardized
vCard and vCalendar formats.
The Bluetooth standard does not itself define how the synchronization is performed,
but uses the synchronization system defined in the Infrared Mobile Communications
(IrMC) standard [15] of the Infrared Data Association.