Downloading of application software for an accessory device to a mobile terminal

The invention relates to a method for supporting in a mobile terminal 10,30 the operation of an accessory device 20,40 connected to this mobile terminal 10,30. In order to enable particularly flexible connections between a mobile terminal and accessory devices, it is proposed that the method comprises downloading application software 23,43 for the accessory device 20,40 to the mobile terminal 10,30 and running downloaded application software 15,35 for the accessory device 20,40 in the mobile terminal 10,30. It is ensured that a data exchange required for the operation of the accessory device 20,40 is enabled as transparent bi-directional bit-stream between the downloaded application software 15,35 and the accessory device 20,40. The invention relates equally to a corresponding mobile terminal, to a corresponding communication system and to a corresponding software for such a mobile terminal.