sync/async bridge

hi,

I have a scenario like:

webdynpro(webservice )->xi->File.

I used Sync/async bridge so that I can send a response back to the webservice(once the file is created). But the problem is it is takin some time for getting the response which is not acceptable in this case. So is there a way that I can get a response quickly or is there a way that I can do this with the synch/asynch bridge?

Or can somebody give an idea of how I can send an acknowledgement as a response to the webservice.

thank you