this fixes the delay of audio caused by stalling of the openbsc process. the use of 'usleep(100000)' for slowing down transmission to nanoBTS is replaced by the tx-delay timer. i did this on bs11 code, so i did it the same way. it actually queues frames for transmission not nanoBTS. on transmission a timer is started and when this timer expires, the next frame in the queue is transmitted (timer restarted) until the queue is empty.