gprs_rlcmac_received_lost() in gprs_rlcmac_meas.cpp

Hello Andreas,

while looking through the osmo-pcu code to figure out why some connections stall we had some problems making sense of the elapsed time calculations in gprs_rlcmac_meas.cpp.

Could you confirm/deny my assumptions about it or explain the idea behind it?

gettimeofday(&now_tv, NULL); elapsed = ((now_tv.tv_sec - loss_tv->tv_sec) << 7)

• ((now_tv.tv_usec - loss_tv->tv_usec) << 7) / 1000000;

I assume here you're calculating the duration of the measurement period so far and since you want to have sub-second accuracy you multiply everything with 128. Why 128? Is it becasue it simplifies the throughput calculation? (tbf->meas.dl_bw_octets/elapsed in gprs_rlcmac_dl_bw())

if (elapsed < 128) return 0;

Is the intention here that the duration of the measurements is supposed to be one second? So every second these measurements are printed out and reset?

Regards Daniel Willmann