Hi Xavier, On Thu, Apr 26, 2012 at 12:22:16PM +0200, carcelle wrote:
> > you can increase the bitrate by adding more PDCH on other timeslots. > > You will lose those for voice, though. The nanoBTS is capable of > > dynamic TCH/F + PDCH switching, but we don't support that in OpenBSC > > yet. > > ok understand, TCH/F + PDCH repartitions based on your > how could i calcultate the theorical layer2/ip troughput available for one > PDCH > and correlate it to the troughput measured from the MS to an external IP ? you can see the raw bitrates for different EDGE coding modes (PDCH coding scheme will vary depending on RF layer performance): https://en.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution so it's 8.8 kbit/second / slot to 59 kbit/second /slot For pure GPRS it's 8 kbit/second / slot to 20 kbit/second / slot >From that bitrate you need to subtract the RLC/MAC overhead. If you need higher bitrates, implementing header and payload compression at the SNDCP level in the SGSN is possible. Also, always keep in mind that while you can offer 7 TS with GPRS/EDGE, almost no phone has support for a multislot class that allows for 7 TS in DL. So multiple phones can fill the 7 TS, but it's unlikely one phone can use all of them. Regards, Harald -- - Harald Welte <[email protected]> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)
