Ralph, On Mon, Feb 3, 2014 at 4:06 PM, Ralph A. Schmid, dk5ras <[email protected]> wrote: > Digging a bit deeper showed me that GPRS uses a somehow strange power > control model, not a closed loop but a kind of dedicated guess, derived from > the downlink RSSI at the ME.
GPRS has two modes of operation - closed loop and open loop. What you're describing here and what is implemented in both OpenBTS and OsmoPCU. I'm pretty sure that commercial networks use closed loop control nowadays, and it's a TBD item in OsmoPCU. > Is similar behavior known with the openbsc familiy GSM systems? I even know > similar effects from commercial operators (O2 Germany with EDGE), not > knowing if it is the same issue or something completely different. It's a different issue with EDGE. EDGE uses 8-PSK modulation scheme, which is a bit more more sensitive to noise than GMSK and thus may not work at the edge of coverage. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru
