Hi,
I am using osmo-bts-trx with a B205-mini-i, using only CS services. I am currently running the following elements on Ubuntu 22.04, all built from source from the latest version: - osmo-trx-uhd - osmo-bts-trx - osmo-bsc - osmo-msc - osmo-hlr - osmo-mgw - osmo-stp - osmo-sip-connector
I have been testing the range of the cell, and I can't seem to get more than around 50 meters, even when I transmit at ~21 dBm using a power amplifier at TX. I find this range too low, since I am used to getting 200-300 meters out of the box when running 4G and 5G networks with the same device, so I suspect I am not configuring the network correctly. I've tried looking at every parameter, so far I've only noticed improvements when setting the min-qual-* to the minimum values and ms_max_power to the maximum.
These are my configs for TRX, BTS and BSC:
OsmoTRX:
``` log stderr ... ! line vty no login ! cpu-sched policy rr 18 trx bind-ip 127.0.0.1 remote-ip 127.0.0.1 egprs disable tx-sps 4 rx-sps 4 clock-ref gpsdo chan 0 ```
``` ! ! OsmoBTS () configuration saved from vty !! ! log stderr ... ! line vty no login ! phy 0 instance 0 osmotrx tx-attenuation 0 osmotrx rx-gain 50 osmotrx ip local 127.0.0.1 osmotrx ip remote 127.0.0.1 bts 0 band GSM900 ipa unit-id 1234 0 oml remote-ip 127.0.0.1 gsmtap-remote-host 127.0.0.1 gsmtap-sapi enable-all min-qual-rach -100 min-qual-norm -100 trx 0 phy 0 instance 0 nominal-tx-power 10 ```
``` ! osmo-bsc default configuration ! (assumes STP to run on 127.0.0.1 and uses default point codes) ! log stderr logging color 1 logging print category-hex 0 logging print category 1 logging timestamp 0 logging print file basename last logging print level 1
e1_input e1_line 0 driver ipa network network country code 1 mobile network code 1 encryption a5 0 neci 1 paging any use tch 0 handover 0 handover algorithm 1 handover1 window rxlev averaging 10 handover1 window rxqual averaging 1 handover1 window rxlev neighbor averaging 10 handover1 power budget interval 6 handover1 power budget hysteresis 3 handover1 maximum distance 9999 ! T3212 is in units of 6min, so below we set 5 * 6 = 30min timer net T3212 5 mgw 0 remote-ip 127.0.0.1 remote-port 2427 local-port 2727 bts 0 type osmo-bts band GSM900 cell_identity 1234 location_area_code 0x0001 base_station_id_code 63 ms max power 40 !default: cell reselection hysteresis 4 cell reselection hysteresis 14 radio-link-timeout 32 channel allocator mode set-all ascending rxlev access min 0 rach tx integer 9 rach max transmission 7 channel-description attach 1 channel-description bs-pa-mfrms 5 channel-description bs-ag-blks-res 1 early-classmark-sending forbidden ipa unit-id 1234 0 oml ipa stream-id 255 line 0 codec-support fr gprs mode none trx 0 rf_locked 0 ! 945M DL/900M UL arfcn 50 nominal power 10 max_power_red 0 rsl e1 tei 0 timeslot 0 phys_chan_config CCCH+SDCCH4 hopping enabled 0 timeslot 1 phys_chan_config TCH/F hopping enabled 0 timeslot 2 phys_chan_config TCH/F hopping enabled 0 timeslot 3 phys_chan_config TCH/F hopping enabled 0 timeslot 4 phys_chan_config TCH/F hopping enabled 0 timeslot 5 phys_chan_config TCH/F hopping enabled 0 timeslot 6 phys_chan_config TCH/F hopping enabled 0 timeslot 7 phys_chan_config TCH/F hopping enabled 0 ms-power-control mode dyn-bts rxlev-thresh lower 0 upper 63
msc 0 allow-emergency allow amr-config 12_2k forbidden amr-config 10_2k forbidden amr-config 7_95k forbidden amr-config 7_40k forbidden amr-config 6_70k forbidden amr-config 5_90k allowed amr-config 5_15k forbidden amr-config 4_75k forbidden bsc mid-call-timeout 0 ```
You might notice I am using the gpsdo as the clock-ref. That's because I've also tried with a B210 with the internal GPSDO, but the results are the same.
Thanks in advance,
Jonathan Pichel