30 Jun
2024
30 Jun
'24
9:53 p.m.
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