| == Configuring OsmTRX |
| |
| OsmoTRX will read the configuration at startup time and configure the |
| transceiver accordingly after validating the configuration. |
| |
| OsmoTRX can handle several TRX channels, but at least one must be configured in |
| order to be able to start it successfully. Channels must be present in the |
| configuration file in incremental order, starting from 0 and be consecutive. |
| |
| Example configuration files for different devices and setups can be found in |
| `doc/examples/` in 'osmo-trx' git repository. |
| |
| === Documented example |
| |
| .Example: Single carrier configuration |
| ---- |
| trx |
| bind-ip 127.0.0.1 <1> |
| remote-ip 127.0.0.1 <2> |
| base-port 5700 <3> |
| egprs disable <4> |
| tx-sps 4 <5> |
| rx-sps 4 <6> |
| chan 0 <7> |
| tx-path BAND1 <8> |
| rx-path LNAW <9> |
| ---- |
| <1> Configure the local IP address at the TRX used for the connection against `osmo-bts-trx`. |
| <2> Specify the IP address of `osmo-bts-trx` to connect to. |
| <3> Specify the reference base UDP port to use for communication. |
| <4> Don't enable EDGE support. |
| <5> Use 4 TX samples per symbol. This is device specific. |
| <6> Use 4 RX samples per symbol. This is device specific. |
| <7> Configure the first channel. As no other channels are specified, `osmo-trx` assumes it is using only one channel. |
| <8> Configure the device to use `BAND1` Tx antenna path from all the available ones (device specific). |
| <9> Configure the device to use `LNAW` Rx antenna path from all the available ones (device specific). |
| |
| [[multiarfcn_mode]] |
| === Multi-ARFCN mode |
| |
| The Multi-ARFCN feature allows to have a multi-carrier approach multiplexed on a |
| single physical RF channel, which can introduce several benefits, such as lower |
| cost and higher capacity support. |
| |
| Multi-ARFCN support is available since osmo-trx release `0.2.0`, and it was |
| added specifically in commit `76764278169d252980853251daeb9f1ba0c246e1`. |
| |
| This feature is useful for instance if you want to run more than 1 TRX with an |
| Ettus B200 device, or more than 2 TRXs with an Ettus B210 device, since they |
| support only 1 and 2 physical RF channels respectively. No device from other |
| providers or even other devices than B200 and B210 from Ettus are known to |
| support this feature. |
| |
| With multi-ARFCN enabled, ARFCN spacing is fixed at 800 kHz or 4 GSM channels. |
| So if TRX-0 is set to ARFCN 51, TRX-1 _must_ be set to 55, and so on. Up to |
| three ARFCN's is supported for multi-TRX. |
| |
| From BTS and BSC point of view, supporting multiple TRXs through multi-ARFCN |
| feature in OsmoTRX doesn't make any difference from a regular multi-TRX setup, |
| leaving apart of course the mentioned ARFCN limitations explained above and as a |
| consequence physical installation and operational differences. |
| |
| .Example: osmo-bts-trx.cfg using 2 TRX against an osmo-trx driven device |
| ---- |
| phy 0 |
| osmotrx ip local 127.0.0.1 |
| osmotrx ip remote 127.0.0.1 |
| instance 0 |
| instance 1 |
| bts 0 |
| ... |
| band GSM-1800 |
| trx 0 |
| phy 0 instance 0 |
| trx 1 |
| phy 0 instance 1 |
| ---- |
| |
| .Example: osmo-trx.cfg using Multi-ARFCN mode to run 2 TRX |
| ---- |
| trx |
| ... |
| multi-arfcn enable |
| chan 0 |
| chan 1 |
| ---- |