Change Gateway Power
Overview:
In LoRaWAN protocol, the gateway transmit packet use the output power base on the Power Index from LoRaWAN server downlink. for example: LoRaWAN server send downlink with this info "rf_power=14", gatewat got this info and it will search the index for rf_power=14 and use the related rf setting to set output power. In some case, the LoRaWAN server might set the rf-power to a quite low value ( for example 0dB) which is not practical for use. In such case, User can manunal change the rf_power=0's rf settings to a higher power out. Below are the methods.
Change Power for Semtech UDP Paket forward connection
In LoRaWAN protocol, the gateway output power refer to the downstream packets sent by Gateway. This output power is controlled by LoRaWAN server.
Gateway maintain a power index in the file: /etc/lora/global_conf.json for example:
"tx_lut_3": {
"desc": "TX gain table, index 3", // Index 3 refer to rf_power: 15dB. device will set the pa_gain,mix_gain,dig_gain
"pa_gain": 2, // to the value mentioned here so to generate 15dB output power.
"mix_gain": 10,
"rf_power": 15,
"dig_gain": 1
},
"tx_lut_4": {
"desc": "TX gain table, index 4",
"pa_gain": 2,
"mix_gain": 10,
"rf_power": 16,
"dig_gain": 0
Note: If when lorawan server specify a rf_power which is not list above. gateway will choose the closest power. profile.
When LoRaWAN server sends a downlink stream, server will also ask the gateway to use which rf_power as output. So user don't need to consider to control in the gateway side.
If user want to always use a higher power or a lower power. User can modify the pa_gain,mix_gain,dig_gain for specify rf_power to achieve this purpose. This is not recommended, because this might break the regulator for specific country.
Please note, that the global_conf.json file will be overwritten by the match region files in /etc/lora/cfg-30x when changing settings in the web. So user needs to change the files in /etc/lora/cfg-cfg-30x instead of global_conf.json