Type C device delays. LinckCheckReq

ChirpStack Network Server
1

Hello!

I have a device(type C), when it turns on it sends first message with LinkCheckReq - I see it in live logs.
Loraserver answers on this message immediately(max delay i saw was 1 sec) and my device cant see it. As i was said the server have to follow delay1, delay2 Is that right? Is there possible to fix it for now?

2

Please note, LoRa Server sends the downlink immediately to the gateway but it doesn’t mean it gets transmitted immediately as the delay you are referring to is added to the timestamp on which the gateway must transmit the frame.

3

Here my logs from base-station:

JSON up: {“rxpk”:[{“tmst”:176402116,“chan”:6,“rfch”:1,“freq”:869.100000,“stat”:1,“modu”:“LORA”,“datr”:“SF12BW125”,“codr”:“4/5”,“lsnr”:10.0,“rssi”:-48,“size”:45,“data”:“QBVeHwGBAAACAjw4gerXAgi/ScVhVmrTsuiBGTUpYmHkxjYZjaJNSGy59dUo”}]}
INFO: [up] PUSH_ACK received in 13 ms
INFO: [down] PULL_RESP received - token[102:110] )

JSON down: {“txpk”:{“imme”:false,“tmst”:177402116,“freq”:869.1,“rfch”:0,“powe”:14,“modu”:“LORA”,“datr”:“SF12BW125”,“codr”:“4/5”,“ipol”:true,“size”:20,“data”:“YBVeHwGIAAACHgEDUQMAARRfla4=”,“brd”:0,“ant”:0}}
INFO: tx_start_delay=1495 (1495.500000) - (1497, bw_delay=1.500000, notch_delay=0.000000)

INFO: Received pkt from mote: 011F5E15 (fcnt=0)

JSON up: {“rxpk”:[{“tmst”:178721012,“chan”:5,“rfch”:1,“freq”:868.900000,“stat”:1,“modu”:“LORA”,“datr”:“SF12BW125”,“codr”:“4/5”,“lsnr”:-19.0,“rssi”:-111,“size”:20,“data”:“YBVeHwGIAAACHgEDUQMAARRfla4=”}]}
INFO: [up] PUSH_ACK received in 14 ms

first rx is the message with LinkCheckReq

also maybe you know why tx message is the same with last rx? :slight_smile:

PS: when i`m sending pure downlinks - there no repeating tx

4

So as I undestand from logs - downlink message was sent just in the same tume without rx delay.

5

RX timestamp = 176402116
TX timestamp = 177402116

177402116 - 176402116 = 1000000 = 1sec

I can’t explain why the second rxpk is in the log.