The downlink can't be sent in the Class-B mode.

[andrewrene]

Is this a bug or a feature request?

Bug

What did you expect?

In the Class-B mode, the ping-solt downlink should be sent from the forwarder side.

What version are your using?

ISM Band : EU868 Beacon Packet Forwarder for Lora Gateway : 4.0.1 Lora concentrator HAL library version info : 5.0.1 End-Node : LoRaWAN1.1 LoRa Gateway Bridge : 2.4.1 GNSS module : GMM-G3

Could you share your log output?

I tested the class-b function but alway get the jit error during downlink, the value in the tmms field from JSON down message seems wrong so the ping-solt downlink is always rejected by forwarder side, the logs as below,

*. On the end-node side log

Network Joined ~DEVICE_STATE_REQ_BEACON_TIMING Frame send ~DEVICE_STATE_BEACON_ACQUISITION MLME_BEACON_ACQUISITION, Received Acquisition. MLME_BEACON, Received BEACON:1 ~DEVICE_STATE_REQ_PINGSLOT_ACK Frame send ~DEVICE_STATE_REQ_PINGSLOT_ACK Frame send MLME_PING_SLOT_INFO, CLASS_B Frame send Frame send Frame send Frame send MLME_BEACON, Received BEACON:2 ….

*. On the forwarder side log

…. JSON down: {"txpk":{"imme":false,"tmms":1217653456000,"freq":869.525,"rfch":0,"powe":14,"modu":"LORA","datr":"SF12BW125","codr":"4/5","ipol":true,"size":23,"data":"oAys0wGFBAADVwcAAQozTmQZLi4QsYM=","brd":0,"ant":0}} INFO: [down] a packet will be sent on timestamp value 344686124 (calculated from GPS time) src/jitqueue.c:140:jit_enqueue(): Current concentrator time is 346122413, pkt_type=1 src/jitqueue.c:251:jit_enqueue(): ERROR: Packet REJECTED, timestamp seems wrong, too much in advance (current=346122413, packet=344686124, type=1) ERROR: Packet REJECTED (jit error=2) ……

*. The downlink command mosquitto_pub -h 192.168.88.136 -t application/1/device/2000000000000021/tx -m "{\"reference\": \"abcd1234\",\"confirmed\":true,\"fPort\":10,\"data\":\"OTQ1Mwo=\"}" -q 1 -u admin -P admin

*. The device profile

[brocaar]

Let me validate this. I'll come back to this next week.

[brocaar]

I can't reproduce the issue and all is working fine here (tested with Multitech Conduit with onboard GNSS module). I don't think your GNSS module is supported for Class-B:

https://github.com/Lora-net/lora_gateway/blob/a955619271b5d0a46d32e08150acfbc1eed183b7/libloragw/src/loragw_gps.c#L281