COLLISION_BEACON AND RADIO BUSY

LPWAN Industrial Gateways / Concentrators RAK7249
1

Issue:
The downlinks are rejected when a collision_beacom is detected, even though the downlink is on a different frequency, as a result the downlink communication fails on the rx1 and rx2 lora window.
Setup:
RAK7249 fw.1.3.1_RAK b71
Channel Plan EU868

LoRa® Server:
ChirpStack v3.15.5
Details:
Log of Lora Packet Logger

lora_packet_forworder
lora_packet_forworder1582×366 17.4 KB

System Logs
Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: INFO: [down] PULL_ACK received in 1 ms
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: gps sat : 9, gps mod : D, gps status: 2
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: rrd_statistic_up 367 uplinkTqByAirtime : dr = 5, timeonair = 71, tm = 1643360615
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: rrd_statistic_up 369 uplinkTqByPkt : dr = 5, tm = 1643360615
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: rrd_statistic_up 371 ChanBusyByAirtime chan 2, timeonair = 71, tm = 1643360615
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: Uplink Frame :
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 80 99 B9 55 01 80 95 0B
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 0A 18 8D FA B8 BA EE D0
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 6B D1 AD 87 C7 84 7F F4
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 79 BF F4 9A 04 40 7E 4C
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 2B 0F
Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: JSON up: {“rxpk”:[{“tmst”:1583941987,“time”:“2022-01-28T09:03:35.504332Z”,“tmms”:1327395833504,“chan”:2,“rfch”:0,“freq”:867.500000,“stat”:1,“modu”:“LORA”,“datr”:“SF7BW125”,“codr”:“4/5”,“lsnr”:7.5,“rssi”:-79,“size”:34,“data”:“gJm5VQGAlQsKGI36uLru0GvRrYfHhH/0eb/0mgRAfkwrDw==”}]}
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: gwBridgeReadCB: Frame size 280
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Enter gwBridgeFrameRcv, mdCreateEvent 0 Frame Len 280
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Uplink Packet from Gateway 60c5a8fffe76635d
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Uplink - {“rxpk”:[{“tmst”:1583941987,“time”:“2022-01-28T09:03:35.504332Z”,“tmms”:1327395833504,“chan”:2,“rfch”:0,“freq”:867.500000,“stat”:1,“modu”:“LORA”,“datr”:“SF7BW125”,“codr”:“4/5”,“lsnr”:7.5,“rssi”:-79,“size”:34,“data”:“gJm5VQGAlQsKGI36uLru0GvRrYfHhH/0eb/0mgRAfkwrDw==”}]}
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: [Uplink] - Protobuf size 173
Fri Jan 28 10:03:35 2022 daemon.info mqttEv[3973]: mqttEvPublish : [[gwBridgeS Mqtt Client]] publish - [173][ "���U�� ������kѭ�DŽ�y���@~L+��ӝ }a4/5t Ũ��vc]��Ώ���������ܩ�(���������1] Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: INFO: [up] PUSH_ACK received in 0 ms Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: mosqMsgCB topic : gateway/60c5a8fffe76635d/command/down Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: gwBridgeParseMosqDownlink mqtt downlink packet - size 205 Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: INFO: [down] PULL_RESP received - token[160:76] :) Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: JSON down: {"txpk":{"imme":false,"tmst":1590941987,"freq":867.500000,"rfch":0,"powe":24,"ncrc":false,"modu":"LORA","codr":"4/5","datr":"SF7BW125","ipol":true,"size":13,"data":"YJm5VQGhlAsG1NybSg=="}} Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: DownLink Frame : Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 60 99 B9 55 01 A1 94 0B Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 06 D4 DC 9B 4A Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: src/jitqueue.c:291:jit_enqueue(): ERROR: Packet (type=0) REJECTED, collision with beacon already programmed at 1590437322 (1590941987) Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: gwBridgeReadCB: Frame size 53 Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Enter gwBridgeFrameRcv, mdCreateEvent 0 Frame Len 53 Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Uplink Packet from Gateway 60c5a8fffe76635d Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: [TxAck] - Protobuf size 50 Fri Jan 28 10:03:35 2022 daemon.info mqttEv[3973]: mqttEvPublish : [[gwBridgeS Mqtt Client]] publish - [50][ Ũ��vc]��COLLISION_BEACON"L����Mr��[lô]
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: mosqMsgCB topic : gateway/60c5a8fffe76635d/command/down
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: gwBridgeParseMosqDownlink mqtt downlink packet - size 150
Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: INFO: [down] PULL_RESP received - token[160:76] :slight_smile:
Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: JSON down: {“txpk”:{“imme”:false,“tmst”:1591941987,“freq”:869.525000,“rfch”:0,“powe”:24,“ncrc”:false,“modu”:“LORA”,“codr”:“4/5”,“datr”:“SF12BW125”,“ipol”:true,“size”:13,“data”:“YJm5VQGhlAsG1NybSg==”}}
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: DownLink Frame :
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 60 99 B9 55 01 A1 94 0B
Fri Jan 28 10:03:35 2022 user.debug lora_pkt_fwd[4026]: 06 D4 DC 9B 4A
Fri Jan 28 10:03:35 2022 user.info lora_pkt_fwd[4026]: src/jitqueue.c:291:jit_enqueue(): ERROR: Packet (type=0) REJECTED, collision with beacon already programmed at 1590437322 (1591941987)
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: gwBridgeReadCB: Frame size 53
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Enter gwBridgeFrameRcv, mdCreateEvent 0 Frame Len 53
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: Uplink Packet from Gateway 60c5a8fffe76635d
Fri Jan 28 10:03:35 2022 daemon.info gwBridge[3973]: [TxAck] - Protobuf size 50
Fri Jan 28 10:03:35 2022 daemon.info mqttEv[3973]: mqttEvPublish : [[gwBridgeS Mqtt Client]] publish - [50][ `Ũ��vc]��COLLISION_BEACON"L����Mr��[lô]
Fri Jan 28 10:03:36 2022 user.debug lora_pkt_fwd[4026]: gps sat : 9, gps mod : D, gps status: 2
Fri Jan 28 10:03:37 2022 user.debug lora_pkt_fwd[4026]: gps sat : 9, gps mod : D, gps status: 2

2

A gateway can only transmit on one frequency at a time - and can’t receive on any while it is doing so.

Did you mean to be using beacons?

If you switch to Chirpstack’s gateway software (from their site) they may have some capability to choose between RX1 and RX2 later in the process and avoid this, but not sure if that’s complete or if they’ve only taken preliminary steps towards having that.

Also even with beacons on this should be relatively infrequent?

3

I solved the problem by minimizing the gateway logging rate. Now when it detects an inability to transmit, it tries again on rx2 and it works

4

That should have nothing to do with it, but glad things are working for you.

5

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