For UPLINK only messages (not BIDIR), there is no way to get confirmation on the device that the message was actually delivered to the SIGFOX backend, correct?
Answer by lbertaux · Jun 14, 2016 at 05:14 PM
Indeed, there is no acknowledgement sent by the network when a Uplink only message has been received by a base station. This choice was made to optimize the battery life-cycle of the device (similarly, there is no Link layer connection and no signalling between devices and stations)
We choose to use frequency, time and spatial diversity to optimize the delivery of Uplink messages instead of the signalling/acknowledgements.
One alternative would be to use Downlink messages to send to your device the number of Uplink messages received during the day.
Answer by testsigfox · Jan 04 at 10:24 AM
regarding your answer, if I want to ack my up-link messages I should use down-link messages; However, I can send up to 140 up-link messages but only 4 down-link messages, so I could only "ack" 4 messages ....is there any other solution beside using ack down-link messages?
Another question: if the "ack" it not received within the 45 secs time window, even thought the up-link message has been sent and received correctly by the back-end, the sigfox module will not receive the ACK message. Under this conditions, I think a way to know "how probable" an up-link message has arrived to the backend is to check the "signal strenght" in the module side... is there any way to know that with a Telit module or any other module?
Thanks a lot
Answer by lbertaux · Jan 04 at 10:40 AM
As stated in my previous answer, the nominal way to acknowledge your messages would be to send 1 or 2 'downlink' messages per day and to answer with the number of messages received by your servers (for that, you need to push callbacks to your servers and configure downlink callbacks).
If you want to check the signal strength on module side, you need to receive the downlink message :)
Regarding the reception window on the device, if the downlink messages status is marked as '[ACKED]' in Sigfox backend, it means that the message was sent correctly AND in time by the base station (this information is accessible by hitting the small green down arrow in the device message list). On the device side, certified modules have been tested to be compliant with Sigfox protocol.
Did you try your device outside ?
Answer by firstname.lastname@example.org · Jan 05 at 04:20 PM
Sigfox type radio systems are not meant for critical real-time data.
You send the data and hope it gets there, you could repeat it a few times, doing a resend at night probably will have best result. So develope products with that in mind.