I know that in for FCC compliance a small bandwidth transmitter must use frequency hopping ( 25 or 50 channels). Or use Digital modulation ( wide bandwidth). How does LoRa comply with FCC? Does it frequency hop in the US or does the LoRa chirp modulation give enough wide bandwidth so that frequency hopping isn't necessary? Thanks for great channel!
Congratulation! Your videos are very useful and easy to understand. However, please review the definition of ToA. As long as I know, it is the time the message takes to be fully transmitted and depends on the amount of data and bitrate. Anyway, this does not affect your calculations which are all correct.
The definition of ToA as mentioned in the video was wrong! Several viewers have commented about this. The correct definition is: The Time on Air (ToA) is the amount of time that the transmitter antenna is energised and transmitting data. Note: ToA is not the time from Tx to Rx. See: www.mobilefish.com/download/lora/lora_part3.pdf
Great Video - thank you for sharing! - One question - regarding transmission power - you say that downlink can be up to 27 dBm - can you point to where in the ETSI regulations this is stated. Would be very interested in getting this info. thank you.
Hi, I have a question: In 9:32, for example, you say that we have to wait the calculated time to send the SAME signal again. What if we want to send a completely different signal? The same applies to that case? Thank you for your videos!
Hello where can I purchase the most cost effective lora end nodes (i.e sensor + lora) , gateways, network server and application servers from ? Your videos are very informative .. thankyou ..
@mobilefish. Good video. have you got a good video or recommend a good resource explaining capacity of Lora at scale . E.g. 200 to 1000 nodes under 1 gateway with 1 TX and 8 rx. How do I work out how many messages or capacity of the gateways? Tks
your videos are very interesting, for FCC what are the restrictions and the maximum antenna gain? this only applies to the node, or also to the Gateway? Thanks
I think it is 6 dBi (Applies to Gateway and node) www.semtech.com/uploads/documents/an1200.26.pdf www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf I am not 100% sure, please verify this: Goto www.thethingsnetwork.org/forum and check this your self.
Hello. Thanks for you video(s). Very usefull.... I have a question regarding the duty cycle (1% to 0,1%).... So it means in your example (400ms 0,1%) that the node can send data every 400 seconds? Every 6 minutes? => the message has to be super short, because if an information needs 4-5 messages it will take too long time for the receiver.... Am I correct?
Pascal, If 1% duty cycle is applied, a node is allowed to transmit only for 36 seconds per hour and stay inactive for the rest of the 1 hour period. Note 1 hour = 3600 sec If 0.1% duty cycle is applied, a node is allowed to transmit only for 3.6 seconds per hour and stay inactive for the rest of the 1 hour period.
Thank you for the efforts . At the video, you say ToA its the time between the transmitter and the receiver but in the PDF presentation you mention that Time on Air (ToA) is the amount of time that the transmitter antenna is energised and transmitting data. Note: ToA is not the time from Tx to Rx. so its the time between the transmitter and receiver or what thanks
Haidar, thanks. Several months ago "Sest Se" has already mentioned this to me. Time on Air (ToA) is the amount of time that the transmitter antenna is energised and transmitting data. Note: ToA is not the time from Tx to Rx. I have updated this in my presentation, see: www.mobilefish.com/download/lora/lora_part3.pdf
Thanks for the presentation. Well crafted one. I live in Oman. I see that there aren't any frequency allocated here. It says EN 302 208. It just mentions some radio standards. Does that mean that allocation is still yet to be done??
I have a question, "At 7:09 minute of your video, you said that maximum allowed antenna gain is +2.15 dBi, is this rule valid both uplink or downlink?"
Muhammed, well that's embarrassing, i have been searching the Internet where I have taken this number from. To my surprise I could not find it anywhere. In fact the antenna gain is not mentioned in the "rules" anywhere. But it makes sense that the antenna gain is not mentioned in the "rules" because it is already part of the ERP/EIRP. In the "rules" only the maximum ERP/EIRP (transmission power) and duty cycles are specified. Again thanks, and I will update my presentation. www.mobilefish.com/download/lora/lora_part3.pdf
I think EIRP values are important, I have watched all of your presentations in the next parts of the videos, it is said EIRP values are restricted by regulations. There is an info at 17. page at this document, lora-alliance.org/sites/default/files/2018-04/lorawantm_regional_parameters_v1.1rb_-_final.pdf It is written about a table for power levels, so important thing is max. EIRP, so you said this is restricted by ETSI for G, G1, G2, G3, G4 bands. So I can understand that if it is limited to 25 mW (14dB) by ETSI, so transmitter plus antenna gain and cable losses total should be 14 dB. For example, If my application is battery powered and I need 14 dB to send info to end node, and if I am using G1 band (limit is 25mw(14dB)), I can use 9 dB transmitter and 6 dB antenna and -1dB cable loss, sum of all result is 14 dB, and this is valid for ETSI and LORA. Also, If my application is grid powered and I need 14 dB to send info to end node, and if I am using G1 band, (limit is 14 dB) I can use 14 dB transmitter and 1 dB antenna and -1dB cable loss, sum of all result is 14 dB, and also this is valid for ETSI and LORA. So if you are using high gain antenna, this is a stable cost that you are spending one time, but I am saving money while communication in years, but if I have power on the site, I don’t need an expensive high gain antenna, but I am spending money in years for getting power from the grid. Another example is if I am using G3 band (limit is 500 mW(27 dB)), I can use 20 dB transmitter and 8 dB antenna and -1dB cable loss, sum of all result is 27 dB, and also this is valid for ETSI and LORA. I think ETSI restricted G, G1, G2, G4 bands are commercial purposes, and G3 band is needed for long range communication and maybe urgent things like flood control, fire alarm etc. Thank you for your effort, all of your videos are amazing.
what happens where there are millions of devices in the relatively small area like same town or something like that? will it become unusable? Or maybe even a couple of hundred in the same street
I am NOT an FCC expert, but I have found this statement: "Under FCC there are no duty cycle limitations but there is a 400msec max dwell time per channel. " See page 13 lora-alliance.org/sites/default/files/2018-04/what-is-lorawan.pdf
Hi Thank you for the nice tutorial. I have some doubts with the regional frequency specifications(India), How do i specify frequency, bandwidth and spread factor if i am using lora only(not lorawan). Is there any specifications available for that??
Sorry, my tutorials focusses only on LoRaWAN. LoRa can be used for peer to peer communication. Search Google for "LoRa P2P communication" and you will find several libraries and information about the subject.
Is it possible to send a packet to a node through multiple gateways to reach extra long distances (like 40miles between the 1st gateway and the end device)?
Hello, Thank you for very much for the whole series of tutorials. Unfortunately, you have got one error - like in many papers and tutorials - the frequency of 868MHz is not in the ISM Band (source: www.ecodocdb.dk/download/2ca5fcbd-4090/ERCREP025.pdf - I think that error occurs because most of the sources are American where LoRa is in the Region 2 - ISM Band) and what is important in some countries in Europe the duty cycle is calculated as a percentage in 1 hour - so for example, 1% means that you may use ALL channels at maximum 36 s for the transmission in 1 hour period. But on the other hand, there is 'Polite spectrum access' and with it, the "restrictions are loosened" (source: www.researchgate.net/publication/335582952 ). Cheers.
Piotr, Thanks for your comment. I probably have make more than one mistake. I have investigated your remark. In the ERCREP025.pdf it refers to standard: ETSI EN302208 www.etsi.org/deliver/etsi_en/302200_302299/302208/03.02.00_20/en_302208v030200a.pdf In this standard: Radio Frequency Identification Equipment operating in the band 865 to 868 MHz with power levels up to 2 W and in the band 915 MHz to 921 MHz with power levels up to 4 W. But in LoRa they are using lower power levels. It uses standard: ETSI EN3002202 www.etsi.org/deliver/etsi_en/300200_300299/30022002/03.02.01_60/en_30022002v030201p.pdf Here is my proof, see: line number 308 lora-alliance.org/sites/default/files/2018-04/lorawantm_regional_parameters_v1.1rb_-_final.pdf
Great information on these videos, but there's a minor error - It doesn't take 530ms to travel from one antenna to the other - it takes 530ms of transmission time to send the message. The time to travel through the air is negligible
At 7:45 or so you say that TOA is the time for the receiver to receive the signal from the transmitter... THIS IS DEAD WRONG!! The TOA is the amount of time that the transmitter is sending out signal from his/her antenna. IT has nothing to do with the receiver. If transit (not transmit) time were important the transmitter would have not have to wait at all. Why, you ask. Because at the speed of light a signal would travel around the world over 4 times in 530ms. Essentially the first bit of date would be at the RX antenna well before the Transmitter would send the second. Also the TOA as you define it would be different for each and every receiver. How would the transmitter know how long to wait and which RX antenna would he use for the calculation?? So to properly state it TOA is the amount of time that the transmitter antenna is energized and transmitting data.
Hi guys. I see you pretty much experts here. And I need help. I have a base station for LoRa on my roof. How harmful it is? Please don't laugh, I'm not savage, but I know that EMF (electromagnetic field) can be harmful and it depends from transmitter power of base station. I measured this base station, with cheap EMF mesure device and it looks legit with up to 1 microWatt/sm2. But sometimes on the way on signal (as I understand) it can be up to 8 microWatt/sm2 and even more which is danger. But I'm not sure that it was from LoRa base station maybe it was something else, roof actually has lot of stuff. So I doubt about this device, which is some company installed on roof of my building. Can you help me and describe, is LoRa base station can be possible harmful if installed on your roof and what you'll do if such device, will sudenly appear on your roof? Thanks.
And again... I'm really glad for having found your videos.
They are really good !!!
Thanks for the good job
Duty cycle was not clear to me.
Apart from 433MHz, believe 923MHz is also widely used in the Asia region (or at least in Singapore).
Thank you. You are doing great job
I know that in for FCC compliance a small bandwidth transmitter must use frequency hopping ( 25 or 50 channels). Or use Digital modulation ( wide bandwidth). How does LoRa comply with FCC? Does it frequency hop in the US or does the LoRa chirp modulation give enough wide bandwidth so that frequency hopping isn't necessary? Thanks for great channel!
Congratulation! Your videos are very useful and easy to understand. However, please review the definition of ToA. As long as I know, it is the time the message takes to be fully transmitted and depends on the amount of data and bitrate. Anyway, this does not affect your calculations which are all correct.
The definition of ToA as mentioned in the video was wrong! Several viewers have commented about this. The correct definition is: The Time on Air (ToA) is the amount of time that the transmitter antenna is energised and transmitting data.
Note: ToA is not the time from Tx to Rx.
See: www.mobilefish.com/download/lora/lora_part3.pdf
Great Video - thank you for sharing! - One question - regarding transmission power - you say that downlink can be up to 27 dBm - can you point to where in the ETSI regulations this is stated. Would be very interested in getting this info. thank you.
Hi, I have a question: In 9:32, for example, you say that we have to wait the calculated time to send the SAME signal again. What if we want to send a completely different signal? The same applies to that case? Thank you for your videos!
Hello where can I purchase the most cost effective lora end nodes (i.e sensor + lora) , gateways, network server and application servers from ? Your videos are very informative .. thankyou ..
@mobilefish. Good video. have you got a good video or recommend a good resource explaining capacity of Lora at scale . E.g. 200 to 1000 nodes under 1 gateway with 1 TX and 8 rx. How do I work out how many messages or capacity of the gateways? Tks
your videos are very interesting, for FCC what are the restrictions and the maximum antenna gain? this only applies to the node, or also to the Gateway? Thanks
I think it is 6 dBi (Applies to Gateway and node)
www.semtech.com/uploads/documents/an1200.26.pdf
www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf
I am not 100% sure, please verify this:
Goto www.thethingsnetwork.org/forum and check this your self.
what are the two different channels?the 0.1 and the 1?how can i distinguish them?
Hello. Thanks for you video(s). Very usefull.... I have a question regarding the duty cycle (1% to 0,1%).... So it means in your example (400ms 0,1%) that the node can send data every 400 seconds? Every 6 minutes? => the message has to be super short, because if an information needs 4-5 messages it will take too long time for the receiver.... Am I correct?
Pascal,
If 1% duty cycle is applied, a node is allowed to transmit only for 36 seconds per hour and stay inactive for the rest of the 1 hour period.
Note 1 hour = 3600 sec
If 0.1% duty cycle is applied, a node is allowed to transmit only for 3.6 seconds per hour and stay inactive for the rest of the 1 hour period.
Thank you for the efforts . At the video, you say ToA its the time between the transmitter and the receiver but in the PDF presentation you mention that Time on Air (ToA) is the amount of time that the transmitter antenna is energised and
transmitting data.
Note: ToA is not the time from Tx to Rx. so its the time between the transmitter and receiver or what thanks
Haidar, thanks. Several months ago "Sest Se" has already mentioned this to me. Time on Air (ToA) is the amount of time that the transmitter antenna is energised and transmitting data. Note: ToA is not the time from Tx to Rx. I have updated this in my presentation, see: www.mobilefish.com/download/lora/lora_part3.pdf
@@Mobilefish Thank you dear again
Thanks for the presentation. Well crafted one. I live in Oman. I see that there aren't any frequency allocated here. It says EN 302 208. It just mentions some radio standards. Does that mean that allocation is still yet to be done??
Hi,How r u..can I have your mail
I am also in Oman and I am interested in LoRa and I would like to ask u something if possible
Oman is PROBABLY using the standard sets by ETSI. But you should check your country’s regulations.
I have a question, "At 7:09 minute of your video, you said that maximum allowed antenna gain is +2.15 dBi, is this rule valid both uplink or downlink?"
Muhammed, well that's embarrassing, i have been searching the Internet where I have taken this number from. To my surprise I could not find it anywhere.
In fact the antenna gain is not mentioned in the "rules" anywhere.
But it makes sense that the antenna gain is not mentioned in the "rules" because it is already part of the ERP/EIRP.
In the "rules" only the maximum ERP/EIRP (transmission power) and duty cycles are specified.
Again thanks, and I will update my presentation.
www.mobilefish.com/download/lora/lora_part3.pdf
I think EIRP values are important, I have watched all of your presentations in the next parts of the videos, it is said EIRP values are restricted by regulations.
There is an info at 17. page at this document, lora-alliance.org/sites/default/files/2018-04/lorawantm_regional_parameters_v1.1rb_-_final.pdf
It is written about a table for power levels, so important thing is max. EIRP, so you said this is restricted by ETSI for G, G1, G2, G3, G4 bands.
So I can understand that if it is limited to 25 mW (14dB) by ETSI, so transmitter plus antenna gain and cable losses total should be 14 dB.
For example, If my application is battery powered and I need 14 dB to send info to end node, and if I am using G1 band (limit is 25mw(14dB)), I can use 9 dB transmitter and 6 dB antenna and -1dB cable loss, sum of all result is 14 dB, and this is valid for ETSI and LORA.
Also, If my application is grid powered and I need 14 dB to send info to end node, and if I am using G1 band, (limit is 14 dB) I can use 14 dB transmitter and 1 dB antenna and -1dB cable loss, sum of all result is 14 dB, and also this is valid for ETSI and LORA.
So if you are using high gain antenna, this is a stable cost that you are spending one time, but I am saving money while communication in years, but if I have power on the site, I don’t need an expensive high gain antenna, but I am spending money in years for getting power from the grid.
Another example is if I am using G3 band (limit is 500 mW(27 dB)), I can use 20 dB transmitter and 8 dB antenna and -1dB cable loss, sum of all result is 27 dB, and also this is valid for ETSI and LORA.
I think ETSI restricted G, G1, G2, G4 bands are commercial purposes, and G3 band is needed for long range communication and maybe urgent things like flood control, fire alarm etc.
Thank you for your effort, all of your videos are amazing.
what happens where there are millions of devices in the relatively small area like same town or something like that? will it become unusable? Or maybe even a couple of hundred in the same street
Thank you for this interesting video, please what is the regulation for the duty cycle in Canada and USA, thanks
I am NOT an FCC expert, but I have found this statement:
"Under FCC there are no duty
cycle limitations but there is a 400msec max dwell time per channel. "
See page 13
lora-alliance.org/sites/default/files/2018-04/what-is-lorawan.pdf
sir, how to configure Lora ra 01 module for Multipal transimitter & one receiver
Thank you. You are doing great job )
Hi Thank you for the nice tutorial. I have some doubts with the regional frequency specifications(India), How do i specify frequency, bandwidth and spread factor if i am using lora only(not lorawan). Is there any specifications available for that??
Sorry, my tutorials focusses only on LoRaWAN. LoRa can be used for peer to peer communication. Search Google for "LoRa P2P communication" and you will find several libraries and information about the subject.
how did you do it can you share with me , thank you
Is it possible to send a packet to a node through multiple gateways to reach extra long distances (like 40miles between the 1st gateway and the end device)?
No, LoRaWAN is sending messages from an end device to one or more gateways.
Gateways do not send the messages to other gateways.
So LoraWan can't be used in tracking seismic activities or any real-time data acquisition. I'm gonna switch to Bluetooth 5.0.
LoraWan is required for Long Range Transmission Data
If ToA = 530ms and duty cycle = 1% so, time to wait = 530*99% = 0,53s !! Am I wrong ? Your result seems surprisingly high !
You are not looking at it the right way. Try simple cross multiplication:
0,01 .... 0,53s
0,99 .... Toff
Toff = (0,99 * 0,53) / 0,01 = 52,47s
I thought the maximum uplink was 20 dBm
Hello,
Thank you for very much for the whole series of tutorials.
Unfortunately, you have got one error - like in many papers and tutorials - the frequency of 868MHz is not in the ISM Band (source: www.ecodocdb.dk/download/2ca5fcbd-4090/ERCREP025.pdf - I think that error occurs because most of the sources are American where LoRa is in the Region 2 - ISM Band) and what is important in some countries in Europe the duty cycle is calculated as a percentage in 1 hour - so for example, 1% means that you may use ALL channels at maximum 36 s for the transmission in 1 hour period.
But on the other hand, there is 'Polite spectrum access' and with it, the "restrictions are loosened" (source: www.researchgate.net/publication/335582952 ).
Cheers.
Piotr,
Thanks for your comment.
I probably have make more than one mistake.
I have investigated your remark.
In the ERCREP025.pdf it refers to standard: ETSI EN302208
www.etsi.org/deliver/etsi_en/302200_302299/302208/03.02.00_20/en_302208v030200a.pdf
In this standard:
Radio Frequency Identification Equipment operating in the band 865 to 868 MHz
with power levels up to 2 W and in the band 915 MHz to 921 MHz with power levels
up to 4 W.
But in LoRa they are using lower power levels.
It uses standard: ETSI EN3002202
www.etsi.org/deliver/etsi_en/300200_300299/30022002/03.02.01_60/en_30022002v030201p.pdf
Here is my proof, see: line number 308
lora-alliance.org/sites/default/files/2018-04/lorawantm_regional_parameters_v1.1rb_-_final.pdf
Can I ask you about TOA ? I confuse about this .Can you tell me how 530ms come from ? Thank you.
The Time On Air is explained in detail in LoRa/LoRaWAN tutorial 17
I also confused about 530 ms TOA. 530ms it's about 160 000 km, the half distance to the moon. Seems this distance a little bit optimistic for the LoRa
Great information on these videos, but there's a minor error - It doesn't take 530ms to travel from one antenna to the other - it takes 530ms of transmission time to send the message. The time to travel through the air is negligible
@@flatfoot Thank you, I have updated my presentation.
Time in Air is not the time from TX to Rx
Thanks, I have updated my presentation.
At 7:45 or so you say that TOA is the time for the receiver to receive the signal from the transmitter... THIS IS DEAD WRONG!!
The TOA is the amount of time that the transmitter is sending out signal from his/her antenna. IT has nothing to do with the receiver. If transit (not transmit) time were important the transmitter would have not have to wait at all. Why, you ask. Because at the speed of light a signal would travel around the world over 4 times in 530ms. Essentially the first bit of date would be at the RX antenna well before the Transmitter would send the second. Also the TOA as you define it would be different for each and every receiver. How would the transmitter know how long to wait and which RX antenna would he use for the calculation??
So to properly state it TOA is the amount of time that the transmitter antenna is energized and transmitting data.
Thanks, I have updated my presentation.
Hi guys. I see you pretty much experts here. And I need help. I have a base station for LoRa on my roof. How harmful it is? Please don't laugh, I'm not savage, but I know that EMF (electromagnetic field) can be harmful and it depends from transmitter power of base station. I measured this base station, with cheap EMF mesure device and it looks legit with up to 1 microWatt/sm2. But sometimes on the way on signal (as I understand) it can be up to 8 microWatt/sm2 and even more which is danger. But I'm not sure that it was from LoRa base station maybe it was something else, roof actually has lot of stuff. So I doubt about this device, which is some company installed on roof of my building. Can you help me and describe, is LoRa base station can be possible harmful if installed on your roof and what you'll do if such device, will sudenly appear on your roof? Thanks.