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Opinions on LoRa (wireless - long range, low power, sub 1GHz)


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It is a good product.  Semtech has a long history of producing excellent low-power RF transceivers.  Companies like Semtech do not usually just embark on wild projects like LoRa without someone contracting them to do so, and I don't have confirmation on this, but I am pretty sure that SigFox is who contracted Semtech to design LoRa and the associated transceivers.  So, there is an installed base that you can refer-to, which shows at least that the technology works quite well.

 

The main downside of LoRa is that there is not a ton of information about it, so it is going to be difficult to achieve multi-vendor interoperability if you are using the LoRa modulation.   I'm not even sure what it is, but based on the limited descriptions I would guess it is some sort of M-FSK -- in fact, I think it is 64-FSK.

 

The second downside of LoRa is that narrowbanding often works better than DSSS does in the lower bands like 169, 433, etc.  For 862, 866, and certainly US-915, DSSS is either a wise choice or a fundamental requirement, so for these upper bands LoRa makes a lot of sense.

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@@jpnorair thanks

 

I came across LoRa on the AngelBlock KickStarter project http://www.kickstarter.com/projects/1630453569/angelblocks-smart-wireless-building-blocks-for-sma They have some info on why they chose LoRa here http://www.angelblocks.com/index.php/technical-articles/41-angelblocks-radio-technology

AngelBlocks are for home automation and claims they don't need to go to the complexity of mesh networks like Zigbee and Zwave due to the excellent range and low power usage of the LoRa.

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In review, it looks like LoRa uses a proprietary sort of CSS modulation (chirp spread spectrum), although it could be implemented as a sort of MFSK as well -- difficult to say.

 

The basic premise is sound: with good coverage, you don't need mesh routing.  Mesh routing is mostly academic, very few production systems use it.

 

At 1kbps, which is roughly the data rate he is using, a sensitive FSK device such as CC1200 or ST SPIRIT1 can actually achieve superior range to LoRa if a good error coding scheme is used.  With sophisticated error correction -- maybe not possible on MSP430 but certainly no problem for ARM CM3 -- I have observed 1 mile range in open outdoor conditions with 433 MHz, regular FSK set to a higher data rate, and using even less transmit power (for example, 1mW vs 100mW of AngelBlocks).  For AngelBlocks, the advantage of the LoRa implementation is that the US 915 MHz band is an interference nightmare.  Without sophisticated frequency hopping or a good spread-spectrum technique, the message just isn't going to get through.

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Interesting comment on Kickstarter

 

"LoRa will include time of flight ranging so we can triangulate accurate positions within a foot anywhere on your property. People are trying to do that with BLE today using RSSI but that won't work. Right now LoRa is obscure, but guys like Cisco are building it into their cell tower equipment as I write this. Its under the radar for now, but in another year we are going to look like geniuses for settling on LoRa. Think about our AngelTags being able to be located anywhere in the city with better accuracy than GPS via cell towers. That is the future. In fact, I would say we are not even 18 months away from that."

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Time-based location is tricky.  If the location is done by a transmitting tag and a listening infrastructure, which is the low-power way, it is actually called Time-difference of Arrival (TDOA).  With only 500kHz bandwidth and a short transmission, the TDOA performance will be OK but not exceptional.

 

I am also skeptical that in 18 months LoRa will be widespread.  I would be happy if it were, but telecom doesn't tend to work that way -- nothing is ever "under the radar" in telecom.  SigFox has some limited infrastructure in France, but I don't know if it actually is LoRa.

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  • 5 months later...

Hello,
I am passionate about M2M technologies and I have several questions about it; in the hope that someone can answer :-)

1) Who are the customers / users of the Semtech Lora Technology in USA and Europe ?
2) Do you know any other chipset vendor that microchip ?
3) Do you know where I can get the LoRa roadmap and especially the future functionality on the indoor triangulation ?

Thanks !

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Hello,

I am passionate about M2M technologies and I have several questions about it; in the hope that someone can answer :-)

 

1) Who are the customers / users of the Semtech Lora Technology in USA and Europe ?

2) Do you know any other chipset vendor that microchip ?

3) Do you know where I can get the LoRa roadmap and especially the future functionality on the indoor triangulation ?

Thanks !

 

Question 1 is something that you can figure-out just by reading marketing brochures on Semtech's website.

 

Question 2: the answer is NO.  However, I believe it is possible to license the LoRa technology from CSEM, if you want to build your own chip with LoRa.

 

Question 3: only Semtech or CSEM can give you this.

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