TDoA algorithm Implementation


#21

Have you found a good source for nanosecond-accurate gateways? Kerlink offers more than one gateway nowadays and I was searching for an appropriate hardware solution.


#22

I believe the iBTS (Compact) gateway from Kerlink does provide the fine timestamp :slight_smile: I hope to have one myself soon for testing and better integration (as this gateway also supports multiple antennas and modules).


#23

Hi,

Actually, i was unable to find gateways that are designed for TDoA algorithm. And the one i purchased (Multitech LoRa conduit) are rather poor for Geolocation. Therefore, my results are not encouraging. The clocks are highly unreliable in terms of precision. I am using clocks with micro second resolution and the achieved accuracy in terms of distance is above 500 meters (for ideal cases). As a result, i would try to integrate RSSI alongwith TDoA and see if it improves the performance. Because as of now, the system is highly unreliable and unstable.
If you are going for Kerlink gateways, they have their own TDoA solver as well but i guess you need to pay more.
Please read the following article “TDoA-Based Outdoor Positioning with Tracking Algorithm in a Public LoRa Network” where the authors have used the Kerlink gateways and their TDoA solver. The results in the paper are encouraging as the authors have made improvements in the algorithm itself. But the basic TDoA solver was provided by Kerlink


#24

You can also look here for more information about Kerlink gateways and their TDoA solver.

Best Regards,

Usman


#25

Hello everyone,

No progress on the Gateway + Fine timings but I am doing research on implementing gps modules on Gateways so I can take advantage of their fine timing because the Kerlink Gateway are way too expensive. I still couldn’t confirm any gps that provide this timing. Plus you will need a way to keep this timing with an external clock afterwards.


#26

Dear LoRaServer friends,

I am following your steps. I am also willing to deploy a geolocation solution based on lora Geolocation capability. I am still trying to find a gateway vendor. So far, Kerlink is offering a big package with hardware + software (bloatware?). MAXIIoT said that their hardware support Geolocation, but theyr never have heard nothing about a fee nor have tested Geolocation by thyself.
Do you know if that fee for fine timings is based on messages, devices, monthly, or what?

With best regards

Sebastian


#27

In the next LoRa Server release support will be added to integrate with an external geolocation server. An open-source geolocation server which integrates with the Semtech Collos platform will also be released :slight_smile:

Support for this has already been merged into the LoRa Server master branch. LoRa Server will also support the decryption of the fine-timestamp (given a decryption-key has been configured).


#28

The ‘external geolocation server’ you mentioned already exists? if so what is it.

Also,
I sadly cannot find any fully compatible Gateway for the United states(915Mhz) with network-based LoRa native geolocation…

if anyone has a suggestion of a LoRa gateway with fine-timestamp support and a license the key to decrypt and encrypted the payload…it would be greatly appreciated for the US.

As someone above suggested Kerlink…
The BTS (Compact) gateway from Kerlink seems to be only offered for EU, and not for the United States yet.

Thanks.


#29

The ‘external geolocation server’ you mentioned already exists? if so what is it.

Please see https://github.com/brocaar/lora-geo-server. This will be announced in the next release and also added to the docs :slight_smile: You’ll find a preview here: https://www.loraserver.io/lora-geo-server/overview/.

I sadly cannot find any fully compatible Gateway for the United states(915Mhz) with network-based LoRa native geolocation…

I think that Kerlink does have an US915 model of their iBTS gateway, but please contact them for more information. Other vendors that sell gateways with geolocation capability (there might be more) are: Tektelic and Cisco.