Mulitech Gateway - Lora Tx Power Output

Gateways MultiTech Gateways
1

Hi everyone,

I m a little bit confused about Lora Tx Power Output drive but the Network Server (TTN in my case)

I have a Multitech Conduit configurated like a Packet Forwarder, and sending the packets to the TheThingNetwork network server.

The Multitech IP67 Conduit has a maximum of 27 dBm of Lora output power before the antenna.
Source: MultiTech_IP67_Base Station_86002221.pdf

And I m using an antena in the Multitech Conduit so introducing a gain of 3.5 dBi

In my country, the maximum radiated power in the frequency band 915 - 928 MHz is 500 mW (corresponds to 27 dBm).

To respect the limit of 27dBm, how the Network Server Manage it?
Is-it used the part of information in the gawetay settings (Brand, Model, Antena)?

Thank you in advance for your help
Greetings

2

The network server does not manage it. You need to specify the gain of your antenna in the local configuration on your gateway. (Keep cable losses in mind, those need to be subtracted from the antenna gain)

3

Many thanks for the response Jac.

I copy Multitech’s answer to the same question

“When the MTCDTIP is configured as a packet forwarder, the transmit power of the MTCDTIP is controlled by the LoRa Network Server.
Any antenna gain settings for the device should also be configured in the LoRa Network Server. The Lora Network Server provider controls the Gateway Transmit power to stay within the channel plans standards, so your questions regarding tx power should be directed to the LoRa Network Server provider.”

Looking on the configuration in the Multitech AEP, I can only modifie the Tx Output value, in “Network Server” mode. But in packet forwarder mode, that option is not available.

A specification exists to determine which element of the network must make it possible to configure the Tx output?

Thanks.

4

Nice MultiTech states that but that does not apply for networks where the Semtech UDP packet forwarder is being used. That statement might hold when BasicStation is being used and there is a user interface to configure the gateways settings for BasicStation which is not the case for TTN at this time.

On you device there should be a file named local_conf.json where you can specify the antenna gain. Given their answer there does not seem to be a way to do this in their webinterface so you probably need to ssh to the gateway and edit the file manually.

5

Thanks a lot for your help Jac.
I hope Multitech will put available that parameter in the next firmware release.

I copy here the workarround propose by Multitech.

"Sorry, after investigating this further I found my response about configuring the antenna wasn’t accurate.

The antenna gain on the Conduit should be adjusted to match the hardware unless the network server is taking it into account for the power level to transmit at.
The gateway will then adjust the output power based on the antenna gain setting to match the intended power output.

There isn’t a menu option for the antenna gain when set as Packet Forwarder, but there are a couple ways to configure it.

API Commands:
You can set it using API commands on a Web browser.
First log into the Conduit as usual with a web browser, and then create a new tab in the same browser and enter the following API commands to set the antenna gain, afterwards enter the next command to save the change. You should see a 200 Success message if successful.
Note: Change the IP address to match the IP address of your Conduit.

https://192.168.2.1/api/loraNetwork?method=PUT&data={"packetForwarder" :{“antennaGain”:8}}

https://192.168.2.1/api/command/save?method=POST

After both API commands were entered, do a “Restart LoRa Services” in the LoRaWAN | Network Setup menu.

Manual Configuration:
Another option is to change the LoRaWAN | Network Settings Packet Forwarder options to Manual Configuration and paste a custom global_conf.json contents.
Please see the “Conduit AEP: Convert to Basic Packet Forwarder” for more details on manual mode and examples of global_conf.json file.

http://www.multitech.net/developer/software/lora/aep-lora-packet-forwarder/

You would select the entire example global_conf.json and copy into the Manual Configuration’s “Config” field, and then modify the antenna_gain, gateway_conf settings to point to the lora network server,"

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