Telecom Design LAN capability is a 9600bps rf 868 transmission you can use with the sigfox modem to communicate between multiple TD120x devices. One of the main use is to have multiple sensors communicating to a sigfox gateway. The communication get benefit of the nice ultra narrow band RF transceiver included in the chip.

TD LAN is based on GFSK modulation on 25kHz channels working at 9600bps.

I did really remember where but I read it could reach long distance in the best conditions, so as it could open many opportunities, I wanted to test it in real conditions to see what we could get from it.

The test was based on a base-stations made with a RaspberryPi and a TD1204 with a 1/2 wave antenna from connit (one of the best for this frequency range). It simply ACK the frame and record the RSSI and data.The base station was located on the top of my home roof.

A mobile is based on a 1204 getting GPS coordinate and transmitting a frame every 3 seconds with maximum power. I tried different antennas, but the tree of them were small one to be able to be use in a mobile object.

The result was not what I was expected, I got good result up to 80-100 meters and many sometime I got a response up to 100-200 meters with multiple frame loss before getting a good one.

Here is a average map of the results :

coverage of a LAN mode with telecom design

I was expecting this mode to be able to be use to connect devices in fields or such environment but this seems to be really limited. It sound good of a indoor use in a home ; it may be optimized to be used outdoor but I don’t think we can use it for really large distances over than 300 meters in real conditions.