Channel collisions & lora orthanal

[Lawrence Griffiths]

Hi can check my understanding on Gateway reception.

1. I have two end-nodes transmitting on the same channel at the same time with different spreading factors the 1301 LoRa Net serve will process both up-link messages as they meet LoRa orthanal rules?

2. Same as 1. above, but both end-node on same spreading factor so collide. So are both uplink messages are lost?

Thanks
Lawrence

[Jason Reiss]

Lawrence,

1. Yes, two packets on the same frequency using different spreading factors can be received simultaneously.

2. When two packets collide, using same frequency/spreading factor, there may be enough signal to receive the stronger one. The weaker signal will just be noise.

[Lawrence Griffiths]

Jason, thanks just out of interest if six end-nodes transmitted at the same time on same channel all with different DR/SF e.g. DR0/1/2/3/4/5 would they all be received.

[Jason Reiss]

The SX1301 can receive up to 8 packets. The emulated demodulators can handle multiple packets on one channel at different spreading factors.

Each channel has a demodulator for each SF attached.
6 SF * 8 channels = 48 emulated demodulators.

With two Sx1255 front ends a packet can also be demodulated by the front end chip, so add 1 lora packet and one FSK.

http://www.semtech.com/wireless-rf/rf-transceivers/sx1301/

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