How can I connect two (or more) lopy with different frequency?

[rloro338]

I'm trying to do a sensor network with three LoPy that communicates through LORA. I want to stablish one of this LoPy as a gateway.
At the moment, i don't need upload data to the internet.

It would be possible that the gateway would recibe data from the other nodes whose lora radio has been sintonized at a different frequency at each node
for avoiding collisions? For example...

node1 ... lora = LoRa(mode = LoRa.LORA, frequency = 868100000, sf = 7)
node2 ... lora = LoRa(mode = LoRa.LORA, frequency = 868300000, sf = 7)
node3 ... lora = LoRa(mode = LoRa.LORA, frequency = 86500000, sf = 7)

I've read in the docummentation that the LoPy device only can work in a single frequency channel... in that case, how can I transmit data from two nodes
to the gateway with different frequency or spreading factor? I necessarily need a multichannel gateway (for example ic880a)?

On the other hand, i don't understand how works the socket.bind() function. After of create sockets, if I try to s1.bind(10) in device node1, s2.bind(20) in device node2 and
s1.bind(10) and s2.bind(20) in the gateway ... when I send data from s1(node1) to s1(gateway), why s2(gateway) receive too?

Sorry for my english.

Thank you people!