[PROJECT] IP network over RF long range

Products & Technology Arduino & Seeeduino
#1

Hello, it’s my first time on this forum so let me introduce myself : I’m a French student and I’m studing IT’s network and Telecommunications.
I will probably work on a future project for making a long range (approx. 2 km with several repeaters) radio link between 2 IP/Ethernet network at differents places around my Town for have an Internet connection, I will probably use the local relief for have a better chance to catch radio signals and with directionnal antennas. I can’t use a DSL or other internet subscription, it’s probably the only way to have remote internet connection and I don’t want to use telephone network.

Technically, I have started looking for it and I think (I’m not already sure, that’s why you’re skills would be very appreciated :slight_smile:) I will use severals arduino boards like the Uno or the Mega 2560 to make point to point connections with two end devices and maybe 1 or 2 repeaters.
So an end device need an Ethernet Shield with RJ45 cable connected to an Ethernet Switch and then it will have to transmit ethernet frame over RF Link for a distance up to [200m - 2km] interval (it depends of the position of the arduino between differents ones).
Now a reapeater needs to be energy efficient (maybe with power cells or other source of energy) and his role will be to transmit data in full duplex mode point to point between two devices.

That’s all for it, so I have spotted some articles around here and I have question about these one :

seeedstudio.com/depot/2KM-L … p-321.html

I’d like to use it for RF transmission because it’s cheap and it like to correspond for my attempt but i’m not sure, so I have a couple of questions for you’re experts :

  • Due to the low Frequency for RF data transmission (433 MHz) what does the bandwith could be ?
  • How can I convert Ethernet 100 Base T signals ino the wished form of data of the encoder and how to decode it into 100 Base T Ethernet again ? Maybe Arduino can make conversion ? Which speed (baudrate or clock signal) it has to be and does can it seriously alter Ethernet signal and making buffer full ?

Thanks for you’re help,
Best Regards,
Valentin BR.

#2

Folks,
It should be clear to everyone buying the 433 MHz long range RF pair, that it was originally designed for a four-button priority switching remote controller. So for example, you can energize any combination of the four transmitter data pins and ONLY THE FIRST one pressed will go HIGH. All others will stay LOW. On the receiver side, the packet is shifted in to registry to match the four pins of the TX and will latch the packet in until the receiver detects all four bits of the incoming RF stream to be LOW. Only then will VT go HIGH and allow the new packet to shift in. Someone with more experience could correct me on the specifics.

So at any point, each packet will only contain ONE HIGH bit and the rest will be low. It should also be clear that this would not mesh well with virtual wire or any serial data scheme. You might warn your friends before they buy a set. Having said that, it has obvious value for the right application.