[lwip-users] Interfacing LwIP for a radio communication

[Marco Jakobs]

Hi,

 

I need to make an interface for LwIP to realize a communication via non-IP capable radio link.

 

We have an existing implementation for cellular systems which supports IP communication via PPP (like GPRS) which works good, we can transport IP data from customer devices (RTU's etc.) via the WAN PPP link using NAT.

 

The challenge now is that I need to use a radio link which does not support PPP as it has no centralized SwMi (let's say it's a peer-to-peer connection).

 

What I think may be the best way is to create a kind of custom "NetIF" with a "virtual" IP address which is set as the standard gateway – so from the behavior like the PPP does. I should get the IP data (header and payload) as a "raw char array" out of this NetIF and can send this via the radio link.

 

All stations which receive these data will then "restore" them in the custom NetIF (as PPP does with incoming data) and find their way back into the LwIP of the receiving devices where they'll be treated in a normal way like any incoming IP data via Ethernet or PPP.

 

Is this concept a reasonable way? If yes, is there any documentation which might help me to write such a "customer NetIF"?

If no … what would be a better option?

 

Thank you for your thoughts.

 

Marco