Thanks for the question @ASSTRIEN. Just to be clear, the TxTenna app is not related directly to any effort to incentive relay nodes. The TxTenna project was only conceived as a way to decentralize the broadcast of bitcoin transactions and to create an alternative path for getting them onto the bitcoin blockchain. TxTenna is just another example of decentralizing communication using a mesh network, in this case messages about value instead of free-form text communication.
That said, doing on-chain payments in bitcoin to incentivize relays is a useful benchmark to compare more elaborate schemes against. It has the advantage of being a straight forward method that doesn’t involve any new cryptography or 2nd layer concepts.
One reason using on-chain transactions, bitcoin or otherwise, for incentives is problematic is that on-chain transaction are large relative to the typical messages we send over the mesh. That means you can’t have a 1 to 1 relationship between the messages we send and incentive payments for those messages if the payments themselves are as large as (or larger) than the original message. Instead, as you said, you’d need to have some sort of ‘points’ that are settled at the end of the month with a single on-chain transaction.
This moves the problem to how to fairly attribute “points” to relays in a decentralized way. Once you had a way to fairly attribute points, you could account for them fairly easily in a centralized way. Just imagine something like how airlines track the miles you fly and have a central database for frequent flyer points. Those systems use a database and don’t need any crypto-currency. But centralized accounting would introduce a central point of failure and control that in my opinion violates the spirit and potential of mesh networking.
So the hard work that needs to be done is to come up with a light-weight and trust-minimized way to track when people use or provide relay capacity to the mesh network, and a decentralized way to settle and track this information. Doing it on a decentralized public ledger means that no company controls balance information and instead it is effectively controlled by the people who use the mesh network.
I’ve got some good ideas for how to do the first part (track usage) in a low-overhead way, but tracking balances in a decentralized way is a non-trivial problem.
Please share any ideas you have about tying off-grid relay accounting to on-grid blockchains.