Backoff timing usually follows an exponential series rather than Fibonacci, because the protocol wants to quickly spread out retry attempts while still keeping the window small enough to avoid congestion. That said, a Fibonacci-based scheme could theoretically reduce the number of collisions for very low traffic loads, but it would also make the algorithm harder to predict and implement. In practice, most routing protocols stick with the exponential or linear increase, because those are mathematically simple enough to guarantee fairness and low overhead. If you want a more detailed comparison, just let me know—I'll dig into the math and pull out the equations.