The existence of packet radio doesn't necessarily constitute prior art. The patents are far more likely to be on certain very narrowly defined processes that a

The existence of packet radio doesn't necessarily constitute prior art. The patents are far more likely to be on certain very narrowly defined processes that are arguably implemented in a WiFi system than on a very broad field like "digital communication over radio". If the hams didn't use the particular techniques at issue, then that wouldn't constitute prior art. You really need to read the specific claims in the patents themselves to figure out how to invalidate or avoid the patents.