Ongoing innovations in open firmware like OpenWRT allow deployment of reasonably robust routing schemes, such that the mesh nodes themselves compute the routes most efficient for transport (and also repair those routes when nodes go down). Groups like Commotion Wireless, Freifunk, Funkfeuer, and LirbeMesh all deploy firmwares derived from OpenWRT to this purpose. The actual capacity, range, and sensitivity of the radio hardware used, whether unlicensed or not, will still be gating factors. Along with ambient noise levels on whatever bands are used.