Unless EMPs also wipe out consumer electronics, there will likely be only islands of connectivity. I'm thinking folks with WIFI gadgets and COTS networking gea

Unless EMPs also wipe out consumer electronics, there will likely be only islands of connectivity. I'm thinking folks with WIFI gadgets and COTS networking gear could very well build local connectivity, but those islands would be unable to talk to each other. The WIFI gadgets would have to mesh up over distances which are likely to exceed their range. Jamming and a generally dirty RF environment is likely in a war of such magnitude, so perhaps distributed laser links would work best, if one could create line of sight between the link nodes.