Military leaders have asserted that future wars will likely be fought in mega cities, cities with more than 10 million people.

“It’s highly probable that the military forces armed conflict will occur in highly dense urban complex terrain, physical terrain,” Army Chief of Staff Gen. Mark Milley, said in May, adding that today there are 10 to 15 of these cities, while in 2050 there might be over 50.

Noting that his service is not optimized to fight in these environments — a realization shared across the branches — he explained the Army must change. Urban environments pose several unique war-fighting challenges to the military, one in particular is communication.

For one, the variety of sensors and communications equipment needed to navigate the large, concrete buildings that comprise cities eat up bandwidth. While the military — and even commercial industry — are looking at employing swarm technology with small unmanned aerial systems, interference and propagation issues can cause major command and control problems, Lt. Col. Jeffrey Kawada, who works electronic warfare, offensive cyber and information operations with headquarters Marine Corps, said during a panel at the annual MilCom conference in Baltimore on Oct. 23.

Some of the solutions commercial industry is working on can enable drone delivery in these congested and complex environments. They are attractive to the military and can potentially be adapted for denied environments against competitors such as the Russians, Chinese or North Koreans that seek to disrupt C2 links.

Given these complex environments in which competitors can more easily find and deliver effects against friendly forces, the military is looking at smaller, more distributed ground units.

These expeditionary forces need to stay connected with one another in degraded environments where their ability to communicate will be disrupted by those environments, such as heavy tree cover, as well as electronic jamming by the enemy, said Thomas Burns, director of the Strategic Technology Office at Defense Advanced Research Projects Agency.

They’re not going to expect reach back to an operations center or the United States, but they are going to expect to be able to talk with one another to fire weapons into different regions, Burns said. He noted that one of the things that stops them today is lack of good scalable mesh networks. If industry can come up with solutions to that, that will be embraced by DoD, he said.

During recent experiments in New York City, propagation was an issue, David Cooper, CNS technical director at BAE Systems, said during the panel discussion. While they were able to get data out of the building to local fire commanders, getting data to the bigger network for situational awareness is really what the military wants. DoD needs some kind of mesh network that can work in mega cities and that technology does not exist, he said.

Burns explained that during DARPA’s experiments in New York City with special forces, one of the key takeaways was the need to have to fight on the “Z” axis in conjunction with the “X” and “Y” axis, which is to say fighting in skyscrapers and subterranean facilities.

“After walking around New York City for three days, I got the impression that that’s just untenable. It’s just crazy to ask our soldiers and for other countries to ask their soldiers to have to fight in those environments unless there is literally no other means,” he said.

One way to deal with that, he said, is to instrument these cities by distributing internet of things devices to gather every type of signal that might be relevant and analyzing them against known parameters.