Internet architecture doesn’t need continuous paths between endpoints, says NASA in an announcement that may one day change the way the internet is envisioned.
The U.S. government space agency says Delay or Disruption Tolerant Networking (DTN) — something it’s been working on for disruption-prone space internet applications — doesn’t need continuous network connectivity, unlike traditional internet.
Importantly, it says the delay and fault-tolerant technology could be used down on Earth, too. The networking protocol suite concept would be particularly well suited to internet in remote locations, it says in a press release, related to demonstrations of the technology.
How Disruption Tolerant Networking works
Spacecraft-friendly DTN handles data differently than current networks: DTN stores chunks of data at a node when paths get interrupted. The bundle of data simply stands by, waiting until another communication path becomes available. That’s not how it is in classic packet-style network routing where the originator holds onto the data in a buffer waiting for an acknowledgement, and then resends as necessary along the entire path. It’s also unlike to point-to-point— similar to a traditional phone call.
In DTN, the nodes take ownership of message bundles along the path, thus relieving memory loads at the data’s origination. That link in the chain (the first one) can thus proceed with handling more incoming data from sensors and so on. The space industry likes that because it’s efficient for its limited real-estate-available craft. It “saves time and more quickly frees up the limited data memory aboard a spacecraft,” NASA says.
DTN also addresses power-depleting issues that affect networks when transmitting over long distances. The moon is 238,000 miles, and Mars is 140 million miles, the group points out. It’s a highly suitable environment for DTN implemented in NASA’s planned Solar System Internet.
Earth-based applications for Disruption Tolerant Networking
DTN may have land-based applications, too, including remote Internet of Things (IoT) deployments.
“DTN could become a communication necessity for all types of terrestrial applications,” NASA says. It would be an “internet style,” but without the necessity of a continuous path between the endpoints and thus suited for scenarios and environments with frequent hiccups. In fact, only the next node, or hop, needs to be accessible.
NASA used the protocol recently in Antarctica at the National Science Foundation’s McMurdo Station where it performed a demo with a non-continuous link. And NASA’s Science Mission Directorate aims to use the disruption tolerant technique in a global climate study analyzing remote and limited connectivity marine environments, planned for the early 2020s.
DTN concepts could apply to other difficult paths, too, says David Israel, a communications architect at NASA Goddard Space Flight Center.
“DTN represents a shift in how data will get delivered in the future,” he says, referring to space.
But land-based disruptions such as radio propagation issues, a concerted attack by a party, and power supply issues, could be alleviated through DTN. Wireless disaster communications is an obvious one, too.
“Any remote location on Earth that has limited network connectivity is a candidate for DTN,” Israel says.
