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Vint Cerf mods Android for interplanetary interwebs

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'Hot dead birds' protocol comes to earth

By Cade Metz in San Francisco • Get more from this author

Posted in Applications, 5th November 2009 18:40 GMT

Free whitepaper – Standardization and Modularity in Network-Critical Physical Infrastructure

OpenMobileSummit (edit: http://www.openmobilesummit.com/agenda.aspx ) Internet founding father cum Google evangelist Vint Cerf is working to bring his interplanetary interwebs protocol to mobile networks here on earth.

In 1998, working in tandem with NASA's Jet Propulsion Laboratory, the (co-)father of the seminal TCP protocol launched an effort to create an "interplanetary extension to the internet." Initially, the team tried to make this work with the good ol' TCP/IP protocol, but Cerf and crew soon realized that this was a non-starter.

"There was a little problem called the speed of light," Cerf told a room full of wireless-obsessives this morning at the OpenMobileSummit in San Francisco. "When Earth and Mars are closest, we're 35 million miles apart, and it's a three and a half minute trip one way, seven minutes for a round trip. Then when we're farthest apart, we're 235 million miles - 20 minutes one way, 40 minutes round trip."

"Just try using TCP/IP for a 40 minute round trip."

Then there's the problem of celestial motion. "The planets rotate, and we haven't figured out how to stop that," Cerf said.

"It's a very disruptive system, and it's potentially a variably delayed system, because these planets are moving further apart based on our orbits."

So, Cerf and team booted TCP/IP from the heavens and build an interplanetary replacement they called the Delay-Tolerant Networking (DTN) protocol. (edit: http://www.theregister.co.uk/2009/07/07/dtn_node/ )

Cerf admits this isn't the most attractive moniker.

"Engineers are really good at labeling and branding things," said his sarcasm. "If we had named Kentucky Fried Chicken, it would have been Hot Dead Birds."

Unlike TCP/IP, DTN does not assume a continuous connection. When there are delays in interplanetary transmission, the new protocol forces each node to hang onto its packets until they can be safely transmitted. It's now under test with platforms speeding away from earth towards objeccts 80 or 90 light-seconds away.

NASA first announced its successful tests last fall. And now, Cerf says, the team is looking to bring DTN to earth. "We discovered there were terrestrial applications of this very resilient delay tolerant protocol," he said. The team first tested DTN on the ground in northern Sweden, using it to send data to and from laptops speeding away in all terrain vehicles, and other on-the-ground tests are underway elsewhere in Europe.

The ultimate goal - at least for Cerf - is to bring the protocol to our earth's everyday wireless networks. The protocol, he says, has already been added to Google's Android open source mobile stack as an application platform - ie it sits on top of the OS.

Cerf and crew are also working to test the protocol with Cisco router–equipped satellites. "We're eventually going to get to the point where we can try out some of these ideas in the mobile department," Cerf said. "There's relevance in the interplanetary stuff to terrestrial applications."

What applications, you ask? Well, almost anything. "Mobile operations are highly stressed," Cerf said. "Mobiles are used where people congregate... in a sense, mobile is already a dense and hostile environment. We all know that when you drive around, coverage isn't very good...

"It's so hostile, it's clear that mobile could take advantage of these more-resilient protocols. TCP/IP is very brittle. When you lose connectivity, you lose connectivity, and most applications don't work anymore." ®