Today on the battlefield, many types of military personnel—such as operators of unmanned-air and all-terrain vehicles, intelligence operators, and commanders—must communicate on a moment-to- moment basis as conditions on the field change. This critical communication occurs over tactical data networks (TDNs)—series of gateways, servers, unmanned vehicles, and operation centers, connected via mobile, wireless, and ad-hoc mesh networks.

TDNs have finite resources such as limited network bandwidth that all network users and components compete for when exchanging information. Allocating bandwidth effectively has always been a challenging problem, but as TDNs become increasingly complex and more closely coupled with moment-to-moment, rational (or self-interested) human decision making, these challenges become daunting. Researchers around the world are investigating the use of market mechanisms to allocate scarce computational resources: Could these ideas be useful in TDNs?

“CMD is all about designing the right incentive structure just like the economics involved in an auction, a voting protocol, or a market. Economics is tailor-made for the kinds of decentralized decision making required by network-centric systems ... ,” said Wallnau.

To find out, researchers at the SEI have been developing auction mechanisms for bandwidth allocation in TDNs. In 2006, the SEI showed how auctions can be used to improve the common operating picture in a prototype TDN based on the Navy’s LINK-11. In 2007, the SEI joined with Harvard University and the Naval Post-Graduate School (NPS) to demonstrate auction mechanisms for bandwidth allocation in a more complex and demanding TDN testbed developed by the NPS, called the Tactical Network Topology (TNT). TNT links equipment in three locations across the United States and manages all communications among them. The NPS is using TNT to pioneer adaptive tactical networks based on the concepts of 8th Layer, which enables adaptive networking by giving every critical node bandwidth adaptation and small-scale network operation capability. The 8th Layer-enabled hyper-nodes adapt their behavior by exchanging services in accordance with the Valued Information at the Right Time (VIRT) concept.

Alex Bordetsky, the principal investigator and founder of the NPS’s TNT testbed, says, “The SEI’s work in mechanism design is helping our forces to cross what we call the ‘last tactical mile.’ It runs from command headquarters to tactical units in remote locations and has information gaps along the way—that’s where 8th Layer adaptation comes in. It helps us bridge those gaps—something that becomes more and more important as systems grow more dynamic, performance becomes more critical, and resources dwindle.”

Applying auction mechanisms this way is cutting edge, says Kurt Wallnau, one of the SEI researchers investigating computational mechanism design (CMD). According to Wallnau, the TNT arena gave SEI researchers a chance to demonstrate CMD as a way to develop self-regulating systems where different actors get different allocations based on economic principles. “CMD is all about designing the right incentive structure just like the economics involved in an auction, a voting protocol, or a market. Economics is tailor-made for the kinds of decentralized decision making required by network-centric systems—systems that are not just being used in the military. This problem affects diverse areas from emergency response systems to large city infrastructures,” said Wallnau.

This successful application of CMD research is part of a larger research effort the SEI is leading in ultralarge- scale (ULS) systems—an effort that began in 2006 with the publication of the report titled Ultra-Large-Scale Systems: The Software Challenge of the Future. Next, Wallnau’s team of researchers plans to continue working with the NPS and Harvard to develop mechanisms for wireless mesh networks that allow nodes across broken or blocked paths to communicate through “hops”—similar to the moves of tokens in a game of Chinese checkers. Wallnau is confident that the SEI’s research will help there too: “Although CMD is leading-edge research, we believe it’s an engineering discipline waiting to emerge and will soon be on par with performance engineering and safety engineering.”