The outposts from which patrols frequently launched saw periods of up to 8 hours without a SIPRNet connection. TIGR’s strength as a web application, accessible from anywhere, was network-vulnerable. When it was down, troops still needed information, such as maps and post reports, on their operational environment.
DARPA found a way to get around the problem by linking dispersed servers. When connectivity was down in one location, other servers were caching TIGR data. While the network was up, servers constantly loaded information in the background, making it accessible even when connections dropped. DARPA developers prioritized and filtered TIGR traffic, building compression algorithms for simplified documents.
“The [software] architecture that we designed limited information shared to what was necessary,” Maeda explained. “For example, only reduced-size photos would get pushed out. We really thought hard about designing the application so it didn’t burden the network.”
Michaelis refers to TIGR as a sort of precursor to the Cloud, with federated servers providing real-time operational intelligence to widely spread formations.
A company commander could log in to TIGR and, using its game-like, map-referenced interface, plot out patrol routes noting changes to buildings, terrain, roads, or bridges. TIGR included before-and-after photos of the changing landscape, updated continuously by its users. As it developed, it allowed not only for notes and maps but also for voice recordings, digital photos, and GPS tracks to be collected and searched.
When connectivity was down in one location, other servers were caching TIGR data. While the network was up, servers constantly loaded information in the background, making it accessible even when connections dropped.
“One of the many reasons people liked TIGR was because we made sure it got the best, freshest satellite imagery,” Maeda said. “The decision-makers said, ‘Oh, that imagery is available to everybody.’ That didn’t mean that someone in an outpost could download it.”