Mobility is a driving force behind the Army’s Warfighter Information Network-Tactical (WIN-T) project, which provides broadband wireless connectivity to troops on the move, whenever and wherever they need it.
The importance of such anytime, anywhere access became apparent during the early days of the war in Iraq, notes Col. William C. “Chuck” Hoppe, WIN-T project manager. In the past, the Army set up network operations only when it stopped moving, but in Iraq, the forces moved too quickly for such “at-the-halt” networking.
“At the time, units had to roll in, stop, set up and then bring in the network to get to what they needed,” Hoppe says. “But when we as an Army pushed off from Kuwait and marched to Baghdad, we literally outran the Army’s existing networking capability.”
The Army built WIN-T to address the issue. Delivered in four increments, WIN-T provides broadband wireless networking capabilities to troops, even while on the move. The first increment provided communications via satellite. Increment 2, which the service is deploying now, will not only increase the bandwidth to 30 megabits per second — a huge improvement over the 32 kilobits per second available previously — but also add on-the-move capability through a blend of terrestrial and satellite IP communications.
When delivered next year, Increment 3 will boost the bandwidth to a full 110Mbps, an important consideration for battlefield operations.
“We’re pushing everything from streaming video from an unmanned aerial sensor to large files for an operations order, which may include graphics,” Hoppe says. “As units complete actions and have people they’ve detained, then biometrics data is taken into the systems as well. It’s all very bandwidth-intensive, but it provides a significant capability to the commander on the ground.”
Hoppe points to three success factors for broadband use:
- Security. The service uses encrypted links across the Internet via secure virtual private network tunnels, either Secure Sockets Layer or IP Security. Today, the wireless battlefield links are fully encrypted and secure; Increment 4 of the program will add the ability to prevent communications detection. “It will use protected comms, so you can’t detect the transmission, and you can’t intercept it,” Hoppe says.
- Signal assurance. Hoppe says the problem of building mobile ad hoc networks (MANETs) is a tough one to crack. “Most people who are working with MANETs today are doing it with omni-directional antennas, but that has some very hard physics problems in it, especially as you start ramping up the number of users in that network,” he says. “We attacked the problem differently, using an antenna developed by BAE. It’s really like a series of 17 antennas inside that case that are addressed separately so they become directional antennas. That lets us get around a lot of the MANET issues associated with an omni-directional network.”
- Flexibility. Troops in battle can’t plan their terrain or their communications needs, so the broadband wireless network has to take every variable into account. For that reason, the Army’s network uses both terrestrial line-of-sight and satellite wireless communications, switching between them on the fly as necessary.
“If you go into a ravine, and it sees the line-of-sight link starting to fade, the network operations software starts looking for neighbors, other vehicles with the same line-of-sight capability it can bounce off of to get to you,” Hoppe says. “But if it loses all of its near-peer neighbors, it will go up over satellite and come back down. And the reverse is true, too. When you come back out of that ravine and reacquire that line-of-sight, it will break down that satcom network link to save the time required to go up to geo-synchronous orbit and come back down.”