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With a goal toward the design of a system enabling the 21st century U.S. soldier to become a more effective instrument of war, recent advances in the US Army's Land Warrior program have focused on providing soldiers with up-to-date technology for wireless communication, navigation and information interchange. The Land Warrior system will make rapid deployable light forces more effective on the future battlefield, providing enhancements of lethality, survivability, mobility and sustainability.

Targeting vastly increased situational awareness for dismounted infantry soldiers, an integrated system of rapid mobile digital and voice connectivity has been developed by product engineering and analysis firm Pacific Consultants, Mountain View, CA.

Two years ago, the U.S. Government Accounting Office (GAO) noted that the project was “over budget, behind schedule and needed more oversight.” The Land Warrior program, started in the early 90s, regularly received widespread negative national front-page newspaper coverage for lack of progress in achieving the program objectives.

A paradigmatic turn-around began in October of 1999 when U.S. Army management, under the direction of Colonel Bruce Jette, took the initiative to treat the project as a “fast track Silicon Valley project,” utilizing new product innovations and commercial-off-the-shelf (COTS) components to develop working prototypes of a wearable computer, voice-over IP radio and the software package needed to control the system. Implementing such an innovative COTS approach was a direct alternative to traditional methods of military procurement and program development.

A goal of the program was to keep costs under control by leveraging the rapid advances taking place in the commercial research and development arena; most notably in the area of wireless communication. This wasn't easy. “One of the stiffest challenges we faced involved taking available commercial standard applications and re-deploying them into military standard applications,” said Pacific Consultants CEO Dr. Hugh Duffy.

Pacific Consultants provided overall systems integration of Land Warrior components including the computer/radio, global positioning system and a weapon with thermal imaging capability for detection of hidden targets. Also provided was a laser range finder and a video sight that allows soldiers to accurately aim and shoot around corners or obstacles without exposing themselves to enemy warfare. This latter feature is especially desirable in urban warfare, where soldiers are continually encountering walls, stairs, doorways and fences.

The Land Warrior wearable computer system is centered around two commercially available data handling platforms — the Land Warrior computer running Windows 2000 on PC 104 hardware and the Land Warrior communications-navigation (CommNav) unit, using Windows CE running on an Intel Strongarm processor. This CommNav unit contains a GPS receiver and dead reckoning positioning module (DRM), as well as a wireless LAN PC card. It also includes DSP hardware for handling audio communications.

Faced with an accelerated timeline, the software engineering process consisted of two parallel, spiral development programs. A series of rapid prototyping and user interface mock-up cycles were valuable in gathering user requirements and validating design choices via user juries. In tandem with this, a more comprehensive production software development process has been used, integrating participatory design and extensive user involvement in all phases of the project.

Land Warrior-equipped soldiers have the capability to originate and disseminate a variety of asynchronous data messages, including operational orders, intelligence information, logistics reports and tactical fire support requests. A rapid call for medical assistance can also be issued. The Land Warrior mapping component provides the capability to show current position information for each member of the platoon. The system automatically generates and transmits regular GPS-based position update messages, so that Land Warrior users can be constantly updated with each other's current location. “Knowing the positions of fellow platoon members minute-by-minute, especially in relation to the enemy's location, provides a tremendous strategic advantage,” said Pacific Consultants' President Dr. Bret Herscher.

Map overlays can be edited to add targets, route plans, rally points, mined areas and a wide range of other geo-located points of interest — these can then be transmitted to all platoon members or a selected group of recipients. A video-mode data server provides the user with overlaid text and graphics when the system is used for displaying real-time video from the weapon-mounted sights. The system includes a still-image handling facility for saving, annotating, and transmitting video scenes that are captured using the weapon sights. The Land Warrior application also incorporates a simple hypertext browser, which soldiers use to access various operations manuals, training texts, and other HTML-based reference material.

The Land Warrior wireless communication system involves an infrastructureless mobile network, a form of peer-to-peer interaction over a wireless LAN that is sometimes characterized as an ad-hoc network. Since each node is mobile, it needs to connect to the network dynamically and in an arbitrary fashion. Each participating node will act as a router when forwarding data packets on behalf of other nodes on the network. They will also take part in connection discovery and route maintenance to other nodes on the network. Sub-nets can form when a larger group of nodes sub-divides into two or more smaller groups that are separated by distance or poor RF propagation circumstances.

This data network uses standard IEEE 802.11 wireless LAN communications protocols. An innovative multicast group IP addressing scheme is used to map individual duty positions within the platoon to their virtual location on the wireless LAN. “This is one of the vast improvements in situational awareness that the Land Warrior system delivers,' said Herscher. “No longer are soldiers reduced to communication via shouts, yells and hand signals, which have a propensity towards giving away a soldier's position to the enemy.”

The addressing scheme obviates the need to closely couple a soldier's LW system (and hence its assigned IP address) with his assigned role in the platoon. Voice-over-IP is used for audio communication within the Land Warrior network. A pool of virtual channels is available for normal audio use, with one additional channel being set aside for emergency calling purposes.

The intrinsic mobile characteristics of the U.S. Army's military operations suggest that the future battlefield will require a variety of wireless data communication networks. The Land Warrior system will eventually participate in extensive networks linking command and control centers, logistic posts, ground vehicles, aircraft and other equipment and facilities. It is expected to form the lowest echelon in the Tactical Internet hierarchy. Thus, a reliable gateway between the internal LW wireless LAN and the rest of the military communications network is required. To this end, as part of the proof-of-concept development activity, the platoon radio-telegraph operator (RTO) was equipped with a Single Channel Ground and Airborne Radio System-Advanced System Improvement Program (SINCGARS ASIP) military radio in addition to his LW system.

The frequency-hopping ASIP radio provides standard military voice and data communications capability. The data network access component of the radio connects to a serial port on the proof-of-concept Land Warrior computer. This link enables the RTO to send and receive certain operational orders and situational awareness data to and from the battle command center. Additional software was provided to drive this radio. Thus, the RTO's Land Warrior system forms the gateway between the two networks.

The Land Warrior's CommNav software, which runs on the Windows CE platform, provides the bridge between the primary Land Warrior application and the wireless LAN. It also handles the GPS and DRM positioning data. It is designed to run independently of the main application, so that the CommNav unit can continue to function autonomously should the PC104 computer fail. This means an individual soldier can still communicate by voice and continue his position update transmissions, in the absence of the Windows 2000 system. Another feature of the computer is its inertial navigation module, supporting the GPS in terrain that satellite signals can't reach, in urban streets between tall structures or in rural areas with dense tree canopies.

The primary Land Warrior peripheral components are attached to the soldier's Personal Area Network (PAN) which, in the proof-of-concept systems, used standard CAN 2.0b technology. The components mounted on the soldier's weapon include a laser rangefinder and digital compass, a daylight video sight, a thermal sighting unit and a mouse device. The PAN also links to the head-mounted display controller and an additional chest-mounted mouse control. In addition, it can be used to attach bio-sensors or other peripheral devices to the Land Warrior system.

The refocusing effort for the Land Warrior program brought flex circuitry application development to center stage. The Pacific Consultants' effort on flex circuitry was led by Joseph Fjelstad. With earlier versions of the Land Warrior system containing interconnected discrete cables, soldiers had complained that the bulky circuitry wasn't easily constrained-this resulted in soldiers regularly becoming snagged by trees, shrub branches and limbs in field trials. Along with this bulk came additional weight for already overburdened soldiers.

The current flex circuitry concept for the Land Warrior that was developed and executed was one where most of the various cables were integrated into a single flexible circuit that was patterned to follow the contours of the modular lightweight load-carrying equipment (MOLLE) or vest that holds the system components. In use, the flexible circuit wraps around the shoulders of the soldier and is invisible as it is sewn into the vest's fabric.

Along with eliminating the problem of snagging, this flexible circuit variation provided significant weight savings. The final cable with connectors weighed in at just 80 grams compared with the 680 grams of the original cables, resulting in an 88% weight reduction.

With all of the improvements both already designed and implemented, plus those planned for future versions of the Land Warrior, the anticipated cost of outfitting each soldier is targeted to be on the order of $15,000 to $20,000, nearly $70,000 less than the original $85,000 estimate provided by previous military contractors. In the future, it is anticipated that modified versions of the Land Warrior software product will be deployed on other hardware platforms, for various simulation and gaming purposes. Utilization of these approaches to user training and engagement with the system will be carefully studied in the coming months.

Version 1.0 of the Land Warrior system is currently under development. This version is slated to be a manufacturable system with numerous added features learned from the Army's experience with the 0.6 development system. The Army expects to eventually outfit 41,000 soldiers with the system, beginning in 2003.