<title>Wireless networks of opportunity in support of secure field operations</title>

Abstract

Under funding from the Defense Advanced Research Projects Ageiy (DARPA) for joint military and law enforcement technologies, demonstrations of secure information transfer in support ci law enforcement and military operations other than war, using wireless and wired technology, were held in September 1996 at several locations in the United States. In this paper, the network architecture, protocols, and equipment supporting the demonstration's scenarios are presented, together with initial results, including lessons learned and desired system enhancements.Wireless networks ci opportunity encompassed inbuilding (wireless-LAN), campus-wide (Metricom Inc.), metropolitan (AMPS cellular, DPD),* and national (one-and twoway satellite) systems. Evolving DARPA-sponsored packet radio technology was incorporated. All data was encrypted, using Multilevel Information System Security Initiative (MIsSr) FORTEZZA technology, for carriage over unsecured and unclassified commercial networks. The identification and authentication process inherent in the security system permitted logging for database sccesses and provided an audit trail useful in evidence gathering. Wireless and wireline communications support, to and between modeled crisis management centers, was &monstrated. Mechanisms for the guarded transport o data through the Secret-high military tactical Internet were included, to supportjoint law enforcement and crisis management missions.A secure World Wide Web (WWW) browser forms the primary, user-friendly interface for information retrieval and submission. The WWW pages were stnictured to be sensitive to the bandwidth, error rate, and cost o the communications medium in use (e.g., the use ol and resolution for graphical data). Both still and motion compressed video were demonstrated, along with secure voice transmission from laptop computers in the field. Issues ci network bandwidth, airtime costs, and deployment status are discussed.