13. Authors' Addresses

   Robert M. Enger
   Advanced Network and Services
   1875 Campus Commons Drive,  Suite 220
   Reston, VA.  22091-1552

   Phone: 703-758-7722
   EMail: enger@reston.ans.net

   Joyce K. Reynolds
   Information Sciences Institute
   University of Southern California
   4676 Admiralty Way
   Marina del Rey, CA 90292

   Phone: (310) 822-1511
   Email: JKREY@ISI.EDU