Information on Travler
Transparent, dynamic composition of adaptive agents to balance protocol requirements with transmission costs and capabilities
Smoothing of video transmission, analysis of impact of wireless channel video stream, and selection of packets to transmit for best video quality for a given channel condition.
Improved mobile IP protocol by caching the location of moving machines throughout the networkWeb page prefetching based on knowledge of access patterns and current network characteristics, plus icon graphics to indicate Web-link delays
Peer-oriented, optimistic, scalable file replication for mobile computing units
Portable simulation environment (Maisie) to support parallel and hybrid simulation and virtual and hierarchical model design
Automatic predictive file-hoarding to ensure that correct files are stored on mobile computing units prior to disconnection
A large-scale, heterogenous, distributed simulation of file replication, for investigating the effects of system attributes on service quality.  A sample application of hybrid simulation.

Welcome to the LASR Lab's Travler project pages (note that this link provides a more detailed discussion of the Travler project, including links to related research, important papers and software downloads). The TRAnsparent VirtuaL EnviRonment (Travler) project was one of several multi-year DARPA-funded research efforts (1994-1999) within the UCLA Computer Science Department. This nomadic computing project focused on developing models, prototyping systems software and conducting experiments to support the needs of not just multiple users using the same files and systems, but users that are increasingly mobile.

The illustration above depicts deployment of the various Travler project components. Some of the call-outs will link you to a page describing that component in detail. Although this illustration depicts Travler within the dynamics of a military environment, Travler is equally valuable in any conceivable mobile computing environment.

Each principal investigator on the Travler project had an extensive background in a project-essential nomadic computing field:


Leonard Kleinrock is recognized as one of the leading experts on modeling of computer networks. Because of his pioneering work on the first ARPANET protocols, he has been acknowledged as one of the "fathers" of the Internet.

Gerald Popek has been developing system software for distributed environments and researching security for system software for over twenty years.

Rajive Bagrodia is a leading expert in the field of parallel discrete event simulation and has taken the lead in designing simulation platforms to support research in mobile computing.

Peter Reiher has been developing system software for unreliable distributed environments for fifteen years, including naming systems, replicated file systems, and systems for secure collaboration over insecure networks.




DARPA Contract No: DABT63-94-C-0080

Last modified: August 2005
Information on Travler Adaptive Agent Framework Smoothed Video Location Tracking Smiley Mobile File Replication Simulation Services Seer File Replication Simulation