Arturo Cisneros

A large ATM switch based on memory switches and optical star couplers

The authors propose a large asynchronous transfer mode (ATM) switch architecture based on memory switches of the type being developed by several research groups and on optical star couplers. Fast contention resolution makes it possible to combine a number of these modules, memory switches, and optical stars in order to attain a capacity of 2.5 Tb/s. This switch architecture has a relatively small failure group size of 128 STS-3 lines out of a total of 16384. The scaling of the switch to smaller capacities is discussed, showing how tradeoffs in the various parameters can be used to overcome particular technological limitations. Fault tolerance and recovery schemes are presented, showing that with minimal increase to the switch complexity and cost, a very reasonable fault recovery scheme is available for almost every sort of failure. >

Self-correcting Adaptive Tracking System

The benefits of Global Positioning System (GPS) are recognized in numerous military as well as civilian applications. In many situations, however, GPS signals are simply not available or, at best, intermittently observable. This paper describes a novel location tracking system, called self-correcting adaptive tracking system (SATS), which focuses on solving group location problem when GPS is not available. In our location tracking system, we use a tracking mechanism that allows locating group members based on their pair wise distance information. A key innovation of SATS is that we use an adaptive search algorithm to find the new position estimate based on constraints given by the ranged data. In addition, our location tracking system is capable of extracting directional information normally unavailable in ranging system, which allows us to adaptively stabilize the orientation of the group. The SATS methodology has been prototyped and tested as part of an Office of Navy Research (ONR) program.