TITLE:   Communications in Binary Fat Trees

AUTHORS: V. V. Dimakopoulos and N. J. Dimopoulos 

IN:      PDCS'95, International Conference on Parallel
	 and Distributed Computing Systems, Florida, USA,
	 pp. 383 - 388, Sept. 1995

ABSTRACT

Fat trees are built around complete b-ary trees but have
processing nodes only at the leaf level and may have
different branch capacities in different levels. Here we study
the communication capabilities of binary fat trees with respect
to five major communication operations: broadcasting, multinode
broadcasting, scattering, gathering and total exchange. We 
present and analyse optimal and nearly optimal algorithms for 
the five operations.