Second Level (1)
Every PE of the first level will be consider a SubMaster.
For each SubMaster we associate a cluster of PE Slaves.
Each Slave executes the calculation on some particular
subspaces with m-index fixed, collects the result and
sends it to its SubMaster. The SubMaster collects all the
results related to the particular part of the image
and sends them to the Master.
The distribution of the Second Level PEs acts in such a way to
balace the different charges of the First Level.