IEX is currently using the signal for undisplayed orders, which are priced off of displayed orders.

In parallel, we performed genome-wide analysis on copy number variations (CNVs) using the signal intensity data from the SNP arrays.

The satellites don't monitor which devices are using the signal, but there is part of system that can pick up search and rescue signals.

Using the SIGNAL statement (expected to be implemented in MySQL 5.2)