A concentration module for concentrating contaminants in a matrix at the site where the matrix is being used. In some examples, an input network interface of a network device receives a roaming protocol message on an interface connecting a first support node of a first mobile network and a second support node of a second mobile network. The method may also include generating quadrature amplitude modulation input signals, the quadrature amplitude modulation input signals each including a term for compensation of the noise based on the calculated noise.