  A scheme for detection of abnormality in molecular nano-networks is proposed.
This is motivated by the fact that early diagnosis, classification and
detection of diseases such as cancer play a crucial role in their successful
treatment. The proposed nano-abnormality detection scheme (NADS) comprises of a
two-tier network of sensor nano-machines (SNMs) in the first tier and a data
gathering node (DGN) at the sink. The SNMs detect the presence of competitor
cells as abnormality that is captured by variations in parameters of a
nano-communications channel. In the second step, the SNMs transmit micro-scale
messages over a noisy micro communications channel (MCC) to the DGN, where a
decision is made upon fusing the received signals. The detection performance of
each SNM is analyzed by setting up a Neyman-Pearson test. Next, taking into
account the effect of the MCC, the overall performance of the proposed NADS is
quantified in terms of probabilities of misdetection and false alarm. A design
problem is formulated, when the optimized concentration of SNMs in a sample is
obtained for a high probability of detection and a limited probability of false
alarm.
