Analysis of Multi-Chemical Transmission in the Macro-Scale

Molecular communications (MC) offers an alternative to established methods (i.e., electromagnetic waves), in areas where the latter might prove ineffective (e.g., underwater or underground) due to the environment's effect on the transmitted signal. In such environments the use of particle (i.e., chemical) based communication may offer a better solution. One of the unique attributes of MC is its ability to employ chemicals as messengers, and transmitting multiple chemicals concurrently offers the potential to significantly increase the information content of the message. In this work, for the first time, the transmission of multiple chemicals with unique mass-to-charge ratios, was studied experimentally and modeled theoretically. Three modulation methods have been proposed and analyzed based on exploiting the uniqueness of the messenger chemicals. Molecular transmission was achieved using an in-house-built odor generator and detection was accomplished by means of a quadrupole mass analyzer. The noise was analyzed for multi-MC and was shown to possess additive white Gaussian noise characteristics with different mean (μ), but similar variance (σ
²
) values. It was shown experimentally that multiple chemical transmission is both feasible and advantageous compared to single chemical transmission and the proposed modulation methods exhibit unique advantages that can be used for different scenarios.