Effects on Power-Plane Communications: Case Study on Textile and Spacecraft Media

Reliable communication requires error detection and correction mechanisms. As the error characteristics depend on the physical layer, we study them for two recent physical layers: power-plane communications (PPC) in fabric and spacecraft multi-layer insulation (MLI). As a first step towards this goal, we investigate the dependency between the medium parameters (such as temperature, wetness, ambient radio, bending and crumpling) and the occurrence of errors in data transfer between sensor nodes in conductive fabric and MLI. Our results indicate that some medium parameters lead to error generation and loss of data transfer while some have no effect on the occurrence of errors. While our earlier work has assumed that it is only capacitance that attenuates the modulated carrier signal in PPC, our results show that other medium parameters such as electrolysis affect data transfer. Electrolysis has two effects: it leads to loss of data transfer in the case of conductive fabric with metallic mesh. In the case of fabric with silver coated threads or copper, electrolysis destroys the channel. In the case of MLI, bending and crumpling lead to error generation with a bit error probability of almost 90%. We also demonstrate that data signals can be used as an indicator of fabric wetness. They can also be used to indicate a micrometeorite impact with a spacecraft. We further show that the use of Manchester encoding and implementation of the data slicer for PPC provides a robust way to restore the transmitted data when the medium parameters change.