Provided is a communication method and a data frame for a communication system having a relay station. In certain embodiments, the pneumatically-reset pilot valve is configured to move to a first position in response to a change in pressure in the cylinder. A first fluid is injected into a part of the portion and a second fluid is produced from the formation. Roughing on the interface may be achieved by depositing a material on a surface of the substrate to act as a mask and then using an etching process to induce the roughness.