A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed symbol. The method includes receiving a first user-entry with a communications device and creating a transient grammar set as a result of receiving the first user-entry, where the transient grammar set is based on the first user-entry. In some embodiments, the fracturing-fluid additive composition is substantially biodegradable and is not toxic.