An industrial truck, such as a fork-lift truck, has an electrical drive system and an energy supply based on gaseous media. One-dimensional input signals are detected in a symbol decoder, implemented using look-up tables, to produce a pair of 1D errors, with each representing a distance metric between the input signal and a symbol in one of two disjoint symbol-subsets. Also provided by the invention are methods of using the Endokine alpha protein andor homomultimeric andor heteromultimeric polypeptide complexes containing Endokine alpha, in the diagnosis, prognosis and treatment of diseases andor disorders associated with aberrant osteoclast development andor activity. By dispensing with complex digitalanalog converters, the principle described allows markedly reduced power consumption in transmitters which use code multiple access methods.