(1) (Trellis-Coded Modulation/Viterbi Decoding) A technique that adds forward error correction to a modulation scheme by adding an additional bit to each baud. TCM is used with QAM modulation, for example.

(2) (Total Cost Management) An umbrella term for managing an organization's expenditures. See supply chain management and e-sourcing.

(3) (Thermal Conduction Module) An IBM circuit packaging technique that seals chips, boards and components into a module that serves as a heat sink. TCMs are mostly water cooled, although some are air cooled.