How does the military try to work around jamming attempts, particularly related to data communcations?

(all links are Wikipedia pages)

jamming (ECM)

counter-jamming (ECCM)

strategy: stay with RF, but modify the signal to reduce the effects of jamming strategy: use non-RF methods to communicate, particularly point-to-point methods strategy: destroy the jammer generally

layer 1 protocols designed with ECCM in mind