| English | German |
| level 1 synchronous transport module | synchroner Transportmodul der Ebene 1 (pulse frame, ITU-T (CCITT) Rec. G.70X, equal to STS-3 or OC-3 155.520 Mbit/s; STM-4 = approx. 4f, i.e. 622.080 Mbit/s, STM-16 = 2.488 Gbit/s, s. SDH hierarchy) |