SDH (synchronous lus thaiv) yog kev teeb tsa mus rau hauv block thav ntawv raws li cov qauv tshwj xeeb, hu ua synchronous modules (STM). Cov qauv no tau hloov ua tus nqi ntawm tus nqi synchronized nrog lub network. Qhov yooj yim tshaj plaws thiab tseem ceeb tshaj plaws module teeb liab hauv SDH yog stm - 1, nrog tus nqi ntawm 155.520 mab / s. Qhov siab dua - qib module stm {17} {{{{18} {18} {18) synchronously tom qab byte interleaving. Nws tus nqi yog n lub sij hawm uas ntawm stm- 1, uas n yog tus lej sib npaug (1, 4, 64, 256). Cov ncauj lus kom ntxaws cov nqi yog qhia hauv rooj. Cov kab mob STM-n optical interface kab yog qhov tshwm sim ntawm electro-hloov pauv hloov ntawm STM-n lub teeb liab tom qab scrambling; Yog li ntawd, nws tus nqi tseem tsis hloov pauv.
| SDH qib | Bitrate (Kbit / s) | Tus nqi (me ntsis / s) |
|---|---|---|
| Stm-1 | 155,520 | 155 M |
| -4 | 622,080 | 622 M |
| 100 16 | 2,488,320 | 2.5 G |
| STM-64 | 9,953,280 | 10 G |
| -256 | 39,813,120 | 40 G |