SDH multiplexing process

SDH provides for multiplexing of 2-Mbit/s (C-12) and 34-Mbit/s (C-3) signals into an STM-1 frame.

Furthermore, multiplexing paths also exist for the SONET specific 1.5-Mbit/s, 6-Mbit/s and 45-Mbit/s signals.

Process

The following describes the process for multiplexing a 2-Mbit/s signal. The SDH digital multiplexing illustrates the multiplexing process.

 
1

Input 2-Mbit/s tributary is mapped

  • Each VC-12 carries a single 2-Mbit/s payload.

  • The VC-12 is aligned into a Tributary Unit TU-2 using a TU pointer.

  • Three TU-2 are then multiplexed into a Tributary Unit Group TUG-2.

  • Seven TUG-2 are multiplexed into an TUG-3.

  • Three TUG-3 are multiplexed into an VC-4.

  • The VC-4 is aligned into an Administrative Unit AU-4 using a AU pointer.

  • The AU-4 is mapped into an AUG which is then mapped into an STM-1 frame.

2

After VCs are multiplexed into the STM-1 payload, the section overhead is added.

3

Scrambled STM-1 signal is transported to the optical stage.

Alcatel-Lucent – Proprietary

Use pursuant to applicable agreements