Page 1167 - 5G Basics - Core Network Aspects

Transport aspects 2

16.5.3 ODU locked (ODU-LCK)

ODU-LCK is specified as a repeating "0101 0101" pattern in the entire ODU signal, excluding the frame
alignment overhead (FA OH) and OTU overhead (OTU OH) (see Figure 16-5).

Figure 16-5  ODU-LCK

NOTE – The repeating "0101 0101" pattern is the default pattern; other patterns are also allowed as long as the STAT
bits in the PM and TCMi overhead fields are set to "101".
In addition, the ODU-LCK signal may be extended with one or more additional levels of ODU tandem
connection, GCC1, GCC2, EXP and/or the APS/PCC overhead before it is presented at the OTN interface.
This is dependent on the functionality between the ODU-LCK insertion point and the OTN interface.
The presence of ODU-LCK is detected by monitoring the ODU STAT bits in the PM and TCMi overhead fields.

16.6 Client maintenance signal

16.6.1 Generic AIS for constant bit rate signals
The generic-AIS signal is a signal with a 2 047-bit polynomial number 11 (PN-11) repeating sequence.

11
9
The PN-11 sequence is defined by the generating polynomial 1 + x + x as specified in clause 5.2 of
[ITU-T O.150]. (See Figure 16-6.)

Figure 16-6  Generic-AIS generating circuit

17 Mapping of client signals

This clause specifies the mapping of:
– STM-16, STM-64, STM-256 constant bit rate client signals into OPUk using client/server specific
asynchronous or bit-synchronous mapping procedures (AMP, BMP);

– 10GBASE-R constant bit rate client signal into OPU2e using client/server specific bit-synchronous
mapping procedure (BMP);

– FC-1200 constant bit rate client signal after timing transparent transcoding (TTT) providing a 50/51
rate compression into OPU2e using client/server specific byte-synchronous mapping procedure;
– constant bit rate client signals with bit rates up to 1.238 Gbit/s into OPU0 and up to 2.488 Gbit/s
into OPU1 using a client agnostic generic mapping procedure (GMP) possibly preceded by a timing

1157