Page 1165 - 5G Basics - Core Network Aspects

Transport aspects 2

16.4 OTU maintenance signals

16.4.1 OTUk alarm indication signal (OTUk-AIS)
The OTUk-AIS (see Figure 16-1) is a generic-AIS signal (see clause 16.6.1). Since the OTUk capacity
(130 560 bits) is not an integer multiple of the PN-11 sequence length (2047 bits), the PN-11 sequence may
cross an OTUk frame boundary.
NOTE – OTUk-AIS is defined to support a future server layer application. OTN equipment should be capable of
detecting the presence of such a signal within OTUk (k=1,2,3) SOTU and OTUk (k=1,2) MOTU interface signals; it is not
required to generate such a signal.

Column #
1 ....... 14 15 ....... 3824 3825 ....... 4080
Row # 1 Repeating PN-11 sequence
2
3
4
G.709-Y.1331(12)_F16-1

Figure 16-1  OTUk-AIS

16.4.2 OTUCn alarm indication signal (OTUCn-AIS)
The OTUCn-AIS is specified as all "1"s in the entire OTUCn signal, excluding the frame alignment overhead
(FA OH) (see Figure 16-2).
The presence of the OTUCn-AIS is detected by monitoring the OTUCn SM STAT bits in the SM overhead
fields.
NOTE – OTUCn-AIS is defined to support a future 3R regenerator application in which the OTUCn is not terminated
and an OTUCn subrating application. OTN equipment should be capable of detecting the presence of such a signal
within OTUCn signals on SOTUm and MOTUm interfaces.

Figure 16-2  OTUCn-AIS

16.5 ODU maintenance signals

Three ODU maintenance signals are defined: ODU-AIS, ODU-OCI and ODU-LCK.

1155