Page 1128 - 5G Basics - Core Network Aspects

2 Transport aspects

Figure 12-3 – ODUflex clock generation for GFP-F mapped packet client signals

12.2.6 ODUflex for IMP mapped client signals

ODUflex(IMP) signals are generated using a local clock or the timing of its client signal. The local clock may
be the local server ODUk (or OTUk) clock, the local ODUCn (or OTUCn) clock, or an equipment internal clock
of the signal over which the ODUflex is carried through the equipment.
In the first method, the clock of the server ODU is used as reference clock and adjusted by means of a fixed
Cm value, similar to the case of ODUflex(GFP). The main difference with the ODUflex(GFP) clock rate is that
this latter rate is the maximum rate that can be supported by M trib slots whereas the ODUflex(IMP) clock
rate should not be such maximum rate, but instead just a rate that is sufficient to carry the FlexE client
signal or the PKT client encapsulated in a FlexE client signal.

In the second method, a local free run clock is used as reference clock and adjusted by means of a fixed X/Y
value.

In the third method, the clock of the FlexE Client signal is used as reference clock and adjusted by means of
a fixed X/Y value, with X = 239 and Y = 238.

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