Page 692 - 5G Basics - Core Network Aspects

2 Transport aspects

NT1 NT2
T
γ R S TE
FTU-R PHY In-premises
DPU network
V
ATA
γ O
HON ODN PHY FTU-O ATA ATA ATA may be either in
NT1, NT2, or TE
U-O2 U-R2
U-O U-R U-R2O
Copper FXS POTS
pair In-premises adapter
wiring U-R2S
U-O2P FXS POTS
adapter
U-R2P
PSU PE
PSE
FXS POTS
U-R2S adapter
G.9701(14)_F5-6

Figure 5-6 – Application reference model for FTTdp
with reverse powering and derived POTS

Table 5-3 – Signal flows applicable at the reference points shown in Figure 5-6

Reference ITU-T G.9701 Reverse power feeding Analogue voice Out-of-band POTS
point signals (RPF) signals signalling
U-O2 Yes No No No
U-O2P No Yes No No

U-O/U-R Yes Yes No No
U-R2P No Yes No No
U-R2O No Option (Note 1) Yes Yes
U-R2S No Yes (Note 2) Yes Yes
U-R2 Yes No No No
NOTE 1 – The FXO POTS adapter will usually be locally powered if the FXO POTS adapter is collocated with an ATA,
but may otherwise use the reverse power feeding option.
NOTE 2 – RPF provides power for FXS POTS adapters implementing signalling conversion.

As a further alternative, the ATA may insert the derived POTS on the in-premises wiring, with the NT and
PSE integrated into the same physical box, and not connected to the in-premises wiring. This deployment
model is illustrated in Figure 5-7. It has the advantage of not exposing ITU-T G.9701 to the bridged taps
caused by the in-premises wiring topology. However, it may make the customer self-installation process
more challenging.

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