5.0 Preparing for Operation
5.1 Equipment Check List
The following tools are required to operate the MTTplus-420 unit for GPON testing:
MTTplus platform unit with MTTplus-420 GPON module installed. SC/APC is the recommended connector.
Cleaning supplies to clean patch cord connectors and equipment optical connectors.
Fiberscope with Universal 2.5mm UPC and APC male tip, SC/APC bulkhead and SC/UPC bulkhead tips to inspect optical connectors.
Patch cord – one to two patch cords depending on what is required to insert the MTTplus-420 module between the splitter and ONT.
Mating blue (UPC) with green (APC) connectors will result in excessive insertion loss, reflectance,
and possible damage to the optical connector.
5.2 GPON ITU-T G.984 Test Standards
The three primary classifications for GPON are Class A, B, and C. According to ITU-T G.984 Test Standards, for a GPON network to operate properly:
Span length must be
≤
20 km (Class C+
≤
60km) and span loss budget must be met.
GPON 2.48 Gbps Downstream/1.244 Gbps Upstream Span
Budget (km)
Class
A
Class
B
Class
B+
Class
C
Class
C+
Min. Span Loss Budget G.984.2
5
13
15
Max Span Loss Budget G.984.2
20
28
30
Min. Span Loss Budget G.984.2/Amd 2 Digital Only
5
13
10
15
Max Span Loss Budget G.984.2/Amd 2 Digital Only
20
28
28
30
Min. 1490nm Loss Budget G.984.2/Amd 2 Vid Overlay
5
10
9
15
17
Max 1490nm Loss Budget G.984.2/Amd 2 Vid Overlay
20
28
27
30
32
Min. 1310nm Loss Budget G.984.2/Amd 2 Vid Overlay
5
10
13
15
17
Max 1310nm Loss Budget G.984.2/Amd 2 Vid Overlay
20
28
29
30
32
ITU-T G.984 Test Standards
A fiberscope must be used to inspect the connectors and ensure that they are free of contaminants, dents, or scratches. Use cleaning supplies to clean off
Optical Fiber Patch Cord Preparation
for contamination, inspection, and cleaning information. Dents or scratches can create
insertion loss and reflectance.
Downstream and upstream launch power must meet signal level specifications. A PON meter must be used to confirm that the signal levels are acceptable
per standards.
Since the MTTplus-420 is only designed to be used between the splitter and ONT (Customer Site), we are only concerned about the ONT received power
for the 1490nm signal and ONT launch power at 1310nm. 1490nm received power and 1310 launch power are both shown below
MTTplus-420_User_Manual_RevC00
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