A particular PSC receives only a single wavelength and splits it into a number of
output ports. All connected ONUs are, therefore, forced to operate at this wavelength
Figure 7.6 ITU-T G.694.2 CWDM wavelength grid
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1200 1300 1400 1500 1600
Wavelength (nm)
Fiber Attenuation (dB/km)
O-Band
1260??“1360
E-Band
1360??“1460
S-Band
1460??“1530
C-Band
1530??“1565
L-Band
1565??“1625
Water
Peak
ITU-TG.652 Fiber
1270 1290 1310 1330 13501370
1390
1410 1430 1450 1470 1490 1510 15301550 1570 15901610
Passive Optical Networks (PONs) 183
and cannot change the downstream/upstream channel??”even if other wavelength channels
in the WDM PON system have free resources to offer. It is anticipated that such a
static wavelength assignment system is an intermediate solution for operators, with a
number of individual PONs deployed in the field, striving to aggregate the system into
a more compact form with higher management capabilities.
Figure 7.7b depicts a tree-and-branch topology with cascaded PSC and AWG elements,
where the component order is opposite the one just described and depicted in
Figure 7.
Pages:
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464