.. ?»n
?»n+1... ?»m
?»n+1 ... ?»m
?»n+1 ... ?»m
?»n+1 ... ?»m
?»n+1 ... ?»m
?»n+1
?»m
PSC
OLT ONU
AWG
?»1 ... ?»n
?»n+1 ... ?»m
?»1
?»3
?»n
?»n+1
?»n+3
?»3 ?»n+3
?»3 ?»n+3
?»3 ?»n+3
?»m
(b)
(c)
(a)
184 Chapter 7
receiver must be tuned and the transmitter module replaced. In other words, the network
operator again ends up with stock problems and wavelength quasi-static channel
assignment. Additionally, this scenario features a greater number of AWG components,
which are still more expensive than PSCs, unless polymer-based, temperature compensated
AWG can be utilized.
Figure 7.7c depicts the target WDM PON architecture, in which a long feeder section
ends up in the first stage PSC (typically a 1 ?— 16 or 1 ?— 32 port device), performing
power-splitting operations with all downstream channels, ?»1 ??¦ ?»n, present at each
output port. A short interconnection section follows, terminated in the second-stage
PSC module, performing another power-splitting operation. This time the port count
depends on the subscriber population and ONU count demand. Typically, 1 ?— 16 or 1 ?— 32
are the expected splitting factors.
Pages:
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466