| Remarks： CWDM passive OMU/ODU multiplexes/ demultiplexes different
wavelength signals, main ports are COM port and relevant wavelength
fiber port. 1. Chain Network structure
1.1 Chain mode point-to-multipoint structure
This solution is aimed at transmitting signals from one central
station to several subsidiary stations. The central station uses
C5000 series system chassis transmit signals to subsidiary stations
through COM ports. Each subsidiary station adopts a passive OADM
unit to download and upload local data, the users’ ends ONU (CWDM
Media Converter) will convert data into local signals, and then
through RJ45 port output them to users’ end switch or direct
terminal.
1.2 CWDM—PON Structure
The advantages of this program are easy for installation and
maintenance. Several data gather in C5000 series chassis, then
output from COM to user’s end CWDM passive ODU/OMU; after
demultiplexing, signals are transmitted to each ONU. CWDM passive
OMU/ODU place conveniently, they are adapted to block’s broad band
and multi-services （C5000 series chassis see above）
2. Products specification
2.1 OADM
OADM（Optical Add and Drop Multiplexer）, in cooperating with CWDM
chassis, download and upload local signals.
Ports:
COM port: public port, receives upper signals, connect to chassis.
Local service ports: for downloading or uploading local signals,
connect to users’ ends ONU (CWDM Media Converters).
Upgrade port: for receiving signal nether, directly connect to COM
ports of nether OADM.
2.2 CWDM passive ODU/OMU
Ports for different wavelengths
CWDM passive OMU/ODU multiplexes/ demultiplexes different
wavelength signals, main ports are COM port and relevant wavelength
fiber port. COM port receives multiple signals from central side,
and then the ODU/OMU demultiplexes signals to different wavelength
fiber port and transmits to relevant user’s end ONU (CWDM media
converter).
Solution 3: Ring mode network This solution has a central station (station A), transmitting
multiple service signals in two opposite directions to B, C, D, E
subsidiary stations, each one can upload/download relevant
wavelength (1270~1610nm) service signals simultaneous, the whole
ring could support net management too. It not only saves up fibers,
but also transmits service signals in both main and backup fiber to
ensure the stability of the communication, is a considerable choice
of MANs construction solution. | 
