EDFA in WDM systems can be used as a preamplifier, line amplifiers and power amplifiers. When EDFA for preamplifier, placed before the optical receiver, in order to improve the sensitivity of optical receivers, usually working in small-signal or linear state, the signal input power of about 40dBm. Requirements of EDFA gain is high enough, the noise figure is the smaller the better.
When used as a line amplifier EDFA can be inserted directly into the optical fiber transmission link as optical repeater amplifiers, eliminating the electrical relay optical/electrical/optical conversion process directly amplify optical signals to compensate for transmission line losses, extend distance relay. Typically operate at near saturation, the signal input power of about a 20dBm.
Require both a high EDFA gain and output optical power, there should be real-time monitoring of its operation state. EDFA is used as a power amplifier, mounted after the optical transmitter, light emitted optical signal is amplified to compensate for loss of passive optical devices and to increase the transmission optical power.
WDM ring network physical topology is a ring, the distribution of its bearer service type determines the wavelength channel distribution structure, and therefore should be based on actual WDM ring bearer service distribution and planning organization structure wavelength channel allocation among WDM nodes. A typical metro service distribution, there are two types, namely centralized convergent and uniform type, and therefore the wavelength WDM ring network path allocation structure can also be divided into centralized converged hybrid form, uniform type (mesh) or the above two types of . Converged distribution business in general is a star or binary form, ie, traffic distribution focused on one or two special nodes (such as tandem or pass office); distribution business metro aggregation layer is generally a single star or binary shaped.
Triple play video multiplexing optical fiber 1000M / 100M rate and Internet edge router or switch linked pooled to achieve cell network access to Internet, through the optical fiber and optical fiber CATV networks linked by fiber switch.
Broadband Internet access, cable television (CATV) access and IP telephony triple play fiber to the home (FTTH) solutions for networking.
Network core equipment is placed in the community room or building room triple play video multiplexing optical switches, the triple-play video multiplexed optical fiber 1000M / 100M rate and Internet edge router or aggregation switches linked by optical fiber switch, to achieve residential network access Internet, via optical fiber and optical fiber CATV network linked.
Generally, CATV optical signal through an erbium-doped fiber amplifier (EDFA) amplification and then access triple play video multiplexing optical switches.
Triple play video multiplexing and placed in the user's home optical network units linked by fiber-optic switches and point the way through the fiber, while providing users with high-speed duplex 100M speed Internet, CATV broadcasting and IP phone access.