■ EPON+EOC Networking
Network signals are transmitted from the ISP central office to the ONU at the community optical node, then over Ethernet cable to the EOC headend, where they are modulated and mixed with TV signals for output over CATV coaxial cable, and finally distributed to each home via branch splitters. At the user's home, the TV signal is used directly, while the network signal is demodulated by an EOC terminal for Internet access.
Solution Advantages:
· High bandwidth: EPON transmission speed is significantly improved, achieving symmetric 1.25G/1.25G rates within 20km
· High reliability and security: supports industrial-grade operating temperatures with hermetic TO packaging; passive ODN components resist lightning and electromagnetic interference
· High cost-effectiveness: fiber raw materials are abundant and inexpensive, offering higher rates and more users covered within 20km
■ Single-fiber Three-wavelength Transmission
The 1550nm optical transmitter wavelength carries TV programs; EPON downstream 1490nm and upstream 1310nm wavelengths are used for bidirectional data and interactive video services such as IPTV. Through CWDM (coarse wavelength division multiplexing), the three wavelengths 1310, 1490 and 1550 share the fiber and splitting platform, delivering all three FTTH wavelengths to the home—preserving broadcast TV coverage while enabling bidirectional broadband data and IPTV multimedia services.
■ Dual-fiber Three-wavelength Transmission
CATV service is carried over a separate fiber, split via a splitter to the ONU, converted by the ONU's built-in optical-to-electrical converter, and delivered to the TV via the RF interface. CATV and broadband services are carried on different fibers, so fiber faults do not affect each other.
■ Broadcasting Network Options Comparison
· EPON+LAN: good scalability, high access bandwidth, mature technology, but difficult home-wiring construction and high maintenance requirements
· EPON+EOC: solves home-entry problems, low construction cost, fully leverages existing HFC resources
· FTTH: multi-service, high bandwidth, easy maintenance, fiber-to-the-home—the core goal of triple-play convergence
