Why promote fiber?
“Why do access networks demand fiber?” The answer is simple: currently single-mode silica fiber is the best transmission medium and is rapidly becoming the most cost-effective medium. Compared to coax, it has the following advantages:
An extremely low-loss of physical channel (0.2dB/km at 1550nm); resistance to electromagnetic interference; an extremely wide frequency range plus the ability to transmit electrical signals in any protocol format and to carry any information service, now and in the future.
The international standard (ITU-T G.983 series ATM-PON/BPON, G.984 series GPON, G.987 series XGPON-1; IEEE 802.3ah EPON, 802.3av 10G-EPON) specifies the device composition and technology index of TDM-PON, which guarantees the formation of global industry chain, builds an industry foundation for FTTB/H and guarantees large-scale market application.
The reliability and security of FTTH has been greatly improved: less susceptibility to lightning strikes and illegal interventions make broadcasting more secure.
Fiber has been cost-effective for CATV operators and their customers to deploy: for example, the cost of fiber (2 cores) is US$ 6-7cents/m and the cost of coax (-5) is US$22-24 cents/m, however, fiber displays better performance (bandwidth; frequency response; loss; anti-interference performance; lifetime; volume and weight) than coax.
The demands of customer service and triple play
CATV operators need to enrich their services: hundreds of HD programmes, thousands of interactive programmes, 4K UHD programmes, which require over 1G indoor bandwidth.
Under the background of government pushing Triple Play policy, facing up with high pressure from telecom’s IPTV and OTT. CATV operators must become communication business full service providers.
Fierce competition with Telecom operators forces CATV operators to speed up the construction of FTTH
Up to Q1 of 2017, the total number of telecom FTTH/O subscribers in China reached 314m, including 264m (84%) subscribers with 20Mbps or higher bandwidths and 157m (50%) subscribers with 50Mbps or higher bandwidths. The number of IPTV subscribers reached 97.88m and OTT subscribers reached 40m.
The combining strategy of Video + Content + Broadband + Mobile Phone + Smart Home increases subscriber loyalty (the average churn rate decreases by 60%). FTTH solutions that Telecom operators choose make an undeniable contribution to this!
Under such competitive conditions, unless CATV operators in China implement their own FTTH strategies, they will not achieve government construction targets for triple-play networks (telephone, broadband and TV).
Partial experience on FTTH field test and construction
Since 2006, CATV operators all over China started FTTB construction by adopting EPON. NGB proposals in 2008 promoted the large-scale construction of FTTB. Some operators therefore started experiment with FTTH, especially the one in SJZTV (Shijiazhuang CATV operator) has attracted much attention:
Dual-fiber TV + PON transmission platform: SJZTV firmly believed that an RF broadcasting channel displays better performance than EPON + EoC/IP broadcasting/RFoG. It is also different from the FTTH deployed by telecom operators.
Break through the limitation of tradition technical index and originally proposed -18dBm optical receiver: working together with Luster, SJZTV increased EDFA incident power up to +21dBm, breaking through the limit of +19dBm incident power, which decreases the quantity of EDFA in FTTH links, and lays the foundation for constructing efficient, cost-effective and high-quality two-way interactive networks.
Prospective FTTH ODN network design facilitated a smooth network upgrade with minimum change of ODN network: depending upon network conditions (e.g. multi-storey building, bungalows or villas), deployed suitable series of splitters and developed corresponding distribution boxes and terminal boxes, which got several patents.
SJZTV recorded better economic and social benefits from its FTTH experiment.
Over three years of deploying large-scale FTTH networks (since 2014), SJZTV recorded a US$ 10m accumulated income and US$ 1.2m indirect income (US$ 0.88m energy charge + US$ 0.32m maintenance). With the launch of a full service, SJZTV has made a significant contribution to the Wireless City, Skynet and Smart Transportation projects.
CATV operators carry out a lot of FTTH construction in rural areas in China, especially for newly built networks and indoor bandwidth can be up to 1Gbit. The main reason is that in rural areas, subscribers are dispersed which means the cost of coax is very high, construction and maintenance is difficult and outdoor devices are susceptible to lightning strikes. However, adopting FTTH is more cost-effective and easy to deploy.
Urgent FTTH strategy issues need to be solved
FTTH is the final version of CATV next-generation access networks in China. Launching FTTH is important – it requires strategy planning and proper design. Strategy planning must solve the following issues:
Which is the proportion of all fiber access networks in next three to five years? What is the milestone to achieve FTTH coverage and access rates?
What is the milestone of improving user bandwidth in FTTH? What is evolution process of network structure, including evolution process from FTTB to FTTH?
New technology challenges and the corresponding R&D layout.
We should make technical and management training programmers and a talent generation recognition strategy.
FTTH construction in China’s CATV industry is ushering in a historic opportunity. We need to seize the chance to build all fiber networks in China to meet future service demands in the next ten years.