FTTH in China: Juggling 100 million users

China International Optoelectronic Expo (CIOE) held its 13th annual conference in Shenzhen, China; the FTTH/ODN/OTN China Conference (FOOCC) ran concurrently. Previously called the China Lightwave Conference, the FOOCC has broadened it focus beyond FTTH to include optical distribution networks and optical transport networks.

China's service providers will have substantial fiber networks under management with millions of fibers and many millions of ONU/ONT devices sitting at customer premises. China Telecom is building an FTTH network that will reach 100 million homes by 2014. Within Shanghai, a city of 23 million people, Shanghai Telecom will pass 50% of the city's 9 million households by year-end 2011 and 100% by year-end 2012.

The focus of service providers and equipment vendors is shifting from debates around PON technologies to lowering the costs of fiber deployment and long-term fiber network management. China's service providers are developing internal standards for ODN but open, shared standards are unlikely to emerge.

The EPON-versus-GPON debate misses the point; China is deploying both.

In earlier conferences, communications chip companies presented respective views on GPON versus EPON. The panel discussions at this year’s conference were intense and the audience hung on every word in a presentation from Wang Bo, Business Manager of the Technology Department of China Telecom, in which he discussed PON specifications, testing of EPON and GPON, and the subsequent results. While his presentation was central to the conference, his topics included not just EPON, GPON, and 10G PON but also installation and remote management of CPE (customer premise equipment).

Both EPON and GPON are being deployed in China. EPON OLT port shipments for China represented more than 60% of all PON OLT ports for China's consumption in the first and second quarters of this year. Initial China Telecom provincial FTTx network rollouts began with EPON and are continuing with EPON, while newer FTTx networks are beginning with GPON.

10G EPON deployments have begun in several provinces in China. According to Wang Bo, XG-PON (10G GPON) is behind 10G EPON in maturity and interoperability; however, we expect to see XG-PON deployments in the future. Bottom line, China will deploy both flavors of 10G PON over time.

FTTx networks need optical layer management solutions.

Service providers want to avoid traffic disruptions on their FTTx networks and they also need to lower network deployment and maintenance expenses. To facilitate this, PON equipment vendors and service providers are working on solutions that embed OTDR (optical time-domain reflectometer) diagnostics and reporting data into both central office and CPE, thereby improving the quality of network installations and ongoing network management.

Broadcom's FOOCC presentation included a discussion of the shared wavelength OTDR for PON and the need for the PON component ecosystem to embed optical layer management features. Ideally, the embedded OTDR management and diagnostic functions would be standardized across the PON MAC SoC vendors and equipment vendors. With standardization, consistent optical layer monitoring and management would be possible even when an FTTx network has equipment from multiple vendors.

China Telecom presented general requirements for embedded OTDRs in PON equipment. The embedded OTDR should be applicable to all types of PON technologies and across all speeds, without impacting normal service.

The costs of PON equipment continue to decline rapidly. China Unicom stated that the costs for PON equipment, OLT ports and ONUs/ONTs, account for less than 10% of the total FTTx network build. Consequently, service providers are seeking ways to lower installation costs, such as the cost of bringing up the ONT at the subscriber's home. China Telecom is exploring user card identification based on an integrated terminal management system (ITMS). China Telecom’s ITMS enables “zero-touch” whereby the ONT is brought online without the need for an on-site technician.

China Telecom developed 14 internal standards for ODN in 2010, covering zero-touch installation, intelligent ODN, and centralized installation procedures. When Ovum asked the panel of service providers and vendors if industry standards for ODN will emerge, the overall response was "unlikely." Every service provider has its own understanding of ODN and related innovations. Sometimes the innovation is at the provincial/city level based on localized network history and habits.

The bottom line is that ODN planning and standards are proprietary. We will see best practices but the emergence of worldwide standards is unlikely.

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