Pon Technology and FTTH

First, the introduction

Although ADSL has become the current mainstream broadband access technology, but if you want to provide high-definition or interactive video business, ADSL will be powerless. The bandwidth potential of optical access is not protected by other access modes, replacing copper cables with fiber in the access network environment can bring a series of benefits: eliminate the bottleneck of telecom network, reduce maintenance cost, easy to realize business integration and provide new business, improve information transmission quality and communication reliability, facilitate system future expansion, save construction investment and so on. Major operators attach great importance to the construction of optical fiber access network, such as the Beijing communication as early as the late 90 in the Beijing area of 100 new users of optical cable ring, which covers most of the more than 100 cable rings in Beijing, the basic realization of the Beijing area of fiber to the building or community (FTTB/FTTC). Although optical fiber to the user (FTTH) is the fundamental solution to broadband access, but the current large-scale implementation of FTTH is not economical. At the present stage is to realize FTTB/FTTC, the transmission technology can be used by active optical access (including PDH, ATM, SDH, GE/FE, etc.) mainly, but passive optical access (PON) began to be applied. For Ftth,pon, it will be the most economical and effective technical means.

Second, passive optical network (PON)

Compared with the active optical access technology, PON eliminates the active equipment between the end and the client, which makes the maintenance simple, high reliability, low cost, and can save the fiber resources, is the future FTTH main solution. With the gradual reduction of the cost of PON, not only does Pon have a certain application market in FTTB/FTTC, but also the use of PON to achieve FTTH in Japan and other developed countries have made great progress. At present, the PON technology mainly has apon, EPON and Gpon, the main difference is that different two-layer technology is used.

Apon is the 90 's in the middle of the ITU and the full Service Access Network Forum (FSAN) standardized PON technology, Fsan at the end of 2001 Apon renamed to Bpon,apon the highest rate of 622Mbps, the second layer is the ATM packaging and transmission technology, Therefore, there are insufficient bandwidth, complex technology, high price and low efficiency of carrying IP service, which fail to achieve success in the market.

To better adapt to IP services, the first Mile Ethernet Federation (EFMA) introduced Epon technology at two-tier Ethernet instead of ATM in early 2001, and the IEEE 802.3ah Working Group standardized it Epon can support a 1.25Gbps symmetric rate and will upgrade to 10Gbps in future. Epon products get a greater degree of commercial, because it combines Ethernet technology and PON technology, thus becoming a very suitable for IP Services broadband access technology. The EPON system for gbit/s rate is also often called ge-pon.

At the same time, EFMA proposed the Epon concept, Fsan also proposed that Gpon,fsan and ITU have standardized it, and its technical feature is to use the ITU-T definition of GFP (Universal frame code) to encapsulate and map the Ethernet, TDM, ATM and other services in the two-layer. can provide 1.25 and 2.5gb/s downlink rate and all standard uplink rate, and has powerful OAM function. Gpon has a clear advantage in terms of high rates and support for multiple businesses, but the cost is now higher than epon, and the maturity of the product is also inferior to epon.

Third, the development prospect of FTTH in China

According to the consultancy, the number of FTTH users worldwide will reach 8 million in 2005 and will reach 34 million by 2008. According to IDC data, the global FTTH fiber access market will increase from 503 million U.S. dollars in 2003 to 2.4 billion U.S. dollars in 2008, an annual growth of 37%.

China has begun to promote the application of ftth/fttp in local areas, mainly the following models: First, the emerging operators in the pipeline/fiber resources in the region using FTTP rapid business, such as Chongqing Netcom, Changsha Netcom and other internet cafes a street, the Great Wall broadband Pon community access, etc. The second is that some of the resident network operators use FTTP to occupy the access and user station network market, and then provide the basic business operators with public access platform; Third, the government or equipment manufacturers to promote commercial testing, such as the Wuhan Long FEI apartment FTTH pilot achieved 158 of "three nets in one", Among them, 110 of them use Pon mode access, 48 use point-to-point MC access, but also plans to further expand the scale of the test; four is the FTTH test and local business, such as the Beijing communication to carry out epon test and FTTH demonstration Community construction, Guangzhou Telecom's Epon broadband access test.

FTTH is the development direction of broadband access, but it is not possible to deploy FTTH fully because of economic reasons. FTTH success needs to depend on a number of factors, such as equipment prices and deployment costs must continue to decline, must have more broadband applications to drive users to generate higher bandwidth requirements, FTTH in the competition with other broadband access technology (such as ADSL2,VDSL,BWA, etc.) must be able to show a more full advantage, Further liberalisation of the telecommunications market and strong government policy and economic support are also crucial to promoting FTTH development. As time goes on, the cost of fiber optic cable and optical components is declining steadily, and the progress of various optoelectronic technologies has created the conditions for the realization of FTTH; the demand for new broadband services, such as IP TV, will further stimulate the development of FTTH; the increasing burden of the existing copper cable network maintenance has also prompted operators to favor the fiber network , pressure from rivals such as emerging operators could force traditional telecoms operators to implement FTTH in advance to ensure a competitive advantage in the broadband sector. Therefore, there is reason to believe that FTTH should have a broad prospects for development.

As the PON is still in the market start-up and promotion stage, for FTTC/FTTB, active access is still the main means of optical access. In the business building, due to a wide range of business, it is advisable to use a variety of business interface integrated optical access equipment, the typical equipment is mainly based on SDH MSTP transport platform, Ethernet or ATM based on the multi-service access platform. MSTP has been favored in recent years because of its good compatibility with the SDH network of traditional operators, and has been widely used.

The 2008 Beijing Olympic Games will become the first true meaning of the broadband Olympic Games, broadband access is to achieve the foundation of the Broadband Olympics. By the 2008 Olympic Games, optical fiber will be deployed to all Olympic venues, it is expected that in the Beijing area, in addition to the implementation of fiber to the building/community, but also to achieve the fiber to some of the client's office and even to some families, SDH (MSTP), Ethernet, ATM, pon these fiber access technology can be applied , especially with the development of optoelectronic devices and the declining price, the superiority of PON technology will gradually appear and play more and more important role. Although the Olympic communications mainly rely on the current large-scale use of sophisticated technologies and networks, new technology in the market share will not be too large, the 2008 Olympic communications business demand for FTTH market pull is limited, but due to the Olympic Games during the inevitable use of a large number of new technologies to show the latest achievements of communications development, So the 2008 Olympic Games to FTTH and other broadband technology in China's application will have a greater incentive effect and exemplary role.