Fixed construction potential solutions - VDSL

"Broadband China Strategy" by 2020 China's fixed broadband subscribers to reach 400 million fixed broadband household penetration rate reached 70%, the number of Internet users reached 1.1 billion urban broadband access capacity of 50Mbps, rural broadband access capacity 12Mbps. How to effectively implement such an ambitious communications project is placed in front of the major operators of a problem. China from the current mainstream carriers fixed construction situation, FTTH undoubtedly get the operator's favor, but full use of technology to achieve FTTH broadband speed, how many there are some problems, such as high construction costs, low profitability, engineering deployment long period, the old district FTTH difficult, interoperability and so on. So, how to solve these problems the operator's problem? VDSL technology is a promising solution.

From the perspective of technical maturity perspective, VDSL technology in Europe, North America, after years of business we have been popular. FTTH construction interoperability issues that exist in a relatively different manufacturers PON and PON terminal between the central office, the interconnection and VDSL VDSL central office terminal has been quite mature. VDSL infrastructure currently the main chip only Broadcom, Lantiq, Ikanos, the mainstream of the terminal VDSL chip includes Broadcom, Lantiq, MTK, Triductor, Ikanos, central office and terminal chip must follow the DSL interoperability specification TR67/TR100/TR114, and must Broadband Forum the IOP testing before commercial DSL interoperability lab. VDSL equipment interoperability is guaranteed by the main chip firmware, qualified VDSL CO or CPE main core must Broadband Forum certification, including TR67 (ADSL), TR100 (ADSL2/2+), TR114 (VDSL2), TR115 (VDSL SRA etc) specification test. Chinese shipments of mainstream VDSL terminal chip manufacturers have Broadcom, Lantiq, MTK, Triductor, 2013 China Telecom organized the interoperability testing VDSL, including interoperability testing G.vector, G.INP and other advanced features of the ideal test case and can meet the requirements of different manufacturers interoperability. In addition, VDSL terminal chips in addition to support VDSL2 central office, but also backward compatible with ADSL/2/2+, ADSL and VDSL to meet then mixed scenarios.

From the perspective of the carrying capacity in terms of bandwidth, VDSL technology also meet the 2020 Chinese urban broadband access broadband China strategy proposed to achieve 50Mbps, 12Mbps rural broadband access capacity requirements. VDSL2 technology is quite mature, with a capacity of over 300 meters 50Mbps bandwidth. In addition, Vectoring technology has been in commercial quantities in 2014, found within 300 meters downstream can support 100Mbps of bandwidth capability, within 500 meters of 80Mbps bandwidth capabilities. G.fast technology is expected after 2015 with commercial power to support bandwidth capability within 100 meters of 1Gbps. Therefore, VDSL+FTTB or VDSL+FTTC this application mode can well meet the requirements of broadband speed broadband China strategy.

From the perspective of the construction costs, the use of FTTH technology deployment laying fiber to the home network requires a comprehensive, but VDSL technology can take full advantage of the existing network of the original copper line resources already deployed in some twisted family, if need to deploy VDSL, you do not need to reproduce the wiring line cost savings. Secondly, VDSL network without deploying FTTH networks like optical splitter, optical connectors and other devices, which are very expensive period, saving the cost of network components. In addition, VDSL terminal and infrastructure costs are much lower than FTTH terminal and infrastructure costs, which reduces the equipment cost. Overall, construction costs line VDSL users about one-third of the construction cost of the first-line PON subscribers. This cash-strapped operators provincial company or to the city, it means they can spend less money, construction of a high-bandwidth network, which also meets the requirements of the national broadband strategy.

From an engineering point of view deployment, FTTH network construction is equivalent to re-building the access network, the central office OLT main work includes deployment, debugging, fiber optic cabling, terminal and infrastructure interoperability testing and so on, a long construction period. The VDSL network deployment is relatively simple, and can utilize the existing copper line resources, eliminating the need for network cabling link, simply replace the ADSL central office VDSL central office, and there are no interoperability issues, VDSL terminal equipment can be directly and VDSL infrastructure equipment to achieve docking, greatly simplifies the difficulty of engineering deployment, while compressing the construction period and construction costs of the project deployment.

Simply put, in China FTTH construction in full swing wave, there VDSL technology still has great significance:

(A) for the network construction funds tight provinces or cities, you can take advantage of VDSL technology for broadband speed, while saving construction costs;

(B) to ensure high-bandwidth fiber to the home at the same time an effective solution to difficult issues, improve user viscosity;

(C) the requirements for the network construction period short speed network transformation project, the network may consider the use of VDSL technology to FTTB+VDSL or FTTC+VDSL way to achieve broadband speed, significantly shorten the construction period.

Here are the main scenarios VDSL terminal:

(A) DSLAM upgrade part of the current network by ADSL DSLAM support the board upgrade to VDSL cards, VDSL gateway can be directly mounted at DSLAM, ADSL cat replace user's original VDSL terminals, broadband upgrade and provide IPTV, OTT etc. can control business.

(B) replace the existing ADSL infrastructure by MDU
If the original can not be upgraded to support VDSL DSLAM central office, FTTB+VDSL technology can be used in new residential MDU or replace the original can not be upgraded DSLAM. VDSL gateway can be directly mounted in the MDU, the user to replace the original cat ADSL VDSL terminals, broadband upgrade and provide IPTV, OTT, etc. can control business.