EXFO - Squeezing Copper into Delivering More

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By Chris Dunford, Product Line Manager, EXFO Wireline Division


The insatiable thirst of consumers for more broadband services (IPTV and high-speed Internet) continues to increase, and this, while today's economic woes push back on the installation of newer last-mile fiber solutions (FTTH). This reality is forcing service providers to pursue high-speed alternatives.


One convenient high-speed alternative to fiber is squeezing and enhancing DSL to support greater capacity broadband services; this is known as bonding. Bonding is covered by multiple ITU-T standards depending on Ethernet or ATM implementations (G.998.x). Bonding ADSL2+ and/or VDSL2 allows service providers to reuse their copper infrastructure and to offer higher speeds within a given serving area, or to expand their reach to new areas, to attract more customers with high-speed package service offerings.


The Changing Environment


Traditional DSL offers a 1:1 capability, that is, one DSLAM port to one customer modem over a single copper pair, and bonding the DSLAM means doubling the capacity using two ports over two copper pairs. Converting the typical DSLAM to bonding is a question of loading new firmware/software into their fieldprogrammable gate arrays (FPGA) and DSPs to couple together two existing DSL ports. The biggest change is to the customers' modems, since they only contain a single-port DSL chipset. To adopt bonding, a customer's modem must change to make use of dual chipset capability to capitalize on the two pairs into the subscriber premises.


Doesn't a service provider only have so much copper? Yes, of course. However, over the last decade, service providers have been losing landline voice customers to mobile operators and now have unused copper pairs. By supporting bonding, not only is the service provider recovering from lost voice revenue, but they have the potential to increase their revenues substantially by offering bonding. Bonding can attract new customers or influence existing customers to subscribe to new service...

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