eSP : Home Networking : Broadband Access : xDSL Modems

xDSL

Overview

Most options for increasing modem speeds (from the standard 56 Kbps today to Mbps rates) involve changing the "wire" - cable, fiber optics, or satellites. But installing fiber optic cable to the home can cost $1000 to $1500 for ISDN support.

The telephone company's switching equipment, designed for short-duration telephone calls, is better used by separating data connections onto more efficient equipment. DSL modems are available primarily from the service providers (the telco or Internet Service Provider). While initially expensive, prices have dropped recently to $49/month from several suppliers for 384 Kbps speeds.

The x in xDSL refers to the number of DSL modem types which include ADSL, SDSL, VDSL, HDSL, and others.

Market Research

Dataquest expects manufacturers to sell 3.7 million DSL modems in the U.S. in 2000, outselling cable and ISDN combined. International Data Corporation predicts the worldwide installed base of DSL modems from the total Internet connectivity methods to be growing rapidly from 1.1% in 2000 to 4.4% in 2002.

Market Trends

Phone companies are excited about the coming of DSL. Their customer base stays with them for faster Internet access which translates to additional revenues. And, a typical telephone call lasts 3 minutes, while a person logged on through the 56 Kbps modem uses the same phone line for Internet traffic for more than three hours with no increased revenue for the telcos. Increased traffic requires increased investment in switching equipment, and DSL services enable local telcos to generate revenue from investments in additional switching equipment.

Competition from digital ISPs such as satellite and cable have caused a steep reduction in service costs.

Xilinx Solutions

Xilinx provides significant value in a DSL modem when used to interface various ASSPs together, resolving differences in their interface control signals. The functions typically performed will be in the areas of DMA control, interface controls to the buffer memory, data buffering, or the interface to the host computer. When the host computer interface is a bus standard such as PCI, Xilinx has a 32-bit, 33 MHz PCI solution available for integration with the Xilinx solution. The in-system programming capability of Xilinx devices enables features to be upgraded while the product is in the field, as well as decreasing the time-to-market for the product. The Spartan™-II FPGA or XC9500XL™ CPLD devices are ideal candidates for this low-cost application.

The Xilinx Spartan-II programmable logic solutions offer the flexibility to build products that can be reprogrammed in the field, at costs unparalleled to any programmable solution. As DSL modems evolve into residential gateways they will support multiple home networking interfaces. Spartan-II FPGAs provide system integration and interconnectivity to these interfaces, decreasing time-to-market, increasing time-in-market and rapidly proliferating products in this market. Please view the presentation to see how Xilinx solutions can help you build products for this fast evolving market place.

Types:

ADSL (Asymmetric DSL)
SDSL (Symmetric DSL)
HDSL (High Bit Rate DSL)
VDSL (Very High Bit Rate DSL)
RDSL (Rate Adaptive DSL)