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             Overview 
            In the past, video, audio, voice, and data services required at 
              least four separate networks. Video was distributed on coaxial lines, 
              audio over balanced lines, voice used copper cable pairs, and data 
              services required coaxial or twisted pair cables. This multiple 
              network environment was expensive to install and difficult to maintain. 
              ISDN is different. It integrates voice, video, and data over the 
              same network and cable plant with quality not available in previous 
              switched services. It offers features such as on demand networking, 
              automatic bandwidth availability and on the fly connectivity. These 
              advanced services are available, in large part, because ISDN is 
              digital.  
            The Integrated Services Digital Network (ISDN) is becoming a mainstream 
              telecommunications network that will serve a wide variety of users' 
              needs. Experts call ISDN the telecommunications network of the 21st 
              century, the foundation upon which to further build the information 
              age. With its narrowband and broadband aspects, the ISDN data highway 
              will evolve from today's switched telephone and dedicated leased-line 
              networks to become a unified global network carrying voice, data, 
              video, interactive pictures, and other services to homes and businesses. 
             
            Once touted as the ultimate subscriber technology, ISDN has seen 
              slow deployment until recently, due to lack of standardization and 
              high cost. Most Regional Bell Operating Companies (RBOCs) deliver 
              ISDN as a dial-up, metered service. This means that during business 
              hours users are charged for each minute the ISDN connection is operating. 
             
            ISDN has also lost appeal as analog modems have reached the 56 
              Kbps level. Modem suppliers now provide software that lets users 
              use two 56K modems as a single 112 Kbps connection, close to the 
              data rate available from an ISDN connection.  
            At the other end of the spectrum, DSL and cable modem services 
              are delivering bandwidths that are an order of magnitude greater 
              than ISDN. While ISDN will not be disappearing any time soon, all 
              projections indicate that growth in the ISDN market is flattening. 
              It is expected that ISDN will be relegated to applications where 
              cable modem or DSL service is not available.  
             Market Research 
            Analysts indicate there are approximately 2 million ISDN lines 
              deployed in the U.S., representing about 1.1% of all lines. International 
              Data Corporation predicts the worldwide installed base of DSL modems 
              from the total Internet connectivity methods to be growing from 
              14.9% in 2000 to 20.4% in 2002, with a worldwide installed base 
              growing from 14.87 million to 28.61 million units. 
            Xilinx Solutions 
            Xilinx provides significant value in an ISDN modem when used to 
              interface various ASSPs together, resolving differences in their 
              interface control signals. 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.  
            As ISDN modems evolve into residential gateways, they will support 
              multiple home networking interfaces. Spartan-II FPGAs provide system 
              integration and interconnectivity to these interfaces, hence provide 
              decreased time-to-market, increased time-in-market, and the rapid 
              product proliferation in this market. Please view the presentation 
              to see how Xilinx solutions can help you build products for this 
              fast evolving market place. 
                     Analog 
              / Dial-up 
               Cable 
               xDSL 
               ISDN 
               Satellite 
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