2. ADSL Yanmei Tong (103801) Asymmetric Digital Subscriber Line

3. Frequently Asked Questions About ADSL n What is it? n What are the benefits? n How fast is it? n How does it work? n What can I use it for? n Where is the technology headed? n How do I get ADSL?

4. What Is ADSL? n ADSL is a type of DSL which is best suited for residential use. n ADSL is a new broadband communication technology that creates high-speed access to the Internet and remote networks using the phone lines that are already present in your home. ADSL is superior to analog modems in many respects.

5. What Are the Benefits of ADSL? n You can talk on the phone and use the Internet at the same time n You can connect to the Internet at up to 140 times faster than analog modems n Your connection to the Internet is always on

6. What Are the Benefits of ADSL? n Your home has its own dedicated connection n Your connection is highly reliable and secure

7. What Can I Use ADSL for? n Faster downloads of anything digital n CD-quality audio n Graphics-rich web sites n Faster and better multimedia n High-speed multiplayer games

8. Lightning Fast Internet n ADSL offers different speeds –Full-rate ADSL has the potential to deliver data at speeds up to 8 megabits per second. –Service providers can also offer slower rates (from 256 kilobits per second) at lower costs.

9. Always-on, Simultaneous Connection n Because the data signals are transmitted separately from voice signals, your Internet connection stays on all the time –No more logging on and off –Connect to the Internet without having disable call waiting –No more waiting-just open your browser and go!

10. Dedicated Connection n Unlike a cable modem, ADSL gives you a dedicated line to the Internet. With cable modems, you are using a shared line with all the others users in your neighborhood.

11. ADSL Reliability n One strength of phone providers is their small number of service outages per year, something cable company cannot claim. n Even if the power goes out, you will still be able to make phone calls. n Unlike cable modems, your connection speed will not be affected by how much bandwidth your neighbors use.

12. ADSL Security n The dedicated connection that ADSL uses provides more security than cable. n Cable modem users share bandwidth with their neighbors. Information traveling across the network is easier to snoop.

13. How Does ADSL Work? n One phone line delivers voice and a high-speed Internet connection n Voice/fax calls only use the frequencies below 4 khz n Frequencies above 4 khz are reserved for data transmission

14. ADSL History n 1995-Bell Labs discovers a new way to make traditional copper wires support new digital services. n 1990-phone companies start deploying high-speed DSL (HDSL) to offer T1 service on copper lines without the expense of installing repeaters.

15. ADSL History n Phone companies begin to promote ADSL as a way to enter the video market n 1995-innovative companies begin to see ADSL as a way to meet the need for faster internet access. n Now-ADSL is being deployed for faster internet access across the united states.

16. Different Types of ADSL n Full rate ADSL (G.Dmt) n Universal ADSL (G.Lite)

17. Full-rate ADSL n Full-rate ADSL boasts data rates ranging from 1.5 to 8 megabits per second “downstream” from the internet to your computer. n “Upstream” data rates from your computer to the internet are as high as 1 megabit per second

18. Full-rate ADSL n Potential data rates decrease with increased distance from the phone company CO (central office)

19. G. Lite ADSL n G.Lite ADSL is a scaled-down version that delivers up to 1.5 mbps downstream and 384 kbps upstream n Less expensive than full-rate ADSL n G.Lite performance is unacceptable for voice and entertainment applications

20. Splittered Vs. Splitterless n Conventional phone wiring can transmit –Voice signals (phone service) –Data signals (DSL service) n Some DSL providers separate the wiring used for voice from data n A splitter is used to achieve this and influences how you should –Build your home network –Select your DSL modem or residential gateway

21. ADSL Future n Broadscale, nationwide ADSL rollouts are happening today n “Given a choice... Those most willing to pay for the service choose the telephone company 4 1/2 times more differently than cable.” Survey. The yankee group. November 1998

22. ADSL Future n ADSL service “ in the end will be nearly ubiquitous”-peter mcgrath, newsweek. November 23, 1998

23. ADSL Summary n ADSL provides a new way to use existing phone lines. n It’s faster! n It’s always on! n Voice and data on one line at the same time! n ADSL is the best way to get online!