ADSL vs CABLE

1. ADSL vs CABLE This project is a direct comparison between Mpowered’s ADSL modem and EastLink’s Cable modem. Robert Allen Chris Angione Micheal Hunsley Jeffery Learning

2. Mpowered PC • Advertised: 8 Mbps down stream and 2 Mbps up stream. • Stated Actual: 250 Kbps down stream and uploading varies too much to be stated even in an average form. • Dedicated line for each customer. • Can be divided indefinately but up to 3 IP addresses can be purchased. • Created via ANSI standards for the modems.

3. Eastlink Cable • Advertised: 10 Mbps downstream and 3 Mbps upstream. • Stated Actual: 250 Kbps downstream and again no stated average for the upstream. • Proxy Server to save and buffer files (makes the subsequent download faster) • Dynamic IP addresses. Up to 4 may be purchased under one account.

4. Barriers • Noise in all shapes and sizes • Distortions • Slower systems between nodes or between the major server and the user’s computer • Number of times the signal must change medium • Distance

5. The two comparedDownloading and Uploading speeds • The download speed of Netscape navigator 4.76 (22683B) was about 45 seconds on Mpowered PC and 30 seconds on Cable. Uploading speeds are compariable but varied greatly.

6. ADSL Pro’s • Mpowered PC have a dedicated line. Which means that each customer is given so much bandwidth. Which means that if the systems between the phone company and the user are improved so will the service provided. • Developed under ANSI stated standards which allow the modems to maintain a certain level of consistency. • www.stfx.ca/people/x97/x97hdq/projects/info465/ADSL.GIF • Mpowered PC use a standard internal IP address and an external dynamic IP address (for security).

7. ADSL Con’s • Mpowered PC have no proxy server which means there are no queued files or any buffering of any kind. • Standards can impede innovation • Connection must be physically close to the nearest phone company (18000ft but it is expanding) • Inhouse networking. (Mpowered only allows the line to be split 3 ways)

8. Cable Pro’s • Proxy Server (This is the server that saves and buffers files for quicker access to these files for future use) • Can have up to 4 computers working on one line • A lot further reaching in distance area of effect • Use QPSK and QAM interchangeably

9. QPSK • Phase-shift keying (PSK) is a method of transmitting and receiving digital signals in which the phase of a transmitted signal is varied to convey information. • Quadtrature- Means that the phases differ by either -90 degrees or +90 degrees • The digital signal is broken up timewise into individual binary digits • This allows binary data to be transmitted at a faster rate per phase change than is possible with biphase modulation. In four-phase modulation, the possible phase angles are 0, +90, -90, and 180 degrees; each phase shift can represent two signal elements

10. QAM • QAM (Quadratrue Amplitide Modulation) • Has one major carrier wave which is used as a means of comparison (it never fluctuates in amplitude) • LSB (Lower Side Band) is any wave that is below the carrier signal • USB (Upper Side Band) is any wave that occurs above the carrier signal • QAM is wasteful (75-80% of power used by the carrier signal during voice and 66% during other QAM communications)

11. Cable Con’s • Virutal IP addresses are slower then static IP addresses • Lack of standards amoung competing companies (less consistency between products) • Increased traffic will affect your performance adversely

12. Conclusion • Both are very comparable in current services provided. As the population increases, the Cable modem system performance will be adversely effected. On like terms if the overall system is improved (routers, connecting cables etc…) Cable will be a more effective do to their bandwidth usage of QPSK communication.