Asymmetric Digital Subscriber Line(ADSL): Asymmetric Digital Subscriber Line (ADSL)
Table of Contents: Table of Contents Introduction
Conclusion Introduction: Introduction High speed data link.
Pure network connection.
Coming with different schemes:
CAP, QAM, and DMT.
Using special modems called endpoints Slide4: Server Internet CORE
Network ADSL Existing Copper ADSL 1.5 to 9 Mbps 16 to 640 kbps ADSL Connection Advantages: Advantages Connectivity – always connected
Ease of use
Speed Slide6: FDM POTS POTS Upstream Upstream Downstream Downstream Echo Cancellation Frequency Frequency 1 Mhz 1 Mhz Create Multiple Channel Nyquist’s Theorem: Nyquist’s Theorem Maximum data rate = 2H log2 V bits/sec
H = low-pass filter of bandwidth
V = signal discrete levels Drawbacks: Drawbacks Availability
Cost of installation and equipment
Not standardization Slide9: Splitter ADSL
modem Phone Phone Telephone line Voice + ADSL Voice (only) ADSL (only) Fig. 1 ADSL Problem Slide10: Splitter ADSL
modem Phone Phone Telephone line Voice + ADSL Voice (+ ADSL leakage) ADSL (only) Fig. 2 ADSL Problem ADSL Filter Conclusion: Conclusion ADSL is a high speed access to internet.
ADSL has advantages but it also has limitations.
ADSL needs to extend the access distance.
ADSL might improve the speed.
ADSL needs to be standardized.