DSL and Cable Modem

DSL and Cable Modem

Introduction

In the recent years, great development has been seen in the technologies of DSL. The task of DLS technologies is to enable the use of wide installed twisted pair cables i.e. base of copper set by the companies of telephone in order to provide such phone service i.e. ubiquitous for digital transmission of high speed (RAD, n.d.).

There are 2 methods that are applicable in DSL and they are ADSL and SHDL:

ADSL i.e. Asymmetrical Digital Subscriber Line is able to support around 1 Mega bits per second in the uplink direction and 8 Mega bits per second in the downlink direction. DMT i.e. Discrete Multitone code is used for ADSL interfaces as a line code.

SHDSL i.e. Single pair High speed Digital Subscriber Line technology supports 2.312 Mega bits per second for symmetrical transmission (RAD, n.d.).

DSL

Cybermind DSL service providers are efficient and reliable service provider in the United States. They provide the following features in their DSL services (Cybermind, 2009).

Fast Broadband Internet Service

Unlimited personal e-mail accounts

DSL can be used without phone line

Spam protection (SpamSlam™ behind-the-scenes)

Spyware and Virus protection

Personal Web Space of 50MB

super high speed and cost effective Internet service (Cybermind, 2009)

Email access can be speed up by the use of high speed Cybermind internet access. Fats uploads and fast downloads are possible through high speed Cybermind internet access. It provides downloading of web pages and e-mail which is 10 times faster as compared to dial up. DSL provides direct connection to the internet whereas in cable technology shared bandwidth is used which fluctuates the speed. DSL provides the more steady speed to the user (Cybermind, 2009).

The Cybermind DSL provides many classes of DSL. These classes are given below.

ADSL

ADSL is considered to be the most promising DSL technologies. ADSL makes influence in small office and in residential access. The bandwidth for downstream is higher than the bandwidth of upstream which implies that ADSL is asymmetric. Traffic in the course of subscriber is said to be downstream and in upstream, data is sent to the network from the subscriber. Te asymmetry of ADSL is utilized in order to increase the bandwidth of downstream (Sabatino, 2000). The crosstalk among the channels of downstream is reduced rather eliminated because of the same amplitude of downstream signals. More interference will be tolerated by the upstream signals because upstream signals possess smaller amplitude. The reason of the smaller amplitude is that they originate from distinct distances. The nature of asymmetry of ADSL offers good support to client server applications and web applications (Sabatino, 2000). The bandwidth is divided into 4 classes of transport in order to make it asymmetric:

lower bandwidth duplex channel

higher bandwidth simplex channel

POTS channel

duplex control channel

With the help of POTS channel, transmission on the lower bandwidth duplex channel and the high bandwidth simplex channel do not interfere. In this way, ADSL is able to hold and bear the data for small office and residential use. Line condition, local loop length and wire gauge are the factors ...