This document provides an overview of Digital Subscriber Line (DSL) technology. It begins by explaining that DSL allows data and voice to be sent over the same phone line by using different frequency bands. It then describes the main types of DSL, including Asymmetric DSL (ADSL), which provides faster downstream speeds, and Symmetric DSL (SDSL), which provides equal upstream and downstream speeds. The document outlines some specific DSL technologies and their speed capabilities. It also provides a basic diagram of how a DSL connection is configured and discusses advantages like simultaneous phone and internet use, as well as disadvantages like slower speeds over longer distances from the central office.

1. République Algérienne Démocratique et Populaire
Ministère de l'Enseignement Supérieure et de la Recherche
Scientifique
Université d'Adar
Faculté des Sciences et de la Technologie
Département des Mathématiques et Informatique
Présenté par: Aissa Eldjouzi
Moulay Omar Rabiaa
Année Universitaire 2021 / 2022.

2. DSL

3. INTRODICTION

4. What is la technology DSL?
Send data and voice in the same phone line
Originally the wiring has been installed for POTS (“plain old telephone service”) purposes and only has
been using frequencies from 300- to 3300 kHz. At the same time, wiring is having available bandwidth of 1
MgHz. Since POTS is occupying only a portion of frequencies, technology allows using the rest of the
bandwidth for data transmission without affecting telephone services.
This is thanks to the way the splitter works, which differentiates between the existing signals by frequency
(frequency multiplexing), as the frequency of the human voice is low and the high frequencies are
transmitted through which information and the Internet (upload and download)

5. Types of DSL
 Asymmetric DSL – ADSL, provides a wider frequency range for downstream transfers, which
offers several times faster downstream speeds. an ADSL connection may offer 20 Mbps
downstream and 1.5 Mbps upstream
Forms of asymmetric DSL include:
 ADSL has a downstream rate of up to 8 Mbps and an upstream rate of 384 Kbps.
 ADSL 2+ delivers download speeds of up to 20 Mbps and upload speeds of up to 850 Kbps.
 ADSL Lite offers slower speeds of up to 1 Mbps downstream and 512 Kbps upstream.
 R-ADSL (rate-adaptive digital subscriber line) delivers the same transmission rates as ADSL, but
the transmission speed can be adjusted by the modem.
 VDSL (A very high bit-rate digital subscriber line) is the fastest DSL service. It offers
downstream rates of up to 52 Mbps and upstream rates of up to 2.3 Mbps over a single copper

6.  Symmetric DSL – SDSL, splits the upstream and downstream frequencies evenly,
providing equal speeds to both uploading and downloading data transfer. This
connection may provide 2 Mbps upstream and downstream.
Forms of symmetric DSL include:
 SDSL offers equal upstream and downstream transmission speeds of up to 1.54 Mbps.
 HSDL (high bit-rate digital subscriber line) was developed in the early 1990s, making it
one of the oldest forms of symmetric DSL. HDSL offered data rates up to 2.048 Mbps
but required multiple phone lines

7. Dsl design
DSLAM (Digital Subscriber Line Multiplexer or multiplexer for access to the subscriber's digital line
ISP Internet service provider
PSTN Public Switched Telephone Network (PSTN)

8. DSL configuration

12. Disadvantages
 As you move from the central office the connection becomes slower
 DSL connection works better when the PC in question is nearer to the
provider’s office.
 DSL connection receives data faster, but it lacks speed during
transmission.
 DSL connection receives data faster, but it lacks speed during
transmission.

13. Advantages
 You can use the internet and the phone line at the same time.
 DSL technology doesn’t require new wiring, as it uses the existing phone
line that you already own.
 Service providers provide the DSL modems.
 You can choose between different connection speeds and prices from
various providers.