• INTRODUCTION OF DSL TECHNOLOGY
• GENERAL MODEM FOR DSL CONNECTION
• BASIC TECHNOLOGY(OPERATION)
• TYPES OF DSL TECHNOLOGY
• DSL VS CABLE
• ADVANTAGES OF DSL
.DSL stands for DIGITAL SUBSCRIBER LINE.
.DSL is a broadband high-speed Internet technology that brings high bandwidth
information to home and offices over ordinary copper telephone lines.
.DSL technology provides high-speed, broadband network connections to
homes and small businesses.
.DSL utilizes the same cabling used for normal telephones, but it can offer
higher data rates through use of the digital modem technology
ADSL(Asymmetric Digital Subscriber Line)
VDSL(Very high-bit-rate Digital Subscriber Line)
SDSL(Symmetric Digital Subscriber Line )
RADSL(Rate Adaptive Digital Subscriber Line)
HDSL(High bit/data rate Digital Subscriber Line)
ISDN DSL(Integrated Service Digital Network)
Asymmetric Digital Subscriber Line (ADSL):
.Most home and small business users typically use ADSL.
.The transfer of data from the internet to PC is much faster
than the transfer from PC to internet.
.Downstream speeds for ADSL range from 1.59 Mbps, while
upstream speeds are up to 1.5 Mbps, for a distance of 18,000
feet from the service providers premises.
Very high-bit-rate Digital Subscriber Line(VDSL):
.Provides high speed internet connection but works only over a short distance.
Symmetric Digital Subscriber Line (SDSL):
.Does not allows to use the phone at the same time. But internet speed of sending and receiving data is
Rate Adaptive Digital Subscriber Line (RADSL):
.This service is a variation of ADSL but the modem can adjust the internet speed .
High bit/data rate Digital Subscriber Line(HDSL):
.HDSL was the first DSL technology that used a higher frequency spectrum of copper, twisted pair
Integrated service digital network(ISDN DSL):
.Symmetric data rates of up to 144 kbps using
existing phone lines.
.Capable of using the same modem or terminal
adaptor used for ISDN and is always available.
.Both DSL and Cable Modem technologies offer high-speed
.Even though they are similar in many respects, the two
technologies differ on some fundamental
aspects such as:
Speed:.Cable can achieve, theoretically, up to 30 Mbps, while most
forms of DSL cannot reach
beyond 10 Mbps.
· Interactive Video – movies on demand, video on demand,
· High-speed Data communication – Internet access,
Telecommuting, Remote LAN access ,specialized network
.DSL service is always ON and we can still use the phone for
.Broadband speed is much faster than dial up service.
Fixed monthly billing , regardless of time usage.
.Digital data is directly transmitted to computer as digital
data which uses much wider bandwidth for transmitting.
DSL has one significant downside:
.As you move away from the central office ,the connection
.This results is distortion of signal.
.International Telecommunication Union (ITU). G.992.1 (G.dmt), G.992.2 (G.lite)
standards information. http://www.itu.int
· American National Standards Institute (ANSI). ANSI TI.413-1998, ADSL Metallic
· Universal ADSL Working Group. G.lite standards information. http://uawg.org
· Standards Committee T1-Telecommunications. XDSL standards and relevant
documents from T1E1.4 Working group. http://www.t1.org
· European Telecommunications Standards Institute (ETSI). ADSL, VDSL and SDSL
· Internet Engineering Task Force (IETF). ADSL MIB working group.