Introduction to Asymmetric Digital Subscriber Line (ADSL)
When we consider the development of telecommunication technology
at this time, it can almost be the most
rapidly in telecommunications technology in the future is
The terminology can be defined as multimedia many media.
Therefore, the service can be made through the many missed
media. Whereas once, translated as multimedia
integration of voice, data and images.
The multimedia services are the most primary needs akan
a very large bandwidth. The need for this is that the bandwidth
initially to be problems on the network access. Akan
but after finding the optical fiber as transmission media
with very large capacity of the above problems are
can be technical.
Ironically, however the majority of the network is now tergelar
use the copper cable network. Therefore required a
“Injection technology” to improve the ability of copper cable
transmit information in signals.
Glance seem very contradictory, when we discuss the cable
copper as the media access services in the community-wide ribbed,
because the copper cables have limitations in
transmit signals berpita wide.
Meanwhile, in the last ten years this has been developed
a number of signal processing techniques to increase the bit rate of
dijital transmission via copper cable. Digital Subscriber line (DSL)
is a modem technology that uses telephone lines twisted
existing pair to transmit data berpita wide.
Development of DSL technology xDSL is the “technology series
broadband “that utilize the media for copper cable
stream services / service berpita wide. In the end technology
xDSL is a technology alternative that should
consider the technical and economic stage in the era
Development of the Copper Cable Network Technology
We already know the modem-modem which is circulating in the market
(voice-grade modem data) use copper cable as
transmission or the physical media can also use the said
physical transmission media access copper. Voice-grade modems generally
have a 28.8 kbps transmission speed through phone lines
normal. Twenty years ago, because of limitations in the field,
speed is only around the 1.2 kbps. May not have previously
who believe that the speed of the modem speed can reach 33.6
kbps, such as at the moment. However voice-grade modem
still not pass the limit of 3.4 kHz wide band. For example
V.34 modem that is capable of allocating 10 bits / hz band width,
is a picture that is quite interesting and
technology product development approach that seeks batasbatas
theoretical. Not only that, V.34 modem capable of sending and
receive data simultaneously in the same frequency band.
Even when the modem is U.S.. With the robotics technology has X2TM
able to achieve 56.6 kbps transmission speed through the channel
regular phone. This can be achieved as a result of development
the forward algorithm of data communication, signal processing dijital
and semiconductor technology.
Voice-grade modem operating at the point on the customer channel
regular voice and transmit signals through the core network
(main network switching). Treat it exactly the same network
as in the voice signal. This is the main advantage,
although the speed is lower, but it can be in
anywhere as long as there are phone lines are available.
The limited band width of the channel, especially not because of sound
by the channel on the customer, but due to the core network.
Filter on the core network to limit the wide band channel sound
approximately 4.4 kHz. If the filter without the constraints of this cable
copper (copper access network) is able to skip the frequency
Mhz on the area, although it will be big enough redaman.
Redaman a straight akan increased proportionate with the increase
frequency and length of the channel, is a major constraint factor
increase in the speed of data transmission.
Overview of the development of network access technology that utilizes
copper cable to distribute information is as wide-band
a. Digital Subscriber Line (DSL)
Modem is used in the basic rate ISDN service.
DSL akan transmit data in duplex (two-way
at a time), at the speed of 160 kbps over copper cable (channel
regular telephone) with a range up to 6 km, and to multiplex
demultiplex the data stream in 2 B channels (each 64 kbps),
one D channel (16 kbps) and include some overhead
required by the terminal device. Based on the ANSI standard
T1.601 or ITU I.431 DSL also use echo canceller for
separating the received signal coming from the reflection signal
sent. Following table of DSL technology:
Access Technology Type Bit rate mode Applications
Digital Subscriber Line
Duplex 160 kbps ISDN, data communications,
High data rate Digital
Subscriber Line (HDSL)
1.544-2 Mb, 048 Mb duplex T1/E1 services, WAN,
LAN, server access
Single line Digital
Subscriber Line (SDSL)
Mb 1.544 – 2.048
Same with duplex HDSL
added access to basic
the symmetrical service
16 kbps – 640 kbps upstre
Subscriber Line (ADSL)
1.544 Mb – 8 Mbps downs
Internet access, video on
demand, remote access
LAN, Interactive Multimedia
1.5 Mbps – 2.3 Mbps upstre
Very high data rate Digital
Subscriber Line (VDSL)
13 Mbps – 52 Mbps downs
Same as ADSL
plus the HDTV
b. High data rate Digital Subscriber Line (HDSL)
Is a continuation of DSL technology and use 2 twisted
Cooper pair cable. HDSL is used for both channels
T1 or E1 signal. HDSL uses a wide band narrow
and do not need a repeater, such as T1 or E1 channel on the
generally. Usually the device on the channel using a T1 or E1
AMI protocol (self-clocking Alternate Mark Inversion) and
requires repeater at distance of 1000 meters from the central and each
2000 meters further. AMI requires wide band at 1.5 MHz
T1 and E1 is for 2 MHz. By using the modulation
better able to transmit the HDSL signal on
speed of 1.544 Mbps or 2.048 Mbps using only
wide-band 80 kHz to 280 kHz, depending on the modulation technique
and pengkodeannya. HDSL signals is able to deliver without a repeater
on copper cables up to 4 km far, of course, with
2 using a cable to T1 and E1 to 3 cable, which masingmasing
operate at half speed, or third.
Typical applications for HDSL connection is as PBX, station antenna
provider, the DLC system has matured enough in giving
services with bit rates above 1 Mbps, and has been widely used
applications in remote LAN access and the internet.
c. Single line Digital Subscriber Line (SDSL)
SDSL will be needed in many applications that require access
symmetrical and therefore can be said that the service is SDSL
komplementari application of ADSL. Things that need to be aware that
the reach of SDSL will not exceed 3000 m, where the distance
ADSL is able to achieve 6 Mbps bit rate.
d. Asymmetric Digital Subscriber Line (ADSL)
This technology has a bit rate between the different directions tell
(Upstream) and receive direction (downstream). Upstream speed is
ranging between 16 kbps to 640 kbps, while the speed
downstream is between 1.544 Mbps to more than 7 Mbps.
Because of ADSL service is ideal for internet / intranet, video
on demand and remote LAN access. Because usually penggunapengguna
applications need to receive more
information / download of sending information.
e. Very high data rate Digital Subscriber Line (VDSL)
Initially have a VDSL Very high data rate Asymmetric
Digital Subscriber Line (VADSL) because they assume VDSL
will not be using the symmetrical transmission and is certain asymmetric
so no need to divide in two names, VDSL (for symmetric)
and VADSL (for asymmetric). VDSL will distribute the data
asymmetric on the transmission speed is faster than ADSL
with a channel length shorter. In general, VDSL
projected to have a speed Upstream and downstream
as shown in table 1. There are still many things that need to
Diperjelas in VDSL, the good standards, service environment,
interface is also about cost.
ADSL circuit will connect each other from each end of the ADSL modem
on ordinary phone lines (copper cable) and make a three-channel
information. High-speed downstream channel, channel duplex
medium speed and POTS channel. Channel by separate POTS
dijital modem with a filter, to ensure uninterrupted POTS.
High-speed channel speed at 1.544 Mbps – 6 Mbps, and
duplex at the speed of 16kbps – 640 kbps. Each channel can be
submultiplex, which can be formed multiplikasi canals with
bit rate is lower. Following table the characteristics of ADSL
based on the cable used:
Data rate (Mbps) type cable (AWG) cable Size (mm) Distance (km)
1.5 or 2 24 0.5 5.5
1.5 or 2 26 0.4 4.6
6.1 24 0.5 3.7
6.1 26 0.4 2.7
Depending on the downstream speed by several factors, including
length of copper cable, cable size, the quality of the physical connection
from the clutch cable and cross-interference. Channel Redaman akan
proportionate increase in line length of straight channel and frequency,
and will decline if the diameter of the cable increases. With
ignore the influence of the quality of the ADSL connection has
characteristics as shown in the table above. Next
general ADSL configuration:
Configure ADSL in general, as is shown
image above. Digital Subsriber Line Access Multiplexer (DSLAM)
multiplexer is a device on the service provider / central,
while there are customers on the Customer Premises
Equipment (CPE). Both were connected by phone line, where the
between them, there are pots splitter (on the promoter / central)
Microfilter and (on the customer side), which divides the frequency function.
Flowed to the low-frequency analog line, while the high frequency
is for the ADSL service.
Many applications will benefit from the benefits of ADSL
especially in the compressed digital video. For real-time signal,
dijital video signal can not use the error control procedure
on the link or network level that are usually used in the system
a general data communication. While the ADSL modem capable
provide forward error corection which is capable of dramatic
reduce errors caused by impulse noise. Error
base symbol for the symbol will also be much reduced
errors caused by continuous noise that occurs on
ADSL uses signal processing technology so that dijital
and using sophisticated algorithms that are able to create
distribution of data on very high speed through copper cable
Line coding technique used is Carrierless Amplitude / Phase
Modulation (CAP) or discrete Multi Tone (DMT). Line coding techniques
CAP and DMT provides benefits where the system more resistant
to roar / noise or interference. In addition to the
using DMT, ADSL allows a rate adaptive
(speed of transmission may change the relative performance
copper cable network that is used as transmission media).
With DMT also allows the network to initiate the process
to determine the level of the network speed copper
can transmit data securely. While the technique
conventional, if its quality performance down the cable, the signal
in the modulation / demodulasi akan damaged by modem.
Asymmetrical Digital Subscriber Line (ADSL) technology is a transmission in the access network where the speed signal Upstream and downstream are not simetrik or asymmetric. ITU-T international standards body as has been recommend the size of the speed (bit rate). Sending a signal to the ADSL is up to 64 Kbps to 640 Kbps Upstream signal direction and 1.5 Mbps to 6 Mbps downstream to the signal direction. With ADSL technology is the need of the customer services that include voice, data and video can be met easily without a lot of changes because the media infrastructure that is used in the transmission of ADSL technology is still the form of copper cable network. This is a recommendation, why ADSL is selected as one of the sate network access technology to deliver future services pitalebar.
Although ADSL pengimplementasian conditions can optimize the network cable that already exist and can save the cost of investment but the cable network reliability in the services provided to customers from Central still has limitations-limitations. Some of the measurements into the cable network reliability is the quality of service (QoS) for media penstramisian through copper cable, long distance or cable coverage to reach the service area (customer), the influence of cross-skilled (crosstalk) that may occur between the cable sating adjacent interference and influence of radio waves in the surrounding areas. Besides, the key to the success of the performance on the copper cable network pengimplementasian ADSL is also determined by the quality of material / material copper cable is used, the installation process / penggelaran and maintenance of the network cable correctly.
The discussion in this thesis is focused on the analysis and calculation of performance in the channel network access services using ADSL technology based on the parameters required. This thesis also give some consideration to obtain the limits of coverage and limits the distance skilled cross-cable subscribers on the network. So with this analysis and the calculation will be able to access the network performance in the copper cable channel service pitalebar.
Problem – a problem in the Jar lok at
One roll cable (haspel) primair max 100 m
held digorong – gorong roads (underground cable)
Keep continuation Man in the Hole
Man Hole akan submerged water, then the continuation must be both protected and (waterproof). ® unless akan cross talk.
There are pumps air into the cables from the central primair
Problems penanggal channel
Kena sewings layang – layang ® injured, is the air, rust and drop out.
Channels penanggal strengthened by iron wire.