Sistem Telekomunikasi Modul 6.2

How DSL Works DSL adalah teknologi yang mengasumsikan bahwa data

digital tidak perlu diubah ke dalam bentuk analog, dan sebaliknya.

Data digital ditransmisikan melalui jaringan lokal langsung dalam bentuk sinyal digital.

Hal ini memungkinkan digunakannya teknologi modulasi/multiplexing digital yang memungkinkan jaringan dapat digunakan untuk bandwidth yang lebih tinggi.

Sinyal juga dapat dipisahkan, sebagian bandwidth dapat digunakan untuk mentransmisikan sinyal analog, sehingga komunikasi data melalui komputer dan percakapan melalui telepon dapat dilakukan melalui saluran yang sama dan pada waktu yang bersamaan

1SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

Konfigurasi xDSL

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Core Network

DSL DSLAM

DSL DSL

DSLDSLAM

DSL DSL

CPE

DSLAM = DSL Access Multiplexer

Jaringan kabel tembaga

Asimetris


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Core Network

Down stream

Up stream

Core Network

Down stream

Up stream

Simetris

Sifat Transmisi xDSL

Biasanya digunakan oleh pelanggan untuk akses Internet, di mana arah down stream lebih besar daripada arah up stream (lebih banyak download daripada mengirim data)

Biasanya digunakan untuk hubungan yang memerlukan kecepatan data yang tinggi untuk kedua arah

Beberapa Type xDSL

• Assymetric DSL (ADSL)– G.992.1 (G.DMT)– G.992.3 (ADSL2)– G.992.5 (ADSL2+)

• High data-rate DSL (HDSL)– G.991.1

• Single-line Digital Subscriber Line (SDSL)• Very high data-rate DSL (VDSL)

– G.993.1– G.993.2 (VDSL2)


Perbandingan Type xDSLType Transmission Data Rate Application

ADSL G.992.1 Asymmetric 7 Mbps down

800 kbps up

Internet and Web access, motion video, video on demand, remote LAN access

ADSL2 G.992.3 Asymmetric 8 Mb/s down

1 Mbps up

ADSL2plus G.992.5 Asymmetric 24 Mbps down

1 Mbps up

HDSL G.991.1 Symmetric 2 Mbps up/down T1/E1 service between server and phone company or within a company;WAN, LAN, server access

SDSL Symmetric 2 Mbps up/down Same as for HDSL but requiring only one line of twisted-pair

VDSL G.993.1 Asymmetric 55 Mbps down

15 Mbps up

Supporting new high bandwidth applications such as HDTV, as well as telephone services (Voice over IP) and general Internet access, over a single connection

VDSL2 G.993.1

12 MHz long reach

Asymmetric 55 Mbps down

30 Mbps up

VDSL2 G.993.1

30 MHz Short reach

Symmetric 100 Mbps up/down


www.dslforum.orgwikipedia

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1985 --

1990 --

1993 --

1995 --

1998 --

1999 --

Bell Labs develop OFDM to make traditional copper wires to support new digital services - especially video-on-demand (VOD)Phone companies start deploying High-Speed DSL (HDSL) to offer T1 service (1.544 Mb/s) on copper lines without the expense of installing repeaters - first between small exchangesPhone companies begin to promote HDSL for smaller and smaller companies and ADSL for home internet access

Innovative companies begin to see ADSL as a way to meet the need for faster Internet access

DMT adopted by almost all vendors following ANSI T1.413 - issue 2 (in contrast to CAP)ITU-T produced ADSL standards G.992.1 (G.full: 8M/640k)

and G.992.2 (G.lite: 1.5M/512k)

Evaluation of three modulation technologies for ADSL: QAM, DMT and CAP. DSL Forum established on 1994

Short History of xDSL


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2001 -- Number of DSL subscribers 18.7 million worldwide

2002 -- ITU-T completed G.992.3 and G.992.41 standards for ADSL2

2003 -- ADSL2plus released (G.992.5). It can gain up to 20 Mbps on phone lines as long at 1.5 km. 30 million DSL users worldwide

2004 -- VDSL2 standards under preparation in DSL forum

2005 -- VDSL2 standard verified (G.933.2) – symmetrical 100 Mb/s. 115 million DSL users

Short History of xDSL

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008www.dpu.ac.thwww.dpu.ac.th

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Motivation / properties of ADSL

• Need for high-speed Internet access– Telephone modem have only moderate rates (56 kb/s)

• ADSL Transmits high speed data to local loop by using unshielded 2-wire twisted pairs

• The the most popular commercial ADSL (G.992.1) allows maximum rate 800 kbit/s upstream and 7 Mb/s downstream

• Different xDSL techniques developed to serve symmetric and asymmetric traffic requirements and different rates


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ResidentialCustomer

ADSL Modem or Gateway

Customer Premises

Equipment

Central Office Building

ADSL Rackof Line Cards

Standard Telephone Lines

ADSL Equipment


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Contoh Pembagian Bandwidth ADSL

Contoh pembagian bandwidth ADSL dengan teknik modulasi Digital Multi Tone (DMT)



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Implementasi BB Access dg ADSLImplementasi BB Access dg ADSL

• Pada saat ini, di TELKOM, yang dimaksud dengan service broadband adalah

Deskripsi Produk• Speedy adalah produk Layanan Internet access end-to-end

dengan basis teknologi ADSL

• Paket Layanan


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PaketLayanan

Speedy OfficeSpeedy Warnet

Speedy Personal

Speedy Professional

Speedy Time Based

Kuota Unlimited Unlimited 1000 MB/bln 3000 MB/bln 50 Jam/bln

www.telkomspeedy.com


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Speedy yang sekarang diposisikan sebagai akses Speedy yang sekarang diposisikan sebagai akses akan dikembangkan menjadi produk multimediaakan dikembangkan menjadi produk multimedia

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Sistem Telekomunikasi Modul 6.2