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 SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Konfigurasi xDSL DSL

DSL Jaringan kabel tembaga

DSL

DSL

DSLAM

Core Network

DSLAM

DSLAM = DSL Access Multiplexer

DSL

DSL

CPE SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Sifat Transmisi xDSL Asimetris Down stream Up stream

Core Network

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

Simetris Down stream Up stream

Core Network

Biasanya digunakan untuk hubungan yang memerlukan kecepatan data yang tinggi untuk kedua arah SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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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) SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Perbandingan Type xDSL Type ADSL G.992.1

Transmission Asymmetric

Data Rate 7 Mbps down 800 kbps up

ADSL2 G.992.3

Asymmetric

8 Mb/s down

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

1 Mbps up ADSL2plus G.992.5

Asymmetric

24 Mbps down 1 Mbps up

HDSL G.991.1

Symmetric

2 Mbps up/down

SDSL

Symmetric

2 Mbps up/down

VDSL G.993.1

Asymmetric

55 Mbps down 15 Mbps up

VDSL2 G.993.1

Asymmetric

12 MHz long reach VDSL2 G.993.1

55 Mbps down 30 Mbps up

Symmetric

T1/E1 service between server and phone company or within a company; WAN, LAN, server access Same as for HDSL but requiring only one line of twisted-pair Supporting new high bandwidth applications such as HDTV, as well as telephone services (Voice over IP) and general Internet access, over a single connection

100 Mbps up/down

30 MHz Short reach www.dslforum.org wikipedia

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Short History of xDSL 1985 -1990 --

1993 -1995 --

Bell Labs develop OFDM to make traditional copper wires to support new digital services - especially video-ondemand (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 exchanges Phone companies begin to promote HDSL for smaller and smaller companies and ADSL for home internet access Evaluation of three modulation technologies for ADSL: QAM, DMT and CAP. DSL Forum established on 1994 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)

1998 --

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Short History of xDSL

2001 -2002 -2003 -on phone

Number of DSL subscribers 18.7 million worldwide ITU-T completed G.992.3 and G.992.41 standards for ADSL2 ADSL2plus released (G.992.5). It can gain up to 20 Mbps lines as long at 1.5 km. 30 million DSL users worldwide

2004 --

VDSL2 standards under preparation in DSL forum

2005 -Mb/s.

VDSL2 standard verified (G.933.2) – symmetrical 100 115 million DSL users

www.dpu.ac.th

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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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

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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ADSL Equipment Standard Telephone Lines

Central Office Building Residential Customer

ADSL Rack of Line Cards

Customer Premises Equipment

ADSL Modem or Gateway

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Contoh Pembagian Bandwidth ADSL

Contoh pembagian bandwidth ADSL dengan teknik modulasi Digital Multi Tone (DMT) SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Implementasi BB Access dg ADSL • Pada saat ini, di TELKOM, yang dimaksud dengan service broadband adalah

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Deskripsi Produk • Speedy adalah produk Layanan Internet access end-toend dengan basis teknologi ADSL • Paket Layanan Paket Layanan

Speedy Office

Speedy Warnet

Kuota

Unlimited

Unlimited

Speedy Personal

Speedy Professional

1000 MB/bln 3000 MB/bln

Speedy Time Based

50 Jam/bln

www.telkomspeedy.com

SM241013 - Pengantar Sistem Telekomunikasi Semester genap 2007-2008

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Speedy yang sekarang diposisikan sebagai akses akan dikembangkan menjadi produk multimedia

Streaming

IP TV

Access

Game

Near Future

Internet

Access + Internet

Today

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