Media dan Teknologi Transmisi Macam Media Transmisi Circuit

Media dan Teknologi Transmisi Macam Media Transmisi Circuit Switch dan Packet Switch Satellite system 3/3/2021 1

SATELIT GELOMBANG MIKRO KABEL SENTRAL 3/3/2021 Koaksial, Fiber optik, Multipair SENTRAL 2

HIRARKI BANGUNAN TELEKOMUNIKASI WIRELINE DAN RADIO Transmisi Tertier Setra Sekunder Fiber Optik Satelit Mikrowave Setra Sekunder Primer STO Subcriber s Kota A 3/3/2021 Kota B 3

Media Transmisi • Ada empat media transmisi – Kabel Tembaga (‘copper wire’) – Kabel Koaksial (‘coaxial cable’) – Fiber (‘fiber optic’) – Tanpa Kabel / Nirkabel (‘wireless’) 3/3/2021 4

Kabel Tembaga • Masih merupakan media utama ke pelanggan dan sudah banyak terpasang. • Secara teknis disebut Unshielded Twisted Pair (UTP). Mis. UTP class 5 • Frekuensi tinggi dapat ‘bocor’. Induksi. 3/3/2021 5

Koaksial • Kabel Tembaga sebagai inti dikelilingi oleh serabut konduktor. Diantaranya ada isolator / dielektrik • Karena konstruksinya, frekuensi tinggi dapat dilalukan, misalnya TV (6 Mhz) • Sering digunakan untuk TV kabel 3/3/2021 6

Fiber • Untuk kecepatan tinggi, mis 10 Gbps • Ensiklopedi Britannica, 1 detik transmisi • Efisiensi: – FTTH (fiber-to-the-home) – FTTC (fiber-to-the-curb) – FTTN (fiber-to-the-neighborhood) – HFC (hybrid fiber/coax) 3/3/2021 7

Fiber: Single / Multi mode 3/3/2021 8

Tanpa Kabel • • 3/3/2021 Microwave Satelit (LEO, MEO, GEO) Cellular Personal Communication Sevices 9

Cellular 3/3/2021 10

HIRARKI BANGUNAN TELEKOMUNIKASI WIRELINE DAN RADIO Transmisi Tertier Setra Sekunder Fiber Optik Satelit Mikrowave Setra Sekunder Primer STO Subcriber s Kota A 3/3/2021 Kota B 11

JARINGAN JARINGN UNTUK PRIVATE JARINGAN UNTUK UMUM TELEPON 3/3/2021 TGP/TLX DATA LC BB 12

Transmisi di jaringan • Signal dapat ditransmisikan dalam dua metoda : secara Circuit dan secara Packet • Ada sentral circuit (Circuit switch) ada sentral Paket (Packet switch) • Komunikasi suara: Circuit • Komunikasi data : Packet 3/3/2021 13

Metoda Circuit Switch • Pembentukan Sirkuit (‘Circuit Establishment’) • Pengiriman Informasi (‘Call Transfer’) • Pembubaran Hubungan (‘Call Disconnect’) 3/3/2021 14

Metoda Packet Switch • Paket: Data (informasi) dan Control (Header/Trailer) • Packet Switch: memproses setiap header/trailer untuk menentukan jalan yang ditempuh data 3/3/2021 15

Keuntungan dan Kerugian • Circuit Switch – Setelah jalan ditentukan tidak bisa digunakan yang lain – Bandwidth tertentu, 64 kbps, 2 M, dst … – Tidak ada ‘delay’ – ‘Real Time’ 3/3/2021 • Packet Switch – Penggunaan jaringan lebih efisien – Bandwidth dapat diatur – Kemungkinan ada data yang hilang – ‘Delay’ 16

Satellite Earth Satellite Communication 3/3/2021 17

Introduction v Satellite communication became a possibility when it was realized (by the science fiction writer, Arthur C. Clarke) that a satellite orbiting at a distance of 36000 Km from the Earth would be geostationary, i. e. would have an angular orbital velocity equal to the Earth's own orbital velocity. It would thus appear to remain stationary relative to the Earth if placed in an equatorial orbit. v In principle, three geostationary satellites correctly placed can provide complete coverage of the Earth's Satellite Earth 3/3/2021 18

Advantages and Limitation Advantages v The laying and maintenance of intercontinental cable is difficult and expensive v The heavy usage of intercontinental traffic makes the satellite commercially attractive v Satellites can cover large areas of the Earth. This is particularly useful for sparsely populated areas Limitations v Technological limitations preventing the deployment of large, high gain antennas on the satellite platform v The high investment cost and insurance cost associated with significant probability of failure v Atmospheric losses above 30 GHz limit carrier frequencies 3/3/2021 19

Satellite Communication Basic Elements The Satellite (Space Segment) v Composed of three separate units • the fuel system, • the satellite and telemetry controls • the transponder which includes the antenna, a broad band receiver, an input multiplexer, and a frequency converter which is used to reroute the received signals through a high powered amplifier for downlink. v The primary role of a satellite is receive signals from a ground station and send them down to another ground station. The Ground Station (Earth Segment) The ground station's job is two-fold • In the case of an uplink, or transmitting station, terrestrial data in the form of baseband signals, is passed through a baseband processor, an up converter, a high powered amplifier, and through a parabolic dish antenna up to an orbiting satellite. • In the case of a downlink, or receiving station, works in the reverse fashion as the uplink, ultimately converting signals received through the parabolic antenna to base band signal. 3/3/2021 20

Various Uses of Satellite Communications Traditional Telecommunications v Long distance network to connect the telecommunications networks of one country, or one region in a country, to another v Groups like the international satellite consortium Intelsat have fulfilled much of the world's need for this type of service Cellular v Provides service for a network of cells v Allows its own bandwidth to be used by any cell that needs it without being bound by terrestrial bandwidth and location restrictions Television Signals v Satellites have been used for since the 1960's to transmit broadcast television signals between the network hubs of television companies and their network affiliates v In the 1970's, it became possible for private individuals to download the same signal that the networks and cable companies were transmitting, using c-band reception dishes v The direct-to-home industry has gathered even greater momentum since the introduction of digital direct broadcast service 3/3/2021 21

Types of Satellite Networks • Telephony Networks • Television Networks • Data Networks • Public plus Non-public Networks • Open (accessible) Vs Closed Network (non public) 3/3/2021 22

Satellite System Configuration MOD U/C TX D/C RX (LNA) BB DEM DCME BB DEM DCME : Digital Circuit Multiplication Equipment 3/3/2021 23

The Satellite Communication System Operational Schematic 3/3/2021 24

Geostationary Earth Orbit (GEO) v Geostationary earth orbit(GEO) is 22, 282 miles (35, 790 km) above the equator 0. 24 second of latency v The orbit is important because it allows a satellite to orbit the earth at a fixed location in relation to the earth v From GEO, three satellites can cover all but the polar regions and transmissions can be received through fixed antennas v Traditionally satellites have been given two degrees of separation, which means only 180 satellites could be parked in the orbit 3/3/2021 25

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Low Earth Orbit (LEO) v LEO satellites can be divided into "Big LEOS" and "Little LEOS. " v "Little LEOS" provide pager, cellular telephone and location services. An examples of a "Little LEO" system is Motorola's Iridium v "Big LEOs" carry voice and data broadband services. v "Big LEOS" hope to be an internet in the sky. v Low earth orbit is approximately 300 to 1, 000 miles above the earth 20 to 40 milliseconds of latency v LEO constellations may be costly. Earth coverage requires many more satellites from LEO than from GEO. And the LEO-satellite technology is not as advanced as GEO technology v LEOs are expected to be in demand for three markets: rural conventional telephone service, global mobile service, and international broadband service 3/3/2021 27

Medium Earth Orbit (MEO) v Medium Earth Orbit satellites move around the earth at a height of 5, 000 to 10, 000 miles. v Their signal takes from 50 to 150 milliseconds to make the round trip. v MEO satellites cover more earth area than LEOs but have a higher latency. v MEOS are often used in conjunction with GEO satellite systems v Telstar, one of the first and most famous experimental satellites, obited in MEO 3/3/2021 28

Different Types of Sat. Com System 3/3/2021 29

Satellites for Data Incorporating satellites into terrestrial networks is often hindered by three characteristics possessed by satellite communication v. Latency (propagation delay): Due to the high altitudes of satellite orbits, the time required for a transmission to navigate a satellite link (more than 2/10 ths of a second from earth station to earth station) could cause a variety of problems on a high speed terrestrial network that is waiting for the packets v. Poor Bandwidth: Due to radio spectrum limitations, there is a fixed amount of bandwidth allocable to satellite transmission v. Noise: A radio signals strength is in proportion to the square of the distance traveled. Due to the distance between ground station and satellite, the signal ultimately gets very weak. This problem can be solved by using appropriate error correction techniques, however 3/3/2021 30

Satellites Terms • • 3/3/2021 Satellites Transponder Tail Links Satellite MCS Small Earth Station VSAT Mobile Satellite Services Satellite Networks 31

Mobile Satellite System q Komunikasi bergerak satelit umumnya menggunakan frekuensi 1 Ghz – 30 GHz yang kita kenal dengan nama microwave. q Keuntungan satelit dapat mengcover seluruh permukaan bumi. q Satelit mobil pertama digunakan untuk hubungan pantai dengan kapal, karena dengan radio terestrial agak sulit akibat pergerakan kapal dalam pelayarannya. Sistem ini juga cocok untuk digunakan bagi penerbangan dan kendaraan bergerak. q Konsorsium yang menyelenggakakan komunikasi satelit mobil adalah INMARSAT (International Maritime Satellite) q Disamping keperluan diatas eksplorasi minyak dan tambang dapat menggunakan INMARSAT untuk hubungan yang lebih cepat dan fleksibel. 3/3/2021 32

Satellite INMARSAT SYSTEM Inmarsat Terminal PSTN 3/3/2021 Vehicle Mobile 33

LEO dan MEO Penggunaan satelit bagi komunikasi bergerak makin mengedepankan kemudahan sejalan dengan perkembangan jaringan satelit global bagi sistem komunikasi mobil. LEO dan MEO digunakan untuk komunikasi tersebut. Salah satu jaringan yang sudah dicanangkan namun secara operasional belum berjalan sempurna adalah IRIDIUM. Jaringan ini terdiri dari 77 satelit yang bergerak mengelilingi bumi pada orbit rendah beada pada jarak kurang lebih 780 Km diangkasa. Jumlah satelit pada desain akhir dikurangi menjadi hanya 66 buah saja. Satelit tersebut berfungsi sebagai Base Station yang bergerak dan sebagai switching, dan dapat menghubungkan seluruh permukaan bumi denagn perantaran ke 66 satelit tersebut. IRIDIUM menggunakan teknologi GSM. Handset yang dugunakan relatif kecil dengan daya rendah, bisa berkomunikasi bagi pengguna yang beada baik di gurun, lautan maupun kutub. Jenis lain jaringan satelit mobil adalah Global Star dapat digunakan untuk pengguna sistim komunikasi mobil di Australia dan Eropa. Satelit mobile phone menggunakan dualmode yaitu satelit dan terestrial selular. 3/3/2021 34

LEO 3/3/2021 35

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