Lesson 05: Satellite Orbits

Satellite Orbits

Satellites (spacecraft) which orbit the earth follow the same laws that govern the motion of the planets around sun.

Type of Satellite Orbit

• Equatorial Orbit
• Inclined Orbit
• Polar Orbit

Type of satellite (in term of orbit)

• GEO (Geostationary Earth Orbit) satellites orbit about 36,000 km above Earth’s surface.

• LEO (Low Earth Orbit) satellites are about 500-1500 km above earth’s surface.

• MEO (Medium Earth Orbit) satellites are about 6000-20,000 km above earth’s surface.

• HEO (Highly Elliptical Orbit) satellites.

source: UTM note.

Lesson 04: What is Satellite?

What is a Satellite?

A satellite is a space vehicle launched by humans and orbits Earth or revolves around another object in space.

A communications satellite is a microwave repeater in the sky that consists of a receiver-transmitter combination called a transponder.

A communications satellite consists of two major units: bus and payload.

• The Bus includes control mechanisms (electrical and mechanical) that support the payload operation from launch through the end of its life.

• The payload is all the specialized equipment needed to perform its designed function (communication between earth stations).

RazakSAT: Malaysia's second remote sensing satellite after TiungSAT-1.

source: wiki, ATSB, UTM note.

Lesson 03:Introduction of GSM System

GSM System

GSM :Global System for Mobile Communications, originally known as Groupe Spécial Mobile

• A standard set to describe protocols for second generation (2G) digital cellular networks used by mobile phones.

• GSM is a cellular network, which means that mobile phones connect to it by searching for cells in the immediate vicinity.

• Use TDMA for greater capacity

Frequency Band

MS communicates with base station via radio channel.

Transmission Link

Both Base station & mobile station transmits with different frequency to create full-duplex communication path

• Downlink: transmission path from Base station to mobile station

• Uplink: transmission path from mobile station to Base station

source: wiki-GSM, UTM note.

Lesson 02: Mod Penghantaran

MOD PENGHANTARAN DATA
 
Mod - pergerakan data antara dua titik.
 
Tiga jenis mod penghantaran dalam komunikasi data adalah:

1. simpleks (simplex)
2. dupleks separuh (half-duplex)
3. dupleks penuh (full-duplex)

SIMPLEKS (SIMPLEX)
Maklumat  dihantar dalam satu hala sahaja.
Contoh; penyiaran radio dan TV.
 

  

DUPLEKS SEPARUH (HALF DUPLEX)
Maklumat dihantar secara dua hala tetapi tidak pada masa yang sama. 
Contoh: walkie-talkie.
 
       
 
DUPLEKS PENUH (FULL DUPLEX)
Maklumat dihantar secara dua hala serentak pada masa yang sama.
Contoh: telefon.

source: Data Comm, Rigacci, Sony Ericson.

Lesson 01: Asas Sistem Telekomunikasi

  

 Blok Diagram Sistem Telekomunikasi

Tiga (3) Komponen asas sistem telekomunikasi:-

1. Penghantar (Transmitter)
2. Medium penghantar (Transmission Line)
3. Penerima (Receiver)

Fungsi setiap komponen:

Penghantar (Transmitter)

Bahagian yang menghantar isyarat maklumat yang dihasilkan. Contoh: isyarat audio/ video,analog dan digital.

Medium penghantar (Transmission Line)

Laluan yang digunakan untuk penghantaran isyarat elektrikal di antara dua

Peralatan(penghantar dan penerima). Contoh: dawai, kabel sepaksi, fiber optik atau gelombang mikro.

Penerima (Receiver)

Bahagian yang berfungsi untuk menerima dan melakukan pengesanan isyarat pembawa dan menghasilkan semula isyarat asal.

KenaL DiRi

hi again..

 to whom it may concern,

RF stand for Radio Frequency..

hehehe...

pix credit to www.webdesign.org

Langkah pertama !

hi there..!
 ni first time ak text dalam alam blogging ni...
 kenape nk buat blog ni??? i have to..!
itu saje..
 c u on next post.