Transmission Media in Computer Networks

Transmission Media Kya Hota Hai?

Jab do devices (jaise computers, mobile phones ya routers) ek dusre se data share karte hain, to data ko ek jagah se doosri jagah pahuchne ke liye rasta chahiye hota hai.

Ye jo rasta ya channel hota hai, jisse data travel karta hai, use hi Transmission Media kehte hain.

Transmission Media Kyu Zaroori Hai?

Data ko send/receive karne ke liye medium zaroori hai
Ye medium decide karta hai:
- Kitni speed se data jaayega
- Kitni door tak jaa sakta hai
- Kitna secure hai
- Kitna costly ya cheap hoga

Transmission Media Ke Types

Transmission media do categories mein divide hota hai:

1. Guided (Wired) Media
2. UnGuided (Wireless) Media

1. Guided Media (Wired Media)

Ismein data cable ya wire ke through travel karta hai. Ye media secure, reliable, aur fast hota hai.

a) Twisted Pair Cable

Do copper wires ko twist karke banaya jaata hai taaki interference kam ho.

Types:

UTP (Unshielded) – ghar/office mein use hota hai
STP (Shielded) – industrial areas mein use hota hai

Feature	Detail
Speed	100 Mbps – 1 Gbps (Cat5, Cat6)
Distance	100 meters tak
Use	LAN, telephone line
Cost	Sasta

b) Coaxial Cable

Ismein ek central copper wire hota hai, jise insulation aur shielding se cover kiya jaata hai.

Use hota hai: Cable TV, CCTV cameras

Diagram:

[Copper Core]
     ↑
[Insulation]
     ↑
[Shielding]
     ↑
[Outer Jacket]

Feature	Detail
Speed	10 Mbps (basic use)
Distance	200-500 meters
Use	TV signals, old LAN
Cost	Moderate

c) Optical Fiber Cable

Ismein data light pulses ke form mein bheja jaata hai. Ye sabse fast aur secure media hota hai.

Types:

Single-mode (long distance)
Multi-mode (shorter distance)

Optical Fiber Cable mein:

[Glass Core] → Light Travel
[Cladding] → Light reflect karta hai
[Coating] → Protection

Feature	Detail
Speed	100 Gbps+
Distance	10+ kilometers
Use	Internet backbone, ISPs
Cost	Mehenga, par worth it
Security	Highly secure, no interference

2. Unguided Media (Wireless Media)

Ismein data air mein travel karta hai, bina kisi cable ke — jaise Wi-Fi, mobile networks.

a) Radio Waves

Signals har direction mein jaate hain
Wall ke paar bhi jaa sakte hain

Feature	Value
Range	Few meters to kilometers
Use	Wi-Fi, FM, Bluetooth
Frequency	3 kHz – 1 GHz

b) Microwaves

Straight line mein travel karte hain
Satellite aur telecom towers mein use hota hai

Feature	Value
Range	30–50 km
Use	Satellite, telecom towers
Frequency	1 GHz – 300 GHz
Note	Line of sight hona chahiye

c) Infrared

Short range communication
Wall ke paar nahi jaa sakta

Feature	Value
Range	1–5 meters
Use	TV remote, wireless mouse

Comparison – Wired vs Wireless

Feature	Wired Media	Wireless Media
Physical Medium	Cable ya wire	Air
Speed	Fast (especially fiber)	Moderate to fast
Cost	High (fiber), Low (twisted)	Generally low
Security	Secure	Thoda risky (hacking possible)
Setup	Time-consuming	Easy & mobile

Quick Summary

Medium	Best Use
Twisted Pair	Ghar, Office LAN
Coaxial	TV, Security camera
Fiber Optic	Internet backbone, ISP
Radio Waves	Wi-Fi, FM, Bluetooth
Microwaves	Satellite, Telecom communication
Infrared	Remote control, short distance

Final Thoughts

Transmission Media = Rasta jisse data ek device se doosri device tak jaata hai
Wired = Cables jaise twisted pair, coaxial, fiber
Wireless = Air through radio, microwave, infrared
Har media ka apna speed, cost, range aur use case hota hai
Use case ke hisaab se sahi media choose karna important hota hai

The Hingineer