Communication infrastructure: sandesh kaise jaate hain

Sandesh kaun le jaata hai?

Phone, computer aur tablet ne baatcheet tez aur aasaan bana di hai. Inke peeche communication infrastructure hai: cables, wireless devices, mobile towers, satellites aur data centres jo sandesh, tasveerein aur videos le jaate hain.

Madhya Pradesh ke ek gaon ki Rani ko socho, jo Tamil Nadu mein apni cousin ko voice note bhejti hai. Wo bas tap karti hai, record karti hai aur bhej deti hai. Par pehle bijli uske gaon ke paas ke mobile tower ko chalaati hai. Phir note khet aur sadak ke neeche bichhi fibre cables se tezi se jaata hai, antariksh ke satellites tak pahunchta hai aur door ke shehron ke bade servers se guzarta hai, tab jaakar cousin ke phone pe aata hai. Ek chhote se Namaste ko India ke paar pahunchaane ke liye ek chhupi duniya milkar kaam karti hai.

Dikhne waale aur chhupe hisse

Kuch hisse aasaani se dikhte hain: dono phone, mobile tower aur bijli ki line. Baaki lagbhag adrishya hain: zameen ke neeche fibre cables, upar door satellites, data centres ke servers aur hawa mein sandesh le jaane waale radio signals.

Baatcheet kaise badli

Sadiyon tak kabootar, harkaare aur ghudsawaar sandesh le jaate the. Chhapaai se akhbaar aaye; India ka pehla chhapa akhbaar, Bengal Gazette, 1780 mein nikla. 1840s mein Alexander Bain ki fax machine ne tasveerein bhejin aur Samuel Morse ke telegraph ne dot aur dash mein sandesh bheje. Alexander Graham Bell ne 1876 mein telephone banaaya. Phir radio, television, personal computers, email aur internet, social media aaye, aur aaj 5G, cloud sevaayein aur AI se chalne waale chat aur voice. 1947 mein Shanmukham Chetty ne All India Radio pe budget sunaaya.

J. C. Bose aur wireless signal

Jagadish Chandra Bose (1858–1937) ne microwaves se wireless transmission ki shuruaat ki. 1895 mein Calcutta mein unhone dikhaaya ki signal deewar ke paar ja sakte hain: ek ghanti bajaakar aur remote se ek bandook chalaakar. Unhone naye tarah ka coherer banaaya, jo shuruaati wireless sets ka mukhya hissa tha, aur galena crystal detector, jo ek shuruaati semiconductor tha, saath mein antennas aur waveguides bhi. 1901 mein Guglielmo Marconi ne milta-julta device patent karaaya aur Atlantic ke paar radio signal bheja; unhe 1909 mein Physics ka Nobel Prize mila. Bose ne mushkil haalaat mein kaam kiya aur patent kam hi liye, isliye videsh mein unke kaam ko kam pehchaan mili, haalaanki unhe kai sammaan mile. Unhone paudhon pe bhi research ki aur 1917 mein Bose Institute ki sthaapna ki.

Mehngi calls se saste data tak

Telephone 1880s ke shuruaati sets se dial waale phone, button waale phone, mobile phone aur aaj ke smartphones tak badla hai. 1990s mein India mein ek mobile call ₹17 per minute tak ki thi, aur incoming calls ke bhi paise lagte the. Aaj India mein duniya ke sabse saste mobile aur internet rates mein se kuch hain, aur 2025 mein 116 crore wireless phone subscribers aur lagbhag 90 crore internet connections the.

Network se kya mumkin hai

Door ke ilaakon ke vidyaarthi online class le sakte hain, digital library aur shaikshik videos dekh sakte hain. Turant SMS alert aur apps praakritik aapdaaon se pehle chetaate hain. Chhote-bade vyapaar e-commerce se duniya bhar mein bechte hain, aur log seconds mein online bhugtaan karte hain. E-governance se naagrik documents ke liye apply karte hain, shikaayat darj karte hain aur aasaani se jaankaari paate hain, jaise DigiLocker app mein documents rakhna.

Ye kyun zaroori hai

Jis infrastructure pe hum nirbhar hain uska bada hissa dikhta nahi, isliye ek sandesh ke peeche ki mehnat bhoolna aasaan hai. Iski tulna sadak aur rail se karo India mein transport infrastructure mein, aur badi tasveer dekho infrastructure kya hai mein. Textbook ke sawaalon ke jawab Part 2 Chapter 7 ke NCERT solutions mein hain; poore Part 2 Chapter 7 ke notes dekho.