Information_and_study_blog

  ⭐ 🔥 MOST IMPORTANT & REPEATED QUESTIONS (Absolutely Must Do) These come in almost every exam (either directly or indirectly). ✅ UNIT 1 – Networking Basics (Very Frequently Asked) 1. CIDR – Concept + Advantages (Repeated in 2020 Q3(b) cs-702-c-wireless-and-mobile-co… ) 2. Subnetting & Supernetting – Problems (Asked in 2024 Q2(b) cs-702-c-wireless-and-mobile-co… ) 3. IPv4 vs IPv6 – Differences (2024 Q2(a) ✔ repeated every year) 4. Routers vs Bridges + Internet explanation (2024 Q1(a) ✔) ✅ UNIT 2 – Routing + Transport Layer (Always Asked) 5. OSPF – Working + Message Types (2020 Q2(a) cs-702-c-wireless-and-mobile-co… ) 6. BGP – Characteristics (2020 Q2(b) – very important) 7. Silly Window Syndrome – Cause + Solutions (2020 Q3(a) – repeated topic) 8. TCP vs UDP – Format + Features (Asked multiple times → 2020 Q8(iv) ✔) 9. TCP Window Size Problem (2024 Q4(a) – numerical type) ✅ UNIT 3 – WLAN + Mobile IP + Ad-hoc (Most Scoring, Most Repeated) 10. Hidd...

  ⭐ 1. Hidden, Exposed, Near & Far Terminal Problems Hidden Terminal Problem Two nodes (A & C) cannot hear each other but both send to B. Their signals collide at B. Solution: RTS/CTS mechanism (IEEE 802.11), directional antennas. Exposed Terminal Problem Node C hears B’s transmission to A and assumes medium is busy. But C could safely transmit to D (since A & D are out of range). Solution: RTS/CTS, directional antennas. Near–Far Problem Nodes A and B transmit with same power, but B is closer to C, so B’s signal overpowers A. A’s packet never reaches. Solution: Power control & signal balancing. ⭐ 2. OSPF – Working + Messages OSPF (Open Shortest Path First) Link-State routing protocol. Each router shares its link information with all others. Builds the Shortest Path Tree using Dijkstra Algorithm . Fast convergence, supports VLSM & CIDR. OSPF Messages Hello – Discover neighbors DBD (Database Description)...

  ⭐ UNIT – 3 (Easy Notes + PDF References) Wireless LAN • MAC Problems • Hidden/Exposed Terminal • Near/Far • Infrastructure vs Ad-hoc • IEEE 802.11 • Mobile IP • Ad-hoc Routing I have rewritten everything in easy school-level English so you can understand quickly. 🔵 1. What is WLAN? (Wireless LAN) (Page 1 U-3 Wireless & mobile computing ) WLAN = Wireless Local Area Network. It allows devices to connect without cables using radio, infrared, or microwave signals. Why WLAN? ✔ No wires needed ✔ Quick installation ✔ Can attach to existing wired network ✔ Useful in disasters or old buildings where wiring is impossible 🔵 2. Design Goals of WLAN (Page 2–3 – Table shown in PDF U-3 Wireless & mobile computing ) ✔ Simple to use Users should easily connect. ✔ Low power use Mobile devices need long battery life. ✔ No license needed Using license-free bands reduces cost. ✔ Handle interference There is a lot of radio noise; WLAN must work even in interference. ...