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CCNA Wireless Network Fundamentals

by Elena Mofar, Published on May 22, 2023

The Need for Wireless Networking

Meron tayong 2 ways to connect yung mga computers natin to the network:

  • Wired Connection
  • Wireless Connection

Yung Wired Connection uses LAN/UTP cable to connect yung mga end devices natin sa network para ma-enable to access network resources and the internet.

Kaya lang may mga limitations ang isang Wired network.

Una, isa syang Bounded Medium.

Bounded ibig sabihin nakatali. Nakatali yung mga computers natin dun sa kable na nagko-connect satin. Kung saan nagte-terminate yung kable - dun ka.

LAN Cables also have a maximum theoretical length of implementation - hanggang 100meters lang. Kung i-implement mo syan in distances more than 100meters, yung electrical signals would have attenuated so much na hindi na maintindihan yung signal na nare-receive.

At syempre, kasama na rin sa pagiging bounded medium ng wired network natin is a fixed location.

In a wired network design, kailangan mong i-plano kung saan ang mga magiging location ng mga end devices - and terminate yung mga kable na yun sa exact location na yun.

So hindi pwede na iusog or irelocate yung kable kasi gusto mong lumipat ng location.

Kung sa bahay mo naman, pwede rin, kaya lang matrabaho at makalat. Tuwing lilipat ka ng lugar kailangan mo palaging magre-cable.

Wala namang problema yung pagiging bounded and fixed ng wired connections natin provided isang desktop PC yung nakakabit.

Hindi mo naman inuusog-usog yan kasi hassle. Kung saan mo sya pinlano na ilagay, more often than not, dun na sya forever wala nang usugan.

Kaya lang ang problema sa panahon ngayon - more and more people are using their mobile devices.

Alam mo naman na may pagka-ADHD yung mga tao ngayon at parang sinasakal pag ilagay mo lang sila sa ilang location.

So, isa sa mga requirements ngayon is mobility.

Ang mga tao ngayon mas gustong gamitin yung mga portable devices nila - laptops, tablets, mobile devices.

Mukha namang sira kung may nakadikit na LAN cable sa cellphone mo habang palakad-lakad ka para lang may connection ka sa internet.

Or, if may meeting at lahat kayo may dalang laptops tapos may hatak-hatak kayo na mga kable just to connect to the office network.

Makalat. Hassle. Ampanget tignan. It limits yung movement natin.

So, ang solution nila dyan is to add another way to connect to the network - kaya nila inintroduce yung Wireless Local Area Network (Wireless Connection)

Kung ang wired network natin uses electrical pulses para makapag-padala ng data sa network, paano naman nakakapagpadala ng data yung mga computer devices natin wirelessly?

Introduction to Wireless Communication

Sa Wired Communicatiion, yung mga data natin is sent as electrical pulses through a copper cable, or a light pulse through a fiber optic cable.

Sa wireless communication, yung mga data natin is sent thru space.

Paano?

Tignan mo yung image dito sa baba:

Wireless transmitter sending out Electromagnetic waves

Imagine air as a big body of water.

Ngayon, yung kuryente (AC) na binibigay ng wireless transmitter papuntang antenna ay nagke-create ng force para iwagayway nya yung energy na nasa hangin to form Electric and Magnetic Waves.

Parang sa battle ropes:

Battle Ropes signifying rf waves

Yung energy exerted ni kuya para iwagayway yung battle ropes ay equal sa energy meron sa kuryente (AC) na binibigay ng transmitter para makapag-form ng waves.

Mas mataas yung effort ni kuya - mas mataas yung wave na nafo-form sa battle ropes.

Mas mataas yung kuryente, meaning more Power, na ibigay ang transmitter - mas mataas yung height nafo-form na electromagnetic wave.

Take note na yung mga electromagnetic waves na yan do not travel in a straight line - it travels in all directions away from the antenna.

So balik tayo sa water analogy, tignan mo yung diagram dito sa baba:

Water analogy of an RF antenna

In a still water, pag tayo ay naglaglag ng maliit na bato - yung force of impact ng bato sa tubig will create water ripples kagaya ng nasa diagram natin.

Same din yan sa electromagnetic force generated ng Antenna natin to create ripples sa air - or electromagnetic waves.

Yung mga created ripples/wave na yan ay kumakalat or nagpo-propagate outwards palayo sa source of force - in this instance, the antenna.

This is a sample propagation pattern ng isang Ideal Antenna:

Wave Propagation Pattern of an Ideal Antenna

Ideal antenna - meaning isang perfect antenna na hindi nage-exist. Pero yang ideal antenna na yan yung ginagamit as basis of comparison sa mga actual antenna na ginagamit natin para sa mga wireless transmissions.

Iba-ibang types ng antenna, iba-iba yung hugis ng napo-propagate nyang wave.

Pag tayo ay bumibili ng mga antenna na ikakabit natin sa mga wireless transmitters - may kasama yang wave propagation pattern sa technical specification sheet nya.

Isipin mo na lang na kung saan tumama yung wave, hanggang duon aabot yung signal ng wireless transmitter.

Bakit importante yung mga generated waves na yan?

Kasi dyan pinapasakay yung data na gusto nating i-transmit wirelessly.

So, ibig sabihin, kailangan nating malaman kung ano-ano ba ang characteristics ng mga wave na yan at based sa mga characteristics na yan paano ba nagbabase yung wireless communication natin.

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This blog post ay introduction pa lang ng Wireless Networking Section CCNA 200-301 course and book ko.

Ang Wireless ang isa sa mga major topics sa CCNA 200-301 exam, at yan ay diniscuss ko extensively sa CCNA course and book ko.

ETO YUNG COMPLETE WIRELESS NETWORK SECTION COURSE AND BOOK OUTLINE:

✅A. Wireless Fundamentals

  1. The Need for Wireless Networking
  2. Introduction to Wireless Network Communications
  3. Anatomy of an RF Signal
  4. The RF Spectrum
  5. Introduction to the 2.4Ghz and 5GHz Frequency Bands
  6. The 2.4 GHz Frequency Band Channels Part 1
  7. Wireless Modulation
  8. Time and Frequency Domain
  9. Wireless Multiplexing
  10. The 2.4GHz Frequency Band Channels Part 2
  11. The 802.11 Standards
  12. The 802.11 Standards Applications

✅B. Wireless LAN Topologies

  1. Ad-Hoc Mode
  2. Infrastructure Mode and Basic Service Sets (BSS)
  3. Distribution Systems
  4. Extended Service Sets
  5. Miscellaneous WLAN Topologies – NonInfrastructure Mode

✅C. Wireless Architectures

  1. Autonomous Architecture Introduction
  2. Onsite Autonomous AP Architecture
  3. Cloud Based Autonomous AP Architecture
  4. Split-MAC Architecture Introduction
  5. CAPWAP Tunnels
  6. WLC Deployment Variations
  7. WLC Deployment Architectures – Onsite, Offsite, and Cloud-Based
  8. CAPWAP Tunnels Continued..
  9. Cisco AP Modes

✅D. Wireless Security

  1. Introduction to Wireless Security
  2. Wireless Authentication – Open and WEP Authentication
  3. 802.1x Fundamentals
  4. 802.1x Authentication Types
  5. Wireless Security Encryption and Data Integrity Introduction
  6. Wireless Encryption and Data Integrity Methods
  7. WPA, WPA2, WPA3

✅E. Implementing and Configuration of WLANs

  1. WLC Port Types
  2. WLC Initial Setup
  3. Connecting to the WLC using HTTPS – Initial Connection
  4. Creating a WLAN inside the WLC GUI
  5. Connecting LAP (Lightweight Access Points) to the WLC
  6. Creating AP Groups

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