introduction to wlan

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: , عناية أحمد المهندس الالسلكية الشبكات في مقدمةمحفوظة الطبع حقوق

ع!ن!ا!ي!ة: أ!ح!م!د! ا!ل!م!ه!ن!د!س!

االشبكات في مقدمةالالسلكية

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األجندة

الالسلكية 1. الشبكات عن نبذة

الالسلكية 2. خصائصاإلشارات

االشبكات 3. لتقنين منظمات

الالسلكية

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االشبكات - عن نبذة فوائدهاالالسلكية

1. WLAN or WiFi extends Local Area Network (LAN) using Radio Frequency (RF)

2. It can be used by home users, Enterprises or Operators/Service Providers

3. It provides free mobility and flexibility for work and for entertainment

4. WLAN uses unlicensed bands

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عن الالسلكية - نبذة االشبكاتتطبيقاتها

1. Applications of WLAN

1. Corporate Data access and Mobility

2. Universities and schools

3. Health Care

4. Warehouses and Manufacturing

5. Operators/WISP

6. Temporary offices


AP

الالسلكية - االشبكات عن نبذةتطبيقاتها

PtP

PtMP

Ad Hoc

Infrastructure

AP

Air Mesh

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عن الالسلكية - نبذة االشبكاتمحدداتها

1. Shared Media

2. Half Duplex

3. Security Concerns

4. Subject to Interference CollisionCollision Avoidance

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األجندة

الالسلكية 1. االشبكات عن نبذة

و 2. الالسلكية خصائصاإلشارات

الترميز


الالسلكية

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1. Frequency التردد

2. Amplitude سعة

3. Phase زاوية أو طور

الالسلكية خصائصاإلشارات

TF=1/T

90

180

270

3600

270

0 360

90

180

270

360


4. Wave Length – λ الموجة طول

5. Bandwidth نطاق

الالسلكية خصائصاإلشارات

Distance

crest crest

trough

trough

λ = v/f

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There are 3 main keying methods1. Amplitude Shift Keying

الترميز طرق

0 1 1 0

A0 = 0A1 = 1

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2. Frequency Shift Keying


0 1 1 0

f0

f1

f1

f0

f0 = 0f1 = 1

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3. Phase Shift Keying


0 1 1 0

+180

+180

No chang

e

No chang

e

No change= 0+180 = 1

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األجندة

الالسلكية 1. االشبكات عن نبذة

الالسلكية 2. خصائصاإلشارات


الالسلكية

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االشبكات لتقنين منظماتالالسلكية

1. Institute of Electrical and Electronic Engineer (IEEE)

2. Wi-Fi Alliance

3. Internet Engineering Task Force (IETF)

4. International Telecommunication Union Radiocommunication Sector (ITU-R)

5. Regulatory Bodies

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1. Institute of Electrical and Electronic Engineer (IEEE):

The IEEE 802 LAN/MAN Standards 802.1 Higher Layer LAN Protocols Working

Group 802.3 Ethernet Working Group 802.11 Wireless LAN Working Group 802.15 Wireless Personal Area Network

(WPAN) Working Group 802.16 Broadband Wireless Access Working

Group

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802.11 Wireless LAN Working Group

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2. Wi-Fi Alliance Wireless Ethernet Compatibility Alliance

(WECA) Later called as WiFi – 2002 Members : more than 600 companies Certify interoperability of WLAN products –

18000 Promote WiFi as the global WLAN standard Once product is certified, vendor can use

WiFi logo

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3. Internet Engineering Task Force (IETF)

large open international community of network designers, operators, vendors, and researchers

Standardize Protocols related to Internet, IP and general applications like email and HTTP

Different working groups create Request For Comments (RFCs)

RFCs could become as Internet Standards

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4. International Telecommunication Union Radiocommunication Sector (ITU-R)

Coordinates spectrum management through different regions

Region A: North and South America Region B: Western Europe Region C: Eastern Europe and Northern Asia Region D: Africa (Arab countries in Africa) Region E: Asia and Australia (Arab countries in

Asia)

http://www.itu.int/online/mm/scripts/mm.list?_search=ITUstates



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For the purposes of managing the global radio spectrum, ITU-R defined three regions

Region 1: Europe, Africa, the Middle East west of the Arabian Gulf including Iraq, the former Soviet Union and Mongolia.

Region 2: Americas, Greenland and some of the eastern Pacific Islands.

Region 3: Asia, east of and including Iran, and most of Oceania

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5. Regulatory Bodies Regulations to manage Spectrum and

WLAN RF requirements like: frequencies, power levels, and transmission methods.

For Example: FCC in the USA ETSI in Europe CITC in Saudi Arabia NTRA in Egypt

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شكرا

الالسلكية اللشبكات مقدمة

introduction to wlan

Technology