1. CT1303 LAN
Rehab AlFallaj

2. Wireless network
Is any type of computer network that uses wireless data connections for connecting network nodes and sharing network resources.
So, it differs than previous network with, the type of transmission media, wireless transmission media.
Microwave.
Infrared.
Laser.

3. Wireless network
Wireless network based on its covered and its bandwidth used in its channel frequencies.
Wireless Personal Area Network (WPAN) الشبكة الشخصية المحلية اللاسلكية.
Wireless LANالشبكة المحلية اللاسلكية .
Wireless WANالشبكة الموسعة اللاسلكية .
Wireless Broadbandالشبكة اللاسلكية المدنية عريضة النطاق .
Wireless Cellularالشبكة اللاسلكية الجوالة.

4. Wireless Personal Area Network (WPAN)
Used to link or connect personal devices (PDA Personal Data Assistant), printers, mobile devices embedded in computers.
One hall, room
Controlled by 1 person owned the network.
Microwave, Infrared waves.

5. Wireless LAN Covers a building, or more.
Connects personal computers, Notebooks, printers, storage devices wirelessly.
Controlled by 1 person or more.
Microwave, Infrared waves.

6. Wireless WAN Covered wider geographical area, cities, countries.
Links and connects computers among different cities wirelessly by Satellite.
Controlled by international organization or government or big telecommunication companies.

7. Wireless Broadband Covers a city. Connects computers wirelessly.
Mainly used to transmit large amounts of data very fast,
Ex: Video films, Photos, websites.
Broadband microwaves, laser.
Controlled by organization or government.

8. Wireless Cellular
Used mostly for mobiles, but now can be used for data transmission.
Can connect computers, connect to Internet.
Can be used in a wide area.
Controlled by companies or government.

9. Wireless LAN applications
To extend LAN.
Sometimes it is difficult to extend a wired LAN, so wireless technologies can help.
To connect two to more LANs.

10. Wireless LAN applications

11. Wireless LAN applications
Advantages:
Decrease cost of the new extension.
Easy to change.

12. Wireless LAN applications
Serve mobile devices, laptops, notebooks.

13. Wireless LAN applications
Build a temporary network.
Military camps.
Relief camps.
conferences.
Usually this type of temporary networks have a changing topology ( not fixed or has a permanent topology).

14. Challenges and obstacles of wireless networks
Radio and microwaves and infrared waves is more prone to the interference.
Data transmission is not %100 guaranteed.
Attenuation and fading of waves and signals may occur.
Privacy security concerns.
The limitation of the bandwidth, and the huge number of people connecting with this network demanding the need to manage and granting the right to broadcast to eliminate interference if waves.

15. Challenges and obstacles of wireless networks
Usually transmission rate becomes lower (based on Nyqist rule) when huge number of Subscribers are there.
The limitation of the power that supplies wireless devices , protocols should be made based on it.
“Hidden node” and “Exposed node” .

16. Challenges and obstacles of wireless networks

17. Main structure of wireless LANs
Add-hoc WLANالشبكة العشوائية اللاسلكية .
Routers pass/forwards signals and data.
Service nodes.
A network with a changing and random nature.
Topology cab change
Basic Service Set (BSS) مدى الخدمة الاساسي

18. Main structure of wireless LANs
Multicells wireless networks شبكة متعددة الخلايا .
Many access points AP connect computers.
These AP connected through channel or wired network “ Distributed Systems”
Extended Service Set ESS

19. Main structure of wireless LANs

20. wireless network standards
Institute of Electrical & Electronic Engineers IEEE, The European Telecommunications Standards Institute ETSI, and forums of companies and factories that manufacture these network devices (ex: Bluetooth forum).
204 GHz – 5 GHz frequencies.

21. wireless network standards: Bluetooth wireless network
Bluetooth wireless network standards:
IBM, INTEL, NOKIA, Ericsson, Toshiba
Connect PDAs, printers, mobile devices embedded in computers.
Covers 1 hall, room.
Controlled by 1 person won this network.
Microwave, infrared transmission channel.

22. wireless network standards: wireless LAN standard
IEEE, project
802.11a , b, g
It is called Wi-Fi ( commercial name)
wireless LAN:
Transmission rate: 2 Mbps
Bandwidth: 2.4 GHz
802.11b wireless LAN:
Transmission rate: 11 Mbps

23. wireless network standards: wireless LAN standard
802.11a wireless LAN:
Transmission rate: 54 Mbps
Bandwidth: 5 GHz
802.11g wireless LAN:
Bandwidth: 2.4 GHz
Compatible with b

24. wireless network standards: wireless MAN standard
IEEE, project
802.16:
Line of sight transmission rate: 134 Mbps
Bandwidth: GHz.
Wi-MAX a:
Line of sight transmission rate: 70 Mbps
Bandwidth: 2-11 GHz.

25. wireless network standards: wireless MAN standard

26. Wireless sensor network
For specific purposes, use sensing and digital controlling.
Used for Remote Sensing application, ex: factories, radar application, hospitals.
standards:
Transmission using: Ultra Wide Band (UWB), transmission with lower power with a very high broadband.
No interference and noise.

27. wireless network standards

28. Wireless LAN protocols
Due to noise, interference, hidden and exposed nodes; CSMA can’t be used effectively in wireless LANs.
Aloha can be used.
Multiple Access with Collision Avoidance MACA; similar to CSMA/DA
Multiple Access with Collision Avoidance for Wireless MACAW.
Collisions can be detected at receiver device.
Transmission by Request To Send” frame (RTS) and Confirm To Send” frame (CTS).

29. Wireless LAN protocols
Waiting time after collision is equal with all waiting nodes.
ACK is used to confirm receiving the data correctly.
RTS
CTS
DATA
ACK