2. LYU9903 QoS Schemes in Wireless Networks Ho Pun Mo Matchman Ng Maggie Supervised by Prof. Michael Lyu

3. Outline What is Wireless LAN? Why Wireless? How to Wireless? Examples of Wireless device Applications of Wireless LAN Advantages and Disadvantages of Wireless LAN What is QoS Why QoS is needed in Wireless? QoS Schmemes Application for QoS Scheme Measurement of QoS Scheme Future work

4. 1What is Wireless LAN? A flexible data communications system As an extension to/alternative for wired LAN Using radio frequency (RF) technologies Transmit and receive data over the air

5. 2Why Wireless? Mobility Installation speed and simplicity Installation flexibility Reduced cost-of-ownership Scalability

6. 3How to Wireless? Equipment needed Configuration

7. 3.1Equipment needed Access Points Adapter cards

8. 3.2.1 Configuration - Peer-to-peer A peer-to-peer network Access to resources of each other, but not a central server

9. 3.2.2 Configuration - An Access Point Extend the range of an ad hoc network Doubling range at which the devices can communicate Access to resources of both server and clients

10. 3.2.3 Configuration - Multiple Access Points Blanket the coverage area with overlapping cells Enable roaming

11. 4 Examples of Wireless Device

12. 5 Applications of Wireless LAN Health Care Education and Research Restaurant and Retail Warehousing Trading and Banking Consulting and Sales

13. 6 Advantages & Disadvantages of Wireless LAN Advantages: Inexpensive Have enough bandwidth to handle office tasks Do well in roaming Flexible Easy to install

14. 6 Advantages & Disadvantages of Wireless LAN Disadvantages: Small bandwidth causes problems with multimedia transmission Limit number of connected nodes Limit range of coverage Large battery consumptions For infrared, line-of-sight may be needed

15. 7What is QoS? QoS is the collective effect of service performances which determine the degree of satisfaction of a user of the service. QoS is the guarantee a network makes to an application in terms of providing a certain contracted level of service through out the application session. QoS represents quantities like how fast can data be transferred, how much does the receiver have to wait, how correct is the received data likely to be, how much data is likely to be lost, etc. ATM defines QoS as a collection of rate, latency, jitter loss ratio and error ratio. QoS refers to the ability of a network to deliver time-bounded traffic types (e.g., realtime video or voice) with predictable latencies.

16. 8Why QoS is needed in Wireless? Growth of real-time multimedia applications Wireless to be a trend

17. 9QoS Schemes Architecture Implementation

18. 9.1Architecture A working network Bandwidth reservation mechanism Packet scheduling algorithm Packet classifier

19. 9.2.1 Implementation - RSVP ReSerVation Protocol Reserving bandwidth along the path Works with both IPv4 and IPv6

20. 9.2.2 Implementation - Packet Scheduler FIFO RED CSZ SFQ TBF TFQL PRIO CBQ

21. 10 Application for QoS Scheme MP3 player for demonstrating the use of QoS. Server (store mp3 songs) Client (with mp3 player) Reserve b/w for QoS   

22. 10 Application for QoS Scheme Interface of MP3 player:

23. 11 Measurement of QoS Scheme No QosQos

24. 11 Measurement of QoS Scheme Compare the performance of transmitting FTP & MP3 by using Proxim. QosNo Qos

25. 12 Future Work Implementing Video on Demand in Wireless LAN Measure the QoS of VOD

26. THE END Thank you!