LYU9903QoS Schemes in Wireless Network

sHo Pun Mo Matchman

Ng MaggieSupervised by Prof. Michael Lyu

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

1 What 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

2 Why Wireless?

• Mobility

• Installation speed and simplicity

• Installation flexibility

• Reduced cost-of-ownership

• Scalability

3 How to Wireless?

• Equipment needed

• Configuration

3.1Equipment needed

• Access Points• Adapter cards

3.2.1 Configuration - Peer-to-peer

• A peer-to-peer network

• Access to resources of each other, but not a central server

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

3.2.3 Configuration- Multiple Access Poin

ts

• Blanket the coverage area with overlapping cells

• Enable roaming

4 Examples of Wireless DeviceProxim WaveLAN

Equipment Used:~ PC Card~ Access Point

RangeLAN2 7400rl2 Ethernet Aceess Pt.

IEEE Turbo (Bronze)WavePOINT-II

Freq. Band 2.4GHz 2400-2483.5MHz

Data Rate 1.6Mbps 6-2Mpbs (4 option speed)

Range (Indoor) (Outdoor)

~152m~305m

40m – 115m120m – 540m

Delay Spread dunno 55ns – 500ns

Our Experience slowerlower cover rangeharder to setup

fasterhigher cover rangeeasier to setup

5 Applications of Wireless LAN

• Health Care

• Education and Research

• Restaurant and Retail

• Warehousing

• Trading and Banking

• Consulting and Sales

6 Advantages & Disadvantages of Wireless LAN

Advantages:Advantages:

• Inexpensive

• Have enough bandwidth to handle office tasks

• Do well in roaming

• Flexible

• Easy to install

6 Advantages & Disadvantages of Wireless LAN

Disadvantages: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

7 What is QoS?• QoS is the collective effect of service performances which determine t

he 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 t

ypes (e.g., realtime video or voice) with predictable latencies.

8 Why QoS is needed in Wireless?

• Growth of real-time multimedia applications

• Wireless to be a trend

9 QoS Schemes

• Architecture

• Implementation

9.1 Architecture• A working network

• Bandwidth reservation mechanism

• Packet scheduling algorithm

• Packet classifier

9.2.1 Implementation - RSVP

• ReSerVation Protocol• Reserving bandwidth alo

ng the path• Works with both IPv4 an

d IPv6

9.2.2 Implementation - Packet Sched

uler• FIFO

• RED

• CSZ

• SFQ

• TBF

• TFQL

• PRIO

• CBQ

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

10 Application for QoS Scheme

Interface of MP3 player:

11 Measurement of QoS Scheme

Recieved Bandwidth of FTP & MP3 with 200Kbits(using waveLAN)

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300 350 400 450 500

Time (sec)

Curre

nt B

andw

idth

(Kbp

s)

FTP

MP3No Qos

Qos

11 Measurement of QoS Scheme

Received Bandwidth of FTP & MP3 with 200Kbits(us ing P r o xi m )

0

50

100

150

200

250

0 100 200 300 400 500

Time (sec)

Cur

rent

Ban

dwid

th (K

bps)

FTP

MP3

Compare the performance of tran

smitting FTP & MP3 by using Pr

oxim.

QosNo Qos

12 Future Work

• Implementing Video on Demand in Wireless LAN

• Measure the QoS of VOD

THE END

Thank you!