3 Mitul et al _WIMAX NETWORK_ [ pp10-13].doc

7/28/2019 3 Mitul et al _WIMAX NETWORK_ [ pp10-13].doc

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Performance Evaluation of Wimax Network Using Qualnet

Simulator Mitul R. Khandhedia1, Prof. K.H.Wandra2, Prof. D.N.Khandhar3 and Nirav R. Khandhedia4

1, 2, 3C.U. Shah College of Engineering & Technology, Wadhwan,

4Project Engineer, Wipro Technologies, [email protected]

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Abstract--WiMAX which represents World interoperability

for Microwave Access is a major part of broadband wireless

network having IEEE 802.16 standard provides innovative

fixed as well as mobile platform for broadband internet

access anywhere in anytime. This paper provides the detail

about Mobile WiMAX. Mobile WiMAX gives full mobility of

cellular networks at higher broadband speeds than other

broadband networks like Wi-Fi. Mobile WiMAX and Fixed

WiMAX is analyzed on the base of the variation in FFT size,

Bandwidth and cyclic prefix factor.

Mobile WiMAX operates in 2 to 6 GHz range which is

mainly licensed bands. Mobile WiMAX will be the mostfamous technology in the coming years.

Here, we are considering a network of WiMAX as shown

in figure 2. This network is having two applications of WiMax. One is Fixed WiMAX connection while another

is Mobile WiMAX.

Keywords: WiMax, FFT, IEEE 802.16, Qualnet Simulator

I. INTRODUCTIONMobile WiMAX [1] (802.16e) has allowed users to access

high speed internet access anywhere and anytime, it also provides true mobility. Users that are moving at the speed

of 75 mph can get data and other multimedia supportwithout any problem. Subscribers who are accustomed to

the cellular environment will be able to get data serviceswith a speed comparable to that of wired communications.

Figure 1 Mobile Wimax v/s Other technologies [1]

Mobile WiMAX technology will be able to address the

most users needs, now-a-days wired high speed internetaccess provide high data rates but the problem is mobility

and the same is the case with wireless internet accesswhich has very limited range and very slow transfer rates.

WiMAX [2] provides high broadband internet access at

high transfer rates and meeting the demands of varioususers. Mobile WiMAX can be applied to various fields

other than mobile communications .mobile WiMAX can

be applied to those areas where wired infrastructure cannot

be reached. WiMAX provide high speed internet

regardless of the location.Mobile WiMAX services are cost effective solution as

compared to 3G technologies.

II. CASE STUDY

Figure 2 Case Study WiMax Network

This network is 40 km x 40 km. It has 4 base stations.There are four subscriber stations. There are two CBR

applications under considerations. Node 5 and 7 are fixednodes while 8 is a mobile node and 9 are fixed. Node 8

travels path from node 8 to node 9 as static path shown byflags. This path is taken such that node has to take hand

off from base station 1, 2, 3, 4 and last back to 1.

This network is analyzed on the base of variation of FFTsize, Bandwidth and Cyclic prefix factor. Results are

analyzed on based of the throughput of server, jitter atserver and also end to end delay of packets.



As per IEEE 802.16 power level is 20dbm. But as per FCCnorms any wireless network can have power level up to 3-

dbm and antenna gain up to 6db.

AKGEC JOURNAL OF TECHNOLOGY, vol.1, no.2

So in this network we have varied power level from 15

dbm to 25 dbm to find out optimum level required to reachout every corner of above network. Path loss model for

any wireless network is preferred to be free space model.

Other Parameters:

We have kept other parameter like

FFT Size 128, 512, 1024, 2048

Bandwidth 5, 10, 15, 20 MHzCyclic prefix factor 4, 8, 16, 32

Packet reception model PHY802.16

MAC Protocol 802.16

Station type Subscriber stationBase Station

• Mobility Model 802.16e

• Promiscuous Mode Enable

Network Protocol IPV4

Now let’s see experiment carried out and its analysis.

Variation FFT Size [3]: This parameter specifies the FFT

size used in the device. Four FFT sizes are supported here:2048, 1024, 512, and 128. The FFT size determines the

number of available subcarriers and OFDM symbolduration. In general, for a given bandwidth, a larger FFT

size results in a greater number of available subcarriersand a longer OFDM symbol duration.

Figure 3: Effect of FFT size on throughput

figure 3 shows the comparison of throughput of various

nodes for 128, 512, 1024 and 2048 FFT size. It is clear from above figure that client node throughput remains

constant for any FFT size. Throughput of server 1 – fixedWiMAX remains also almost same, less affected by the

FFT size. But throughput of mobile WiMAX nodeincreases appreciably by increasing FFT size.

Figure 4 shows effect on jitter by increasing the FFT size.In comparison we have two server nodes. One is fixed

WiMAX node, whose jitter almost remains same for anyvalue of FFT size. But when we talk about mobile

WiMAX node, its jitter decreases appreciably as weincrease FFT size. So, we can say that increasing FFT size

decreases jitter of mobile WiMAX

Effect on End to End delay by change in FFT size is

shown in above figure 5. It is clear from above figure thatend to end delay of fixed WiMAX almost remains same

for all size of FFT. But mobile WiMAX decreases verymuch when FFT size is increased. So, we can say that

increasing FFT size, we can decrease end to end delay.

Figure 4: Effect of FFT size on jitter

Figure 5: Effect of FFT size on delay

Effect of Cyclic Prefix Factor [3]

Figure 6: Effect of Cyclic Factor on throughput

This parameter specifies the ratio of useful symbol time to

cyclic prefix time. Four ratios are supported here: 4, 8, 16,and 32.



Now we have varied cyclic prefix factor from 4, 8, and 16to 32. We have compared the effect on throughput, jitter

and end to end delay. First let’s check effect on thethroughput.

From figure 6, it can be seen that throughput of client

nodes remains same for all the values of cyclic prefixfactor. So, it is not affected by variation. Now remaining

are two other nodes, server 1 is fixed WiMAX node andserver 2 is mobile WiMAX node. If we check above

graph, throughput of fixed WiMAX node does not change

appreciably.

But if we check throughput of mobile WiMAX node, it is

clearly visible that it increases appreciably for 4 to 8 andthen it slightly for 16 and 32. We can conclude that

throughput increases of mobile WiMAX node by increase

of the cyclic prefix factor.

Figure 7: Effect of Cyclic Factor on jitter

In figure 7, we have seen the effect on jitter for variation

of cyclic prefix factor on both fixed and mobile WiMAXnodes. It is clearly seen from above figure that jitter of

fixed WiMAX decreases slightly by rise of cyclic prefixfactor. But change in jitter of server 2 i.e. mobile WiMAX

is appreciable. From 4 to 8 it decreases appreciably andalso for values for 16 and 32, it decreases more and more.

So, it means that jitter decreases by rise of cyclic prefixfactor.

Figure 8: Effect of Cyclic Factor on delay

From figure 8, we can see that change in cyclic prefix

factor, decreases end to end delay also. End to end delay

of fixed WiMAX node decreases slightly by change of

cyclic prefix factor.

PERFORMANCE EVALUATION OF WIMAX NETWORK

Now on mobile WiMAX case, end to end delay of thisnode decreases from a very high value to small value

when we change from 4 to 8, and then it changes slightly.

So, we can conclude that it decreases end to end delay of mobile WiMAX.

Hence, we can conclude that by increase in cyclic prefix

factor, we can improve throughput, jitter and end to enddelay.

Effect of Bandwidth [3]: Now we will check effect of

variation of bandwidth on throughput, jitter and end to enddelay.

It is known that increase in bandwidth increases ability to

include more number of subscriber nodes.

From figure 9, we can say that we have varied bandwidthto 5, 10, 15 and 20 MHz. And as we vary client node

throughput remains same. So, it is node affected at all.

Now when we see server nodes, fixed WiMAX node’s

throughput increases as we increase bandwidth and

achieves max value for 15 MHz.

But it decreases for 20 MHz. Similar is the case for themobile WiMAX node that its throughput increases to

higher value for 15 MHz and falls for 20 MHz.

It means that for this network, 15 MHz bandwidth isoptimum for our network.

Figure 9: Effect of Bandwidth on throughput



Figure 10: Effect of Bandwidth on Jitter

AKGEC JOURNAL OF TECHNOLOGY, vol.1, no.2

From figure 10, we can say that jitter is also affected bychange in bandwidth. Jitter of server 1 and 2 both remains

almost constant for 5 to 15 MHz bandwidth. But it

decreases sharply for 20 MHz bandwidth. It means that jitter decreases as we increase bandwidth. So increase in bandwidth improves the jitter, which is desirable.

Figure 11: Effect of Bandwidth on Delay

From figure 11, we can see that end-to-end delay is also

affected by change in bandwidth. End to end delay of fixed WiMAX is less value for 5 MHz but it increases for

10 MHz and then it decreases sharply for higher values of bandwidth. It achieves minimum value for 20 MHz

bandwidth.

End to end delay of mobile WiMAX nodes decreases aswe increase the bandwidth. It has maximum value for 5

MHz bandwidth, and which in turn decreases to minimumvalue for 20 MHz. So, we can say that increase in

bandwidth decreases end to end delay of both mobile andfixed WiMAX nodes.

III. CONCLUSION

From various experiments mentioned, one can concludethat as a result of increase in the FFT size or bandwidth or

cyclic prefix factor for fixed WiMAX network, there is notsignificant change in performance of network.

But for mobile WiMAX network, increase in FFT size, bandwidth or cyclic prefix factor increases throughput,

decreases jitter and end-to-end delay of network. So,

optimizing all above parameters improves performance of network.

IV. REFERENCES[1] “Analysis of Fixed and Mobile WiMAX”, Umar Tarique,Umeer Jilani, Tuafique Siddiqui, Bleking Institute of

Technology.[2] Wireless communications, Andrea Goldsmith, StanfordUniversity, Cambridge University Press.

[3] Dissertation Report “Performance Evaluation of WirelessTechnologies using Qualnet Simulator”, Mitul R. Khandhedia,

C.U.Shah College of Engieering and Technology.[4] Qualnet 5.0 Wireless Model Library.

[5] Qualnet 5.0 Programmers’ Guide.[6]“Implementation of IEEE 802.16a in Glomosim” Benoit

Louzel, Dublin City University.[7] Qualnet 5.0 Developer Model Library.

M.R. Khandhedia obtained M.E.

(E.C) from Sauashtra University,

Rajkot, and B.E (I .C.) fromBhavanagar University in 2003.

Currently working as Sr. Lecturer and

Head of IC Dept. at Atmiya Institute

of Technology and Science, Rajkot,having seven years of teaching

experience, Published / presented

Five International Research Papers. He

is life member of ISTE. Areas of Interest are mobile communication,

control system, process control,

controller, system design and so on.

K.H. Wandra submitted PhD thesis

On Role of Wireless Technology for

Mobile Augmented Reality System.

Obtained ME Microprocessor System Applications from M.S.

University, Vadodara in 1999 andBE in Electronics and

Communication form North Gujarat

University, Patan in 1995.

Currently working as Professor and

Head of CE and IT at C. U Shah

College of Engineering and

Technology, Wdhwan, with over 13years of teaching experience.

Written over 10 Research Papers. Member of IEEE and CSI. Areas of

interest include wireless communication, networks and advancedmicroprocessors. He is Chairman of Board of Studies Computer

Engineering, Saurashtra University, Rajkot.



D. N. Khandhar obtained ME

(EC) CSE from GujaratUniversity, Ahmedabad, and BE

(Power Electronics) from

Saurashtra University.

Currently working as Assistant

Professor at C. U. Shah College

of Engineering and Technology,

Gujarat having 11 years of

teaching experience. Published /

presented seven research papers.

He is Life member of ISTE.

Areas of Interest include mobile

communication, controllers and

VLSI. Nirav Khandhedia completed

Bachelor’s Degree in Electronics andCommunication Engineering from

Atmiya Institute of Technology and

Science, affiliated with Saurashtra

University, Rajkot, in June, 2008 withdistinction. He has 18 months of

experience in teaching as lecturer and

Assistant Professor in Nirma

University. Currently, working as aProject Engineer in Wipro

Technologies, Pune for 6 months.

Prepared final year Project on 32-bit

RISC Pipelined Processor. Guidedfive projects at undergraduate level.

3 Mitul et al _WIMAX NETWORK_ [ pp10-13].doc

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