Mansoura UniversityFaculty of EngineeringComputer and Control Systems Dept.

A Novel Power Saving Technique for VoIP Services over Mobile WiMAX Systems

Presented byEng. Tamer Zakaria Mohamed Emara

SupervisorsProf.

Hesham ArafatVice Dean of Students and Education Affairs,

and Head of Computer Engineering and Control Systems Dept., Faculty of EngineeringMansoura University

Assoc. Prof.Ahmed Saleh

Associate Professor inComputer Engineering and Control

Systems Dept., Faculty of Engineering Mansoura University

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Agenda*Objective*What is VoIP?*Research Area*Power Saving Class Mode in IEEE802.16*Previous Effort*Proposed Mechanism

VPSMANN_VPSM

*Simulation Setup*Result Analysis for VPSM*Result Analysis for ANN_VPSM*Conclusion

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The main objective is to propose a power conservation

mechanism based on artificial neural network which is:

*applicable to VoIP service with silent suppression over WiMAX systems.

*reducing the energy consumption of Mobile Stations (MS) *increasing the bandwidth utilization and reduces the network traffic.*Guaranteeing the Quality of Services (QoS).

Objective

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WHAT IS VOIP?

VOIP APPLICATION

Encoder Packetizer Depacketizer DecoderNetworkPlayback

buffer

Sender Receiver

End-to-end components of VoIP.

VoIP Research Areas

Mobile StationBase Station

Voice QualitySecurity Power Saving

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Power Saving Class Mode in IEEE802.16

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PSC of Type I

PSC of Type II

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PSC of Type III

Previous Effort

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Paper Author Technique Conclusion"An optimal power-saving class II for VoIP traffic and its performance evaluations in IEEE 802.16e", Computer Communications, vol. 31, no. 14, pp. 3204–3208, Sep. 2008

JungRyun Lee, DongHo Cho

PSC II during all conversationFinding the optimal sleep interval for PSC II, based on network delay model.

Energy consumption 40-10%Packet buffering delay 10- 70 ms

“Dual power-saving modes for voice over IP traffic supporting voice activity detection", IET Communications, Vol. 3, no.7, pp. 1239 – 1249, July 2009.

J-R Lee, D-H Cho

PSC II for talk spurtPSC I for mutual silence

1. Energy saved by up to 20%.2. drop probability of less than 1.9%

"On the Use of a Power-Saving Mode for Mobile VoIP Devices and Its Performance Evaluation", IEEE Transactions on Consumer Electronics, vol. 55, No. 3, pp.1537-1545, Aug. 2009.

Choi H-H, J-R Lee, D-H Cho

PSC II for talk spurtPSC I for mutual silence(network delay model)

Talk spurt:Power consumption 20%Buffering delay 100 msMutual silence:Power consumption 20%Packet drop 14%

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Previous Efforts

Paper Author Technique Conclusion

"Power-saving scheduling with a QoS guarantee in a mobile WiMAX system", Journal of Network and Computer Applications , Vol. 32, No. 6, pp. 1144–1152, Nov. 2009.

Wen-Hwa Liao, Wen-Ming Yen,

scheduling scheme They consider that delay and jitter types of QoS should be scheduled at the same time and integrate sleep duration in one MSS.

Average energy efficiency 60 – 90%Packet losses 0- 70%

"Advanced Mechanisms for Sleep Mode Optimization of VoIP Traffic over IEEE 802.16m" Global Telecommunications Conference (GLOBECOM 2010), pp. 1 – 6, 6-10 Dec. 2010. 

Ritesh K. Kalle, Maruti Gupta, Aran Bergman, Elad Levy, Shantidev Mohanty, Muthaiah Venkatachalam and Debabrata Das

1. Reduce the LI duration from active period and reduce the number of DL sub-frames during mutual silence periods.2. During mutual silence periods we also propose to use longer sleep cycles (in the range [20–160] ms) to maximize the power saved between two SID packetarrivals.

reduce power consumption 70% Didn’t calculate packet losses 

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Previous Efforts (cont.)

Paper Author Technique Conclusion

“On exploiting the on-off characteristics of human speech to conserve energy for the downlink VoIP in WiMAX systems", 7th International Wireless Communications and Mobile Computing Conference (IWCMC), vol., no., pp. 337 – 342, 4-8 July 2011. 

Xiao-Hui Lin, Ling Liu,  Hui Wang, Yu-Kwong Kwok

Find the optimal sleep window parameters under the constraints of QoS requirement based on the hybrid method [1]

90% reduction in energy dissipation during silence period.

“Energy-saving centric uplink scheduling scheme for broadband wireless access networks”, EURASIP Journal on Wireless Communications and Networking, 2014:70, May 2014.

Yen-Wen Chen, Yen-Yin Chu, I-Hsuan Peng

Energy-saving centric uplink scheduling scheme(ESC-US)

sleep time 60% - 90%.Delay frame 20-80 ms

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Previous Efforts (cont.)

Proposed Mechanism

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i) Training Mode (VPSM mechanism)After constructing ANN, it needs to be trained. So, the training mode starts firstly. While the conversation running, needed data are collected. To save more power in training mode VPSM is chosen.

Power Saving Strategy

ii) Prediction Mode (ANN_VPSM mechanism)

After the training finished the network is ready to run

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VPSM Mechanism

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VPSM Mechanism (Case 1)

(𝑆𝑀 𝐸𝑆+𝐿𝑇 𝐸𝐿 )𝑆𝑀+𝐿𝑇

Energy Consumption

Buffering delay

(𝑆¿¿𝑀+𝐿𝑇)−1𝜆 ¿

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VPSM Mechanism (Case 2)

(𝑆𝑀 𝐸𝑆+𝐿𝑇 𝐸𝐿 )𝑆𝑀+𝐿𝑇

+∑𝑖=1

∞

𝑝𝑖∑𝑗=1

𝑖

(𝑆 𝑗 𝐸𝑆+𝐿𝑇 𝐸𝐿)

𝐸 [𝐿 ]

Energy Consumption

Buffering delay

∑𝑖=1

∞

𝑝𝑖∑𝑗=1

𝑖

(𝑆 𝑗+𝐿𝑇 )−1𝜆

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1. Start Call

2. FOR EACH Frame DO 3. IF Data sent THEN4. Coding data using voice coder.

5. IF VAD=0 THEN

6. Check last received frame.

7. IF last received frame = SID THEN8. Call proc Mutual_Silent_Case

9. End If10. ELSE11. Call proc Talking _Case

12. END IF

13. ELSE IF Data received THEN

14. Decode received frame using voice coder.

15. IF received frame = SID THEN

16. Check VAD for last sent frame.

17. IF VAD=0 THEN

18. Call proc Mutual_Silent_Case

19. END IF

20. ELSE

21. Call proc Talking _Case

VPSM Mechanism (cont.)

21. END IF

22. END IF

23. NEXT

24. End Call

26. Proc Mutual_Silent_Case

27. Check current PSC

28. IF current PSC = PSCII THEN

29. Request PSCIII

30. ELSE IF current PSC= PSCIII THEN31. Request PSCI

32. END IF33. END Proc

34. Proc Talking_Case

35. Check current PSC

36. IF current PSC = PSCIII OR current PSC = PSCI THEN

37. Request PSCII

38. END IF

39. END Proc

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Proposed ANN_VPSM

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The ANN structure used in this study is

*Multi-Layer Perceptron (MLP).

* MLP works through back-propagation method,

*Inputs: Last silence period, Last talking period.

*Outputs: predicted mutual silence.

ANN Structure

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ANN Structure (cont.)

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ANN_VPSM MechanismSTART

Data?Sending Receiving

Read frame

Is my MS in silence?No

Yes

VoiceCheck received packet

SID

Coding Data using coder

VAD0

1

Received SID Predict SM using

ANN model

PSC II

Request PSC II

Request PSC III PSC II

Request PSC II

Call ended?

END

Yes

No

YesNo

YesNo

YesNo

Simulation Setup

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We assumed a user running a VoIP application and requiring network access to transmit its packets in the uplink towards the destination.

We supposed that parameters of the distribution model have converged and the network connection is in the steady state mode.

Simulation Assumption

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The proposed simulation procedure consists of three stages:

1. Getting training data.

2. Build ANN model.

3. Performance evaluation.

The Proposed Simulation Procedure

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a. Real voice file (usually in .wav format).

b. Using speech codec (ITU-T G.729B ).

c. Then implemented a program using C++ language to get the required data for training the neural network.

Getting Training Data

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The training is automated with the Neuro Solution (version 5)

Build ANN model

The learning rules used for training:

• Momentum.

• Conjugate Gradient (CG).

• Levenberg Marquar (LM).

• Quick prop (QP).

• Delta Bar Delta (DBD).

Transfer Functions:

• Linear Tanh Axon

• Linear Sigmoid Axon

• Bias Axon

• Tanh Axon

• Sigmoid Axon

• Axon

Data60% training

15% cross validation

25% testing

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The performance of the ANN_VPSM and VPSM is validated bySimulation using C++ language G.729B voice codec

Performance Evaluation

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Experiment Parameters Parameter Description Value

PTPacket generation interval of G.729 codec 40 ms

1 frame One frame duration 10 ms

LT Listen interval 10 ms

ST Sleep interval for PSCII 30 ms

SmaxLength of the maximum sleep cycle for PSC I 40 to 10240ms

SM Sleep interval for PSC IIIVPSM: 100, 200, 300 msANN_VPSM: predicted

Result Analysis for VPSM

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Result Analysis for VPSM

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Maximum sleep cycle (ms)

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Maximum sleep cycle (ms)

Aver

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Dro

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

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Call Time (s)60 120 180 240 300

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Call Time (s)

Smax =40 ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

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0.06

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Call Time (s)60 120 180 240 300

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Call Time (s)

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Smax =80 ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

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Call Time (s)60 120 180 240 300

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Call Time (s)

Smax =160 ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

0.02

0.03

0.04

0.05

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0.08

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Call Time (s)60 120 180 240 300

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Call Time (s)

Smax =320 ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

Aver

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Call Time (s)

60 120 180 240 3000

0.01

0.02

0.03

0.04

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Call Time (s)

Smax =640 ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

0.02

0.03

0.04

0.05

0.06

0.07

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0.09

Aver

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Call Time (s)60 120 180 240 300

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0.09

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Call Time (s)Smax =1280

ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

0.02

0.03

0.04

0.05

0.06

0.07

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0.09

Aver

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Call Time (s)60 120 180 240 300

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Call Time (s)Smax =2560

ms

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.01

0.02

0.03

0.04

0.05

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0.09

Aver

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Call Time (s)60 120 180 240 300

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Call Time (s)

Smax =5120 ms

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Result Analysis for VPSM (cont.)

40 80 160 320 640 1280 2560 5120102400

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Buff_Frames=4 Buff_Frames=6 Buff_Frames=8 Buff_Frames=16 Buff_Frames=32

Maximum sleep cycle (ms)

Aver

age

Dro

p Fr

ames

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Result Analysis for VPSM (cont.)

60 120 180 240 3000

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4 HPSM-1HPSM-2VPSM-31VPSM-21VPSM-11VPSM-32VPSM-22VPSM-12VPSM-33VPSM-23VPSM-13

Call Time(s)

Aver

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Dro

p Fr

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60 120 180 240 3000.04

0.05

0.06

0.07

0.08

0.09

0.1HPSM-1HPSM-2VPSM-31VPSM-21VPSM-11VPSM-32VPSM-22VPSM-12VPSM-33VPSM-23VPSM-13

Call Time(s)

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HPSM-1 defines HPSM with maximum sleep cycle =160ms; HPSM-2 defines HPSM with maximum sleep cycle =320ms; VPSM-31 defines VPSM with SM=300ms and Smax=160ms; VPSM-32 defines VPSM with SM=300ms and Smax=320ms; VPSM-33 defines VPSM with SM=300ms and Smax=640ms; VPSM-21 defines VPSM with SM=200ms and Smax=160ms; VPSM-22 defines VPSM with SM=200ms and Smax=320ms; VPSM-23 defines VPSM with SM=200ms and Smax=640ms;VPSM-11 defines VPSM with SM=100ms and Smax=160ms; VPSM-12 defines VPSM with SM=100ms and Smax=320ms; VPSM-13 defines VPSM with SM=100ms and Smax=640ms;

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Result Analysis for ANN_VPSM

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Transfer Function-Tanh axon

30 60 90 120

150

180

210

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270

300

0.03

0.035

0.04

0.045

0.05

0.055

0.06

0.065

0.07

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

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30 60 90 120

150

180

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300

0

0.01

0.02

0.03

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0.06

0.07

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

Aver

age

drop

fra

mes

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Transfer Function-Sigmoid axon

30 60 90 120

150

180

210

240

270

300

0.03

0.035

0.04

0.045

0.05

0.055

0.06

0.065

0.07

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

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30 60 90 120

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0

0.01

0.02

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0.07

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

Aver

age

drop

fra

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Transfer Function-Linear Tanh axon

30 60 90 120

150

180

210

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270

300

0.03

0.035

0.04

0.045

0.05

0.055

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ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

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30 60 90 120

150

180

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270

300

0.025

0.027

0.029

0.031

0.033

0.035

0.037

0.039

0.041

0.043

0.045

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

Aver

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drop

fra

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Transfer Function-Linear Sigmoid axon

30 60 90 120

150

180

210

240

270

300

0.035

0.04

0.045

0.05

0.055

0.06

0.065

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ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

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0.025

0.027

0.029

0.031

0.033

0.035

0.037

0.039

0.041

0.043

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

Aver

age

drop

fra

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Transfer Function axon

30 60 90 120

150

180

210

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270

300

0

0.01

0.02

0.03

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ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

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30 60 90 1201501802102402703000

0.01

0.02

0.03

0.04

0.05

0.06

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0.08

0.09

ConjugateGradientDeltaBarDeltaLevenbergMarquarMomentumQuickpropVPSM

Call Time(s)

Aver

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drop

fra

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Transfer Function-Bais axon

30 60 90 120

150

180

210

240

270

300

0.03

0.035

0.04

0.045

0.05

0.055

0.06

0.065

0.07

ConjugateGradient DeltaBarDeltaLevenbergMarquar MomentumQuickprop VPSM

Call Time(s)

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30 60 90 120

150

180

210

240

270

300

0.02

0.025

0.03

0.035

0.04

0.045

ConjugateGradient DeltaBarDeltaLevenbergMarquar MomentumQuickprop VPSM

Call Time(s)

Aver

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drop

fra

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Conclusion

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In this thesis, the power saving mechanism based on artificial neural network is proposed for VoIP services with silent suppression over WiMax systems. The experimental results indicated that the proposed mechanism can:reduce the power consumption of MS

effectively.increase the bandwidth utilization and

reduce the network traffic. Experimental results shows that the power consumption of an MS can be reduced up to 3.7% with less than 3.7% average frame drop.

CONCLUSION

Outcome

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Tamer Z. Emara, Ahmed I. Saleh and Hesham Arafat, “Power saving mechanism for VoIP services over WiMAX systems”, Wireless Networks, Vol. 20, Issue 5, pp. 975-985, 2014.

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Thank You

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*VOIP – Protocol Stack

Tasks of the various Layers• G.7xx: describes the formats for voice data (Voice-Codecs)

• H.26x: describes the formats for video data (Video-Codecs)

• RTP• Realtime Transport Protocol provides packets with a time stamp and a sequence

number• Used for transport of real-time data (Audio, Video) over paket-oriented network• Supplement by RTCP

• RTCP • Realtime Control Protocol• Control Protocol for RTP

UDP >>> RTP .......... Port (n) RTCP ....... Port (n+1)

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Transfer Function-Linear Sigmoid axon

30 60 90 1201501802102402703000.035

0.04

0.045

0.05

0.055

0.06

0.065

0.07

ConjugateGradient DeltaBarDeltaLevenbergMarquar MomentumQuickprop VPSMHPSM-2

Call Time(s)

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30 60 90 1201501802102402703000.025

0.075

0.125

0.175

0.225

0.275

0.325

0.375

0.425

ConjugateGradient DeltaBarDeltaLevenbergMarquar MomentumQuickprop VPSMHPSM-2

Call Time(s)

Aver

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drop

fram

es