1. EXPLORING POWER SAVING IN 802.11 VOIP WIRELESS LINKS BY BHANUREDDY BATTAPURAM AND SRINIVAS MADLAPELLI

2. ABSTRACT Batteries are primary resource To minimize power consumption Keep entire system in low power mode New power saving scheme and does not require extra protocol overhead or modifications to operate Potential power saving with No adverse effect on VoIP quality Batteries are primary resource To minimize power consumption Keep entire system in low power mode New power saving scheme and does not require extra protocol overhead or modifications to operate Potential power saving with No adverse effect on VoIP quality

3. INTRODUCTION VoIP traffic is becoming more dominant It requires a level of QOS to maintain good voice quality and consumes little bandwidth offered by wireless networks Energy consumption depends on its operating modes

4. Different operating modes of a wireless interface

5. IEEE 802.11 MAC AND VOIP Challenge is to transfer from listening mode to sleeping mode whenever possible without affecting VoIP For this we use power saving schemes such as PAMAS and STEM They use separate channel for control messages that allows main radio to stay in sleep mode

6. POWER SAVING APPROCHES In case VoIP,Transmission Period is 20ms Optimal wake time for packet reception Optimal send/receive contention  Optimal hold off sending packet until successful reception  Optimal send outgoing/incoming packets at same time  Wait to receive packet before transmission  Contend for channel at same time expected incoming traffic

7. Power consumption The considered stations for power saving in VoIP are U.L.MANET testbed wireless stations equipped with Cisco Aironet 350 PCMCIA WLAN. The experiment on application layer proves that transmission times too large for power saving

8. PS WIVOIP ALGORITHM Reducing the power usage in a network with VOIP link for duplexing This approach is shown in algorithm clearly

9. Algorithm

10. ANALYSIS AND SIMULATION

11. CONCLUSION Shows that device can enter into sleep mode up to 75% of the time with no decrease in throughput Without any protocols used it is operated Simulation results show clearly the proposed PS-WIVOIP we can save power and it is shown in table

12. OUTPUT

13. References Bianchi,G. Performance analysis of IEEE 802.11 Distributed coordination function, IEEE journal on selected areas in communications, vol 18 Chen,Y, Smavatkul,N and Emeott,S. Power management for VoIP Over IEEE 802.11 WLAN,WCNC 2004-IEEE Wireless Communication and Networking Conference, vol 5