Exploring power saving in 802.11 VoIP wireless links*

ABSTRACT

Batteries are a primary resource in wireless networks for many mobile devices. Minimizing energy consumption without affecting communication activities is crucial to prolong the lifetime and improve the robustness of the wireless connection. One effective way to reduce energy consumption is to set the entire, or part of the system in a low power mode whenever possible. This paper explores a power saving approach for VoIP and presents a new power saving scheme that does not require extra protocol overhead or modifications to operate. Adopting this scheme potentially allows considerable power savings without any adverse effect on VoIP quality. Evidence of this is in simulation results, showing that a device can enter sleep mode for over 75% of the time, with no decrease in throughput.

REFERENCES

• 1: Bianchi, G. Performance analysis of IEEE 802.11 distributed coordination function, IEEE Journal on Selected Areas in Communications, vol. 18, no. 3, pp. 535--547, March 2000.
• 2: Chen, Y., Smavatkul, N. and Emeott, S. Power management for VoIP over IEEE 802.11 WLAN, WCNC 2004 - IEEE Wireless Communications and Networking Conference, vol. 5, no. 1, March 2004
• 3: Feeney, L.M. and Nilsson, M. Investigating the energy Consumption of a Wireless network interface in ad hoc networking environment, In Proceedings of IEEE INFOCOM, April 2001.
• 4: Chunyu Hu , Jennifer Hou, LISP: Link-Indexed Statistical Traffic Prediction Approach to Improving IEEE 802.11 PSM, Proceedings of the 24th International Conference on Distributed Computing Systems (ICDCS'04), p.292-300, March 24-26, 2004
• 5: IEEE standard for Wireless LAN-Medium Access Control and Physical Layer Specification, 802.11, November 1997. P802.11.
• 6: IEEE 802.11. Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, 1999.
• 7: Network Simulator (ns), University of California at Berkeley, CA, 1997. Available at http://www.isi.edu/nsnam/ns/ns-build.html.
• 8: Qadeer, W., Rosing, T.S., Ankcorn, J., Krishnan, V. and De Micheli, G. Heterogeneous wireless network management In Proceedings of PACS 2003, SanDiego, CA, USA, December 2003,
• 9: Schurgers, C., Tsiatsis, V. and Srivastava, M. STEM: Topology Management for Energy Efficient Sensor Networks. In IEEE Aerospace Conference '02, Big Sky, MT, March 10-15, 2002.
• 10: Suresh Singh , C. S. Raghavendra, PAMAS—power aware multi-access protocol with signalling for ad hoc networks, ACM SIGCOMM Computer Communication Review, v.28 n.3, p.5-26, July 1998 [doi>10.1145/293927.293928]
• 11: Skehill, R., Picovici, D. and Kent, W. Wireless MANET Testbed for reproducible Voice over IP Evaluation, In PROC. Of International Communication Sciences and Technology Association MeshNets, Budapest, July 2005
• 12: WMM Power Save for Mobile and Portable Wi-Fi Certified Devices Wi-Fi Alliance Whitepaper December 2005. Available at http://www.wi-fi.org/

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Wireless communication

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.2 Network Protocols
  C.4 PERFORMANCE OF SYSTEMS

General Terms:
Algorithms, Design, Performance

Keywords:
802.11, power saving, sleep mode, voice over IP, wireless LAN