SoftMAC: Layer 2.5 MAC for VoIP support in multi-hop wireless networks

Haitao Wu, Xin Wang, Yunxin Liu, Qian Zhang, Zhi Li Zhang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

21 Scopus citations

Abstract

In this paper, we present the challenges in supporting VoIP services over multi-hop wireless networks using commercial IEEE 802.11 MAC DCF hardware, and propose a novel software solution, called Layer 2.5 SoftMAC. Our proposed SoftMAC resides between the 802.11 MAC layer and IP layer to coordinate the real-time and best-effort packet transmission among neighboring nodes in a multi-hop wireless network. To effectively support VoIP services, our SoftMAC architecture employs three key mechanisms: 1) distributed admission control for regulating the load of real time-traffic, 2) rate control for minimizing the impact of best-effort traffic on real-time traffic, and 3) non-preemptive priority queueing for providing high priority service to VoIP traffic. To evaluate the efficacy of these mechanisms, we conduct extensive simulations using the network simulator NS2. We also implement our proposed SoftMAC as a Windows Network Driver Interface Specification (NDIS) driver over Network Interface Card (NIC) driver, and build a multi-hop wireless network testbed with 32 wireless nodes equipped with 802.11 a/b/g combo cards. Our evaluation and testing results demonstrate the effectiveness of our proposed software solution.

Original languageEnglish (US)
Title of host publication2005 Second Annual IEEE Communications Society Conference on Sensor and AdHoc Communications and Networks, SECON 2005
Pages441-451
Number of pages11
DOIs
StatePublished - 2005
Event2005 Second Annual IEEE Communications Society Conference on Sensor and AdHoc Communications and Networks, SECON 2005 - Santa Clara, CA, United States
Duration: Sep 26 2005Sep 29 2005

Publication series

Name2005 Second Annual IEEE Communications Society Conference on Sensor and AdHoc Communications and Networks, SECON 2005
Volume2005

Other

Other2005 Second Annual IEEE Communications Society Conference on Sensor and AdHoc Communications and Networks, SECON 2005
CountryUnited States
CitySanta Clara, CA
Period9/26/059/29/05

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