Quality-Aware Voice Convergecast in Mobile Low Power Wireless Networks

Abstract

Several recent disasters have shown the critical need for reliable voice communication for mobile users. Low power ad hoc wireless networks have become a promising alternative for voice communication in emergency scenarios because of their low cost and portability. In order to increase communication amongst moving emergency personnel and disaster victims, we have developed a novel convergecast voice streaming system that guarantees robust voice quality in a low power wireless network. The system integrates routing and mobility-aware admission control along with voice compression adjustment to ensure the quality of voice streams. The system is evaluated using Arduino Due micro-controllers with XBee 802.15.4 radios. We create mobile scenarios by placing the Arduino Dues on iRobot Create mobile robots. Our results show that our system can adequately adapt to changing network and routing conditions to deliver sufficient voice quality by maintaining a certain number of concurrent voice streams. To the best of our knowledge, this work is the first complete system for quality-aware voice streaming in mobile lower power wireless networks.

Quality Preserving Voice Stream Multicast over Mobile Low Power Wireless Networks

“…At a high level, voice over mobile low power wireless networks bears a lot of similarity with voice over MANETs, as they share similar challenges due to multi-hop routing and high error rates. QACM [1] supports convergecast of voice streams in low power mobile wireless networks, while we focus on multicast in this work. MAODV [6] is one of the most commonly used protocol for multicast routing in MANET, which floods the network to maintain the multicast tree.…”

“…In order to measure voice quality in an online fashion, we adopt the E-model [5], which has been used in several previous voice streaming systems [10], [11], [1]. In this model, voice quality is measured using an R value as in Eqn.…”

“…Even when people are not moving, the dynamic environment will cause the link quality to fluctuate over a wide range, so that a node many change its parent. QACM [1] is a voice streaming system that considers node mobility, it is designed for convergecast, which is different from multicast we focus on in this work.…”