The proliferation of smart handhold devices and the development of the various wireless technologies lead the real-time multimedia services on mobile Internet dramatically increasing. One of the current research issues for multimedia services is how to guarantee the service quality that satisfies the user requirement in the variant network condition. Wireless network has more factors that affect the network condition, such as wireless link error and user``s mobility as well as the network congestion, which mostly incur packet losses and service disruption. That``s why we need to clarify what causes packet losses and quality degradation in the multimedia sessions to improve QoS on wireless network properly.
In this paper, we consider three factors that cause packet losses in wireless networks: network congestion, user``s mobility, and wireless link error. While the network congestion indicates lack of the network capability, others do not really indicate that. Thus, the conventional congestion control may reduce the transmission rate unnecessarily even though packet losses are just caused by handoff or wireless link error, and there are plenty of network resources. This significantly reduces the availability of network resources. Among of those factors, we focus on the wireless link error and how to discriminate it from the other factors.
The existing researches discriminate wireless link error from network congestion by using RTT information or by observing the variation of packet inter-arrival time. However, these mechanisms based on the statistical measurement or estimation at the session ends often misestimate the wireless link error because they ignore the buffer overflow at the intermediate routers and the data compression delay. To eliminate this misestimate, we propose a new scheme to discriminate the wireless link error from the network congestion by measuring link layer signal strength at the mobile devices. Our scheme identifies the network condit...