CHASER: content and channel aware object scheduling and error control for wireless Web access in 3G networks

A major bottleneck in satisfying the increasing demand for wireless multimedia access is the dynamic error conditions requiring a very high error protection overhead in terms of energy consumption and access delay. In this paper, we explore ways to use application-level data properties to reduce the error protection cost. We observe that the objects constituting a wireless Web-based access differ in terms of the inherent resiliency to residual error, and the object´s importance to the overall content quality. Additionally, since the cost of achieving a target residual error level depends on the experienced channel conditions, the access cost can be affected by changing the transmission schedule of objects according to the channel conditions. Based on the above observations, in this paper, we present a framework that exploits the application properties, namely content importance and error resiliency, to reduce the cost of error protection by scheduling objects for transmission and adapting the lower-layer error control mechanisms based on the data properties as well as wireless channel conditions. The approach is evaluated under diverse channel conditions using a MATLAB-based simulation environment. Our results show that the proposed approach leads to significant savings in access cost (average 37.4%) with minimal degradation in application quality.