ADQ: Application-Aware Socket Buffer Dequeueing for Mobile Devices

The end-to-end latency requirement in mobile applications is not limited to the time taken from the server to the user device. The perceived latency by the users also includes the time taken for the data to traverse from the mobile operating system's kernel to the application layer. The kernels of modern mobile devices are designed to reduce the network packet processing delay by enqueuing incoming data in socket buffer and quickly dequeueing socket buffer for immediate data delivery to the application layer. However, this approach results in unnecessary CPU load on the mobile device due to the frequent execution of socket buffer dequeueing. We propose ADQ, which utilizes Application Data Unit (ADU) information—the smallest data unit interpretable by the application—in the mobile kernel to conduct minimal socket buffer dequeueing, aiming to reduce unnecessary CPU load without degrading delay performance. Our evaluation in a real-time video streaming scenario shows that ADQ can maintain a minimal level of latency using a restricted amount of CPU resources. Furthermore, in the presence of high CPU loads from competing tasks, we demonstrate that ADQ can improve delay performance compared to the default mobile kernel.