On the Age of Multipath-based Real-time Video Analytics

In this work, we aim to maintain the timeliness of a multipath-based real-time video analytics system by analyzing the age of processed information (AoPI) at the receiver side. In the system, a camera consistently uploads captured frames to different edge servers for processing via corresponding wireless channels. To measure the timeliness of the system, a novel metric named AoPI is proposed, which is the time elapsed since the generation of the latest successfully recognized frame. Hence, AoPI is impacted by the transmission/computation delay on different paths and whether the frames are successfully recognized. We derive the closed-form average AoPI at the receiver side of the system, which is inversely proportional to the recognition probability. Moreover, we prove that adding an identical path can reduce the average AoPI by 37.5% to 50% compared with using a single path. Nevertheless, numerical results show that utilizing a secondary path to access an available edge node will increase the average AoPI in the case of low spectrum efficiency and constrained bandwidth.