Buffer-Driven Rate Control and Packet Distribution for Real-Time Videos in Heterogeneous Wireless Networks.

Video transmission bandwidth can be substantially increased by concurrent transmission through multiple radio interfaces introduced by heterogeneous wireless networks. However, delivering high-quality real-time videos with stringent end-to-end delay constraints is still challenging due to the time-varying multipath channel status. Thus, to integrate available multipath bandwidth and guarantee low end-to-end delay, this paper investigates a real-time concurrent multipath video transmission scheme in heterogeneous access networks. First, we present a multipath buffer analysis model (MBAM) to derive the lower and upper bounds of the target video frame bits. Second, given the low-latency and received video quality smoothness, we propose a buffer-driven rate control and packet distribution (BRCPD) algorithm aided by frame-level rate control and multipath transmission buffer awareness based on MBAM. Finally, we implement the proposed application-layer solution BRCPD algorithm in a real-world testbed. The experiment results verify that different from existing multipath video transmission schemes, the proposed algorithm is able to leverage the MBAM-based frame-level rate control to guarantee the target low end-to-end delay. In particular, the BRCPD algorithm is able to guarantee an overdue loss rate of less than 5% under strictly limited delay constraints (250 ms) in the real-world testbed.