Wi-Fi Offloading for Multi-Homed Hybrid Digital-Analog Video Streaming

Multi-homed wireless video streaming systems concurrently send video frames of one video content from multiple wireless access networks. The coexistence of Long Term Evolution (LTE) and Wi-Fi systems is one of the typical multi-homed wireless environments. To utilize such multiple wireless access links for high-quality streaming, we need to overcome two issues: rate decrement in the LTE channel due to cellular congestion and channel quality fluctuation in Wi-Fi channels due to noise, interference, and channel fading. To this end, we propose a hybrid digital-analog video transmission scheme, which integrates digital video coding, near-analog modulation, and compressive sensing, considering Wi-Fi offloading. To avoid an effect of the cellular congestion, the proposed scheme offloads a part of digital-encoded video data, which are originally transmitted in the LTE channel, to available Wi-Fi channels if LTE's data rate becomes insufficient during the streaming session. In addition, the proposed scheme uses a combination of compressive sensing and near-analog modulation for video delivery in Wi-Fi channels to ensure the received video quality can be proportionally improved according to the instantaneous quality of the Wi-Fi channels. From evaluations, the proposed Wi-Fi offloading technique keeps better video quality even when the capacity of LTE channel becomes limited within a streaming session. In addition, it was found that the received video quality can be gracefully improved according to the number of receivable Wi-Fi access points and each Wi-Fi channel quality.