L3 and L7-driven Dynamic Throughput Balancing over Cellular Networks

Broadcast of live sports and events often requires the coverage of a wide area and portable transmission units for the mobile cameras. In this context, the mobile network aspires to be a professional tool companion for media production to boost mobility and alleviate costs, space and specialist maintenance of satellite equipment. Transmission of live high quality captured video and graphic design to a cloud or distant studio production infrastructure requires high uplink data rates. However, steady and reliable communications are challenging for the network in disperse, distant and sparse areas. This context may need bonding multiple cellular links to ensure a sufficient Quality of Service (QoS). Video uplink solutions at different network layers can shield from QoS degradation. Communications industry solution for IP bonding consists on having different Long-Term Evolution (LTE) network interfaces with several sim cards on the device which transmits the live stream, then having network redundancy. This paper provides an innovative method to dynamically balance the throughput for each concurrently employed network interface in real-time at the live video transmitter. The solution exploits live measurements obtained from the network layer (L3), such as network bandwidth, latency and jitter, which are periodically assessed along the video transmission, and application layer (L7) state, such as the encoding GOP schema, frame type and framerate, to split the video packets in the different network interfaces. The evaluation of the solution is made for a head-end implementation by sending live video streams and measuring the QoS at the production infrastructure. To conclude the benefits when the solution comes into play, results are compared to a scenario without bonding solutions and another one where balance rates are initially fixed.