Preserving Video Quality in IPTV Networks

Growing numbers of service providers are implementing video services over IP networks, and discovering the unique challenges of providing a high quality-of-experience (QoE) to subscribers. Delivering consistent QoE in packet-switched networks can be a complex proposition due to the high sensitivity of video traffic to packet loss, as well as to delay and jitter. Preserving video quality in IP Television (IPTV) networks that mostly rely on copper access lines poses an even greater challenge. Service providers need intelligent mechanisms in core and distribution networks to prevent congestion that deteriorates video quality, as well as intelligence between the aggregation networks and IP set-top box (STB) to repair packet losses, speed up channel change times and monitor the quality of the subscriber experience. This paper discusses a series of core and aggregation-layer approaches, collectively referred to as Visual Quality of Experience (VQE) to address these issues. The VQE approach encompasses on-path video connection admission control (CAC) employing Resource ReSerVation Protocol (RSVP) in the core and aggregation layers, and a real-time signaling mechanism operating between the provider aggregation edge and the IP STBs to address packet losses, long channel change times and quality monitoring.