Establishing and Maintaining Broadcast Quality Video over IP Yannick LE DREAU 4 September 2010 Agenda Attracting and retaining subscribers – What can we realistically do to maintain the best delivery quality to our subscribers ? – What do we mean by Quality of Service and Quality of Experience ? The IP Video Ecosystem – Garbage in, Garbage out – What can we measure and how ? A system wide view - where do we look and what do we look at ? Putting it the Big Picture together – – – – Finding and resolving customer impacting issues quickly Using distributed monitoring and diagnostics Element/Network Management systems Proactive, not reactive; keep your subscriber away from his phone Conclusion 2 Establishing and Maintaining Broadcast Quality Video over IP Attracting and retaining subscribers What are subscribers REALLY interested in ? – Getting the right program – Good picture quality – Synchronised audio and video 3 All these factors impact Quality of Experience (QoE) Establishing and Maintaining Broadcast Quality Video over IP Quality of Service & Quality of Experience Quality of Service (QoS) – In network traffic engineering, QoS can be used provide various priorities to differing data flows, or guarantee a certain level of performance to a data flow. – In IP Video systems, this prioritization is critical to achieve good quality service delivery. – Can be objectively measured by the provider himself Quality of Experience (QoE) – Closely related, but subtly different – Focused on the overall performance of the delivery system from the endusers perspective. QoE is a subjective measurement of the perceived value of the overall service, and customer experience. 4 Establishing and Maintaining Broadcast Quality Video over IP Quality of Service & Quality of Experience QoS and QoE are inextricably linked ! Increasing video compression reduces bandwidth and can therefore improve QoS The end user perceives lower quality video, therefore QoE is reduced 5 Establishing and Maintaining Broadcast Quality Video over IP IP Video Ecosystem IPTV Ecosystem 7 Establishing and Maintaining Broadcast Quality Video over IP The primary functions of the IP Video headend Digital program acquisition: – Content from the satellite or terrestrial sources, and the preparation of that content for digital delivery (National or regional). Digital program storage: – Storage and insertion of additional, non-live broadcast programming like local content, video-on-demand or advertising. Digital program distribution and delivery: – Program preparation and aggregation, rate-shaping, modulation, encapsulation (encoding), encryption and other technical processes for program delivery. 8 Establishing and Maintaining Broadcast Quality Video over IP IP Video Headend 9 Establishing and Maintaining Broadcast Quality Video over IP Headend Ingest - RF Various RF parameters can be proactively used to measure RF signal quality; – Modulation Error Ratio (MER) – Error Vector Magnitude (EVM) – Bit Error Rate (BER) MER particularly is defined as a ‘single figure of merit’ of the RF signal Measurement trending can be used to identify signal degradation 10 Establishing and Maintaining Broadcast Quality Video over IP Headend Ingest – IP traffic QoS refers to the ability of a service provider to support users’ requirements with regard to at least 4 service categories; – – – – Bandwidth Latency or delay Jitter Traffic Loss Measurement Category Key Performance Indicators Bandwidth Total Line Bitrate IP Session Bitrate TS Bitrate Program Bitrate PID Bitrate Latency/Delay Max/Min Packet Inter-arrival Time (PIT) Jitter Max/Min Packet Inter-arrival Time (PIT) PCR_OJ, PCR Inaccuracy PCR-PTS values Traffic/Packet Loss RTP Lost Rate/Count RTP Out of Order Rate/Count Frame Checksum errors TS Continuity Count errors 11 Establishing and Maintaining Broadcast Quality Video over IP Headend Ingest - SDI Multi source, multi format feeds need to be checked as they are brought into the plant. Origination may be 3G-SDI Rapid problem location by tracking video presence and format, luma and gamut errors, and CRC statistics. Comprehensive audio information including clips, mutes, over and silence conditions can be summarized by individual audio channel. 12 Establishing and Maintaining Broadcast Quality Video over IP Headend Ingest – File Based Multi source, multi format feeds need to be checked as they are brought into the plant. Using automated file-based QC solutions can reduce your end-to-end file time, reduce the number of people in the workflow, and reduce churn by having your content accepted the first time. Automated QC can scale with content growth, increase service quality, and get better leverage out of existing staff. 13 Establishing and Maintaining Broadcast Quality Video over IP What and where can we measure ? 14 Establishing and Maintaining Broadcast Quality Video over IP What can we measure – QoE Metrics It is important to look at subjective customer impacting issues such as video and audio impairments. These are the QoE issues most likely to cause customer dissatisfaction, increase churn and therefore directly impact ARPU. Video impairments include; – – – – – 15 Stuck/Frozen Video detection Black Video detection Blockiness and slice error detection Tiling/pixelization detection Display of video metadata; codec type, resolution, display area, aspect ratio, bit rate, Frames per second, scan and AFD Establishing and Maintaining Broadcast Quality Video over IP What can we measure – QoE Metrics Using these video measurements, it is possible to isolate encoding issues from transport issues Examples; – Tiling effects are typically caused by insufficient bit-rate for required image detail rather than any TS stream defect (PCR errors, dropped packets, etc). – Blockiness artifacts are typically due to data loss - dropped packets, PCR jitter, or TS format problems. Normally very noticeable. 16 Establishing and Maintaining Broadcast Quality Video over IP What can we measure – QoE Metrics Audio impairment measurements should include; – – – – – 17 True Peak & Loudness (ITU-1770/1771) Clipping Silence detection Detection of phase problems Display of audio metadata including codec type, number of channels, bit rate and sample rate. Establishing and Maintaining Broadcast Quality Video over IP Quality of Experience Monitoring: Video & Audio QoE scoring Score hundreds of video and audio streams, based on customers’ experiences (QoE), in real time continuously & simultaneously Screen capture of a video clip with low VQoE score 18 Establishing and Maintaining Broadcast Quality Video over IP IP Video Quality Measurements (Who Cares) Visual Control Measures Control IGMP Latency, RTSP Latency, Channel Zap Time Content MPEG-TS RTP Content Measures Picture Quality, Blocking, Blurring, Visual Noise, Audio Drop-outs Media Transport Measures PCR Jitter, Pixelization, Sync Loss, Continuity Errors UDP IP Physical 19 Ethernet QoE Customer IP Network Measures Packet Loss, Jitter, Delay Establishing and Maintaining Broadcast Quality Video over IP QoS Network Engineering Troubleshooting QOE/QOS Correlation Time-based root cause analysis Bit rate Triggered capture capability Audio/Video QoE Audio loudness 60-day historical report Discontinuity event IP statistics By program Splicing event By location 20 Establishing and Maintaining Broadcast Quality Video over IP Where can we measure ? 21 Establishing and Maintaining Broadcast Quality Video over IP Taking a system wide view It has been shown that automated conformance checking and monitoring is possible across all types of ingest. Any point where content is changed is a possible failure point; – Re-multiplexing – Transrating & transcoding – IP encapsulation and transmission 22 Establishing and Maintaining Broadcast Quality Video over IP QoE Monitoring & Reporting Dashboard, Alert Analysis By Program/Location 23 Establishing and Maintaining Broadcast Quality Video over IP Putting the Big Picture together 24 Establishing and Maintaining Broadcast Quality Video over IP Putting the big picture together Using distributed monitoring probes can supply cross layer QoS/QoE metrics. Operators need the ability to ‘tune’ the system to give focus to high priority assets. How can you collate and sort all the information from these probes in order to quickly isolate problems ? 25 Establishing and Maintaining Broadcast Quality Video over IP Putting the big picture together An Element Management System (EMS) can give several layers of features; Engineering – The ability to identify impacted services and enable engineers to drill down for rapid root cause analysis of video service delivery issues is key. – Providing alarms, logs, trending and reporting of key performance metrics Operations – Ability to view video from any probe within the network – Inclusion of integration for STBs or other Customer Premises Equipment (CPE) in order to provide diagnostics from the subscriber network. Management – Provide key video and audio impairment data – Are we meeting our SLAs ? Are our providers meeting theirs ? – Use service data to be proactive; act before your customer does 26 Establishing and Maintaining Broadcast Quality Video over IP Putting the big picture together It can provide managers with the ability to track both network and service performance; – Support for reporting through statistical logging and report generation – Trending analysis for tracking of management performance metrics and service level agreements. 27 Establishing and Maintaining Broadcast Quality Video over IP Conclusion It is clear that carrying high quality digital video across IP networks is a challenging task. Differentiated IP services such as High Speed Data, VoIP and video all have differing bandwidth and QoS requirements. Video requires high availability (in bandwidth and time) which requires implementation of robust network management policies, along with suitable monitoring tools to ensure those policies are maintained 24/7 It has been shown that IP video cannot survive in a “Best Effort” environment - video packets need to arrive in sequence and with no losses. 28 Establishing and Maintaining Broadcast Quality Video over IP Conclusion Use of test equipment in this environment is essential and correctly placed monitoring probes across the network can provide important data in the form of KPIs for both QoS & QoE Combined with the use of EMS/NMS, this can empower operators and engineers to efficiently manage network systems. This can prevent degradation of signal quality which may result in errors which affect the end users experience and ultimately, Operator revenues. 29 Establishing and Maintaining Broadcast Quality Video over IP Questions? 30 Establishing and Maintaining Broadcast Quality Video over IP