10 Things You Need To Know About QoE

As the looming deadline for complying with the Commercial Advertisement Loudness Mitigation (CALM) Act approaches – effective Dec. 13, 2012 – now is a good time for video service providers (VSPs) to reassess their current Quality of Experience (QoE) monitoring capabilities or lack thereof. One of the CALM Act’s chief compliance requirements is for VSPs to identify and catalog instances of overly loud commercials, something a proper QoE monitoring solution can handle.

Though VSPs have been striving for years to deliver a TV viewing experience free from the video and audio impairments that degrade viewers’ QoE, many have relied on quality of service (QoS) monitoring solutions in this effort. While undeniably useful, QoS monitoring is quite simply not enough to ensure an optimal QoE for viewers. 

The following 10 points will help clarify the differences between QoS monitoring and true QoE monitoring and the value of each:
 
1.  Why VSPs should worry about managing QoE
Independent research conducted with VSPs revealed that some of the top customer issues reported were content related: macroblocking, video blackouts, frozen video and silence. Unlike QoE probes, traditional IP and Transport Stream (QoS) probes do not directly detect or alarm on these common causes of complaint. But what exactly is QoE? In the context of video and audio programming, QoE is assuring that you deliver a quality of picture and sound that will keep your viewers happy.

2.  Distinguishing between QoE and QoS
QoS can be defined as an objective set of measurements of network and system performance against pre-defined standards. It is important to recognize that there often is no direct correlation between the adherence to QoS standards and the impact to the end viewer. To put it another way, an individual QoS problem (e.g., a long PAT repetition rate) may not result in a customer impacting QoE problem, but a QoE problem (e.g., macroblocking) may be caused by one or more QoS problems (e.g., dropped IP packets or continuity count errors).

3.  QoS as a measurement technique has limitations when used on its own as a monitoring strategy
In video systems, the most common standard used to monitor transport stream QoS is TR 101 290, designed as an interoperability standard to help ensure that compliant network elements would be guaranteed to work together. Non-compliance with TR 101 290 does not mean that a system will not operate correctly. Indeed, most video networks are not 100-percent compliant with TR 101 290, yet still function correctly. So taking this interoperability standard and applying it to 24/7 monitoring of video services leads to many alarms which may or may not be customer-impacting. TR 101 290 is a valuable diagnostic aid, which is why advance monitoring system’s TR 101 290 measurements, are stored along with the QoE measurements in a multiple-month backed database.

4.  Issues QoE monitoring can identify
Monitoring probes must alert only when an event is deemed “customer impacting,” which is any event that would be noticed by a viewer – thus a QoE issue. These events could include: macroblock errors, slice errors, serious compression artifacts, frozen and black frames, low or excessive audio levels, silence, clicks, and video and audio drop-outs.

5.  QoE issues can only be reliably detected by analyzing the actual content (which must be decoded)
Traditional QoS probes cannot reliably and deterministically measure and determine, in real time, the severity of these customer-impacting events. In order to identify QoE issues, the actual video and audio content must be analyzing, requiring that the content be decoded.

6.  Real-time content analysis is difficult to achieve and requires a scalable monitoring solution
In a modern video network, there may be hundreds of programs that all must be decoded and analyzed in real time. Due to both complexity and the use of entropy bit-stream encoding, H.264 content requires between seven and 10 times the computational resources required to decode MPEG-2, which itself is computationally complex to decode. As a result, QoE monitoring solutions that analyze the video content in real time have in the past, been limited to a few programs, making them expensive and not scalable to deploy. Advanced monitoring systems will have architecture that allows it to monitor the decoded video and audio content of hundreds of programs simultaneously and in real time.

7.  Scalable real-time content analysis technology can help solve a range of other issues
By using efficient, high-performance architecture, advanced solutions also are able monitor and alert on a wide range of customer impacting issues that not specifically video- or audio-related. These include subtitle and teletext presence, carousel cycle times and events, and splicing issues.

8.  Different types of content require monitoring and managing in different ways and to different levels
Innovative program groups and alert templates allow you to group, monitor and set alert thresholds specific to content type (HD, SD, long-tail), content provider or content destination. This allows you to monitor your own internal standards or those of your business partners, making advanced monitoring solutions an ideal tool to assist with Service Level Agreement (SLA) verification.

9.  Detecting issues is one thing, but being alerted to them in a correct and timely fashion is just as important
Flexible alert-and-reporting capabilities also are sought after in monitoring solutions, allowing the system to issue emails with critical alerts, and scheduled reports in CSV and PDF formats. Integration with NMS systems is critical; and MIB and north-bound SNMP traps, which include the alert URL, allow easy and flexible integration into a broader monitoring platform.

10.  Implementing the correct QoE monitoring strategy will help save time and money in addition to keeping viewers happy
The benefits of QoE monitoring with advanced systems can be realized quickly, with lower call-center loading, reduced mean-time-to-repair (MTTR), fewer truck rolls and better-managed SLAs, all resulting in OPEX reductions – and happy viewers.

The benefits of QoE monitoring and thus providing a superior QoE for viewers extend far past reducing operating costs to the broader picture. Happy customers are loyal customers who don’t jump ship for lower-priced competition. Cable, satellite and telecom VSPs are fighting to steal and retain subscribers from their competition, but naturally are loathe to undercut competitors’ prices too much, as it will start a race to the bottom.

QoS monitoring solutions don’t have the capabilities that QoE monitoring technologies provide. In order to proactively monitor and prevent viewer-impacting errors true QoE solutions are the best option for VSPs. In an era where each subscriber counts, keeping viewers happy is paramount. Wall Street stock analysts closely watch VSPs’ subscriber numbers, which makes losing subscribers not just a hit to the bottom line, but possibly resulting in a direct hit to stock prices.

As VSPs prepare to comply with the CALM Act, it is the perfect time for them also to reassess how to best employ QoE solutions to retain subscribers. But first, providers should understand the differences between QoS and QoE monitoring. What does monitoring QoE mean to you?

— Richard Duvall, video marketing manager, Tektronix